WO2005033119A1

WO2005033119A1 - Supramolecular compounds and their use as antitumour and antiviral agents

Info

Publication number: WO2005033119A1
Application number: PCT/GB2004/004227
Authority: WO
Inventors: Michael Hannon; Alison Rodger; Nicholas Harold Mann
Original assignee: University Of Warwick
Priority date: 2003-10-03
Filing date: 2004-10-04
Publication date: 2005-04-14
Also published as: GB2425122B; GB2425122A; WO2005033119A9; GB0323213D0; GB0608741D0

Abstract

The application discloses the use of supramolecular compounds as antitumour, antimicrobial (such as antibacterial and antiprotozoal) and antiviral agents. Such compounds comprise ligands as defined in the application coordinated to at least two metal ions. Pharmaceutical formulations and detergent formulations are also disclosed.

Description

Antitumour and Antiviral Agents

The present invention relates to antitumour, antimicrobial (such as antibacterial and antiprotozoal) and antiviral agents, and more specifically to the use of supramolecular compounds as antitumour, antimicrobial (such as antibacterial and antiprotozoal) and antiviral agents.

Each year, cancer alone is responsible for nearly 500,000 deaths in the U.S., making it the second leading cause of death in that country.

Traditional chemotherapeutic and radiotherapeutic agents target DNA but have low tumour to normal cell specificities. The former gives a number of disbenefits to the patient and the latter exposes the healthcare patient to a radiation dose. The drug usually also has a short shelf life once it has been formulated into a preparation.

The use of metal based drugs, such as transition metal (e.g. Fe, Pt) complexes (e.g. Platinum (II) based cisplatin), are well known for use as therapeutic agents for cancer and viruses. The chemotherapeutic efficacy of cisplatin is derived from its ability to bind and crosslink DNA.

However, there is a need for new metallo-drugs with different modes of action because cis-platin has a limited spectrum of activity, toxic side effects and patients treated with the drug acquire resistance.

Supramolecular compounds are complex structures formed by the interaction of metal ions with ligands based on, for example bis(pyridylimine) and imidazolimines, as ligands, to form a system containing more than one metal ion and a number of ligands. Such structures are often cylindrical helical, double helical or "triple helical" in shape. See for example Hannon M. J. et al., 2001, Angew Chem Int Ed 40, pages 1079- 1080, Hannon et al. 1999 Angew Chem Int Ed 38, pages 1277-1278, Supramolecular compounds are capable of binding to DNA. Hannon M and Rodger A. discuss DNA binding in Pharmaceutical Visions, 2002 (Autumn Edition), pages 14-16. Nucleic acids, such as DNA, and indeed RNA, can form complex double, and indeed triple helical structures. Such structures often have a so- called major groove and minor groove running around the outside of the helix. The paper discusses sequence specific interactions of compounds such as proteins, and nucleic acids such as DNA oligonucleotides, synthetic molecules such as intercalators and molecules as targeting the major groove of DNA. Supramolecular assemblies have been used to bind the major groove of DNA. Such assemblies utilise the cationic charge of the metal ions in the assemblies to interact with the anionic charge on the DNA.

The paper speculates that it may be possible to utilise the metal centres to design cationic DNA binders with large dimensions with polarised H-groups on the outside having the potential to switch genes on and off. Large proof of concept supramolecular cylinders have been produced based on imine-based ligands (see also Hannon M. J. et al. Angew Chem. Int. Ed. 2001, 40, pages 880-884). This was aimed at proving the concept of bridging, synthetically, the size gap between traditional small molecule and larger biomolecule DNA-recognition motifs. An aim of this research was to assist in the investigation of the coding inherent in DNA and how that may be processed or suppressed in biosystems. Binding of such large structures were found to have a dramatic effect on the structure of naked DNA by forming intra-molecular coils. This coiling was speculated as being similar to that found in DNA packaging in the nucleosome. The stated aim of finding assemblies that bind DNA with sequence selectivity is also explicitly stated in the article by Meistermann I et al (PNAS 2002, 99, pages 5069-5074).

From this initial work on naked DNA, the authors of the paper speculated that it might be possible to design molecules to achieve sequence specific recognition to allow specific cancer genes to specifically switched on and off, specifically attack viral material or suppressing the excess genetic material found in trisomic disorders such as Down's syndrome. The supramolecular assemblies used in the prior art were not expected themselves to act as anti-cancer, anti-viral or indeed antibacterial compounds. The limited example used in the prior art is a large molecule by traditional drug standards (2nm length and about lnm diameter). They are also tetracationic and were not expected to cross the cell membrane. The paper by Hannon and Rodger (2002) also states that further work is required to identify compounds that have sequence specificity. There are a large number of DNA binding compounds in the art, such as Hoechst 33258, SYBR Green (tm) and ethidium bromide that are known to bind DNA, but many of which do not have use as anti-cancer agents or antimicrobials. Hence, it was not expected that the limited supramolecular assemblies used in the prior art would be able to cross through cells walls of cells or bacteria, and would be able themselves to be used as anti-cancer, anti-bacterial or anti- viral drugs. Furthermore DNA in cells is considerably more complex, being bound to histones and other proteins to form packaged DNA. The compounds have now also been found to bind RNA. Thus there was a major step in going from such limited work on naked DNA, to applying the technology in cells.

When such compounds were tested by the inventors the compounds were found to be uptaken by cells. Indeed, bacterial cells uptake so much ofthe compounds that they are stained by the compounds. The compounds have now been found to be toxic to cancer cell lines and to bacterial cells. They have also been shown to inhibit protein synthesis and bind RNA. There are a large number of viruses in many forms, including double stranded and single stranded DNA and RNA viruses. The demonstration of the ability to block protein synthesis by binding DNA and RNA is expected to result in antiviral activity for these compounds.

In a first aspect, the present invention is directed to use of a supramolecular compound derived from a ligand (L) of formula I or II as an antittumour, anti microbial or antiviral agent:

Wherein:

Each X for formula I may the same or different and may be C or N, wherein when X=N, there is no R group attached to X;

Rl to R8 may be independently selected from H, OAlkyl, OAryl, CH OAlkyl, CHaOAiyl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, O₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

Z = CH, CAlkyl, CAryl, or CNH and may be the same or diffferent

Y may be present or not present and may be selected from:

wherein:

R may be selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH2O-, CO2-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

A = NH, S, SO₂, O, (CH₂)_n, CHR, CR₂, or NR, where R is as defined above.

n = an integer 1, 2, 3, 4, 5, ... 20. Preferably, n = 1 or 2

Or alternatively the ligand may have a general formula II:

indicates a 5 membered heterocycle such R₂ as imidazole, pyrazole, thiazole, oxazole

Where X in formula II may be independently selected and may be C or N, or X can be NH, S, O, in which case the R group is absent. The different X positions can be the same or different.

The remaining groups may be defined as above for Formula I.

The supramolecular compounds may be used as therapeutic agents in general, and epscailly as antitumour, antimicrobial (such as an antibacterial or anti protozoal) or antiviral agents.

In the present invention:

Alkyl may be straight or branched (e.g. Methyl, ethyl, 2-propyl, 3-propyl etc.) which may itself may bear additional functionality (e.g. halides, alcohols, ethers, alkene groups, alkyne groups, amines, and DNA intercalators such as derivatives of ethidium, peptides, peptide nucleic acids (PNAS), and or oligonucleotides).

Aryl may be any aryl unit e.g. Phenyl, 2-, 3- or 4-tolyl, phenol, 2-, 3 or 4- pyridyl and may itself may bear additional functionality (e.g. halides, alcohols, ethers, alkene groups, alkyne groups, amines, and DNA intercalators such as derivatives of ethidium, peptides, peptide nucleic acids (PNAS), and or oligonucleotides).

Alkyne may be any alkyne units e.g. ethyne, trimethylsilylalkyne may itself may bear additional functionality (e.g. halides, alcohols, ethers, alkene groups, alkyne groups, amines, and DNA intercalators such as derivatives of ethidium.

In use, the ligand (L) (defined above) is coordinated to at least two metal ions (M) to produce a supramolecular compound system. Two or more ligands may be coordinated to the metal ions. Each of the ligands may be the same, or alternatively be different to produce a mixed supramolecular compound.

The metal ion may be preferably Fe, Ni, Co, Cu, Ag, Cd, Zn, Ru, Rh, Mn, Ir, Os, Pd, or Pt. Preferably the metal ion is Fe²⁺, Fe³⁺, Ni²⁺, Co²⁺, Co³⁺, Cu⁺, Cu²⁺, Ag⁺, Cd²⁺, Zn²⁺, Ru²⁺, Ru³⁺, Rh³⁺, Mn²⁺, Mn³⁺, Ir⁺, I Ir³⁴, Os²⁺, Os³⁺, Pd²⁺, Pd³⁺ ,Pd +, Pt²+, or Pt⁴+. Two or more different metal ions may be used

The system may be represented by the formulae: M₂ L₂ or

M₂L₃ or

M₃L₃ or more generally

Mn Lm where n and m are integers of 2 to 20, preferably 2, 3, 4 or 5 and n and m may be the same or different. Most preferable the active agent is M₂L₃.

The systems may also have an associated anion(s) or solvents(s) or ligand(s).

The stoichiometry of the system produced is dependent on the metal and ligand combination. The system may be homo-ligand or hetero-ligand (i.e. Contain different ligands, for example, [M₂ L' L" L'"]).

The term indicating that the supramolecular compound "is derived from a ligand (L) of formula I or a ligand of formula II coodinated to at least two metal ions", indicates that the ligand and metal ions have been mixed and have been allowed to coordinate together to form the supramolecular compound.

The supramolecular compound may have a cylindrical structure. Alternatively, they may be modified by means of substituents (including groups such as Y) to form knots, grids, catenanes, boxes, triangles, linear helices, circular helices, capsules, balls or polyhedra.

The inventors have also recognised that the compounds may be used to treat tumours microbial infections, such as bacterial infections or viral infections in e.g. mammals, such as humans.

The compounds may be used in combination with one or more other drugs known to be used for such purposes.

A further aspect of the invention provides the use of a supramolecular compound derived from a ligand (L) of formula I or II, coordinated to at least two metal ions for the manufacture of a medicament to treat a tumour, a microbial infection (such as a bacterial or a protozoal infection), or viral infection: Formula I

Wherein:

Rl to R8 may be independently selected from H, OAlkyl, OAryl, CH∑OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, O₂Aryl, SO₂Me, N(Alkyl)2 and Alkyne;

Z = CH, CAlkyl, CAryl, and or CNH₂ and may be the same or different

Y may be present or not present and may be selected from:

wherein:

A = NH, S, SO₂, O, (CH₂)_n, CHR, CR₂, or NR, where R is as defined above

n = l, 2, 3, 4, 5, ... 20;

R may be selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH2O-, CO2-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CHzSAryl, OSO₂Alkyl, OSO₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

Alternatively the ligand may have a genera formula II:

indicates a 5 membered heterocycle such as imidazole, pyrazole, thiazole, oxazole

The remaining groups may be defined as above for Formula I.

Preferably, the use is for the treatment of cancer.

A further aspect of the invention provides a method of treating tumours, microbial infections (such as bacterial or protozoal infections) or viral infection comprising administering to a patient supramolecular compound derived from a ligand (L) of Formula I or Formula II, as defined above, coordinated to two or more metal ions. The invention also includes within its scope a method of treating cancer by administering such a compound.

Pharmaceutically acceptable salts ofthe compounds may be used. The compounds may be used in the form of pharmaceutical compositions.

Pharmaceutical compositions comprising supramolecular compounds, or pharmaceutically acceptable salts thereof, are also provided. They may comprise any pharmaceutically acceptable carrier, adjuvant or vehicle. Pharmaceutically acceptable carriers, adjuvants and vehicles that may be used in the pharmaceutical compositions of this invention include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene- polyoxypropylene-block polymers, polyethylene glycol and wool fat.

The pharmaceutical compositions may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir, preferably oral administration or administration by injection. The pharmaceutical compositions of this invention may contain any conventional non-toxic pharmaceutically-acceptable carriers, adjuvants or vehicles. The term parenteral as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques.

The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are mannitol, water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or diglycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant such as PH. Helv or a similar alcohol.

The pharmaceutical compositions may be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, and aqueous suspensions and solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are administered orally, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavouring and/or coloring agents may be added.

The pharmaceutical compositions may also be administered in the form of suppositories for rectal administration. These compositions can be prepared by mixing a compound of this invention with a suitable non-irritating excipient which is solid at room temperature but liquid at the rectal temperature and therefore will melt in the rectum to release the active components. Such materials include, but are not limited to, cocoa butter, beeswax and polyethylene glycols.

For application topically to the skin, the pharmaceutical composition should be formulated with a suitable ointment containing the active components suspended or dissolved in a carrier. Carriers for topical administration of the compounds of this invention include, but are not limited to , mineral oil, liquid petroleum, white petroleum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water, Alternatively, the pharmaceutical composition can be formulated with a suitable lotion or cream containing the active compound suspended or dissolved in a carrier. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. The pharmaceutical compositions of this invention may also be topically applied to the lower intenstinal tract by rectal suppository formulation or in a suitable enema formulation. Topcally-transdermal patches are also included in this invention.

The pharmaceutical compositions of this invention may be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art. The antimicrobial activity of the compounds also means that the compounds may be used in a disinfectant formualtion. The compounds may be used with one or more additives known in the art for use in disinfectants, such as surfactants (e.g. ionic or non-ionic surfactants) , wetting agents, chelating agents etc.. This may be used to disinfect, for example surfaces. Disninfectant comprising a supramolecular compound or a pharmaceutically acceptable salt, derived from a Ligand of Formula I or Formula II, as defined above, coordinated to two or more metal ions.

It is thought that the cationic metal ion assembled supramolecular compounds disclosed are known to have architectures similar to the dimension of protein binding sites that target the major groove in DNA. Hence, the supramolecular compounds recognise the major groove in DNA and induce a structural transformation whereby it warps around the DNA.

The presence of the compound on the DNA may also disrupt the intereaction of the DNA with polymerases such as DNA polymerase and RNA polymerase, resulting in the inhibition of DNA or RNA synthesis and hence indirectly protein synthesis.

Given that, for example, an iron (II) supramolecular compound is helical, it and its analogues exist in two enantimeric forms, and there is cytotoxicity using both the racemic and the two enantiopure forms.

The supramolecular compounds can be cheaply made and, their ability to be modified to give, for example, bi- and poly- metallo-, double- and triple-helicates allows tumours and viruses to be specifically targeted either directly or by tagging onto biomolecules or other targetting agents

Preferred ligand for use in the invention may be one or more of any ofthe compounds, the synthesis of which is shown in the Examples. These include any one of the compounds shown in Figure 1 or Figure 2. These may be used in combination with one or more ofthe metal ions defined above. The invention also provides a compound for use in the production of a supramolecular compound, selected from a compound shown any one ofthe examples and in particular Figure 5. Such compounds may be coordinated to at least two metal ions (e.g. as defined above) to produce a supramolecular compound.

Aspects of the present invention will now be described by way of example only with reference to the following figures:

Figure 1 shows alternative compounds for use in the claimed invention

Figure 2 shows the ligand used in example 1.

Figure 3. The X-ray crystal structures ofthe silver(ι) complexes ofthe L^Rand L^s ligands of example 1 confirming a solid state double helical structure for both complexes (the hydrogen atoms are omitted for clarity). Left hand side A 2L^s ₂ ²⁺.

Figure 4 The growth rate of Synechocystis sp. PCC 6803 was assessed in the presence of varying concentrations of the purple supramolecular agent [Fe₂(C25H₂oN )₃]Cl (0-10. lmM). Synechocystis sp. PCC 6803 cultures were grown in 20ml BGII medium contained in 50ml conical flasks and at constant illumination of 30 microEinsteins m^sec'¹. Cell density was measured at 750nm using uninnoculated BG11 media as a blank. The cells stain visibly purple at lOμM and cell growth is stopped above this concentration.

Figure 5 shows novel compounds for use in the production of supramolecular compounds useful for treating tumours, microbial infections and viral infections.

Production of Supramolecular Compound Coordinated to Metal Ion Supramolecular compounds can be produced using known synthesis pathways. The shape of the compounds formed can be varied by addition of different substituent groups or varying the metal ion and/or ligands used.

Examples 11 OCTOBER 2004

Un cπr¹ 3050-2800w, 1615w, 1587m, 1568m, 1439m, 1305m, 1204m, 1006m, 837s, 776m, 750m, 692m, 672m, 651m, 663m, 585s, 556s, 527m, 511m. nm (MeCN) 229 (e/mol-'dm- .όxlO⁵), 279 (1.0xl0⁵),322(4.0xl0⁴), 360(3.0xl0⁴).

L^R-[Ag₂(C₃₂H22N4)₂][PF6]₂. Preparation as for the (S),(-) silver(ι) salt except for the use ofthe (R),(+)-l,r-binaphthalene-2,2'-diamine spacer group, yield (040 g, 63%) (Found: C, 51.4; H, 3.1; N, 7.4. [Ag2)C₃2H₂₂N₄)2][PF₆]₂.3.5H2O requires C, 51.5; H, 3.4; N, 7.5%): ,H (300 MHz; CD₃CN): g 8.77[4 H, d, J(H_imine-Ag) 9.0 Hz, H_imine], 8.14[4 H td, J(H_4py-H₃py) 7.7, (H₄py-H_5py) 7.7 Hz, H_4py], 7.92 [4 H, d, J(H_4py-H₃py) 7.7 Hz, H_3py], 7.54 [4 H, d, J(H, d, J(H_6bi-H₇bi) 8.1 Hz, H_6bi], 7.41 [4 H, ddd, J(H₅py-H_4py) 7.7, (H₅py-H₆py) 4.7 Hz, H_5py], 7.37 [4 H, d, J(H_3bi-H_4bi) 8.9 Hz, H_3bi], 7.32 [4 H, ddd, J(H_7bi-H₆bi) 8.1, (H_7bi-H₈bi) 6.8 Hz, H_7bi], 7.15 [4 H, ddd, J(H_78bi-H₉bi) 8.3, (H_8bi-H_7bi) 6.8 Hz, H_8bi], 7.07 [4 H d, J(H_4bi-H₃bi) 8.9 Hz, H_4bi], 6.78 [4H, dd, J(H₉b!-H_8bi) 8.3 Hz, H_9bi], 6.72 [4H, dd, J(H₆py-H₅py) 4.7 Hz, H_6py]. ¹³C(75.5 MHz; CD₃CN): g 162.2 (C_imine), 149.5 (C_6py), 147.8 (C_4o), 144.2 (C_4o), 139.0 (C_4py), 132.5 (C_4o), 132.2 (C_4o), 130.6 (C_4bi), 128.9 (C_3py), 128.5 (CM), 128.0 (C_5py), 127.3 (CM), 126.1 (C_7bi), 125.7 (C_4o), 125.0 (C_9bi), 118.6 (C_3bi). Positive-ion FAB, m/z 1285 ([Ag2(C₃₂H22N₄)2][PF₆]⁺, 93%), 1140 ([Ag₂(C₃2H₂₂N₄)₂]⁺, 90%), 571 ([Ag₂(C₃2H2₂N₄)]⁺, 53%). Positive-ion ESI, mlz 1285 ([Ag₂(C₃₂H₂₂N₄)₂][PF₆]⁺), 1033 ([Ag₂(C₃₂H₂₂N₄)₂]⁺), 571 ([Ag₂(C₃₂H₂₂N₄)₂]₂ ⁺). v_m cm 3050-2800w, 1615w, 1567m, 1568w, 1504m, 1439m, 1304m, 1204m, 1005m, 831s, 777s, 757s, 739s, 693m, 673m, 651m, 651m, 632m, 62 lw, 555s, 523w, 509w. k_max/nm (MeCN) 229 (e/mol-'dnr³ cm, 1.6 x 10⁵), 279 (1.0 x 10⁵), 322 (4.0 x 10⁴), 360 (3.0 x 10⁴).

X-Ray Crystallography

Suitable crystals of Ls-([Ag2(C32H22N4)2][PF6]2 from nitromethane-diethyl ether. Crystallographic data are collected in Table 1. Data were measured on a Siemens SMART27 three-circle system with CCD area detector using the oil-mounting method at 180(2) K (maintained with the Oxford Cryosystems Cryostream Cooler).28 Absorption correction by u-scan. The structures were solved by direct methods using SHELXS29 (TREF). CCDC reference numbers 166445 and 166446.

Table 1 Crystallographic data and structural refinements for the L^R and L^s silver(I) double helicates Complex L^R silver(ι) helix L^s silver(l) helix Empirical formula C65.5θH48.5θAg2Fl2N9.5θθ3P2 Cl47.5θHlθ7A 4F₂4Nl6P4 Formula weight 1522.32 3114.85 Temerature/K 180(2) 180(2) Crystal System P3, P2, Space group Trigonal Monoclinic l A 14.38840(10) 13.1740(2) 3 (2) 7(3) 80(17),2 7(17),2 0.36 x 0.2

Independent reflections 15474 (R_lm=0.0266) 31159 (R_int=0.0766) Data/restraints/parameters 15474/1/869 31159/1/1706 Goodness-of-fit on F² 0.958 0.900 Final R indices [I>2r(I)J Rl = 0.370, wR2 = 0.0749 Rl = 0.0662, wR2 = 0.1182 R indices (all data) Rl = 0.0593, wR2 = 0.0820 Λl = 0.2412, wΛ2 = 0.1700 Largest difference peak, hole/ e A^"3 0.506, -0.402 0.566, -0.477 Absolute structure parameter -0.010(14) 0.01(2)

Crystallographic investigations. X-Ray quality crystals of both complexes were obtained from nitromethane solutions by slow diffusion of diethyl ether for the L^R complex and benzene for the L^s complex. The X-ray structural analyses confirm that the solid state structures of the two complexes are dinuclear double helicates. The crystal structures demonstrate that, as anticipated, the chiral twisting of the binaphthalene can be used to control the helicity of the array. The coordination of two L^R ligands around two _4pytetrahedral ions results in the formation of a P (right-handed)⁴ double helix and that the coordination of two L^s ligands around two silver(ι) tetrahedral ions similarly result in the formation of an M (left-handed) double helix (Fig. 3). (For the L^s enantiomer, two very similar but crystallographically distinct cations are present in the solid state structure).

Each silver(ι) centre is four-coordinate pseudo-tetrahedral, bound to two pyridylimine units, each of which is approximately planar (pyridyl-imine torsion angles in the range 3-11°). The naphthalene units are twisted with respect to the imine group (torsion angles in the range 38-44°) and a more dramatic twisting is observed between the naphthalene rings which are almost perpendicular to each other (torsion angles in the range 70-78°). The combination of these twistings gives rise to the formation of the double helical structure, the chirality of the helical arrays being prescribed by the chiral twist inherent in the binaphthalene unit. The two silver(I) centres within the helical dications are separated by 3.61-3.78 A. Within the helical arrays each pyridyl is stacked on top of a naphthalene unit. Such extensive face-face o-stacking interactions are also observed in polypyridyl helicates and presumably contribute to the stabilisation of the structure. Although the conditions used to prepare the helicates were quite vigorous, the chirality of the spacer groups and in consequence the ligands is preserved (steric hindrance in the binaphthalene units result in a relatively high activation energy for inversion of configuration).

Further Examples

Materials All starting materials were purchased from Aldrich and BDH, the compounds were used without further purification.

Measurements

NMR spectra were recorded on Bruker DPX 300 and ACP 400 instruments using standard Bruker software. FAB mass spectra were recorded by the Warwick mass spectrometry service on a Micromass Autospec spectrometer using 3-nitrobenzyl alcohol as matrix. Microanalyses were conducted on a Leeman Labs CE44 CHN analyser by the University of Warwick Analytical service. X-ray crystallography data were measured on a Siemens SMART three-circle system with CCD area detector using the Oxford Cryosystems Cryostream Cooler. Infrared spectra were recorded on a Bruker Vector 220 instrument fitted with an ATR Golden Gate.

Syntheses

6-Hydroxymethylpyridine-2-carboxaldehyde

2,6-Pyridinedimethanol (2 g, 0.014 mol) in isopropanol (70 cm³) was heated to gentle reflux. Then activated manganese (IV) oxide (< 5 micron) (1.25 g, 0.014 mol) was added portion wise over 1 hour. Gentle reflux was continued for 6 hours. After this time the black solution was filtered hot through Celite and the residue washed with hot isopropanol (30 cm³). The solvent was removed in vacuo to yield a pale yellow solid. The solid was subjected to flash chromatography on silica gel 60, loaded in DCM and eluted with 5% methanol: DCM. Fractions with Rf=0.55 (TLC run with 5% methanol: DCM) were collected to yield a yellow oil which crystallised in the fridge to a pale yellow solid. The product was dried under high vacuum over P₂O₅ to constant weight (0.64g, 33%)

Microanalysis: found C, 60.9; H, 5.3; N, 10.1. Calculated from C₇H₇NO₂: C, 61.3; H, 5.1; N, 10.2%

Positive ion Fast Atom Bombardment (FAB): m/z 137 (M⁺), 120 (M⁺-OH)Η NMR (CDC1₃, 400 MHz, 298K):<5 10.06 (IH, s, CHO), 7.89 (2H, 2d, J=7.5 Hz, H⁴+H⁵), 7.52 (IH, t, J=7.3 Hz, H⁴), 4.88 (2H, s, CH₂), 3.81 (H, br s, OH) ppm ^,3C NMR (CDC1₃, 400 MHz, 298K): d 192.9 (C^ald), 148.0 (C²), 138.1 (C⁴), 136.5 (C³), 128.4 (C⁵), 64.9 (C⁶), 53.4 (CHa) ppm

L³ (C2₇H24N₄O₂)6-Hydroxymethylpyridine-2-carboxaldehyde (0.137 g, 1.0 mmol) in ethanol (25 cm³) was added dropwise to an ethanolic solution of 4,4' methylene dianiline (0.099 g in 25 ml, 0.5 mmol) over 30 min. The resulting yellow solution was left stirred at room temperature for 24 hours. A pale cream solid precipitated and was collected by vacuum filtration. The product was dried under vacuum over P2O5 to constant weight (0.156 g, 72 %)Positive ion El : m/z 435 (M⁺, 95%), 418 (M⁺-OH, 15%), 401 (M⁺-2 OH, 20%), 404 (M⁺- CH₂OH, 15%)'H NMR (CDC1₃, 400 MHz, 298K): d 8.73 (IH, s, H^im), 8.19 (IH, d, J=7.8 Hz, H³), 7.85 (IH, t, J=7.8 Hz, H⁴), 7.33 (IH, d, J=7.8 Hz, H⁵), 7.26 (4H, s, H^ph), 4.83 (2H, s, CH₂OH), 4.06 (IH, s, CH₂spacer) 3.80 (IH, br s, OH) ppm

[Cu₂L³ ₂](PF₆)2To a stirred solution of L³ (0.043 g, 0.1 mmol) in dry methanol (5 cm³) was added [Cu(MeCN)4][PF₆] (0.037 g, 0.1 mmol) dissolved also in dry methanol (5 ml) under nitrogen. The red-brown solution was stirred at room temperature under nitrogen for 16 hours. The red-brown solid was subsequently filtered under vacuum and washed with diethyl ether (1 cm³). The product was dried under vacuum over P₂O₅ to constant weight. (0.045 g, 70%)Positive-ion FAB: m/z 1143 ([Cu2(L³)₂(PF₆)]⁺), 1000 ([Cu₂(L³)₂]⁺¹H NMR (CD₃CN, 400 MHz, 298K) : d 9.24 (IH, s, ff), 8.25 (IH, t, J=7.8 Hz, H⁴), 8.02 (IH, d, J=7.9 Hz, H³), 7.91 (IH, d, J=7.9 Hz, H⁵), 7.36 (2H, d, J=8.0 Hz, EP*), 7.18 (2H, d, J=8.2 Hz, EP⁵*¹), 4.32 (2H, bd, QkOH), 3.87 (IH, s, CH₂spacer), 3.47 (IH, bs, OH) ppm

Η NMR (CD₃CN, 500 MHz, 233K) : d 9.37 (2H, s, H¹ box) 9.30 (7H, s, H hel), 8.23 (9H, m, H⁴ box, H⁴ hel), 8.00 (9H, d, J=7.8 Hz, H³ hel„H³ box), 7.88 (7H, d, J=7.8 Hz, H⁵ hel), 7.84 (2H, d, J=7.8 Hz, H⁵ box), 7.43 (4H, d, J=8.2 Hz, H^ph box), 7.33 (14H, d, J=8.2 Hz, H^ph hel) 7.23 (4H, d, J=8.2 Hz, H^ph box), 7.16 (14H, d, J=8.2 Hz, H^Ph hel), 4.29 (7H, dd, J=15.9, 6.2 Hz, CHzOH hel), 4.22 (2H, dd, J=15.9, 5.6 Hz, CH₂OH box), 4.11 (7H, dd, J=16.2, 6.2 Hz, CI£>OH hel), 4.07 (2H, dd, J=16.2, 6.2 Hz, CH₂OH box), 3.90 (IH, d, J= 12.8 Hz CH₂sρacer box), 3.81 (8H, s, CH₂spacer hel, CH₂spacer box) 3.75 (9H, m, OH hel, OH box) ppm. l_max/nm (MeCN) 510 (e/mol-'dm^cm^"1 2.6xl0⁴) MLCT nmax/cm^"1 3500-3000w, 2357m, 1596m, 1501m, 1463m, 1269m, 1200m, 1161, 1079m, 1012m, 910m, 828s, 789m, 737m, 648m, 612m, 603m. [Cu₂L⁴ ₂](PF₆)₂

6-Hydroxymethylpyridine-2-carboxaldehyde (0.137 g, 1.0 mmol) was dissolved in dry methanol (15 ml) with 4,4' methylene bis 2,6 diethyl aniline (0.155 g, 0.5 mmol). The pale yellow solution was left stirring at room temperature under nitrogen for 30 min. Then [Cu(MeCN)₄][PF₆] (0.018 g, 0.5 mmol) dissolved in dry methanol (5 ml) was added to the solution under a blanket of nitrogen. The solution, which quickly becomes red-brown in colour, was stirred at room temperature under nitrogen for 15 hours. The red-brown solid which precipitated was filtered off under vacuum and washed with diethyl ether (2 cm³). The product was dried under vacuum over P₂O₅ to constant weight. (0.27 g, 36%)

Positive-ion FAB: m/z 1369 ([Cu₂(L⁴)₂(PF₆)]⁺), 1224 ([Cu₂(L⁴)₂]⁺) Η NMR (CD₂C1₂, 400 MHz, 298K): d 8.50 (IH, s, H^im), 8.26 (IH, t, J=7.8 Hz, H⁴), 8.12 (IH, d, J=7.8 Hz, H³), 7.89 (IH, d, J=7.8 Hz, H⁵), 7.14 (IH, s, H^Ph), 6.58 (IH, s, H^ph), 4.35 (IH, dd, J=14.1, 4.1 Hz CHzOH), 3.95 (IH, br d, J=13.8 Hz CTLOH), 3.92 (IH, s, CH₂spacer), 3.07 (IH, br s, OH) 2.59 (2H, m, CHaMe), 1.91 (2H, m, CHzMe), 1.03 (3H, t, J=7.4 Hz, Me), 0.64 (3H, t, J=7.3 Hz, Me) ppm. l_max/nm (MeCN) 466 (e/mol^dπrW 3x10⁴) MLCT n_^x/cπr¹ 3500-3000w, 2962m, 1615m, 1583m, 1461m, 1428m, 1399m, 1339m, 1316m, 1194m, 1140m, 1083m, 1003m, 979m, 920m, 880m, 844s, 789m, 735m, 648m, 607m

The chloride salt [Cu2L⁴ ₂]Cl₂ was prepared in an analogous manner from copper(I) chloride

[Ru₂L₃]⁴⁺

Ru(DMSO)₄Cl₂ (0.485 g, 1 mmol) and L (0.564 g, 0.67 mmol) were added to 15 mL of ethylene glycol,purged for 12 h with dinitrogen and then heated at reflux for 10 days under dinitrogen. The orange mixture was cooled to room temperature and poured into a concentrated methanolic solution of NHIPFΘ. The orange-red precipitate was collected by filtration and dried over P Oιo. This crude product was dissolved in acetonitrile and loaded onto a neutral alumina column and eluted with a mobile phase of CH₃CN : H₂O : saturated aqueous KNO₃ 20 : 1 : 1. The triple helical cylinder [Ru2L₃]⁴⁺ was eluted from the column (second band) as an orange band from which an orange solid (0.026g) precipitated on concentrating.

Positive ion ESI-MS (CH₃CN/MeOH): m/z = 333.2 [Ru₂L₃]⁴⁺.

^]H NMR (CD₃CN, 298 K, 300MHz) d = 8.77 (IH, s, Him), 8.48 (IH, d, J = 7.2 Hz, H₃), 8.3 (IH, td, J = 7.7, 1.5Hz, H₄), 7.73, (IH, td, J = 7.5, 4.9 Hz, 1.3 Hz, H₅), 7.66 (IH, d, J= 4.9 Hz, He), 6.97 (2H, d, J= 8.5, H_ph), 5.74 (2H, d, J= 8.7, Hp_h), 4.03 (IH, s, CH2 spacer) ppm

PREPARATION OF LIGAND NH₂-L

Scheme : Ligand NH₂-L

4,4'-diaminodiphenylamine sulphate 85% (0.5 g, 1.43 mmol) was dissolved in water

(50 mL) and mixed with pyridine-2-carboxaldehyde (0.27 mL, 2.86 mmol). The solution was stirred for 1 hour and the green-yellow precipitate collected by filtration. The resulting solid was finally washed with water (10 mL) and dried in vacuo.

NH₂-L. Yield 0.23 g., 43 %; +ve FAB MS: m/z = 378 (M+l);

Η NMR (DMSO-de, ppm): d 6.00 (s, IH), 7.14 (d, 4H, j= 8.3 Hz), 7.34 (m, 6H), 7.80

(t, 4H, J= 8.3 Hz), 8.20 (d, 2H, J=7.5 Hz); 8.66 (s, 2H), 8.71 (d, 2H, J=4.5 Hz).

PREPARATION OF COMPLEX [Fe₂(NH₂-L)₃]Cl4

4,4'-diaminodiphenylamine sulphate 85% (0.5 g, 1.43 mmol) was dissolved in

methanol (50 mL) and treated with excess of Na2CO₃ .The suspension was filtered to

remove the Na2CO₃ excess and to the solution pyridine-2-carboxaldehyde (0.27 mL,

2.85 mmol) and FeCl₂x4H₂O (0.27 g, 2.85 mmol ) were added. The resulting mixture

was heated at reflux for 3 hours with a Dean- Stark trap and concentrated to half volume. The addition of diethyl-ether (10 mL) precipitated a solid which was collected by filtration and dried in vacuo.

[Fe₂(NH₂-L)₃]Cl₄. Yield (0.31 g. 47%); +ve FABMS: m/z = 1313 {Fe₂(NH2-L)₃Cl₂} ; Η NMR (DMSO-d₆, ppm): d 5.54 (d, 4H, 7.5 Hz), 6.69 (d, 4H, 7,5 Hz), 7.39 (d, 2H, J= 5.6 Hz), 7.60 (dd, 2H, J= 7.5, 5.6 Hz), 8.20 (t, 2H, 7.8 Hz), 8.43 (d, 2H, 7.5 Hz), 9.07 (s, IH).

The resolution of the supramolecular iron triple-helicate enantiomers was performed by chromatography using cellulose (-20 micron; Aldrich) as stationary phase and an aqueous 20mM NaCl solution as mobile phase. The solutions obtained at the beginning and at the end of the separation show opposite CD-spectra and correspond to the P and M enantiomers respectively.

Preparation of L:

To a stirred solution of pyrazinecarboxaldehyde (0.237g, 2.2 mmol) in ethanol (10 ml) at room temperature was added dropwise an ethanolic solution of bis(4-aminophenyl)methane (0.218g, 1.1 mmol). After the addition was complete, the reaction mixture was stirred at room temperature for 24 hours. The resultant precipitate was filtered off, washed with ethanol and dried in vacuo under P Oιo to afford 0.27g (71%) of yellow solid. Mass spectrum (FAB): m/z = 379 [M+H]⁺

Elemental analysis calculated (%) for C₂₃Hι₈N₆: C: 73.0, H: 4.8, N: 22.2; found: C: 72.7, H: 4.8, N: 22.0.

'H NMR (300MHz, CDC1₃, 298 K): d = 9.41 (IH, s, H), 8.63 (3H, m, H³, H⁵, H⁶), 7.27 (4H, s, H^ph), 4.05 (IH, s, CH₂).

IR: n = 2930 (s), 1626 (m), 1589 (m), 1574 (s), 1518 (m), 1497 (s), 1467 (m), 1408 (vs), 1345 (m), 1289 (m), 1196 (w), 1166 (s), 1147 (s), 1048 (s), 1012 (vs), 953 (s), 943 (m), 869 (vs), 859 (vs), 816 (m), 787 (vs), 755 (s) 670 (s) cm"¹.

Coordination of L to silver(I):

Care was taken to exclude light during the following procedure. L (O.Olg, 0.03mmol) in chloroform and silver(I) hexafluorophosphate (0.0075g, 0.03 mmol) in methanol were stirred for 6 hours. The yellow precipitate was collected by vacuum filtration, washed with methanol and dried in vacuo under P₄Oιo (O.Olg, 26%). X-ray quality, pale yellow crystals were obtained by slow diffusion of diethyl ether into a solution of the complex in acetonitrile.

Mass spectrum (FAB) m/z = 1117 [Ag₂L₂(PF₆)], 972 [Ag₂L₂]

Elemental analysis calculated (%) for

C: 43.4, H: 2.9,

N: 13.2; found: C: 43.3, H: 2.9, N: 13.0.

IR: n = 2990 (w), 1626 (w), 1582 (w), 1406 (m), 1375 (w), 1317 (w), 1204 (w), 1166

(m), 1153 (m), 1107 (w), 1055 (m), 1030 (m), 970 (w), 837 (vs), 784 (m), 756 (m), 680

(w) cm^"1.

Coordination of L to copper(I):

L (0.017g, 0.048mmol) was dissolved in chloroform and whilst stirring under a nitrogen atmosphere, [Cu(MeCN)₄]BF (0.018g, 0.048 mmol) in methanol was added to give a dark brown solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark brown solid precipitated from the solution and was collected by vacuum filtration, washed with methanol and dried in vacuo under P₄Oι₀ (0.03g, 59%). X-ray quality, dark brown crystals were obtained by slow diffusion of diethyl ether into a solution ofthe complex in nitromethane. Mass spectrum (FAB) m/z = 971 [Cu₂L₂(BF₄)], 884 [Cu₂L₂]

Elemental analysis calculated (%) for [Cu₂(C₂₃Hι₈N₆)₂](BF₄)₂-CH₃OH: C: 51.8, H: 3.7, N: 15.4; found: C: 51.7, H: 3.1, N: 15.3.

Η NMR (300MHz, CD₃CN, 298 K): d = 9.28 (IH, s, H), 9.17 (IH, s, H³), 8.93 (IH, br, H⁵⁶), 8.56 (IH, br, H⁵⁶), 7.37 (2H, d, J = 8.5 Hz, H^ph), 7.24 (2H, d, J = 8.3 Hz, H^ph), 3.92 (lH, s, CH₂).

IR: n = 3029 (w), 2916 (w), 1610 (w), 1505 (m), 1471 (m), 1422 (s), 1404 (s), 1361 (m), 1308 (m), 1203 (m), 1169 (s), 1157 (s), 1095 (s), 1057 (vs), 955 (m), 867 (m), 841 (m), 826 (m), 785 (s), 753 (m), 677 (m) cm'¹.

Coordination of L to iron(II):

L (0.025g, 0.07mmol) and iron(II) tetrafluoroborate (0.016g, 0.046 mmol) in a mixture chloroform-methanol (1:1) were stirred for 24 hours at room temperature. The violet precipitate was collected by vacuum filtration, washed with methanol and dried in vacuo under P₄Oι₀ (0.04g, 54%).

Mass spectrum (FAB) m/z = 1505 [Fe₂L₃(BF₄)₃], 1420 [Fe₂L₃(BF₄)₂], 1352 [Fe₂L₃(BF₅)],

1333 [Fe₂L₃(BF₄)], 1265 [Fe₂L₃].

Elemental analysis calculated (%) for [Fe₂(C₂₃Hi8N₆)₃](BF₄)₄-3H₂O: C: 50.3, H: 3.7, N:

15.3; found: C: 50.4, H: 3.8, N: 15.2.

IR: n = 2987 (w), 1607 (w), 1501 (m), 1468 (w), 1411 (m), 1400 (m), 1352 (w), 1294

(w), 1207 (m), 1170 (m), 1056 (vs), 915 (w), 842 (m), 784 (m), 758 (m), 684 (m) cm^"1.

L Preparation of L:

To a solution of sodium ethoxide prepared from 1.3 g of sodium and 30 ml of absolute ethanol is added a solution of 5-hydroxi-2-methylpyridine (5.0 g, 0.05 mol) in 15 ml of ethanol followed by 6.86 ml (0.05 mol) of 2-benzoethyl bromide. The mixture is refluxed for three hours, poured into 150 ml of water and extracted with ether. The extract is dried and then treated with ethereal hydrogen chloride. The hydrochloride salt is dissolved in water and then the aqueous solution is washed with ether, basified and extracted with ether. The dried extract is evaporated to give 5-ethylbenzyloxy-2-methylpyridine as a yellow oil. (3.2g, 0.015 mol). Η NMR (300MHz, CDC1₃, 298 K): d = 8.15 (IH, d, J= 2.6 Hz, H⁶), 7.3 (5H, m, H^Ph), 7.04 (2H, m, H³, H⁴), 4.14 (2H, t, J = 7.1, 6.9 Hz, CH₂), 3.05 (2H, t, J = 6.9, 6.9 Hz, CHa).

5-ethylbenzyloxy-2-methylpyridine (3.2g, 0.015 mol), hydrogen peroxide 30% (3.5 ml, 0.03 mol) and acetic acid (30 ml) were heated to 80°C for 2.5 hours. The solution was stirred at room temperature for further 24 hours and concentrated under reduced pressure. The resulting yellow oil is neutralized with sodium carbonate. Chloroform is added and the Na₂CO₃ and NaOAc were removed by filtration. The dried filtrate is evaporated to give 5-ethylbenzyloxy-2-methylpyridine-N-oxide (5.2g, 0.02 mol). Η NMR (300MHz, CDC1₃, 298 K): d = 8.22 (IH, d, J = 2.5 Hz, H⁶), 7.3 (5H, m, H^Ph), 6.93 (IH, d, J= 2.5 Hz, H³), 6.90 (IH, d, J= 2.5 Hz, H⁴), 4.14 (2H, t, J= 6.8, 6.7 Hz, CH₂), 3.04 (2H, t, J= 6.8, 6.8 Hz, CH₂).

To 10 ml of acetic anhydride stirred at 135°C is added slowly 5.2 g( 0.02 mol) of the above N-oxide. The solution is stirred at this temperature for 30 minutes and then poured into 100 ml of ice- water. After stirring the mixture for 2 hours it is extracted with a mixture of ethyl acetate and ether. The extract is washed with water, dried and evaporated to dryness. The residue is passed through an alumina column with ether as the eluent. Evaporation of the first fraction yields

2-acetoxymethyl-5-ethylbenzyloxypyridine (1.5g, 0.006 mol).

Η NMR (300MHz, CDC1₃, 298 K): d = 8.24 (IH, d, J = 2.8 Hz, H⁶), 7.3 (5H, m, H^Ph), 7.14 (IH, d, J= 2.2 Hz, H³), 7.12 (IH, d, J= 2.8 Hz, H⁴), 5.1 (2H, s, CH₂), 4.17 (2H, t, J= 7.2, 6.9 Hz, CH₂), 3.07 (2H, t, J= 6.9, 6.9 Hz, CH₂), 2.08 (3H, s, CH₃). A solution of 1.5 g (0.006 mol) ofthe above acetoxymethyl compound in 12 ml ethanol and 3 ml water is treated with 0.41 g NaOH and refluxed for four hours. The solution is evaporated and the residue is taken up in a mixture of ethyl acetate and ether. This solution is washed with water, dried and evaporated to dryness, given 5-ethylbenzyloxy-2-hydroxymethylpyridine as a yellow oil (1.241g, 0.005 mol). Η NMR (300MHz, CDC1₃, 298 K): d = 8.18 (IH, d, J= 1.3 Hz, H⁶), 7.3 (5H, m, H^ph), 7.13 (2H, m, H³, H⁴), 4.64 (2H, s, CHa), 4.17 (2H, t, J= 7.1, 6.9 Hz, CH₂), 3.07 (2H, t, J = 7.1, 6.9 Hz, CH₂).

A well-stirred mixture of 1.241 g (0.005 mol) of the above hydroxymethyl compound and 11.7 g of activated manganese dioxide in 60 ml of chloroform is refluxed for 5 minutes. The manganese dioxide is filtered and the solvent evaporated to give a yellow oil, which is purified on silica column with ether-hexan (7:3) as eluent. The evaporation of the second fraction give 5-ethylbenzyloxy-2-pyridinecarboxaldehyde (l.Og, 0.4 mmol); Mass spectrum (FAB): m/z = 228 [M+H]⁺; Η NMR (300MHz, CDC1₃, 298 K): d = 9.92 (IH, s, H^ald), 8.36 (IH, d, J= 2.6 Hz, H³), 7.88 (IH, d, J= 8.6 Hz, H⁴), 7.25 (6H, m, 5H^ph + H⁶), 4.25 (2H, t, J= 6.9, 6.7 Hz, CH₂), 3.1 (2H, t, J= 6.9, 6.7 Hz, CH₂), To a stirred solution of 5-ethylbenzyloxy-2-pyridinecarboxaldehyde (l.Og, 0.4mmol) in ethanol (10 ml) at room temperature was added dropwise an ethanolic solution of bis(4-aminophenyl)methane (0.435g, 0.2 mmol). After the addition was complete, the reaction mixture was stirred at room temperature for 2 hours. The resultant precipitate was filtered off, washed with ethanol and dried in vacuo under P₄Oιo to afford 0.86g (70%) of white solid.

Mass spectrum (FAB): m/z = 617 [M+H]⁺

Elemental analysis calculated (%) for C4iH3 N₄O₂-0.75H₂O: C: 78.1, H: 6.0, N: 8.9; found: C: 77.9, H: 5.9, N: 8.9.

'H NMR (300MHz, CDC1₃, 298 K): a = 8.57 (IH, s, H), 8.44 (IH, s, H⁶), 8.15 (IH, d, J = 8.6 Hz, H³), 7.26 (10H, m, 5H^ph, 4H^Ph', H⁴), 4.30 (2H, t, J = 6.9, 6.7 Hz, CH₂), 3.17 (2H, t, J= 6.9, 6.7 Hz, CH₂).

Coordination of L to iron(II):

L (O.lg, 0.15mmol) and iron(II) chloride (0.02g, 0.1 mmol) in a mixture chloroform-methanol (1:1) were refluxed for 3 hours. The resulting red-purple solution was cooled and treated with saturated solution of ammonium triflate. The red-purple precipitate was collected by vacuum filtration, washed with methanol and dried in vacuo under P₄Oι₀ (0.8g, 60%). X-ray quality, red-purple crystals were obtained by slow diffusion in a H-tube of a methanolic solution of ammonium triflate into methanolic solution ofthe chloride complex.

Mass spectrum (FAB) m/z = 2409 [Fe₂L₃(CF₃SO₃)₃], 2259 [Fe₂L₃(CF₃SO₃)2], 2111 [Fe₂L₃(CF₃SO₃)].

Positive-ion ESI (MeCN): m/z = 1130 ([Fe₂L₃(CF₃SO₃)]²⁺), 703 ([Fe₂L₃(CF₃SO₃)]³⁺), 490 ([Fe₂L₃]⁴⁺).

Η NMR (500MHz, CD₃CN, 298 K): d = 8.85 (IH, s, H¹), 8.45 (IH, d, = 8.5 Hz, H³), 7.79 (IH, dd, J = 6.0, 2.5 Hz, H⁴), 7.26 (5H, m, 5H^Ph), 6.97 (IH, s, H⁶), 6.90 (2H, br, H^Ph'), 5.48 (2H, br, H^ph'), 4.30 (2H, td, J = 9.0, 7.0, 3.0 Hz, CH₂), 4.00 (2H, s, CH₂), 3.06 (2H, t, J= 7.0 Hz, CH₂).

Preparation of L"

To an ethanol solution (15 mL) of 2-formyl-5-hydroxymethylpyridine (0.274 g, 2 mmol) was added very slowly an ethanol (10 mL) solution of hydrazine monohydrate (0.5 g, 1 mmol). The reaction mixture was stirred at RT for 6 h and the resulting pale yellow precipitate were filtered off, washed with ethanol and dried overnight under P₄Oιo to afford 0.21 g , yield 77,7 %. Mass spectrum (FAB): m/z 271 [M+H]⁺

Η NMR (300 MHz, CDC1₃, 298 K): d = 8.13 (2H, s, Him), 7.65 (IH, d, J = 7.71 Hz H , 7.40 (IH, ά, J= 7.71 Hz, H₃ ), 4.21 (2H, s, OH), 3.82 (IH, s, H₆???), 3.20 (2H, d,

Coordination of L¹¹ to Fe(II).

Ligand L^u was dissolved in methanol and to this solution was added very quickly the

Fe(ClO₄)₂ 4H₂O. Immediately, the purple precipitate formed was collected by vacuum filtration and dried over P₄Oιo.

X-ray quality, purple-black crystals were obtained by slow diffusion of diethyl ether into a solution ofthe complex in acetonitrile.

Mass spectrum (FAB): m/z 1221 [Fe₂L₃(PF₆)₃]⁺, 1121 [Fe₂L₃(PF₆)₂]²⁺ 1022

[Fe₂L₃(PF₆)]³⁺ Η NMR (300 MHz, CD₃CN, 298 K): d = 8.84 (IH, s, Him), 8.36 (IH, d, J= 8.1 Hz, H₄), 8.23 (IH, d, J= 8.1 Hz, H₃), 7.26 (IH, s, H₆), 4.66 (2H, m), 3.71 (IH, m)

Preparation of L^Me:

To a stirred solution of 2-quinolinecarboxaldehyde (0.068g, 0.43 mmol) in ethanol (30 ml) at room temperature was added dropwise an ethanolic solution of

4,4'-methylenbis(2,6-dimethylaniline) (0.0541g, 0.215 mmol). After the addition was complete, the reaction mixture was stirred at room temperature for 24 hours. The resultant precipitate was filtered off, washed with ethanol and dried in vacuo under

P₄Oιo to afford 0.094g (82%) of yellow solid.

Mass spectrum (FAB): m/z = 533 [M+H]⁺

Elemental analysis calculated (%) for C₃₇H₃₂N₄-0.25H₂O: C: 82.7, H: 6.1, N: 10.4; found: C: 82.7, H: 6.1, N: 10.3.

Η NMR (300MHz, CDC1₃, 298 K): a = 8.56 (IH, s, H¹), 8.43 (IH, d, J= 8.5 Hz, H³),

8.30 (IH, d, J= 8.6 Hz, H⁴), 8.20 (IH, d, J= 7.7 Hz, H⁹), 7.90 (IH, d, J= 8.1 Hz, H⁶),

7.78 (IH, t, J = 7.1 Hz, H⁸), 7.63 (IH, t, J= 7.3 Hz, H⁷), 6.97 (2H, s, H^u), 3.88 (IH, s,

CH₂), 2.19 (3H, s, CH₃).

IR: o = 2901 (w), 1634 (s), 1595 (m), 1559 (w), 1502 (m), 1476 (m), 1427 (m), 1378

(m), 1306 (w), 1233 (w), 1200 (s), 1136 (m), 1110 (m), 1020 (w), 972 (w), 894 (m),

880 (w), 852 (w), 828 (vs), 770 (m), 745 (s), 727 (m), 688 (w) cm^"1.

Coordination of L^Me to silver (I):

Care was taken to exclude light during the following procedure. L^Me (0.02g, 0.04 mmol) in chloroform and silver(I) hexafluorophosphate (0.01 g, 0.04 mmol) in methanol were stirred at room temperature for 4 hours. The orange precipitate was collected by vacuum filtration, washed with chloroform and dried in vacuo under P Oιo (0.04g, 75%). X-ray quality, orange crystals were obtained by slow diffusion of diethyl ether into a solution ofthe complex in nitromethane.

Mass spectrum (FAB) m/z = 2210 [Ag₃(L^Me)₃(PF₆)₂], 2065 [Ag₃(L^Me)₃(PF₆)], 1550 [Ag₃(L^Me)3(PF6)(PF₅)], 1424 [Ag₂(L^Me)₂(PF₆)], 1279 [Ag₂(L^Me)₂], 1172 [Ag(L^Me)₂], 766 [Ag₂(L^Me) (HaO)], 746 [Ag₂(L^Me)], 638 [Ag(L^Me)].

Elemental analysis calculated (%) for [Ag3(C37H₃₂N₄)₃](PF₆)3: C: 56.6, H: 4.1, N: 7.1; found: C: 59.9, H: 4.5, N: 6.2.

Η NMR (300MHz, CD₃CN, 298 K): a = 8.75 (IH, d, J= 8.4 Hz, H⁹), 8.72 (IH, s, H), 7.95 (2H, dd, J= 8.2, 7.1 Hz, H³, H⁴), 7.94 (IH, d, J= 8.2 Hz, H⁶), 7.69 (IH, ddd, J = 8.1, 6.9, 1.1 Hz, H^{7 8}), 7.60 (IH, ddd, J= 8.4, 6.9, 1.1 Hz, H^7/8), 6.88 (2H, s, H¹⁰), 3.88 (lH, s, CH₂), 1.97 (3H, s, CH₃).

'H NMR (500MHz, CD₂C1₂, 283 K): a = 8.76 (3H, m, H¹ helix and trimer, H⁹ trimer), 8.70 (IH, ά, J = 6.5 Hz, H⁹ helix), 8.17 (IH, d, J = 8.4 Hz, H³ helix), 8.12 (3H, m, H³ trimer, H⁴ helix and trimer), 8.07 (IH, d, J= 8.4 Hz, H⁸ helix), 7.95 (IH, d, J= 8.4 Hz, H⁸ trimer), 7.73 (3H, m, H⁷ trimer and H⁶,H⁷ helix), 7.66 (IH, dd, J = 6.8, 1.2 Hz, H⁶ trimer), 6.94 (2H, s, Hph helix), 6.87 (2H, s, Hph tπ^' er), 3.93 (IH, s, central CH₂ helix), 3.78 (IH, s, central CH₂ trimer), 1.99 (6H, s, CH₃ helix), 1.79 (6H, s, CH₃ trimer). IR: δ = 2908 (w), 1633 (m), 1588 (m), 1557 (m), 1506 (m), 1477 (m),1463 (m), 1380 (m), 1337 (m), 1303 (m), 1228 (m), 1119 (m), 1143 (m),989 (w), 936 (w), 823 (vs), 780 (m), 750 (1^, 680 (1^ 01^.

Coordination of L^Me to copper(I):

L^Me (0.02g, 0.04mmol) was dissolved in chloroform and whilst stirring under a nitrogen atmosphere, [Cu(MeCN)₄]BF (0.015g, 0.04 mmol) in methanol was added to give a dark violet solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark violet solid precipitated from the solution and was collected by vacuum filtration, washed with methanol and dried in vacuo under P₄Oιo (0.04g,

80%).

Mass spectrum (FAB) m/z = 1278 [Cu₂(L^Me)₂(BF₄)], 1191 [Cu₂(L^Me)₂], 1126 [Cu(L^Me)₂],

672 [Cu₂(L^Me)(H₂O)], 594 [Cu(L^Me)].

Positive-ion ESI (MeCN): m/z = 1279 ([Cu₂(L^Me)₂(BF₄)]⁺), 595 ([Cu₂(L^Me)₂]²⁺).

Elemental analysis calculated (%) for [Cu₂(C37H₃₂N )a](BF₄)₂: C: 65.1, H: 4.7, N: 8.2; found: C: 55.6, H: 4.6, N: 7.2. Η NMR (300MHz, CD₃CN, 298 K): a = 8.86 (IH, s, H¹), 8.80 (IH, d, J= 8.4 Hz, H⁹),

7.95 (2H, br, H³, H⁴), 7.65, (1H, br, H⁷, H⁸), 7.44 (2H, br, H⁶), 6.97 (IH, br, H^Ph), 6.68

(1H, br, H^Ph),3.90 (1H, s, CHa), 1.55 (3H, br, CH₃).

Η NMR (500MHz, CD₂C1₂, 283 K): a = 8.86 (IH, s, H¹ helix), 8.79 (2H, m, H trimer andH⁹ helix), 8.73 (IH, d, J= 8.1 Hz, H⁹ trimer), 8.21 (2H, d, J= 8.1 Hz, H³ helix and trimer), 8.10 (2H, dd, J= 8.1, 3.1 Hz, Η⁴ helix and trimer), 7.76 (IH, d, J= 8.7 Hz, H⁸ trimer), 7.68 (3H, m, H⁷ trimer and H⁷,H⁸ helix), 7.50 (2H, dd, J= 8.1, 6.8 Hz, H⁶ helix and trimer), 6.98 (2H, m, H.?h helix and trimer), 6.75 (2H, m, H_PhΛβ/ά and trimer), 3.93

(IH, s, central CH₂ helix), 3.78 (IH, s, central CH₂ trimer), 2.10 (6H, s, CH₃ helix), 1.89

(6H, s, CH₃ trimer).

IR: δ = 2969 (m), 2910 (m), 1606 (s), 1588 (s), 1508 (s), 1476 (m), 1435 (s), 1379 (m),

1334 (w), 1303 (w), 1228 (m), 1196 (m), 1143 (m), 1052 (vs), 937 (w), 874 (w), 831

(w), 784 (w), 752 (m) cm^"1.

UV-Vis (MeCN): 365 (21830), 380sh (4400), 638sh (a = 2400) nm.

Preparation of L^Et:

4,4'-methylenbis(2,6-diethylaniline) (0.0667g, 0.215 mmol). After the addition was complete, the reaction mixture was stirred at room temperature for 24 hours. The resultant precipitate was filtered off, washed with ethanol and dried in vacuo under

P₄Oιo to afford 0.063g (50%) of yellow solid.

Mass spectrum (FAB): m/z = 589 [M+H]⁺

Elemental analysis calculated (%) for C₄ιH₄₀N₄: C: 83.6, H: 6.8, N: 9.5; found: C: 83.4,

H: 6.8, N: 9.5.

'H NMR (300MHz, CD₃CN, 298 K): a = 8.60 (IH, br, H¹), 8.44 (IH, d, J = 8.6 Hz,

H^3/4), 8.32 (2H, br, H³⁴, H⁹), 7.90 (IH, d, J= 8.5 Hz, H⁶⁷), 7.80 (IH, t, J= 7.9 Hz, H⁵⁸), 7.64 (IH, t, J= 7.9 Hz, H^6/7), 6.98 (2H, s, H^ph), 3.96 (IH, s, central CHa), 2.53 (4H, qd, J= 7.5 Hz, CH₂), 1.14 (6H, t, J= 7.5 Hz, CH₃).

IR: o = 2961 (s), 2927 (m), 2870 (m), 1630 (s), 1594 (m), 1559 (m), 1501 (m), 1453 (s), 1427 (m), 1376 (m), 1306 (w), 1255 (w), 1235 (w), 1198 (s), 1142 (s), 1112 (m), 1079 (w), 1059 (w), 1014 (w), 982 (w), 953 (w), 932 (w), 888 (s), 878 (s), 868 (w), 835 (vs), 788 (m), 770 (m), 740 (vs), 702 (m) cm^"1.

Coordination of L ^t to silver(I):

Care was taken to exclude light during the following procedure. L^Et (0.02g, 0.03 mmol) in chloroform and silver(I) hexafluorophosphate (0.007 g, 0.03 mmol) in methanol were stirred at room temperature for 24 hours. X-ray quality, orange crystals were obtained by slow diffusion of diizopropyl ether into solution (0.042g, 75%).

Mass spectrum (FAB) m/z = 1537 [Ag₂(L^Et)₂(PF₆)], 1392 [Ag₂(L^Et)₂], 1285 [Ag(L^E )₂]

Positive-ion ESI (MeCN): m/z = 1285 ([Ag(L^Et)₂]⁺), 696 ([Ag₂(L^Et)₂]²⁺)

Elemental analysis calculated (%) for [Ag₂(C₄ιH oN₄)₂](PF6)₂-2H₂O: C: 57.3, H: 4.9, N:

6.5; found: C: 57.0, H: 5.0, N: 6.3.

Η NMR (300MHz, CD₃CN, 298 K): a = 8.81 (2H, m, H¹, H³⁴), 8.13 (2H, m, H³⁴, H⁵⁸),

7.95 (IH, d, J= 8.3 Hz, H⁵⁸), 7.70 (IH, ddd, J= 8.1, 6.9, 1.1 Hz, H⁶⁷), 7.62 (IH, ddd, J

= 8.4, 6.9, 1.5 Hz, H⁶⁷), 6.81 (2H, br, H^ph), 3.83 (IH, s, central CH₂), 2.48 (4H, br,

CH₂), 0.7 (6H, br, CH₃).

IR: δ = 2964 (m), 2871 (m), 1633 (m), 1614 (w), 1588 (w), 1558 (w), 1505 (m), 1458

(m), 1433 (m), 1380 (m), 1337 (m), 1305 (w), 1226 (w), 1190 (m), 1143 (m), 990(m),

877 (m), 827 (vs), 787 (m), 775 (m), 753 (s), 693 (w), 666 (w) cm^"1.

Coordination of L³ to Fe(II)

To a stirred solution of acetylpyrazine (0.041 g, 0.30 mmol) and ground 3 A dried molecular sieves in methanol was added dropwise 4, 4' methyledianiline (0.029 g, 0.15 mmol) in methanol and a few drops of glacial acetic acid. The mixture was heated under reflux for 24 h. The molecular sieves were removed by filtration and the filtrate treated with FeCl₂ 4H₂O (0.019 g, 0.10 mmol)and refluxed for 2 hours. The purple solution was treated with methanolic ammoniumhexafluorophosphate solution, the resulting precipitate were filtered off and dried over P Oιo. Recrystalization from CH₃CN/diisopropylether afforded 0.052g, yield 58% of purple crystals of [Fe₂L₃](PF₆) 'HNMR (300MHz, CD₃CN, 298K) d = 9.68 (IH, br, H₆₅), 8.82 (IH, br, H₃), 7.37 (2H, br, H₆/5, H_ph), 6.77 (IH, d, J= 7.0 Hz, H_ph), 6.77 (IH, d, J= 7.0 Hz, H_ph), 4.65 (IH, d, J = 6.4 Hz, H_ph), 4.04 (IH, s, CH₂), 2.47 (3H, s, CH₃).

Copper (I) metallo-supramolecular compounds may be produced as shown in J. Chem. Soc, Dalton Trans., 2002, 164-169. See also Chem. Commun., 1999, 2033-2024.

Triple helicates and planar dimers from silver (I) coordination to bis-pyridylimine ligands may be produced as shown in J. Chem. Soc, Dalton Trans, 2002, 1635-1641.

Metallo-supramolecualar cylinders may be produced as shown in Angew. Chem. Int. Ed. 2001, 40, No. 5 and Chem. Commun. 1997 1807.

Synthesis of [Cu₂(L³)₂][PF₆]2

Ligand L³ (0.296 g, 0.503 mmol) was dissolved in methanol and whilst stirring under a nitrogen atmosphere, [Cu(MeCN) ][PF₆] (0.187 g, 0.503 mmol) was added to give a dark red solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark red solid precipitated from the solution on standing and was collected by filtration and dried with diethyl ether (0.682 g, 85 %).

IR (solid): 2961m, 2922m, 2867m, 1606m, 1591m, 1509m, 1459m, 1431m, 1373m,

1326w, 1295m, 1252w, 1225m, 1194m, 1136m, 1054w, 988m, 941m, 874m, 824s,

781s, 746s, 634m cm^"1.

Mass spectrum (ESI): m/z 1450 {Cu2(L³)₂(PF₆)} ⁺, 652 {Cu₂(L³)₂}²⁺.

(Found: C, 61.0; H, 5.0; N; 7.0. Calc. for Cu₂C₈₂H₈₀N₈P₂F,₂-H₂O: C, 61.1; H, 5.1; N,

7.0 %). Η NMR (CD₂C1₂): δ 8.86 (IH, s, H), 8.77 (IH, d, J= 8.3 Hz, H_3/ ), 8.17 (lH, d, J =

8.5 Hz, H3/4), 8.08 (IH, d, J= 8.1 Hz, H_{5 8}), 7.67 (IH, ddd J= 8.1, 6.2, 1.7 Hz, H₆/₇),

7.54 (2H, m, H₅/₈ & H_{6 7}), 7.02 (IH, s, H_Ph), 6.62 (IH, s, H_Ph), 3.91 (IH, s, central CH₂),

2.72 (IH, m, CH₂), 2.52 (IH, m, CH₂), 2.12 (2H, m, CH₂), 0.84 (3H, t, J = 7.4 Hz,

CH₃), 0.65 (3H, t, J= 7.5 Hz, CH₃).

UV/Vis (MeCN): 641 (e = 2 000), 526 (e = 7 000), 316 (e = 20 000) nm.

Ligand L. L (C₂₂H₂₂N ): 6-Methylpyridine-2-carboxaldehyde (2.00 g, 16.51 mmol) and l,3-bis(aminomethyl) benzene, (1.11 cm³, 8.25 mmol) were stirred in diethyl ether (25 cm³) over anhydrous magnesium sulphate for 2 hours. The orange solution was then filtered and concentrated under reduced pressure. An orange solid (2.57 g, 92%) crystallised out of solution over 14 hours in air and was collected by vacuum filtration and washed with ice-cold ethanol. dn(250 MHz; CDC1₃, 298K): d 8.56 [2H, s, H], 7.95 [2H, d, J= 7.6 Hz, H₃], 7.70 [2H, t, J = 7.6 Hz, H4], 7.37 [4H, m, Haw], 7.28 [2H, d, J= 7.6 Hz, H₅], 5.25 [4H, s, CH₂], 2.98 [6H, s, CH₃] ppm. dc(75.6 MHz; CDC1₃, 298K): d 163.6 (Q), 158.5 (Cvβ/m), 154.3 (C2/6/PI13), 139.4 (C26/Ph₃), 129.2 (Cph2 ph4/phs), 128.5 (Cph2 ph4/Phs), 127.4 (C ph2/ph4/phs), 124.9 (C₅), 118.9 (C₃), 65.3 (C_CH2), 24.7 (Ccro) ppm. Positive-ion El, m/z 343 ({M⁺}, 50%), 236 ({M⁺-C₆H₄N₂}, 60%), 221 ({M⁺-C₇H₇N₂}, 100%). Positive-ion Cl: m/z 343 ({MH⁺}, 100%). Accurate mass, positive-ion Cl: Found m/z 343.1923; Calculated for {C22H22N4H-} 343.1923;. n cra^"1 (KBr) 3062m, 3001m, 2954m, 2910w, 2868m, 2809w, 2018w, 1806w, 1651s, 1606w, 1590s, 1574s, 1491w, 1464s, 1441w, 1412m, 1374w, 1352m, 1327m, 1303w, 1268w, 1254w, 1222w, 1166w, 1086m, 1056w, 1043m, 995m, 984m, 905w, 884w, 803s, 793s, 774s, 746w, 736m, 694m, 650m, 621w, 577w, 546w, 494w.

[Cu₂(L)₂][BF₄]₂ L (0.03 g, 0.088 mmol) and [Cu(MeCN)₄][BF₄] (0.03 g, 0.095 mmol) were stirred in methanol (40 cm³) under dinitrogen for 14 hours. The resulting red solution was concentrated (in vacuo) and diethyl ether (3 cm³) added. The solution was cooled in ice and the resulting red solid collected by vacuum filtration (0.015 g, 34%). [Cu2( )₂][PF6]2 was prepared by an analogous route starting from [Cu(MeCN)4][PF₆]. «(400 MHz; CD₃CN, 233K): 8.63 [4H, s, H], 7.87 [4H, t, J = 7.9 Hz, H₄], 7.64 [4H, d, J = 7.9 Hz, H₃], 7.32 [4H, d, J = 7.9 Hz, H₅], 7.00 [2H, s, H_Ph2], 6.96 [2H, t, J = 6.9 Hz, H_Ph5], 6.87 [4H, d, J = 6.9 Hz, H_Ph ], 4.52 [4H, d, J = 13.3 Hz, CH₂], 4.22 [4H, d, J = 13.3 Hz, CH₂], 2.08 [12H, s, CH₃] ppm. Positive ion FAB: m/z 899 {Cu₂(L)₂(BF₄)⁺}, 812 {Cu₂(L)₂ ⁺}, 405 {Cu(L)⁺}. v_mJcm^'1 (KBr) 2800-3050w, 1624m, 1590m, 1464m, 1383m, 1257m, 1124m, 1084s, 1029m, 797m, 736w, 712w, 533w, 521w, 486w. λ_mJnm (e/mol-¹ dm^"3 cm^'1) (MeCN): 490 (3000). Calculated for [Cu₂(C₂₂H₂₂N₄)₂][BF₄] .lH₂O: C 52.7, H 4.6, N 11.2; Found: C 52.6, H 4.37, N 10.9%.

[Ag₂(L)2][PF₆]2 Care was taken throughout this procedure to exclude light. L (0.03 g, 0.088 mmol) and silver acetate (0.015 g, 0.088 mmol) were heated to reflux for one hour in methanol (30 cm³). The resulting clear solution was then filtered through celite and treated with methanolic ammonium hexafluorophosphate. The resulting white precipitate was collected by vacuum filtration (0.025 g, 48%). The analogous tetrafluouroborate salt [Ag₂(L)₂][BF₄]2 was prepared in a similar fashion by treating the clear solution with ammonium tetrafluoroborate. ^250 MHz; CD3CN, 298K): d 8.57 [4H, s, H], 7.95 [4H, t, J = 7.8 Hz, H₄], 7.60 [4H, d, J = 7.8 Hz, H₃], 7.43 [4H, d, J = 7.8 Hz, H₅], 7.25 [2H, s, H_Ph2], 7.06 [6H, s, Hp_h4&Ph₅], 4.37 [8H, s, CH₂], 2.03 [12H, s, CH₃] ppm. Positive ion FAB: m/z 1045 {Ag₂(L)₂(PF₆)⁺}, 900 {Ag₂(L)₂ ⁺}, 791 {Ag(L)₂ ⁺}, 593 {Ag(L)(PF₆)⁺}, 559 {Ag₂(L)⁺}, 451 {Ag(L)⁺}. VnAcm^"1 (KBr) 2914w, 1645m, 1593m, 1459m, 1383w, 1328w, 1257m, 1212w, 1165m, 1095m, 1050w, 1004w, 839s, 793m, 732w, 655w, 557s. Calculated for [Ag2(C2₂H22N4)₂][PF₆]2.1.33CHCl₃: C 40.3, H 3.4, N 8.3; Found: C 40.3, H 3.1, N 8.1%.

[Cu₃(L)₃(OAc)₃][PF₆]₃ L (0.05 g, 0.146 mmol) in 1:1 methanol/ethanol (7.5 cm³) solution was added to a stirred solution of copper acetate monohydrate (0.029 g, 0.146 mmol) also in 1:1 methanol/ethanol (7.5cm³) solution, under dinitrogen in an ice- water bath. The green solution was then treated with methanolic ammonium hexafluorophosphate. The resulting green precipitate was collected by vacuum filtration and washed with ice-cold diethyl ether (5 cm³), yield (0.047g, 57%). Positive ion ESI (methanol): m/z 1686.7 ({Cu3(L)₃(OAc)₃(PF₆)2⁺}, 5%). 1075.7 ({Cu₂(L)₂(OAc)₂(PF₆)⁺}, 22%). 1016.6 ({Cu₂(L)₂(OAc)₃ ⁺}, 15%). 955.5 ({Cu₂(L)₂(OAc)₂ ⁺}, 6%). 812.9 ({Cu₃(L)3(OAc)2(PF₆)²⁺}, 13%). 769.9 ({Cu₃(L)3(OAc)₃(PF₆)²⁺}, 15%) 464.2 ({Cu₂(L)₂(OAc)₂ ²⁺} or {Cu₃(L)₃(OAc)₃ ³⁺}, 100%). 435 ({Cu₂(L)₂(OAc)²⁺}, 74%). Positive ion ESI (Acetonitrile): m/z 1686.4 ({Cu3(L)₃(OAc)3(PF₆)2²⁺}, 5%). 1075.6 ({Cu₂(L)₂(OAc)2(PF₆)⁺}, 6%). 464.4 ({Cu₂(L)₂(OAc)₂ ²⁺} or {Cu₃(L)₃(OAc)3²⁺} , 100%). 435.5 ({Cu₂(L)₂(OAc)²⁺}, 26%). 290.2 ({Cu₂(L)₂(OAc)³⁺}, 26%). v./cm^"1 (solid) 2850-3 lOOw, 1652w, 1601m, 1575w, 1538w, 1464m, 1442m, 1418w, 1378m, 1326m, 1257m, 1224m, 1171m, 1013w, 831s, 791m, 739m, 704m, 667m, 621w. Calculated for [Cu₃(L)₃[OAc]₃[PF₆]3.3H2O: C 45.9, H 4.3, N 8.9; Found: C 45.7, H 4.0, N 8.6%.

[Ni₃(L)₃(OAc)₃][PF6]3 L(0.50 g, 1.59 mmol) and nickel(II) acetate (0.40 g, 1.59 mmol) were stirred in ethanol (30 cm³) for 1 hour, sonicated for 5 minutes, and treated with ethanolic ammonium hexafluorophosphate. A green precipitate formed immediately. After 24 hours green crystals formed which were collected for X-Ray analysis by manual separation before the bulk precipitate was collected by vacuum filtration, yield (0.56 g, 63%_>). [Ni₃(L)₃[OAc]₃[BF₄]3 was prepared by an analogous route, adding ammonium tetrafluoroborate in place of ammonium hexafluorophosphate. Positive ion ESI (methanol): m/z 1670.0 ({Ni₃(L)₃(OAc)3(PF₆)2⁺}, 100%). 1063.5 ({Ni₂(L)a(OAc)2(PF₆)⁺}, 13%). 805.3 ({Ni₃(L)₃(OAc)₂(PF₆)₂ ²⁺}, 17%). 762.4 ({Ni₃(L)₃(OAc)₃(PF₆)²⁺}, 20%). 488.4 ({Ni₃(L)₃(OAc)₂(PF₆)³⁺}, 7%). 459.8 ({Ni₃(L)₃(OAc)₃ ³⁺} or {Ni₂(L)₂(OAc)₂ ²⁺}, 10%). Positive ion ESI (Acetonitrile): m/z 1670.0 ({Ni₃(L)₃(OAc)₃(PF₆)₂ ⁺}, 24%). 1063.5 ({Ni₂(L)₂(OAc)₂(PF₆)⁺}, 16%). 805.3 ({Ni3(L)₃(OAc)2(PF₆)2²⁺}, 23%). 762.4 ({Ni₃(L)3(OAc)₃(PF₆)²⁺}, 60%). 488.4 ({Ni₃(L)3(OAc)2(PF₆)³⁺}, 35%). 459.8 ({Ni₃(L)₃(OAc)3³⁺} or {Ni₂(L)₂(OAc)2²⁺}), 100%. Vmax/cm^"1 (solid) 3100-3500w, 1652m, 1601m, 1538m, 1456m, 1418w, 1393w, 1327w, 1256m, 1223w, 1171w, 1107w, 1059w, 1007m, 946w, 830s, 788s, 740m, 702w, 680m, 665m, 625w. Calculated for [Ni₃(L)₃][OAc]3[PF6]3.3H₂O: C 46.3, H 4.4, N 9.0; Found: C 46.1, H, 4.0, N 8.8%.

Ligand L: 2-Pyridine carboxaldehyde (1.4 cm³, 15.1 mmol) and 4,4'-methylenedianiline

(1.5 g, 7.6 mmol) were stirred in ethanol (25 cm³) at room temperature for 12 hours.

The yellow solid that precipitated was collected by vacuum filtration, recrystallised from ethanol and dried in vacuo (2.6 g, 84 %).

IR (KBr): 1624m, 1581m, 1565m, 1502s, 1465s, 1433s, 1347m, 1197w, 1146m,

1088w, 989s, 880m, 865m, 827s, 783s cm^"1.

Mass spectrum (=ve FAB): m/z 377 {M + H }.

(Found: C, 79.4; H, 5.3; N, 14.7. Calc. For C₂₅H₂₀N₄-0.125H₂O: C, 79.3; H, 5.4; N, 14.8

%).

^!H NMR (CDCU) (250 MHz) at 298 K: d 8.73 (2H, d, J= 4.0 Hz, H₆), 8.65 (2H, s, H),

8.23 (2H, d, J= 7.0 Hz, H₃), 7.83 (2H, td, J= 8.3, 1.9, 0.6 Hz, H₄), 7.39 (2H, ddd, J =

7.6, 4.9, 1.2 Hz, H₅), 7.29 (8H, m, H_Ph), 4.07 (2H, s, CH₂).

[Fe₂L₃][PF₆]₄: Ligand L (0.0301 g, 0.08 mmol) and iron(II) chloride (0.0106 g, 0.05 mmol) were heated under reflux in methanol (20 cm³) under dinitrogen for 2 hours. The resulting purple coloured solution was cooled and treated with saturated methanolic ammonium hexafluorophosphate. On cooling a purple precipitate separated and was isolated by filtration (0.0408 g, 84 %).

IR (KBr): 1615m, 1585m, 1558w, 1502s, 1473m, 1440m, 1414w, 1302s, 1256w,

1239m, 1206s, 1162m, 1111m, 1018s, 832vs cm^"1.

Mass spectrum (+ve FAB): m/z 808 {FeL₂}, 827 {FeL₂F}, 883 {Fe₂L₂F}, 902

{Fe₂L₂F₂}, 919 {Fe₂L₂F₃}, 1047 {Fe₂L₂(PF₆)F₂}, 1386 {Fe₂L₃(PF₆)}, 1403

{Fe₂L₃(PF6)F}, 1421 {Fe₂L₃(PF₆)F2}, 1531 {Fe2 ₃(PF₆)2}, 1551 {Fe2L₃(PF₆)₂F}, 1675

Mass spectrum (ESI): m/z 311 {Fe₂L₃}⁴⁺ 100 %, 421 {Fe₂L₃F}³⁺ 1 %, 462

{Fe₂L₃(PF₆)}³⁺ 1 %.

(Found: C, 47.3; H, 3.3; N, 8.7. Calc. For Fe₂C₇₅H₆₀Ni2P4F2₄-4H₂O: C, 47.6; H, 3.6; N,

8.9 %).

•H NMR (CD₃CN) (400 MHz) at 233 K: d 8.75 (IH, s, Hi), 8.48 (IH, d, J= 7.4 Hz, H₃),

8.34 (IH, t, J= 7.4 Hz, H₄), 7.68 (IH, t, J= 6.4 Hz, H₅), 7.22 (2H, m, H₆,_Ph), 6.55 (IH, d, J = 7.8 Hz, HPH), 5.75 (IH, d, J = 6.9 Hz, H_Ph), 5.17 (IH, d, J = 7.4 Hz, H_Ph) 3.98

(lH, s, CH₂).

Η NMR (CD₃COCD₃; 300 MHz; 298K) d 9.32 (IH, s, H), 8.80 (IH, d, J= 7.7 Hz, H₃),

8.56 (IH, t, J= 7.7 Hz, H₄), 7.95 (IH, t, J= 6.2 Hz, H₅), 7.71 (IH, d, J- 5.1 Hz, H₆),

7.05 (2H, br d, H^), 5.75 (2H, br d, H^), 4.06 (IH, s, CH₂).

UV/Vis (MeCN): 524 (e = 11,000), 572 (e = 15,000) nm. The chloride salt was prepared by an analogous route.

Η NMR (DaO) (300 MHz) at 298K: d 8.89 (IH, s, Hi), 8.44 (IH, d, J= 7.7 Hz, H₃),

8.27 (IH, t, J= 7.7 Hz, H₄), 7.58 (IH, t, J = 6.6 Hz, H₅), 7.27 (IH, d, J = 5.5 Hz, H₆),

7.1 (IH, br, Hph), 6.6 (IH, br, H_Ph), 5.7 (IH, br, H_Ph), 5.3 (IH, br, Ha), 3.89 (IH, s,

CHa).

'H NMR (CD₃OD) (300 MHz) at 298K d 9.17 (IH, s, HO, 8.72 (IH, d, J= 7.5 Hz, H₃),

8.48 (IH, t, J = 7.5 Hz, H₄), 7.85 (IH, t, J= 6.5 Hz, H₅), 7.45 (IH, d, J= 5.3 Hz, H₆),

7.1 (2H, br, H_Ph), 5.6 (2H, br, H_Ph), 4.05 (IH, s, CH₂).

[Ni₂L₃][PF₆]4: Ligand L (0.0309 g, 0.08 mmol) and nickel(II) acetate (0.0136 g, 0.05 mmol) were heated under reflux in methanol (20 cm³) for 12 hours. The resulting yellow coloured solution was cooled and treated with saturated methanolic ammonium hexafluorophosphate. On cooling, yellow crystals separated and were isolated by filtration (0.0360 g, 72 %).

IR (KBr): 1635w, 1598s, 1504m, 1446w, 1308m, 1206m, 1018s, 841vs cm^"1.

Mass spectrum (+ve FAB): m/z 434 {NiL}, 810 {NiL₂}. 1014 {Ni₂L₂(PF₆)}, 1032

{Ni₂L₂(PF₆)F}, 1052 {Ni2 ₂(PF6)F₂}, 1391 {Ni₂L₃(PF₆)}, 1410 {Ni₂L₃(PF₆)F}, 1429

{Ni₂L₃(PF₆)F₂}, 1537 {Ni₂L₃(PF₆)2}, 1554 {Ni₂L₃(PF6)₂F}, 1682 {Ni₂L₃(PF₆)₃}.

Mass spectrum (ESI): m/z 312 {Ni₂L₃} ⁺ 100 %, 464 {Ni₂L₃(PF₆)}³⁺ 10 %, 768

{Ni₂L₃(PF₆)₂}²⁺ 1 %, 1073 {Ni₄L₆(PF₆)5} ⁺ 1 %, 1681 {Ni₂ 3(PF₆)3}⁺ 1 %.

(Found: C, 47.2; H, 3.5; N, 8.6. Calc. For NizC^HsoN^Fw^O: C, 47.4; H, 3.6; N,

8.9 %).

[Co₂L₃][PF₆]₄: Ligand L (0.0307 g, 0.08 mmol) and cobalt acetate (0.0135 g, 0.05 mmol) were heated under reflux in methanol (20 cm³) for 12 hours. The resulting orange coloured solution was cooled and treated with saturated methanolic ammonium hexafluorophosphate. On cooling, orange crystals separated and were isolated by filtration (0.0368 g, 74 %).

IR (KBr): 1628s, 1596m, 1505m, 1444m, 1308m, 1205m, 1017s, δMvs cm-¹.

Η NMR (CD₃CN; 400 MHz; 298K) d 245, 87, 72, 51, 22, 15, 0-5, -22

'H MR (D₂O; 400 MHz; 298K) d 244, 87, 72, 51, 23, 15, 1, -20

Mass spectrum (+ve FAB): m/z 435 {CoL}, 811 {CoL₂}, 889 {Co₂L₂F}, 908

{Co₂L₂F₂}, 923 {C02L2F3}, 1015 {Co₂L₂(PF₆)}, 1034 {Co₂L₂(PF₆)F}, 1053

{Co₂L₂(PF₆)F₂}, 1392 {Co₂L₃(PF₆)}, 1411 {Co₂L₃(PF₆)F}, 1426 {Co₂L₃(PF₆F}, 1537

{Co₂L₃(PF₆)₂}, 1556 {Co₂L₃(PF₆)₂F}, 1682 {Co₂L₃(PF₆)₃}.

Mass spectrum (ESI): m/z 313 {Co₂L₃}⁴⁺ 100 %, 465 {Co₂L₃(PF₆)}³⁺ 5 %, 769

{Co₂L₃(PF₆)2} ⁺, 20 %, 1073 {Cθ4L₆(PF6)₅}³⁺ 5 %, 1225 {Co₆L₉(PF₆)8}⁴⁺ 1 %, 1683

{Co₂L₃(PF₆)₃}⁺ 10 %.

(Found: C, 47.5; H, 3.3; N, 9.0. Calc. For Coz sHeoN^FzHHzO: C, 47.4; H, 3.6; N,

8.9 %).

Preparation of L: 4,4'-Methylenedianiline (0.793 g, 4 mmol) and

4(5)-imidazolecarboxaldehyde (0.768 g, 8 mmol) were stirred in methanol (30 ml) for 10 minutes, two drops of glacial acetic acid were then added and the mixture was further refluxed for 2 hours. An off-white solid precipitated and was collected by filtration, washed with methanol and dried in vacuo over P4O10. Yield: 95 %. m.p. 260-261°C. Anal. Calcd. for C₂ιH,₈N₆: C, 71.2; H, 5.1; N, 23.7%. Found: C, 70.9; H, 5.1; N, 23.5%. Mass spectrum (EI⁺): m/z 354 [M⁺]. Η NMR (DMSO, 400 MHz, 300K): d 12.8 (IH, s, NH), 8.42 (IH, s, H_im), 7.80 (IH, s, H₂/ ), 7.62 (IH, s, H_2/4), 7.23 (2H, d , J = 7.8 Hz, HPH), 7.15 (2H, d, J = 7.8 Hz, H_Ph), 3.98 (IH, s, CH2). IR data (KBr, cm"¹): 3060sh, 3024m, 2970w, 2906w, 2832m, 2647w, 2589w, 1629vs, 1600s, 1546vw, 1502s, 1438m, 1414w, 1351w, 1331w, 1298w, 1222m, 1202w, 1170w, 1155sh, 1094m, 1014w, 991m, 918w, 874m, 845m, 808w, 787w, 752w, 710w, 622s, 601w, 539m, 480vw.

Preparation ofthe Complexes [Fe2(L)₃][PF₆]₄ (1). Ligand L (0.106 g, 0.3 mmol) and iron(II) chloride tefrahydrate (0.040 g, 0.2 mmol) were stirred in methanol (15 mL) for 45 minutes. The resulting orange solution was filtered through Celite and treated with methanolic ammonium hexafluorophosphate (excess). Slow evaporation of the solvent at room temperature yielded an orange microcrystalline product, which was collected by filtration, washed with cold methanol and dried in vacuo over P₄Oι₀. Yield: 67 % Anal. Calcd. for [Fe2(C2iH₁₈N₆)3][PF₆]4 .2H₂O: C, 42.2; H, 3.2; N, 14.1%. Found: C, 41.9; H, 3.0; N, 14.0%. Mass Spectrum (FAB): m/z 1609 [Fe₂(L)₃(PF₆)₃], 1463 [Fe₂(L)2(L-H)(PF₆)₂], 1317 [Fe₂(L)(L-H)₂(PF₆)], 1171 [Fe₂(L-H)₃], 837 [Fe₂(L-H)₂(F)], 818 [Fe₂(L-H)₂], 766 [Fe(L)(L-H)], 409 [Fe(L-H)]. Positive-ion ESI (MeCN): m/z 1609 ([Fe₂(L)₃(PF₆)3]⁺), 1315 ([Fe₂(L)(L-H)₂(PF6)]⁺), 1256 ([Fe₂(L)2(PF₆)3]⁺), 1171 ([Fe₂(L-H)3]⁺), 732 ([Fe₂(L)3(PF₆)2]²⁺), 658 ([Fe2(L)₂(L-H)(PF₆)]²⁺), 585 ([Fe₂(L)(L-H)₂]²⁺), 439 ([Fe₂(L)₃(PF₆)]³⁺), 409 ([Fe(L-H)]⁺), 391 ([Fe₂(L)₂(L-H)]³⁺), 355 ([HL]⁺). Η NMR (CD₃CN, 500 MHz, 298K): d 158.3 (IH, br s, H₂), 92.1 (IH, s, NH), 42.5 (IH, br s, H_im), 37.9 (IH, s, H₄), 24.7 (IH, s, CHz), 14.6 (2H, s, H_Ph), -5.6 (2H, br s, H_Ph) UV-Vis (MeCN): l_max [nm] (e [M^cm^"1]): 283 (53200), 313 (58000), 443 (1390), 810 (10). IR data (KBr, cm^"1): 3622w, 3396br, 3134br, 2934w, 2860w, 2588vw, 1621vs, 1600sh, 1556w, 1501m, 1437m, 1347vw, 1294w, 1232w, 1208w, 1174vw, 1144vw, 1094m, 101 lw, 848vs, 757sh, 710w, 617m, 559s. Orange crystals suitable for X-ray analysis were grown by slow evaporation of a methanolic solution of complex 1. [Fe2(L)₃][BF ]₄ (2). Ligand L (0.127 g; 0.36 mmol) and iron(II) chloride tefrahydrate (0.048 g, 0.24 mmol) were stirred in methanol (15 mL) for 40 minutes. The resulting orange solution was filtered through Celite and treated with methanolic ammonium tetrafluoroborate (excess) to yield an orange product, which was isolated by filtration, washed with methanol and dried in vacuo over P4O10. The product was then dissoluted in 10 mL of acetonitrile. The solution was filtered through Celite, concentred in vacuo, diluted with 15 ml of methanol and allowed to stay at room temperature for 24 hours. An orange polycrystalline powder resulted, which was collected by filtration, washed with cold methanol and finally dried in vacuo under P4O10. Yield: 65 %. Anal. Calcd. for [Fe2(C₂₁Hι₈N6)3][BF₄]4.2H₂O: C, 48.5; H, 3.7; N, 16.2%. Found: C, 48.4; H, 3.4; N, 16.0%. Mass Spectrum (FAB): m/z 1347 [Fe₂(L)₂(L~H)(BF₄)₂], 1259

[Fe₂(L)(L-H)₂(BF₄)], 1171 [Fe₂(L-H)₃], 837 [Fe₂(L-H)₂(F)], 818 [Fe₂(L-H)₂], 766 [Fe(L)(L-H)], 409 [Fe(L-H)]. Positive-ion ESI (MeCN): m/z 586 ([Fe₂(L)(L-H)₂]²⁺), 420 ([Fe₂(L)₃(BF₄)]³⁺), 409 ([Fe(L-H)]⁺), 355 ([HL]⁺). Η NMR (CD₃CN, 500 MHz, 298K): d 159.2 (IH, br s, H₂), 92.7 (IH, s, NH), 42.9 (IH, br s, H_im), 38.1 (IH, s, H₄), 24.8 (IH, s, CH2), 14.7 (2H, s, H_Ph), -5.7 (2H, br s, H_Ph). UV-Vis (MeCN): l_max [nm] (e [M^'W]): 285 (54400), 310 (58300), 438 (1400), 822 (12). IR data (KBr, cm^"1): 3376w, 3131br, 2932w, 2856w, 2588vw, 1620vs, 1599s, 1555w, 1501m, 1437m, 1347vw, 1294m, 1232w, 1207w, 1082vs, 1054sh, 935vw, 892w, 861w, 814w, 757w, 710w, 617m, 547w, 534w, 522w. X-ray quality, orange crystals of 2 were obtained from a saturated acetonitrile solution by diffusion of di(isopropyl)ether.

[Fe₂(L)₃][ClO₄]4 (3): Ligand L (0.096 g; 0.27 mmol) and iron(II) chloride tefrahydrate (0.036 g, 0.18 mmol) were stirred in methanol (15 mL) for 45 minutes. The resulting orange solution was filtered through Celite and treated with 0.4 mmol of lithium perchlorate dissoluted in 10 ml of MeOH/H₂O (4:1) solvent mixture. An orange product instantaneously formed, and was collected by filtration, washed with methanol and dried in vacuo over P4O10. Yield: 72%. Anal. Calcd. for [Fe₂(C2iH₁₈N₆)₃][ClO₄]4.2H2O: C, 47.0; H, 3.6; N, 15.7%. Found: C, 46.9; H, 3.3; N, 15.5%. Mass Spectrum (FAB): m/z 1473 [Fe₂(L)₃(ClO₄)3], 1372 [Fe₂(L)₂(L-H)(Clθ4)2], 1271 [Fe₂(L)(L-H)2(ClO₄)], 1171 [Fe₂(L-H)₃], 817 [Fe₂(L-H)(L-2H)], 766 [Fe(L)(L-H)], 409 [Fe(L-H)]. Positive-ion ESI (MeCN): m/z 1470 ([Fe2(L)₃(ClO₄)3]⁺), 685 ([Fe₂(L)₃(ClO₄)₂]²⁺), 636 ([Fe₂(L)₂(L-H)(ClO₄)]²⁺), 586 ([Fe₂(L)(L-H)₂]²⁺), 424 ([Fe₂(L)2(ClO₄)]³⁺), 409 ([Fe(L-H)]⁺), 355 ([HL]⁺). ^■H NMR (CD₃CN, 500 MHz, 298K): d 158.3 (IH, br s, H₂), 92.1 (IH, s, NH), 42.5 (IH, br s, H_im), 37.9 (IH, s, NH), 24.7 (IH, s, CH₂), 14.6 (2H, s, H_Ph), -5.6 (2H, br s, H_Ph). UV-Vis (MeCN): [nm] (e [M' ]): 286 (57400), 306 (sh), 438 (1410), 834 (12). IR data (KBr, cm^"1): 3242sh, 3135br, 2933w, 2856w, 2588vw, 1620vs, 1599s, 1556w, 1501s, 1436m, 1346vw, 1294m, 1232w, 1207w, 1088vs, 1008m, 969vw, 934vw, 892m, 861w, 814m, 757w, 710w, 625s, 617s, 547w. Orange crystals suitable for X-ray analysis were obtained by slow diffusion, in an H-shaped tube of two 10^'4 M methanolic solutions containing [Fe₂(L)₃]Cl4 and LiClθ4, respectively.

CAUTION! No problems were encountered during the preparation of the perchlorate derivative described above. However, suitable care must be taken when handling such potentially explosive materials.

[Ni₂(L)3][PF₆]₄ (4). Ligand L (0.053 g; 0.15 mmol) and nickel(II) chloride hexahydrate (0.024 g, 0.10 mmol) were stirred in methanol (10 mL) for 30 minutes. The resulting green solution was treated with methanolic ammonium hexafluorophosphate (excess), filtered through Celite and the filtrate allowed to standing for 48 hours at 4 °C. Green crystals formed and were collected by filtration, washed several times with small amounts of cold methanol, and finally dried in vacuo over P₄Oι₀. Yield: 68 %. Anal. Calcd. for [Ni2(C2iHι₈N₆)3][PF₆] .2H₂O: C, 42.1; H, 3.2; N, 14.0%. Found: C, 41.9; H, 3.1; N, 13.8%. Mass Spectrum (FAB): m/z 1615 [Ni₂(L)₃(PF₆)3], 1469 [Ni₂(L)₂(L-H)(PF₆)2], 1323 [Ni₂(L)(L-H)₂(PF₆)], 1177 [Ni₂(L-H)₃], 823 [Ni₂(L-H)(L-2H)], 412 [Ni(L-H)]. Positive-ion ESI (MeCN): m/z 1615 ([Ni₂(L)3(PF₆)₃]⁺), 733 ([Ni₂(L)₃(PF₆)₂]²⁺), 660 ([Ni₂(L)₂(L-H)(PF₆)]²⁺), 588 ([Ni₂(L)(L-H)₂]²⁺), 441 ([Ni₂(L)₃(PF₆)]³⁺), 411 ([Ni(L-H)f), 392 ([Ni₂(L)₂(L-H)]³⁺), 355 ([HL]⁺). Η NMR (CD₃CN, 500 MHz, 298K): d 229.0 (IH, br s, H₂), 93.1 (IH, s, NH), 58.7 (IH, br s, H_ira), 40.9 (IH, s, H₄), 27.5 (IH, s, CH₂), 15.4 (2H, s, H_Ph), -6.7 (2H, br s, H_Ph). UV-Vis (MeCN): l_max [nm] (e [MAm^"1]): 262 ( 48300), 308 (66200), 554 (24), 900 (25). IR data (KBr, cm^"1): 3629w, 3379m, 3139w, 3099w, 3033w, 2933w, 2847w, 2589vw, 1622vs, 1600s, 1560w, 1499s, 1438m, 1337vw, 1289m, 1234w, 1207w, 1174vw, 1151w, 1094m, 1017m, 964vw, 847vs, 755sh, 710w, 618m, 604sh, 558s, 425vw. Single crystals suitable for X-ray analysis were directly collected from the reaction mixture, after standing at 4 °C for 2 days.

[Co₂(L)₃][PF₆]4 (5). Ligand L (0.053 g; 0.15 mmol) and cobalt(II) chloride hexahydrate (0.024 g, 0.10 mmol) were stirred in methanol (15 mL) for 30 minutes. 2 mL of water were added and the reaction mixture was further stirred for 45 minutes. The resulting orange solution was treated with potassium hexafluorophosphate (excess), filtered through Celite and the filtrate allowed to stay for 24 hours at room temperature. Orange crystals formed and were collected by filtration, washed with methanol, and finally dried in vacuo over P4O10. Yield: 75%. Anal. Calcd. for [Co₂(C2iHι₈N6)3][PF6]4 .CH₃OH.H₂O: C, 42.4; H, 3.3; N, 13.9%. Found: C, 42.4; H, 3.0; N, 13.8%. Mass Spectrum (FAB): m/z 1615 [Co₂(L)₃(PF₆)₃], 1469 [Co₂(L)₂(L-H)(PF₆)₂], 1323 [Co₂(L)(L-H)₂(PF₆)], 1177 [Co₂(L-H)₃], 823 [Co₂(L-H)(L-2H)], 412 [Co(L-H)]. Positive-ion ESI (MeCN): m/z 1615 ([Co₂(L)₃(PF₆)₃]⁺), 1174 ([Co₂(L-H)₃]⁺), 734 ([Co₂(L)₃(PF₆)2]²⁺), 662 ([Co₂(L)₂(L-H)(PF₆)]²⁺), 588 ([Co₂(L)(L-H)₂]²⁺), 442 ([Cθ2(L)₃(PF₆)]³⁺), 411 ([Co(L-H)]⁺), 392 ([Co₂(L)₂(L-H)]³⁺), 355 ([HL]⁺). Η NMR (CD₃CN, 500 MHz, 298K): d 235.0 (IH, br s, H₂), 99.6 (IH, s, NH), 52.9 (IH, s, H₄), 23.8 (IH, br s, H_im), 22.1 (IH, s, CHb), 2.0 (2H, s, H_Ph), -19.1 (2H, br s, H_Ph). UV-Vis (MeCN): λ_maκ [nm] (ε [M-'cm^'1]): 285 (55600), 318 (38250), 490 (42). IR data (KBr, cm^'1): 3629w, 3379m, 3127w, 3096w, 3031w, 2929w, 2847w, 2589vw, 1621vs, 1600s, 1559w, 1500s, 1439m, 1336vw, 1290m, 1233w, 1207w, 1174vw, 1150w, 1094m, 1014m, 965vw, 847vs, 756sh, 710w, 618m, 602sh, 558s, 419vw. X-Ray quality, orange crystals were obtained from a saturated 1:1 acetonitrile: acetone solution by slow diffusion of diethylether.

[Mn2(L)₃][PF₆]₄ (6): Ligand L (0.106 g; 0.3 mmol) and manganese(II) chloride tefrahydrate (0.039 g, 0.2 mmol) were stirred in methanol (15 mL) for 45 minutes. The resulting yellow solution was treated with methanolic ammonium hexafluorophosphate (excess), filtered through Celite and allowed to stay at room temperature overnight. A pale yellow polycrystalline product formed and was isolated by filtration, washed with methanol, and dried in vαcuo over P4O10. Yield: 74 %. Anal. Calcd. for [Mn₂(C2iH₁₈N6)₃][PF₆]₄ .H₂O: C, 42.7; H, 3.2; N, 14.2%. Found: C, 42.5; H, 3.0; N, 14.2%. Mass Spectrum (FAB): m/z 1607 [Mn₂(L)₃(PF₆)3], 1461 [Mn₂(L)₂(L-H)(PF₆)2], 1315 [Mn₂(L)(L-H)₂(PF₆)], 1169 [Mn₂(L-H)₃], 815 [Mn₂(L-H)(L-2H)], 408 [Mn(L-H)]. Positive-ion ESI (MeCN): m/z 731 ([Mn₂(L)₃(PF₆)₂]²⁺), 658 ([Mn₂(L)₂(L-H)(PF₆)]²⁺), 585 ([Mn₂(L)(L-H)₂]²⁺), 408 ([Mn(L-H)]⁺, [Mn₂(L-H)₂]²⁺), 355 ([HL]⁺). UV-Vis (MeCN): λ_mm [nm] (ε [M^'W]): 267 (51600), 318 (112100). IR data (KBr, cm^"1): 3631w, 3386m, 3142w, 3102w, 3037w, 2927w, 2848w, 2590vw, 1623vs, 1600s, 1556w, 1502s, 1440m, 1347vw, 1295m, 1232w, 1207w, 1178vw, 1152w, 1093m, 1005m, 970vw, 847vs, 756sh, 710w, 620m, 602sh, 558s, 425vw. Yellow crystals suitable for X-ray analysis were grown by slow diffusion of diethylether into a solution of complex in 1:1 acetonitrile/acetone.

L ^e (R= Me) and L^Et (R= Et)

Synthesis of Ligands L^Meand L Et

Ground 3A dried molecular sieves (5 g) and 4,4'-methylenebis(2,6-diethylaniline) or 4,4'-methylenebis(2,6-dimethylaniline) (0.678 g, 2.67 mmol) were added to methanol (90 cm³) and stirred under a nitrogen atmosphere until the methylenedianaline had dissolved (approximately 5 minutes). Pyridine-2-carboxyaldehyde (0.571 g, 5.34 mmol) was added and the mixture stirred at room temperature for 24 hours. The molecular sieves were removed by filtration and the filtrate concentrated by rotary evaporation to produce a yellow solid. L^Me Yellow solid (0.934 g, 81 %).

IR (KBr): 2996w, 2905m, 2846w, 1638s, 1583m, 1476s, 1433s, 1385s, 1318w, 1283w, 1200s, 1141m, 1089w, 1042w, 987m, 876m, 837m, 774s, 742m, 695w, 647w, 616w cm'¹.

Mass spectrum (+ve Cl): m/z 433 [M+H]⁺.

(Found: C, 80.5; H, 6.6; N; 13.0. Calc. for C29H28N4: C, 80.5; H, 6.5; N, 13.0 %). 'H NMR (CDC1₃): δ 8.72 (IH, d, J = 4.9 Hz, H₆), 8.35 (IH, s, H), 8.28 (IH, d, J =

7.9 Hz, H₃), 7.84 (IH, td, J = 7.9, 1.7 Hz, H₄₅), 7.40 (IH, ddd, J = 7.5, 4.7, 1.1 Hz, H_4/5), 6.94 (2H, s, HPH), 3.85 (IH, s, central CH₂), 2.15 (6H, s, CH₃).

¹³C NMR (CDC1₃): d 163.83 C₇, 154.94 C i, 149.99 C₆, 148.76 C₂/₈/π, 137.53

C_2/8/π, 137.11 C4/5, 129.11 C10 & C12, 127.43 C₉ & C13, 125.68 C₄/₅, 121.59 C₃, 41.28

L^Et From 4,4'-methylenebis(2,6-diethylaniline) (4.087 g, 13.16 mmol) and

pyridine-2-carboxyaldehyde (2.820 g, 26.33 mmol). Yellow solid (5.459 g, 85 %).

IR (KBr): 2953s, 2925s, 2862s, 1642s, 1587s, 1563s, 1468s, 1456s, 1433s, 1381w,

1362w, 1338w, 1314w, 1291m, 1220w, 1192s, 1141s, 1078w, 995s, 936m, 892m,

853s, 770s, 742m, 691w, 659m cm^'1.

(Found: C, 80.0; H, 7.4; N; 11.4 Calc. for CjsfteNcO.SCHsOH; C, 79.7; H, 7.6; N,

11.1 %).

Mass spectrum (+ve EI): m/z 488 [MJ ^÷.

>H NMR (CDCI3): d 8.72 (IH, dq, J= 4.9, 0.9 Hz, H₆), 8.35 (IH, s, Hi), 8.27 (IH, dt,

J= 7.7, 1.1 Hz, H₃), 7.85 (IH, td, J= 7.5, 1.1 Hz, H₄/₅), 7.41 (IH, ddd, J= 7.5, 4.9, 1.1

Hz, H4/5), 6.97 (2H, s, H_Ph), 3.94 (IH, s, central CH₂), 2.50 (4H, q, J = 7.5 Hz, CH₂),

1.13 (6H, t, J= 7.5 Hz, CH₃).

¹³C NMR (CDCI3): d 163.46 C₇, 154.92 C₂/₈/π, 150.00 C₆, 147.96 C_{2 8}/π, 137.57

Ca/s/π, 137.15 C₄₅, 133.30 C₉& C₁₃, 127.34 C₁₀& C₁₂, 125.67 C₄₅, 121.59 C₃, 41.54

Cis, 25.11 C₁₄& Ci6, 15.18 Ci5 & Cι₇.

Synthesis of [Cu„(L^Me)„][PF₆]„

Ligand L^Me (0.084 g, 0.19 mmol) was dissolved in methanol and whilst stirring

under a nitrogen atmosphere, [Cu(MeCN)₄][PF₆] (0.072 g, 0.19 mmol) was added to

give a dark red solution. The solution was heated under reflux overnight and then cooled to room temperature. A black solid precipitated from the solution on standing.

This was collected by filtration and washed with diethyl ether (0.173 g, 71 %). X-ray quality crystals were obtained by the slow diffusion of diethyl ether into a solution of the complex in nifromethane.

The same compound can be prepared in a single pot simply by mixing the aldehyde and diamine and then adding the cuprous salt. It can also be prepared in a solventless reaction by grinding the three compounds together.

IR (KBr): 2902w, 1586m, 1474m, 1440m, 1380m, 1303w, 1200m, 1140w, 900w,

836s, 772m, 742w, 558m cm^'1.

Mass spectrum (ESI): m/z 1135 {Cu₂(L^Me)₂(PF₆)}⁺, 927 {Cu(L^Me)₂}⁺, 816

{Cu₃(L^Me)₃(PF₆)}²⁺, 495 {Cu₂(L^Me)2}²⁺, {Cu(L^Me)}⁺.

Mass spectrum (÷ve FAB): m/z 1137 [Cu₂(L^Me)₂(PF₆)] ⁺, 495 [Cu₂(L ^e)₂] ⁺.

Η NMR: (CD₂C1₂): d 8.67 (4H, d, J = 4.9 Hz, H₆), 8.49 (3H, s, Hi helix), 8.40 (IH, s, Hi, trimer), 8.21 (3H, td, J= 7.7, 1.5 Hz, helix), 8.15 (IH, td, J= 7.7, 1.5 Hz, H₄ trimer), 7.99 (4H, d, J = 7.9 Hz, H₃), 7.85 (3H, ddd, J = 7.7, 5.1, 1.3 Hz, H₅ helix),

7.77 (IH, ddd, J= 7.7, 5.1, 1.3 Hz, H₅ trimer), 6.99 (3H, s, H_Ph helix), 6.90 (2H, s, H_Ph trimer), 6.67 (3H, s, Hph helix), 3.92 (3H, s, central CH₂ helix), 3.76 (IH, s, central

CH₂ trimer), 2.04 (24H, broad s, CH₃).

UV/Vis (MeCN): 470 (e = 12 000), 334 (e = 28 000), 328 (e = 75 000) nm.

Synthesis of [Cu₂(L^Et)₂][PF₆]2 Ligand L^Et (0.107 g, 0.284 mmol) was dissolved in methanol and whilst stirring

under a nitrogen atmosphere, [Cu(MeCN)₄][PFβ] (0.106 g, 0.284 mmol) was added to give a dark red solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark red solid precipitated from the solution on standing and was collected by filtration and dried with diethyl ether (0.336 g, 85 %).

The solid was recrystallised from acetonitrile by the slow diffusion of benzene to afford dark red crystals.

IR (KBr): 2965m, 2927w, 2867w, 1611m, 1586m, 1556w, 1504w, 1470m, 1436m,

1380m, 1303m, 1252w, 1192m, 1145m, 836s, 772m, 738w, 549s cm^'1.

Mass spectrum (ESI): m/z 1247 {Cu₂(L^Et)₂(PF₆)}⁺, 1040 {Cu₂(L ^t)(PF₆)}⁺, 551

{Cu₂(L^Et)₂}²⁺.

Mass spectrum (+ve FAB): m/z 1247 [Cu₂(L^Et)₂(PF₆)] ⁺.

(Found: C, 56.0; H, 5.2; N; 7.9. Calc. for Cu2C66H₇2N₈P₂F₁₂-H₂O : C, 56.1; H, 5.3; N,

7.9 %).

Η NMR (CD₂C1₂): δ 8.56 (IH, s, H), 8.53 (IH, broad d, J= 4.9 Hz, He), 8.22, (IH, td, J = 7.9, 1.4 Hz, H- , 8.00 (IH, broad d, J= 7.4 Hz, H₃), 7.83 (IH, ddd, J= 7.8, 4.9,

1.4 Hz, Hs), 7.03 (2H, broad d, J = 1.4 Hz, H_Ph), 6.52 (2H, broad d, J = 1.5 Hz, Ha),

3.86 (IH, s, central CHa), 2.68 (2H, m, CH₂), 2.58 (2H, m, CHa), 2.19 (2H, m, CH₂),

2.00 (2H, m, CHa), 1.02 (3H, t, J= 7.9, CH₃), 0.45 (3H, t, J= 7.4, CH,).

UV/Vis (MeCN): 475 (ε = 1300), 339 (ε = 42000), 275 (ε = 17 000) nm.

Synthesis of [A_gπ(L^Me)_n][PF6]„ Care was taken to exclude light during the following procedure. L^Me (0.1 g,

0.231 mmol) was dissolved in chloroform and silver(I) hexafluorophosphate (0.058 g, 0.231 mmol) dissolved in methanol was added and stirred at room temperature for 2 hours. The yellow precipitate was collected by vacuum filtration, washed with chloroform and dried in vacuo under P4O10 (0.22 g, 70%). IR (KBr): 2923m, 2855w, 1643m, 1586m, 1478m, 1439m, 1386m, 1303w, 1260w,

1197w, 1143w, 1007w, 842s, 770m, 741w cm^'1.

Mass spectrum (ESI): m/z 1225 {Ag₂(L^Me)₂(PF₆)}⁺, 973 {Ag(L^Me) }⁺, 883

{Ag₃(L^Me)3(PF₆)}²⁺, 540 {Ag₃(L^Me)₃}³⁺, {Ag₂(L^Me)₂}²⁺.

(Found: C, 49.4; H, 4.1; N; 7.8. Calc. for Ag₂C₅₈H₅₆N₈P₂Fι₂-2H₂O: C, 49.6; H, 4.3; N,

8.0 %).

'H NMR (CD₂C1₂, 283 K): δ = 8.75 (2H, s, H), 8.41 (IH, d, J= 7.5 Hz, R₆helix), 8.31

(IH, d, J= 6.5 Hz, H₆ trimer), 8.20 (IH, td, J= 7.8, 1.5 Hz, H₄ helix), 8.15 (IH, td, J =

7.8, 1.5 Hz, Y trimer), 7.88 (2H, dd, J = 9.7, 7.8 Hz, H₃), 7.81 (IH, ddd, J = 7.8, 5.0,

2.8 Hz, H₅ helix), 7.81 (IH, ddd, J= 7.8, 5.0, 2.8 Hz, H₅ trimer), 6.92 (2H, s, H_PhΛe/ά),

6.85 (2H, s, Hp_h trimer), 3.92 (IH, s, central CH₂ helix), 3.76 (IH, s, central CH₂ trimer), 1.94 (6H, s, CH₃ helix), 1.77 (6H, s, CH₃ trz^'mer).

Synthesis of [Ag₂(L^Et)₂][PF₆]2 Ligand L^Et (0.106 g, 0.217 mmol) was dissolved in methanol and whilst stirring under a nitrogen atmosphere and excluding light, silver(I)acetate (0.036 g, 0.217 mmol) was added to give a yellow solution. The solution was heated under reflux in the dark for 1 hour and then cooled to room temperature. The solution was filtered through celite and the yellow filtrate collected. A yellow solid precipitated on addition of excess methanolic [NH₄][PFe] to the filtrate and was collected by filtration (0.238 g, 74 %). X-ray quality crystals were obtained by the slow diffusion of diethyl ether into a solution ofthe complex in acetonitrile.

IR (KBr): 2964m, 2928m, 2870w, 1643s, 1571w, 1473m, 1432w, 1384s, 1309w, 1258w, 1196w, 1145w, 1104m, 903m, 838s, 775w, 61 lw cm^'1. Mass spectrum (ESI): m/z 1338 {Ag₂(L^E,)₂(PF₆)}⁺ 1083 {Ag(L^Et)₂}⁺, 551

{Ag₂(L^Et)₂}²⁺.

Mass spectrum (Ae FAB): m/z 1338 [Ag₂(L^Et)₂(PF₆)]⁺.

(Found: C, 52.8; H, 4.9; N; 7.3. Calc. for Ag₂C₅oH4oN₈P₂F₁₂-H2O: C, 52.9; H, 5.0; N,

7.5 %).

Η NMR (CD2CI2): δ 8.73 (IH, d, J= 4.9 Hz, H₆), 8.47 (IH, d, J= 8.3 Hz, Hi), 8.22 (IH, td, J= 7.7, 1.7 Hz, H₄), 7.89 (IH, d, J= 7.7 Hz, H₃), 7.83 (IH, ddJ- 7.5, 4.7, Hz, H₅), 6.71 (2H, s, H_Ph), 3.79 (IH, s, cenfral CH₂), 2.31 (4H, m, CH₂), 0.72 (6H, t, J = 7.4 Hz, CH₃).

7.1.13 Synthesis of Ligand L^s

Ground 3 A dried molecular sieves (5 g) and 3,3'-methylenedianiline (0.200 g, 1.009 mmol) were added to toluene (30 cm³) and stirred under a nitrogen atmosphere until the 3,3'-methylenedianiline had dissolved (approximately 5 minutes). 2-quinolinecarboxaldehyde (0.317 g, 2.017 mmol) was added and the mixture stirred at room temperature for 24 hours. The molecular sieves were removed by filtration and the filtrate concentrated by rotary evaporation to produce a yellow oil (0.416 g, 87 %).

IR (oil): 2369m, 2356m, 1626m, 1585s, 1558w, 1505s, 1482m, 1424m, 1357w,

1308w, 1240w, 1200w, 1146w, 1115w, 1084w, 954w, 904w, 828s, 752s, 730s, 690s cm^"1.

Mass spectrum (+ve FAB): m/z 477 [M+H]⁺.

H NMR (CDC1₃): δ 8.72 (2H, s, H), 8.29 (2H, d, J= 8.7 Hz, H₃), 8.19 (2H, d, J =

8.7 Hz, H₄), 8.09 (2H, d, J= 8.5 Hz, H₉), 7.80 (2H, dd, J= 8.1, 1.3 Hz, H₆), 7.70 (2H,

ddd, J= 9.2, 5.1, 1.7 Hz, H₈), 7.54 (2H, ddd, J= 8.1, 7.0, 1.1 Hz, H₇), 7.32 (2H, t, J =

7.6 Hz, Ho), 7.10 (6H, m, H_a, H_{b &} H_d), 4.03 (2H, s, central CH₂).

¹³C NMR (CDCI3): δ 161.28 G, 155.24 Ca, 151.45 C5/10 12/16, 148.35 Cs iwia iβ, 142.48

C5/10/12/16, 137.06 C₄, 130.33 Cg, 130.10 C₉, 129.86 C₁₄, 129.44 C₅/.o/ι₂/i6, 128.63 C₇,

128.11 Cβ, 128.08 C,₇, 122.53 d₅, 119.37 C₁₃, 119.08 C₃, 42.27 CH₂.

Synthesis of [Cu2(L⁵)2][PF₆]₂

Ligand L⁵ (0.173 g, 0.363 mmol) was dissolved in methanol and whilst stirring under a

nitrogen atmosphere, [Cu(MeCN)4][PF₆] (0.135 g, 0.363 mmol) was added to give a purple solution. The solution was heated under reflux overnight and then cooled to

room temperature. A purple solid precipitated from the solution on standing and was

collected by filtration and dried with diethyl ether (0.373 g, 75 %). The solid was

recrystallised from acetonitrile by the slow diffusion of benzene to afford dark purple

crystals.

IR (solid): 1594m, 1298w, 1143w, 1002w, 837vs, 779m, 745m, 677m cm^'1.

Mass spectrum (ESI): m/z 1225 {Cu₂(L^s)₂(PFβ)}⁺, 1016 {Cu(L⁵)₂}⁺, 539

{Cu₂(L⁵)2}²⁺, {Cu(L⁵)}⁺. (Found: C, 53.7; H, 3.4; N; 7.5. Calc. for Cu₂C₆₆H₄₈N₈P₆F₁₂-(H₂O)₆: C, 53.6; H, 4.0;

N, 7.6 %).

Η NMR (CD2CI2): δ 9.35 (7H, s, Hi Λe/α), 9.25 (2H, s, Hi box), 8.73 (2H, d, J= 8.5

Hz, U box), 8.72 (7H, d, J= 8.3 Hz, Hw helix), 8.32 (7H, d, J= 8.3 Hz, Η^ helix),

8.26 (2H, d, J= 8.5, H₃/₄ box), 8.02 (9H, d, J= 7.9 Hz, H₆₉), 7.77 (9H, d, J= 7.9 Hz,

H₆/9), 7.57 (27H, m, H_b/_dH_{7 &}H₈), 7.31 (9H, t, J= 7.3 Hz, H_c), 6.82 (9H, d, J= 7.3 Hz,

Hb/d), 6.67 (9H, s, H_a), 3.51 (7H, s, central CH₂ helix), 3.46 (2H, d, J= 5.3 Hz, central

CH₂bσx).

UV/Vis: A 569.0 nm, ε 131000

A 340.2 nm, ε 97000 dnr'mol^{' 1}; 1

254.4 nm, e 16300 dn^molAm^'1.

The tetrafluoroborate salt was prepared in 75 % yield by the same route replacing

[Cu(MeCN)₄][BF₄] with [Cu(MeCN)₄][PF₆].

The perchlorate salt was prepared in 72 % yield by the same route followed by the addition of excess methanolic NaO₄Cl.

Synthesis of [Ag₂(L⁵)₂][PF_<;]₂

Ligand L^s (0.186 g, 0.390 mmol) was dissolved in methanol and whilst stirring under a nitrogen atmosphere and excluding light, silver(I)acetate (0.065 g, 0.390 mmol) was added to give a yellow solution. The solution was heated under reflux in the dark for

40 minutes and then cooled to room temperature. The solution was filtered through celite and the yellow filtrate collected. A yellow solid precipitated on addition of excess methanolic [NH ][PFβ] to the filtrate and was collected by filtration (0.410 g,

72 %).

IR (solid): 2992w, 2620w, 1590m, 1500m, 1370w, 1339w, 1142w, 989w, 842vs, 792w, 743 w cm^'1.

Mass spectrum (ESI): m/z 1314 {Ag₂(L⁵)₂(PF₆)}⁺, 1060 {Ag(L⁵)₂}⁺, 839

{Ag₂(L⁵)(PF₆)}⁺, 584 {Ag2(L⁵)₂}²⁺, {Ag(L^s)}⁺.

Η NMR: (CD2CI2): δ 9.23 (2H, s, H), 8.77 (2H, d, J= 8.0 Hz, H₃/ ), 8.33 (2H, d, J=

8.0 Hz, H34), 8.09 (2H, d, J = 8.0 Hz, H_6/9), 7.92 (2H, d, J = 7.4 Hz, H_Wd), 7.62 (6H, m, H₆/9,H_{7 &}H₈), 7.19 (2H, t, J= 7.4 Hz, H₀), 6.96 (2H, s, H.), 6.85 (2H, d, J= 7.4 Hz,

Hb/d), 3.58 (2H, s, central CHa).

The tefrafluoroborate salt was prepared in 70 % yield by the same route followed by the addition of excess methanolic [NH ][BF ].

The perchlorate salt was prepared in 74 % yield by the same route replacing silver(I) perchlorate instead of silver(I) acetate.

Synthesis of Ligand L 10

2-nifrosopyridine (0.003 g, 0.024 mmol) was dissolved in dichloromethane. 4,4'-methylenedianiline (0.002 g, 0.012 mmol) and glacial acetic acid (1 drop) were added and the orange solution was stirred at room temperature overnight. The solution was evaporated to dryness to provide an orange coloured solid (0.003 g, 73 %).

IR (KBr): 3064w, 2928w, 1643m, 1585s, 1497m, 1463m, 1410s, 1308w, 1260w,

121 lw, 1148s, 1104m, 988m, 876m, 818w, 794s, 740s, 658w, 615w cm^'1.

Mass spectrum (+ve FAB): m/z 379 [M+H]⁺.

(Found: C, 70.4; H, 4.7; N; 21.5. Calc. for C₂₃H₁₈N₆-0.5H₂O: C, 70.7; H, 5.1; N,

21.5 %).

Η NMR (CDC1₃): d 8.75 (IH, dq, J= 4.7, 0.75 Hz, H₆), 8.03 (2H, d, J= 8.5 Hz H^),

7.92 (IH, td, J= 7.9, 1.9 Hz, H₄/₅), 7.83 (IH, dt, J= 7.9, 1.0 Hz, H₃), 7.40 (3H, m, Ha/b

& H₄/₅), 4.17 (IH, s, cenfral CH₂).

¹³C NMR (CDC1₃): d 163.5 C2/7/10, 152.0 C2/7/10, 149.9 C₆, 145.3 C2/7/10, 138.7 C₄/₅,

130.2 C_8/9/n/i2, 125.5 C₄₅, 124.4 C_{89 U}/ι₂, 115.9 C₃, 42.2 G₃.

Synthesis of [Cu₂(L¹⁰)2][PF₆]₂

Ligand L¹⁰ (0.020 g, 0.053 mmol) was dissolved in methanol and whilst stirring under a

nitrogen atmosphere, [Cu(MeCN)4][PFe] (0.020 g, 0.053 mmol) was added to give a

dark red solution. The solution was heated under reflux overnight and then cooled to

room temperature. A dark red solid precipitated from the solution on standing and was

collected by filtration and dried with diethyl ether (0.053 g, 85 %). The solid was

recrystallised from nitromethane by the slow diffusion of diethyl ether to afford dark

red crystals.

IR (KBr): 2914w, 2846w, 1628m, 1594s, 1492w, 1468w, 1444m, 1420m, 1381s,

1308w, 1274w, 1231w, 1192w, 1153s, 1012w, 954w, 843s, 789s, 741m cm^"1. Mass spectrum (ESI): m/z 1029 {Cu₂(L¹⁰)₂(PF₆)}⁺, 650 {Cu₂(L¹⁰)(PF₆)}⁺, 253

{Cu₂(L¹⁰)}²⁺.

NMR (CD₂C1₂): δ 8.51 (IH, d, J = 7.7 Hz, H₃), 8.47 (IH, d, J = 4.7 Hz, H₆), 8.38

(IH, t, J= 7.5, 1.7 Hz, H₄₅), 7.89 (2H, d, J= 8.3 Hz, H_Ph), 7.83 (IH, ddd J= 7.3, 5.1,

1.1 Hz, H₄/₅), 7.30 (2H, broad s, H_Ph), 4.02 (IH, s, central CH₂).

UV/Vis (MeCN): 573 (ε= 16 000), 390 (ε= 87 000), 339 (ε= 188 000), 227 (ε=

170 000) nm.

Synthesis of [Ag2(L¹⁰)₂][PF₆]2

Ligand L¹⁰ (0.011 g, 0.029 mmol) was dissolved in methanol and whilst stirring and excluding light, silver(I)acetate (0.005 g, 0.029 mmol) was added to give a yellow solution. The solution was heated under reflux in the dark for 30 minutes and then cooled to room temperature. The solution was filtered through celite and the yellow filtrate collected. A dark yellow solid precipitated on addition of excess methanolic

[NH4][PF₆] to the filtrate and was collected by filtration (0.029 g, 78 %).

IR (KBr): 2918w, 2846w, 1599s, 1502m, 1458w, 1415s, 1386m, 1279s, 1250s, 1221s,

1153s, 1104w, 1027m, 1007m, 845s, 789s, 736m, 639s cm^'1.

Mass spectrum (ESI): m/z 1338 {Ag2(L¹⁰)₂(PF₆)}⁺, 1083 {Ag(L¹⁰)₂}⁺, 551

Η NMR (CD2CI2): (58.64 (IH, d, J= 4.5 Hz, H₆), 8.34, (2H, m, H₃ & H₄/₅), 7.93 (2H, d, J= 8.3 Hz, H_Ph), 7.79 (IH, ddd, J= 7.3, 4.9, 2.8 Hz, H4/5), 7.36 (2H, d, J= 8.5 Hz,

Hp_h), 4.10 (IH, s, cenfral CH₂). Synthesis of [Fe2(L¹⁰)₃][PF₆]4

Ligand L¹⁰ (0.019 g, 0.050 mmol) was dissolved in methanol and whilst stirring under a

nitrogen atmosphere, FeCl₂.4H₂O (0.007 g, 0.034 mmol) was added to give a dark green solution. The solution was heated under reflux for three days and then cooled to room temperature. Excess methanolic [NHt][PF₆] was added and a dark green solid precipitated from the solution on standing. This was collected by filtration and dried with diethyl ether (0.049 g, 79 %).

IR (KBr): 2923w, 2851w, 1633m, 1599s, 1497w, 1449m, 1415m, 1361s, 1313m,

1264w, 1240m, 1201w, 1167m, 1104w, 1051w, 1012w, 959w, 846s, 779s, 741m cm^'1.

Mass spectrum (ESI): m/z 768 {Fe2(L¹⁰)3(PF₆) }²⁺, 464 {Fe₂(L¹⁰)₃(PF₆)}³⁺, 312

{Fe₂(L¹⁰)₃}⁴⁺.

Η NMR (CD₃CN):<5 9.13 (IH, ά, J= 4.5 Hz, H₆), 8.69, (IH, t, J= 7.3 Hz, H_4/5), 7.88

(IH, t, J = 6.0 Hz, H₄/₅), 7.02 (3H, m, H₃ & H_Ph), 6.25 (2H, d, J = 7.7 Hz, H_Ph), 4.10

(IH, s, central CH₂).

UV/Vis (MeCN): 597 (ε= 31000), 395 (ε= 119000), 295 (ε= 126000), 235 (ε=

181000), 206 (ε= 304000) nm.

Synthesis of Half-Ligand L¹¹

2-nitrosopyridine (0.03 g, 0.278 mmol) was dissolved in dichloromethane. An excess of 4,4-methylenedianiline (0.220 g, 1.112 mmol) and glacial acetic acid (1 drop) were added and the orange solution was stirred at room temperature overnight. The solution was evaporated to dryness to provide an orange coloured solid. Column chromatography was carried out on silica gel using CH₂C1₂ as an eluant. The product was collected at Rf = 0.4 (0.03 g, 40 %).

IR (solid): 3434s, 3342s, 3015m, 2916m, 1618s, 1600s, 1581s, 1519s, 1464m, 1412s,

1309m, 1280s, 1225m, 1173m, 1136s, 1100m, 1045w, 1008w, 986w, 861w, 824m,

795s, 776s, 740s, 655w, 618w cm^'1.

Mass spectrum (+ve FAB): m/z 289 [M+H]⁺.

'H NMR (CDC1₃): δ 8.70 (lH, d, J= 3.4 Hz, H₆), 7.99, (2H, d, J= 8.5 Hz, H_Ph), 7.92

(IH, td, J= 7.5 Hz, H_4/5), 7.83 (IH, d, J= 7.7 Hz, H₃), 7.41 (IH, dd, J= 7.4, 4.5 Hz,

H4/5), 7.36 (2H, d, J = 8.3 Hz, H_Ph), 7.03 (2H, d, J = 8.3 Hz, H_Ph), 6.67 (2H, d, J = 8.3

Hz,_H_Ph), 3.98 (2H, s, CH₂), 3.64 (2H, broad s, NH₂).

Synthesis of Asymmetric Ligand L 12

The half-ligand L" was dissolved in methanol. One equivalent of pyridine-2-carboxaldehyde was added and the orange solution was stirred at room temperature for seven days. The orange solution was then reduced to dryness to produce an orange coloured oil. The 'H NMR spectrum contained overlapping resonances, some of which corresponded to the starting material pyridine-2-carboxaldehyde. Mass spectrum (+ve FAB): m/z 378 [M+HJ ⁺.

Synthesis of [Cu₂(L¹²)₂][PF₆]₂

Ligand L¹² was dissolved in methanol and whilst stirring under a nitrogen atmosphere, [Cu(MeCN)₄][PFe] was added to give a dark red solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark red solid precipitated from the solution on standing and was collected by filtration and dried with diethyl ether. The solid was recrystallised from acetonitrile by the slow diffusion of diethyl ether to afford dark red crystals. Η NMR spectroscopy in both CD₃CN and CD₂C1₂ provided overlapping signals and in both solvents there was evidence for the existence of more than one species in solution. X-ray quality crystals were obtained by the slow diffusion of diethyl ether into a solution ofthe complex in acetonifrile. IR (solid): 2950w, 1630w, 1591s, 1501m, 1470m, 1439m, 1420w, 1392w, 1365m, 1299w, 1272w, 1225w, 1190w, 1155m, 1093w, 1003m, 972w, 816s, 774s, 727m, 649w, 637w cm^''.

Mass spectrum (ESI): m/z 1027 {Cu₂(L¹²)₂(PF₆)}⁺, 817 {Cu(L¹²)}⁺, 441 {Cu(L¹²)}⁺.

UV/Vis (MeCN): 570 (ε= 11 000), 337 (ε= 85 000), 236 (ε= 67 000) nm.

Synthesis of Ligand L^1S

2-nitrosopyridine (0.106 g, 0.981 mmol) was dissolved in dichloromethane. 4,4'-diaminodiphenylether (0.098 g, 0.491 mmol) and glacial acetic acid (1 drop) were added and the orange solution was stirred at room temperature overnight. The solution was evaporated to dryness to provide an orange coloured solid (0.138 g, 74 %). IR (solid): 1579s, 1482s, 1462s, 1373m, 1291w, 1237s, 1132s, 1089m, 988m, 957w, 828m, 781m, 731m, 610w cm^'1. Mass spectrum (+ve EI): m/z 382 [M+2H] ⁺. 'H NMR (CDC1₃): < 8.72 (lH, d, J= 4.9 Hz, H₆), 8.07, (2H, d, J= 9.0 Hz, H_Ph), 7.88 (lH, td, J= 8.1, 1.9 Hz, H_4/5), 7.79 (IH, d, J= 8.1 Hz, H₃), 7.38 (IH, dd, J= 7.4, 4.9, 1.3 Hz, H_4/5), 7.18 (2H, d, J= 8.9 Hz, H_Ph).

¹³C NMR (CDC1₃): <S163.2 C_2/7/ιo, 160.1 C2/7/10 , 149.9 C₆, 148.0 C₂₇/₁₀, 138.9 C_4/5, 126.1 C₈&ι₂/9&π, 125.6 C /5, 119.9 C₈&ι₂/₉&n, 116.0 C₃. Synthesis of [Cu₂(L¹⁵)₂][BF₄]₂

Ligand L¹⁵ (0.042 g, 0.111 mmol) was dissolved in methanol and whilst stirring under a

nitrogen atmosphere, [Cu(MeCN)₄][BF₄] (0.035 g, 0.111 mmol) was added to give a dark solution. The solution was heated under reflux overnight and then cooled to room temperature. A black solid precipitated from the solution on standing and was collected by filtration and dried with diethyl ether (0.076 g, 65 %). Η NMR specfroscopy revealed a broad set of peaks indicating the presence of a copper(II) species.

IR (solid): 1574s, 1482s, 1379m, 1309w, 1247s, 1136s, 1048s, 872m, 835m, 780m,

736w, 637w cm^"1.

Mass spectrum (ESI): m/z 973 {Cu₂(L¹⁵)₂(BF₄)}⁺, 823 {Cu(L¹⁵)₂}⁺, 443 {Cu(L¹ )}⁺.

•H NMR (CD₃CN): 8.44 (IH, broad s, H₆), 8.13, (2H, broad m, H₃ & H4/₅), 7.95 (2H, broad d, J = 8.5 Hz, H_Ph), 7.62 (IH, broad m, H₄₅), 7.00 (2H, broad d, J = 8.5 Hz,

UV/Vis (MeCN): 573 (ε= 5 000), 347 (ε= 80 000) nm.

Synthesis of [Ag₂(L¹⁵)₂] [PF₆]₂

Ligand L^ls (0.013 g, 0.035 mmol) was dissolved in methanol and whilst stirring and excluding light, silver(I)acetate (0.006 g, 0.035 mmol) was added to give a yellow solution. The solution was heated under reflux in the dark for 30 minutes and then cooled to room temperature. The solution was filtered through celite and the yellow filtrate collected. A dark yellow solid precipitated on addition of excess methanolic

[NH₄][PF₆] to the filtrate and was collected by filtration (0.031 g, 70 %). IR (solid): 2934w, 1571s, 1486s, 1431m, 1408m, 1307w, 1225s, 1128s, 1097w,

1003m, 813s, 770m, 727w, 634w cm'¹.

Mass spectrum (+ve FAB): m/z 1121 [Ag₂(L¹⁵)₂(PF₆)]⁺, 869 [Ag(L^ls)₂]⁺.

(Found: C, 42.2; H, 2.6; N; 13.0. Calc. for Ag2C44H₃2Ni2O₂P₂F,₂: C, 41.7; H, 2.6; N,

13.3 %).

'H NMR (CD₃CN): (58.71 (IH, d, J= 3.2 Hz, H₆), 8.10, (3H, m, H_Ph & H₄₅), 7.86 (IH, d, J= 7.9 Hz, H₃),

7.30 (2H, dd, J= 9.0 Hz, H_Ph).

Synthesis of Ligand L 16

2-nitrosopyridine (0.042 g, 0.389 mmol) was dissolved in dichloromethane. 3,3 -methylenedianiline (0.039 g, 0.194 mmol) and glacial acetic acid (1 drop) were added and the orange solution was stirred at room temperature overnight. The solution was evaporated to dryness to provide an orange coloured solid (0.056 g, 76 %). Mass spectrum (+ve CI): m/z 379 [M+H]⁺.

'H NMR (CDC1₃): (58.73 (IH, d, J = 4.7 Hz, H₆), 7.93, (3H, m H_b> H_d & H₄₅), 7.81 (IH, d, J= 8.1 Hz, H₃), 7.47 (IH, t, J= 7.7 Hz, H_c), 7.40 (2H, m, H₄₅ & H_a), 4.19 (IH, s, central CH₂).

Synthesis of [Cu₂(L¹⁶)₂][BF₄]₂

Ligand L¹⁶ (0.105 g, 0.278 mmol) was dissolved in methanol and whilst stirring under a nitrogen atmosphere, [Cu(MeCN) ][BF ] (0.087 g, 0.278 mmol) was added to give a dark red solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark red solid precipitated from the solution on standing and was collected by filtration and dried with diethyl ether (0.217 g, 74 %).

IR (solid): 1595m, 1571m, 1494w, 1455w, 1439m, 1385m, 1272w, 1229m, 1143m,

1046s, 941s, 785s, 735m, 696m, 665m cm'¹.

Mass spectrum (ESI): m/z 969 {Cu₂(L¹⁶)₂(BF₄)}⁺, 819 {Cu(L¹⁶)₂}⁺, 441

{Cu₂(L¹⁶)₂}²⁺; {Cu(L¹⁶)}⁺.

Η NMR (CD₃CN): d 8.54 (IH, d, J= 7.2 Hz, H₃), 8.45, (2H_! m H₆& H_4/5)_J 7.95 (IH, d, J= 8.3 Hz, H_{b d}), 7.83 (IH, t, J= 6.4 Hz, H₄₅), 7.39 (IH, t, J= 7.7 Hz H_c), 7.15 (IH, d, J= 7.4 Hz Hb/d), 6.95 (IH, s, H_a), 3.66 (IH, s, central CH₂).

UV/Vis (MeCN): 575 (ε= 11 000), 336 (ε= 77 000) nm.

Synthesis of [Ag2(L¹⁶)₂][PF₆]2

Ligand L¹⁶ (0.048 g, 0.127 mmol) was dissolved in methanol and whilst stirring and excluding light, silver(I)acetate (0.021 g, 0.127 mmol) was added to give a yellow solution. The solution was heated under reflux in the dark for 30 minutes and then cooled to room temperature. The solution was filtered through celite and the yellow filfrate collected. A dark yellow solid precipitated on addition of excess methanolic [NH₄][PF₆] to the filtrate and was collected by filtration (0.107 g, 76 %). X-ray quality crystals were obtained by the slow diffusion of diethyl ether into a solution of the complex in deuterated acetonitrile.

IR (solid): 1600m, 1497w, 1475w, 1441m, 1305w, 1221m, 1140m, l lOOw, 1070w,

912m, 875m, 820s, 806s, 780s, 743m, 684m, 633w cm'¹.

Mass spectrum (+ ve FAB): m/z 1117 [Ag₂(L¹⁶)₂(PF₆)]⁺.

(Found: C, 43.2; H, 2.8; N; 13.0. Calc. for AgaCeHaeN^F -^O: C, 43.2; H, 3.0; N,

13.1 %).

'H NMR (CD₃CN): δ 8.59 (IH, d, J= 4.0 Hz, H₆), 8.27, (2H, td, J= 7.7, 1.7 Hz H /₅), 8.14 (IH, d, J= 7.9 Hz, Ha), 7.70 (2H, m, H ₅& H_b/d), 7.43 (IH, s, H_a), 7.35 (IH, t, J = 7.7 Hz, H_c), 7.26 (IH, d, J= 7.4 Hz, H_{b d}), 3.85 (IH, s, central CHa).

Synthesis of Ligand L¹⁸

2-nitroso-6-methylpyridine (0.034 g, 0.279 mmol) was dissolved in dichloromeffiane. 1,4-phenylenediamine (0.015 g, 0.139 mmol) and glacial acetic acid (1 drop) were added and the orange solution was stirred at room temperature overnight. The solution was evaporated to dryness to provide an orange coloured solid (0.032 g, 74 %). IR (solid): 1649m, 1599s, 1564s, 1509m, 1455w, 1432m, 1303s, 1373s, 1326s, 1299s,

1229m, 1198m, 1124s, 980m, 898w, 851m, 834m, 778s, 727m, 602w cm^'1.

Mass spectrum (+ve Cl): m/z 317 [M+H]⁺. Η NMR (CDCI3): <5 8.18 (2H, s, Hp_h), 7.90 (IH, d, J= 7.6 Hz, H_3/5), 7.78 (lH, t, J =

7.8 Hz, H₄), 7.62 (IH, d, J = 8.0 Hz, H₃/₅), 2.70 (3H, s, CH₃).

¹³C NMR (CDC1₃): δ 159.3 C2/6/9, 154.3 C2/6/9, 151.8 C2/6/9, 138.9 C₄, 126.6 C3/5, 124.9

Synthesis of [Ag„(L¹⁸)„][PF₆]„

Ligand L¹⁸ (0.015 g, 0.047 mmol) was dissolved in methanol and whilst stirring and

excluding light, silver(I)acetate (0.008 g, 0.047 mmol) was added to give a yellow solution. The solution was heated under reflux in the dark for 30 minutes and then

cooled to room temperature. The solution was filtered through celite and the yellow

filtrate collected. A dark yellow solid precipitated on addition of excess methanolic

[NH₄][PF₆] to the filtrate and was collected by filtration (0.016 g, 61 %).

IR (solid): 1592m, 1567w, 1467m, 1434w, 1379w, 1323w, 1298w, 1261m, 1217m,

1173m, 1140m, 1088m, 1011m, 912m, 824s, 728m, 625m cm^'1.

Mass spectrum (+ve FAB): m/z 2133 [Ag₄(L¹⁸)₄(PF₆)3]⁺, 1564 [Ag₃(L¹⁸)3(PF₆)₂]⁺,

995 [Ag₂(L¹⁸)₂(PF₆)₂]⁺.

(Found: C, 35.2; H, 2.6; N; 13.6. Calc. for Ag„(C₁₈H₁₆N6)n(PF6)n(CHCl₃)n/₂: C, 70.7;

H, 5.1; N, 21.5 %).

'H NMR (CD₃CN): δ 8.07 (lH, t, J= 7.8 Hz, H₄), 7.97 (2H, s, H_Ph), 7.85 (lH, d, J= 7.8 Hz, H3/5), 7.59 (IH, d, J = 7.5 Hz, H_{3 5}), 2.72 (3H, s, CH₃).

Synthesis of Ligand L⁴

3,3'-methylenedianaline (0.128 g, 0.646 mmol) was dissolved in methanol and whilst stirring, pyridine-2-carboxyaldehyde (0.123 cm³, 1.291 mmol) was added causing the colourless solution to turn pale yellow. The solution was stirred overnight and the solvent removed by rotary evaporation to leave a yellow oil (0.197 g, 81 %).

IR (oil): 3050m, 2365s, 2329s, 2297m, 1742m, 1715w, 1657m, 1585s, 1469s, 1437m,

1343w, 1222w, 1088w, 1048w, 989w, 904w, 864w, 779s, 739, 694m, 658m cm^'1.

Mass spectrum (+ve FAB): m z 377 [M+H] ⁺.

Mass spectrum (+ve El): m/z 376 [M] ⁺.

^■H NMR (CDC1₃): δ 8.69 (2H, d, J= 4.0 Hz, H₆), 8.57 (2H, s, H), 8.18 (2H, d, J =

7.9, H₃), 7.80 (2H, td, J= 7.4, 1.5 Hz, H₄), 7.35 (4H, m, H_{5 &}H_C), 7.15 (6H, m, H_a>H_{b &}

H_d), 3.97 (2H, s, CH₂).

¹³C NMR (CDCI3): 5 161.02 Ci, 154.94 C₂, 151.59 C_2/8/12, 150.07 C₆, 142.43 C_2/8 ι₂,

137.05 C₄, 129.80 do, 127.80 Cπ, 125.70 C₅, 122.41 C13, 122.27 C₃, 119.13 C₉,

42.21 CH₂.

Synthesis of [Cu₂(L⁴)₂][PF₆]2 Ligand L⁴ (0.107 g, 0.284 mmol) was dissolved in methanol and whilst stirring under a nitrogen atmosphere, [Cu(MeCN)₄][PF₆] (0.106 g,

0.284 mmol) was added to give a dark red solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark red solid precipitated

from the solution on standing and was collected by filtration and dried with diethyl

ether (0.282 g, 85 %). The solid was recrystallised from acetonitrile by the slow diffusion of benzene to afford dark red crystals.

IR (KBr): 2920w, 1650w, 1591m, 1472m, 1447m, 1303m, 1084w, 844s, 785m, 743m,

698m, 558s cm^'1.

Mass spectrum (ESI): m/z 1025 {Cu2(L⁴)₂(PF₆)}⁺, 816 {Cu(L⁴)₂}⁺, 504 {Cu₂(L⁴)}²⁺,

440 {Cu₂(L⁴)₂}⁺.

(Found: C, 51.6; H, 3.4; N; 9.5. Calc. for Cu₂C₅oH4oN₈P2Fι₂: C, 51.3; H, 3.5; N, 9.6 %).

Η NMR (CD₃CN): δ 8.98 (2H, s, Hi), 8.43 (2H, broad d, H₆), 8.18 (2H, broad d, H₃),

8.12 (2H, broad t, H₄), 7.68 (2H, broad t, H₅), 7.45 (2H, d, J= 7.4 Hz, H_{b d}), 7.28 (2H, broad t, He), 6.94 (2H, d, J= 7.4 Hz, H_b/d), 6.64 (2H, s, H_a), 3.65 (2H, s, CH₂).

UV/Vis: 1 507.2 (ε 4000), 330.0 (ε 31 300), 241.8, (ε 31 000) nm.

The tetrafluoroborate salt was prepared in 83 % yield by the same route replacing

[Cu(MeCN)₄][BF₄] with [Cu(MeCN)₄][PF₆].

The perchlorate salt was prepared in 79 % yield by a similar route followed by the

addition of excess methanolic NaO Cl.

Synthesis of [Ag₂(L⁴)2][PF₆]₂ Ligand L⁴ (0.106 g, 0.282 mmol) was dissolved in

methanol and whilst stirring under a nitrogen atmosphere and excluding light,

silver(I)acetate (0.047 g, 0.282 mmol) was added to give a yellow solution. The

solution was heated under reflux in the dark for 1 hour and then cooled to room

temperature. The solution was filtered through celite and the yellow filtrate collected.

A yellow solid precipitated on addition of excess methanolic [NfLKPFβ] to the filtrate

and was collected by filtration (0.259 g, 73 %). IR (solid): 2377m, 1680w, 1586m, 1484w, 1437w, 837vs, 775m cm'¹.

Mass spectrum (ESI): m/z 1113 {Ag₂(L )₂(PF₆)}⁺, 860 {Ag(L )₂}⁺, 484

{Ag₂(L⁴)₂}²⁺;{Ag(L⁴)}⁺.

(Found: C, 46.9; H, 3.1; N; 8.6. Calc. for Ag2C₅oH₄oN₈P2F₁₂.2H₂O: C, 46.4; H, 3.4; N,

8.7 %).

Η NMR (CD₃CN):<5 8.74 (2H, s, H»), 8.61 (2H, dd, J= 4.9, 0.6 Hz, H₆), 8.17 (2H, td,

J= 7.9, 1.7 Hz, H₄), 7.98 (2H, d, J= 7.5 Hz, H₃), 7.68 (2H, ddd, J= 6.4, 4.9, 1.3 Hz,

H₅), 7.32 (2H, ά, J= 7.3 Hz, H_b/d), 7.21 (2H, t, J = 7.3 Hz, H_c), 6.91 (2H, d, J = 7.3

Hz, Hb/d), 6.75 (2H, s, H_a), 3.60 (2H, s, CH₂).

The tetrafluoroborate salt was prepared in 73 % yield by the same route followed by the

addition of excess methanolic [NH4HBF4].

The perchlorate salt was prepared in 70 % yield by the same route replacing silver(I) perchlorate instead of silver(I)acetate.

FURTHER LIGANDS

General Preparation of the Ligands. To a solution of toluene (50 cm³) containing vacuum dried 3 A molecular sieves (5 g) and either 4,4'-methylenedianiline or 4,4'-diaminodiphenyl ether (0.010 mol), two equivalents of the relevant pyridine aldehyde/ketone (0.020 mol) were added. The solution was refluxed for 24 hours. Following filtration through celite, the solvent was removed in vacuo to yield a yellow solid/oil. The ligand was recrystallised from hot ethanol on several occasions to improve purity. The structures ofthe ligands investigated are summarised in figure 2. Preparation of the iron (II) triple helicates. To a refluxing methanolic solution (50 cm³) of each ligand, 2/3 molar equivalents of iron (II) chloride tefrahydrate in the minimum amount of methanol was added. After 2 hours, the deep purple solution, characteristic of iron (II) tris-pyridylimine compounds was observed and the iron (II) triple helicate was precipitated upon the addition of excess ammonium hexafluorophosphate dissolved in methanol. Following filtration, the solid was washed with ether and allowed to dry in a vacuum desiccator. The chloride salt was obtained by anion metathesis in acetonifrile using tetrabutylammonium chloride. The same complexes could be prepared directly by treating mixtures of the diamine and aldehyde/ketone in methanol solution in the appropriate ratios. Complex 1. Anal. Calc. for

C, 56.6; H, 4.2; N, 9.8%. Found: C, 56.6; H, 4.3 ; N, 9.7 %. Positive-ion ESI (MeOH): ([Fe₂(L)₃]⁴⁺), 331.0; Η NMR ((MeOD) 400 MHz, 300 K): (54.10 (3H, s, Me), 4.64 (3H, s, Me), 4.79 ( 2H, dd, Hp_h J = 8.3 Hz, J = 1.5 Hz), 5.57 (2H, dd, H_Ph J = 8.3 Hz, J = 1.5 Hz), 6.89 (2H, dd, H_Ph J = 6.3 Hz), 7.26 (2H, d, H₆ J = 6.3 Hz), 7.42 (2H, dd, H_Ph J = 6.3 Hz, J = 1.1 Hz), 7.81 (2H, t, H₅ J = 6.3 Hz), 8.50 (2H, t, H₄ J = 7.8 Hz), 8.78 (2H, d, H₃ J = 7.8 Hz); Selected IR data (cm^'1): 3386w, 1626w, 1588w, 1559w, 1503s, 1474m, 1441m, 1380m, 1334m, 1308w, 1256m, 1166w, l l lOw, 1060w, 1019w, 828vs, 771 vs, 750vs, 691m, 674m.

Complex 2. Anal. Calc. for [Fe₂(C₂₇H₂₄N₄)3][PF₆]4: C, 51.1; H, 3.8; N, 8.8%. Found: C, 50.8; H, 4.1; N, 8.8%. Positive-ion ESI (MeCN): m/z ([Fe₂(L²)₃(PF₆)₃]⁺), 1760.1 ([Fe₂(L²)3(PF₆)2]²⁺), 807.2, ([Fe₂(L²)₃(PF₆)]³⁺), 489.9 ([Fe₂(L²)₃]⁴⁺), 331.2. Η NMR ((CD₃CN) 300 MHz, 300 K): (52.85 (3H, s, Me), 4.02 (IH, s, Me), 5.28 (IH, bs, H_Ph), 5.74 (IH, bs, H_Ph), 6.63 (IH, bs, Ha), 7.06 (IH, d, H₅ J = 4.5 Hz), 7.31 (IH, bs, H_Ph), 7.61 (IH, bt, H₄ J = 6.0 Hz), 8.15 (IH, d, H₃ J = 7.0 Hz), 8.96 (IH, s, H_im); Selected IR data (cm^'1): 3386w, 1626w, 1588w, 1558w, 1503s, 1474m, 1441m, 1380m, 1335m, 1308w, 1256w, 1166w, l l lOw, 1060w, 1019w, 828vs, 771vs, 750vs, 691m, 674m.

Complex 3. Anal. Calc. for [Fe₂(C₂₇H₂₄N₄)3][PF₆]4: C, 51.1; H, 3.8; N, 8.8%. Found: C, 50.8; H, 4.0; N, 8.6%. Positive-ion ESI (MeCN): m/z ([Fe₂(L³)3(PF₆)3]⁺), 1761.1 ([Fe₂(L³)₃(PF₆)2]²⁺), 807.4 ([Fe₂(L³)₃(PF₆)]³⁺), 490.2 ([Fe₂(L³)₃]⁴⁺), 331.4. 'H NMR ((MeOD) 400 MHz, 300 K): (52.48 (3H, s, Me), 4.08 (IH, s, Me), 5.59 (2H, vbs, H_Ph), 7.04 (2H, vbs, HPH), 7.31 (IH, s, H₅), 8.33 (IH, d, H₃/ , J = 7.5 Hz), 8.62 (IH, d, H₃/₄, J = 8.0 Hz), 9.16 (IH, s, H_im); Selected IR data(cm^''): 3137w, 2350w, 1625m, 1597w, 1561w, , 1499s, 1354w, 1221m, 1197s, 1106w, 1040m, 1016w, 912s, 836s, 770m, 748w, 658w.

Complex 4. Anal. Calc. for [Fe₂(C₂9H₂₈N₄)3][PF6]4: C, 52.5; H, 4.3; N, 8.5%. Found: C, 52.0; H, 4.2; N, 8.3%. Positive-ion ESI (MeOH): ([Fe₂(L⁴)₃]⁴⁺), 352.4. Η NMR ((CD₃CN) 300 MHz, 300 K): (52.35 (3H, s, Me), 2.71 (3H, s, Me), 4.67 (IH, dd, H_Ph, J = 6.4 Hz, J = 1.9 Hz), 5.47 (IH, dd, H_Ph, J = 6.0 Hz, J = 2.0 Hz), 6.76 (IH, dd, H_Ph, J = 8.1 Hz, J = 1.8 Hz), 6.93 (IH, d, H_5/6, J = 5.6 Hz), 7.31 (IH, dd, H_Ph, J = 7.6 Hz, J = 1.8 Hz), 7.51 (IH, d Hs6, J = 5.3 Hz), 8.45 (IH, s H₃); Selected IR data (cm^'1): 3386w, 1613w, 1590w, 1503s, 1475m, 1441m, 1379m, 1335m, 1310w, 1221w, 1166w, l l lOw, 1042w, 1018w, 828vs, 773vs, 750vs, 691m, 674m.

Complex 5. Anal. Calc. for [Fe2(C₂4Hi₈N4O)₃][Cl]₄(H2O)i2: C, 54.1; H, 4.5; N, 10.5%. Found: C, 54.5 ; H, 4.1 ; N, 10.0%. Positive-ion ESI (MeOH): ([Fe₂(L)₃]⁴⁺), 311.0; Η NMR ((D₂O) 400 MHz, 300 K): (55.32 (2H, broad d, H_Ph J = 6.3 Hz), 5.86 (2H, broad d, Hp_h J = 6.0 Hz), 6.38 (2H, bd, H_Ph J = 5.1 Hz), 6.98 (2H, bd, H_Ph J = 6.0 Hz), 7.25 (2H, d, H₆ J = 3.9 Hz), 7.57 (2H, t, H₅ J = 6.0 Hz), 8.23 (2H, t, H₄ J = 6.9 Hz), 8.43 (2H, d, H₃ J = 6.6 Hz), 9.01 (2H, s, H_im); Selected IR data (cm^'1): 1626w, 1591w, 1488vs, 1441w, 1357w, 1310w, 1227s, 1195s, 1158m, 1105w, 1043w, 101 lw, 834vs, 774vs, 691w, 674w.

Complex 6. Anal. Calc. for [Fe₂(C₂₆H22N₄O)₃][PF₆]₄.l¹/₂FeCl2 : C, 44.6 H, 3.2; N, 8.0%. Found: C, 44.4; H, 3.4; N, 7.7%. Positive-ion ESI (MeCN): m/z ([Fe₂(L⁶)₃(PF₆)₃]⁺), 1765.5 ([Fe₂(L⁶)₃(PF₆)2]²⁺), 810.2 ([Fe₂(L⁶)3(PF₆)]³⁺), 491.9 ([Fe₂(L⁶)₃]⁴⁺), 332.8. 'H NMR ((CD₃CN) 300 MHz, 300 K): (52.31 (3H, s, Me), 2.44 (3H, s, Me) 4.88 (IH, d, H_Ph J = 8.9 Hz), 5.62 (IH, d, H_Ph J = 7.5 Hz), 6.57 (IH, d, H_Ph J = 7.1 Hz), 7.10 (IH, d, H₆ J = 5.1 Hz), 7.24 (IH, d, H_Ph J = 8.1 Hz), 7.69 (IH, t, H₅ J = 6.0 Hz), 8.38 (IH, t, H₄ J = 7.4 Hz), 8.62 (IH, d, H₃ J = 7.7 Hz); Selected IR data (cm^'1): 3381w, 1626w, 1588w, 1558w, 1503s, 1474m, 1441m, 1380m, 1335m, 1308w, 1256m, 1166w, ll lOw, 1060w, 1019w, 827vs, 771vs, 750vs, 691m, 674m.

Complex 7. Anal. Calc. for [Fe₂(C26H22N₄O)3][Cl]42FeCl2.3H₂O: C, 52.6; H, 4.1; N, 9.4%. Found: C, 52.9; H, 4.7; N, 8.5%. Positive-ion ESI (MeOH): m/z ([Fe₂(L⁷)₃(PF₆)₃]⁺), 1765.3 ([Fe₂(L⁷)₃(PF₆)₂]²⁺), 810.2 ([Fe₂(L⁷)₃(PF₆)]³⁺), 491.9 ([Fe₂(L⁷)₃]⁴⁺), 332.6. 'H NMR ((CD₃CN) 400 MHz, 300 K): (52.87 (3H, s, Me), 5.49 (IH, s, Hp_h), 5.94 (IH, s, H_Ph), 6.44 (IH, s, H_Ph), 7.04 (IH, d, H₅ J = 6.1 Hz), 7.22 (IH, s, HPH), 7.60 (IH, t, H4 J = 7.2 Hz), 8.15 (IH, d, H₃ J = 7.0 Hz), 9.04 (IH, s, H_im). Selected IR data (cm^'1): 3356w, 1614w, 1590w, 1490vs, 1446w, 1378w, 1311w, 1231s, 1164m, 1108w, 1038w, IOIOW, 833vs, 792s, 69 lw, 674m. Complex 8. Anal. Calc. for [Fe₂(C26H22N₄O)3][PF₆] - 3¹/2EtOH: C, 49.0; H, 3.5; N, 8.8%. Found: C, 49.5; H, 4.1; N, 8.3%. Positive-ion ESI (MeCN): m/z ([Fe₂(L⁸)3(PF₆)₃]⁺), 1768.5 ([Fe2(L⁸)₃(PF₆)₂]²⁺), 810.6 ([Fe₂(L⁸)3(PF₆)]³⁺), 492.2 ([Fe₂(L⁸)₃]⁴⁺), 332.9. ^!H NMR ((CD₃CN) 400 MHz, 300 K): (52.70 (3H, s, Me), 5.70 (2H, vbs, H_Ph), 6.70 (2H, vbs, H_Ph), 7.44 (IH, s, H₄), 7.72 (IH, d, H₆ J = 5.9 Hz), 8.51 (IH, d, H₃ J = 7.8 Hz) 9.30 (IH, s, H_im). Selected IR data(cm^''): 3386w, 1589w, 1562w, 1503s, 1474m, 1441m, 1380m, 1335m, 1308w, 1256m, 1166w, l l lOw, 1060w, 1019w, 828vs, 771vs, 750vs, 691m, 674m.

Complex 9. Anal. Calc. for

C, 44.2; H, 3.1; N, 7.9%. Found: C, 44.3; H, 3.7; N, 8.8%. Positive-ion ESI (MeCN): ([Fe₂(L⁹)₃]⁴⁺), 333.1. Η NMR ((MeOD) 400 MHz, 300 K): (52.48 (3H, s, Me), 5.77 (2H, vbs, H_Ph), 6.78 (2H, vbs, Hp_h), 7.60 (IH, s, H₅), 8.30 (IH, d, H₃₄ J = 8.0 Hz), 8.73 (IH, d, H₃₄ J = 8.0 Hz) 9.60 (IH, s, H_im); Selected IR data (cm^'1): 3386w, 1626w, 1589w, 1558w, 1503s, 1474m, 1441m, 1380m, 1335m, 1308w, 1256w, 1198w, 1166w, l llOw, 1060w, 1019w, 827vs, 771vs, 750s, 691m, 674m.

Complex 10. Anal. Calc. for [Fe₂(C2₈H26N₄O)₃][PF₆]4.5¹/2H2O : C, 48.2; H, 4.3; N, 8.0%. Found: C, 48.0; H, 3.9; N, 8.0%. Positive-ion ESI (MeOH): Fe₂(L¹⁰)₃(Cl)]³⁺), 483.5 ([Fe₂(L¹⁰)₃]⁴⁺), 353.9. Η NMR ((D₂O) 400 MHz, 300 K): (52.31 (3H, s, Me), 2.56 (3H, s, Me) 4.88 (IH, dd, H_Ph J = 6.2 Hz, J = 2.5 Hz), 5.65 (IH, d, H_Ph J = 6.2 Hz, J = 2.5 Hz), 6.55 (IH, dd, H_Ph J = 6.4 Hz. J = 2.5 Hz), 6.91 (IH, d, H_5/6 J = 5.9 Hz), 7.14 (IH, dd, Hp_h J = 6.0 Hz, J = 2.4 Hz), 7.41 (IH, d, H₅/₆ J = 5.8 Hz), 8.44 (IH, s, H₃); Selected IR data (cm^'1): 3356w, 1615m, 1591m, 1490vs, 1446m, 1378m, 1311w, 1233s, 1202s, 1164m, 1104m, 1034m, 1010m, 831s, 690m, 674m.

Preparative Cellulose Column Chromatography for separation of the enantiomers. Cellulose columns were packed into 2 cm ' 30 cm unsintered columns using cellulose particles (~20 micron) as the stationary phase and aqueous 20 mM sodium chloride as the solvent in which the cellulose was suspended for packing. To 6 g of cellulose, 40 cm³ of 20 mM sodium chloride was added and the solution stirred to a smooth consistency. The column was packed by pouring the aqueous saline suspension of cellulose onto a glass wool pad located just above the stopcock and excess solvent was eluted. The sample, as the chloride salt (the equivalent PF₆ salt is not soluble in aqueous solution), was then loaded onto the column as a saturated aqueous solution (approx. 5 mg in 1 ml) and the column eluted with 0.02 M aqueous NaCl mobile phase (compounds 1,3,5,7,10) or 90% MeCN (compound 9). The fractions collection was guided by visual inspection ofthe profile.

Preparation of L:

To a stirred solution of isoquinaldaldehyde (0.314g, 2 mmol) in ethanol (30 ml) at room temperature was added dropwise an ethanolic solution of bis(4-aminophenyl)methane

(0.198g, 1 mmol). After the addition was complete, the reaction mixture was stirred at room temperature for 24 hours. The resultant precipitate was filtered off, washed with ethanol and dried in vacuo under P₄Oιo to afford 0.33g (69%) of yellow solid.

Mass spectrum (FAB): m/z = 477 [M+H

Elemental analysis calculated (%) for C33H₂4N4-0.25H₂O: C: 82.4, H: 5.1, N: 11.6; found: C: 82.6, H: 5.1, N: 11.6.

•H NMR (400MHz, CDC1₃, 298 K):δ = 9.67 (IH, d, J = 7.7 Hz, H⁹), 9.09 (IH, s, H¹),

8.66 (IH, d, J= 5.8 Hz, H³), 7.90 (IH, d, J= 7.5 Hz, H⁶), 7.75 (3H, m, H⁴, H⁷, H⁸), 7.35

(4H, m, H¹¹, H¹²), 4.09 (IH, s, H¹³).

IR: v = 3048 (s), 1620 (m), 1582 (m), 1550 (s), 1500 (s), 1388 (m), 1347 (m), 1312(m),

1140 (m), llll (w), 1061 (w), 1011 (w), 966 (m), 905 (m), 866 (w), 847 (w), 823 (vs),

799 (m), 781 (s) 641 (s) cm^'1.

Coordination of L to silver(I):

Care was taken to exclude light during the following procedure. L (0.023g, 0.05mmol) in chloroform and silver(I) hexafluorophosphate (0.012g, 0.05 mmol) in methanol were stirred for 4 hours. The yellow precipitate was collected by vacuum filfration, washed with methanol and dried in vacuo under P4O10 (0.043g, 69%). X-ray quality, pale yellow crystals were obtained by slow diffusion of benzene into a solution of the complex in acetonitrile:methanol (1:1).

Mass spectrum (FAB) m/z = 1312 [Ag₂L₂(PF₆)], 1167 [Ag₂L₂], 1060 [AgL₂]

Elemental analysis calculated (%) for [Ag2(C33H₂₄N₄)2](PF₆)2-1.5CHCl3: C: 49.5, H: 3.0,

N: 6.9; found: C: 49.8, H: 3.1, N: 7.0.

Η NMR (400MHz, CD₃CN, 298 K): δ = 9.79 (IH, s, H¹), 8.93 (IH, d, J= 8.3 Hz, H⁹), 8.63 (IH, d, J= 5.8 Hz, H³), 8.11 (2H, m, H⁴, H⁶), 7.93 (2H, m, H⁷, H⁸), 7.51 (2H, d, J= 8.2 Hz, H^{11 12}), 7.23 (2H, d, J= 8.5 Hz, H^{u 12}) 3.92 (IH, s, H¹³).

IR: v = 3051 (w), 1612 (m), 1578 (s), 1552 (m), 1503 (s), 1427 (w), 1324 (s), 1249 (w), 1147 (m), 1018 (m), 825 (vs), 745 (s), 700 (m), 647 (m) cm^'1.

Coordination of L to copper(I):

L (0.0235g, 0.05mmol) was dissolved in chloroform and whilst stirring under a nitrogen atmosphere, [Cu(MeCN)₄]BF (0.015g, 0.05 mmol) in methanol was added to give a dark violet solution. The solution was heated under reflux overnight and then cooled to room temperature. A dark violet solid precipitated from the solution and was collected by vacuum filtration, washed with methanol and dried in vacuo under P₄Oιo

(0.05g, 80%). X-ray quality, dark violet crystals were obtained by slow evaporation of the complex in acetonitrile.

Mass spectrum (FAB) m/z = 1167 [Cu₂L₂(BF₄)], 1080 [Cu₂L₂]

Positive-ion ESI (MeCN): m/z = 1167 ([Cu₂L₂(BF₄)]⁺), 1015 ([CuL₂]⁺), 540 ([Cu₂L₂]²⁺)

Elemental analysis calculated (%) for [Cu2(C33H24N₄)2](BF4)2-3H₂O: C: 60.6, H: 4.2, N:

8.6; found: C: 60.9, H: 3.9, N: 8.3.

•H NMR (300MHz, CD₃NO₂, 298 K): δ = 10.07 (IH, s, H'box), 10.67 (3H, s, H'helix)

8.73 (4H, d, J= 8.2 Hz, H⁹), 8.42 (3H, d, J= 5.8 Hz, H³helix), 8.34 (3H, d, J= 5.0 Hz,

H³box), 8.05 (4H, m, H⁴, H⁶), 7.87 (4H, m, H⁷, H⁸), 7.58 (2H, d, J= 7.9 Hz, H^11/12box),

7.44 (6H, d, J= 8.2 Hz, H^{11 12}helix), 7.15 (2H, d, J= 8.1 Hz, H^{11 12}box), 7.07 (6H, d, J=

8.4Hz, H^11/12helix), 3.76 (3H, s, H¹³helix), 3.71 (IH, s, H¹³box).

IR: v = 3049 (w), 2917 (w), 1610 (w), 1581 (m), 1537 (m), 1504 (s), 1429 (m), 1401

(s), 1371 (m), 1322 (s), 1241 (w), 1199 (w), 1169 (m), 1053 (vs), 911 (m), 825 (vs),

785 (s), 747 (vs), 647 (s) cm^'1.

UV-Vis (MeCN): 365 (59000), 380sh (55000), 570sh (ε = 13500) nm.

Coordination of L to iron(II):

L (0.0705g, 0.015mmol) and iron(II) tetrafluoroborate (0.034g, 0.01 mmol) in a mixture chloroform-methanol (1:1) were stirred for 24 hours at room temperature. The blue precipitate was collected by vacuum filtration, washed with methanol and dried in vacuo under P4O10 (O.Olg, 53%). X-ray quality, blue crystals were obtained by slow diffusion of benzene into a solution ofthe complex in acetonitrile.

Mass spectrum (FAB) rø/z = 1801 [Fe₂L₃(BF₄)3], 1715 [Fe₂L₃(BF₄)₂], 1628 [Fe₂L₃(BF₄)],

1541 [Fe₂L₃].

Positive-ion ESI (MeCN): m/z = 542 ([Fe₂L₃(BF₄)]³⁺), 385 ([Fe₂L₃]⁴⁺)

Elemental analysis calculated (%) for

C: 59.7,

H: 4.6, N: 8.1; found: C: 59.6, H: 4.5, N: 8.1.

Η NMR (400MHz, CD₂C1₂, 298 K):(5 = 9.81 (IH, s, H¹), 8.81 (IH, dd, J= 9.0, 4.2 Hz,

H³), 8.63 (IH, ddd, J= 5.2, 4.2, 1.7 Hz, H⁹), 8.13 (3H, m, H⁴, H⁶, H⁸), 7.27 (IH, broad,

H¹¹), 7.09 (IH, d, J = 6.2, Hz H⁷), 6.86 (IH, broad, H¹¹), 5.74 (IH, broad, H¹²), 5.54

(IH, broad, H¹²), 4.07 (IH, s, H¹³).

IR: v = 2973 (w), 1612 (m), 1579 (m), 1500 (s), 1433 (m), 1400 (m), 1365 (m), 1312

(s), 1220 (w), 1149 (m), 1049 (s), 824 (vs), 785 (s), 748 (s), 648 (s) cm^'1.

UV-Vis (MeCN): 340sh (57000), 380sh (50000), 560sh (15000), 620sh (ε= 28000) nm.

Preparation ofL and coordination to iron(II)

4,4'-Methylenedianiline (0.059 g, 0.3 mmol) and 2-benzoylpyridine (0.110 g, 0.6 mmol) were stirred in ethanol (25 ml) for 10 minutes, two drops of glacial acetic acid were then added and the mixture was heated under reflux for 12 hours. The resulting orange solution was concentrated by rotary evaporation to produce an orange oil, which further was treated with a methanolic solution (30 mL) of iron(II) chloride tefrahydrate (0.040 g, 0.2 mmol). The mixture was heated under reflux for 72 hrs. The resulting purple solution was filtered through Celite and the filtrate concenfrated to 10 mL by rotary evaporation. The complex was isolated from this solution as follows:

[Fe₂(L)₃]Cl₄: A purple solid resulted when 5 mL of diethyl ether were added to the above mentioned solution. It was isolated by vacuum filfration, washed with cold methanol and dried in vacuo over P4O10. Yield: 65 %. Anal. Calcd. for [Fe₂(C₃₇H₂₈N₄)₃]Cl₄.H₂O: C, 71.8; H, 4.7; N, 9.0%. Found: C, 71.9; H, 4.7; N, 8.8%. Positive-ion ESI (MeOH): m/z 884 ([Fe₂(L)₃(Cl)₂]²⁺), 578 ([Fe₂(L)₃(Cl)]³⁺), 425 ([Fe₂(L)₃]⁴⁺). Η NMR (CD3OD, 300 MHz, 298K):(58.48 (IH, t, J= 6.1 Hz, H₄), 8.18 (IH, d, J= 6.9 Hz, H₆), 7.98 (IH, t, J= 6.5 Hz, H₅), 7.38-7.50 (5H, m, H_Ph), 7.23 (IH, t, J= 7.8 Hz, Hp_h), 6.71 (IH, d, J= 6.7 Hz, H₃), 6.11 (IH, d, J= 7.8 Hz, H_Ph), 5.99 (IH, d, J= 7.5 Hz, H_Ph), 4.37 (IH, d, J= 8.1 Hz, H_Ph), 3.81 (IH, s, H_CH2). UV-Vis (MeOH): λ_max [nm] (εtM' ¹]): 213 (212900), 281 (85200), 338 (36500), 534 (25800), 580 (35300). IR data (KBr, cm^'1): 3425br, 3054w, 2958w, 2926w, 2856w, 1623s, 1598sh, 1575w, 1543w, 1502s, 1463w, 1441m, 1412vw, 1384s, 1356s, 1304w, 1259m, 1179vw, 1160w, 1106w, 1077vw, 1019m, lOOOw, 924vw, 821w, 796w, 742m, 700s, 665 w, 649vw, 617w, 604w, 556vw, 540vw, 419w, 403 w.

Further details of methods for manufacturing ligands for use in the production of supramolecular compounds which may be used in the claimed invention are shown in the following papers:

Readily prepared metallo-supramolecular triple-helicates designed to exhibit spin-crossover behaviour F. Tuna, M.R. Lees, G.J. Clarkson and M.J. Hannon, Chem. Eur. J., 2004, Using non-covalent intra-strand and inter-strand interactions to prescribe helix formation within a metallo-supramolecular system L.J. Childs, M. Pascu, A.J. Clarke, N.W. Alcock and M.J. Hannon, Chem. Eur. J., 2004, 10, 4291-4300 Binding sites on the outside of metallo-supramolecular architectures; engineering coordination polymers from discrete architectures M. Pascu, F. Tuna, E. Kolodziejczyk, G.I. Pascu, G. Clarkson and M.J. Hannon., Dalton Trans., 2004, 1546-1555

Aggregation of metallo-supramolecular architectures by metallo-assembled hydrogen bonding sites. A. Lavalette, F. Tuna, J. Hamblin, A. Jackson, G. Clarkson, N.W. Alcock and M.J. Hannon, Chem. Commun., 2003, 2666-2667

Metallo-supramolecular libaries: friangles, polymers and double-helicates assembled by copper(I) coordination to directly linked bis-pyridylimine ligands. F. Tuna, J. Hamblin, A. Jackson, G. Clarkson, N.W. Alcock and M.J. Hannon, Dalton Trans., 2003, 2141-8.

The effect of phenyl substituents on supramolecular assemblies containing directly linked bis-pyridylimine ligands: synthesis and structural characterisation of mononuclear nickel(II) and dinuclear silver(I) and cobalt(III) complexes of (2-pyridyl)phenylketazine. F. Tuna, G. Clarkson, N.W. Alcock and M.J. Hannon, Dalton Trans., 2003, 2149-55.

Interfacing supramolecular and macromolecular chemistry: Metallo-supramolecular triple-helicates incorporated into polymer networks. A. Lavalette, J. Hamblin, A. Marsh, D.M. Haddleton and M.J. Hannon, Chem. Commun., 2002, 3040-3041.

Assembly of a nanoscale chiral ball through supramolecular aggregation of bowl-shaped triangular helicates.

L.J. Childs, N.W. Alcock and M.J. Hannon, Angew. Chem., Intl. Ed., 2002, 41,

4244-4247.

Helical (Isotactic) and Syndiotactic Silver(I) Metallo-Supramolecular Coordination Polymers assembled from a readily-prepared Bis-Pyridylimine Ligand containing a 1,5-Naphthalene Spacer.

F. Tuna, J. Hamblin, G. Clarkson, W. Errington, N.W. Alcock and M. J. Hannon, Chem., Eur. J., 2002, 8, 4957-4964.

Triple helicates and planar dimers arising from silver(I) coordination to directly linked bis-pyridylimine ligands.

J. Hamblin, A. Jackson, N.W. Alcock and M. J. Hannon, J. Chem. Soc, Dalton Trans., 2002, 1635-1641.

Directed one-pot syntheses of enantiopure dinuclear silver(I) and copper(I) metallo-supramolecular double helicates.

J. Hamblin, L.J. Childs, N.W. Alcock and M.J. Hannon, J. Chem. Soc, Dalton Trans., 2002, 164-169.

Paper: a cheap yet effective chiral stationary phase for chromatographic resolution of metallo-supramolecular helicates.

M.J. Hannon, I. Meistermann, C.J. Isaac, C. Blomme, J.R. Aldrich- Wright and A. Rodger, Chem. Commun., 2001, 1078-1079.

Assembly of nano-scale circular supramolecular arrays through π-π aggregation of arc-shaped helicate units.

L.J. Childs, N.W. Alcock and M.J. Hannon, Angew. Chem., Intl. Ed., 2001, 40, 1079-1081.

A metallo-supramolecular double helix containing a major and a minor groove. M.J. Hannon, CL. Painting and N.W. Alcock, Chem. Commun., 1999, 2023-4.

Spacer control of directionality in supramolecular helicates using an inexpensive approach.

M.J. Hannon, S. Bunce, A.J. Clarke and N.W. Alcock, Angew. Chem., Intl. Ed.,

1999, 38, 1277-8. An inexpensive approach to supramolecular architecture. M.J. Hannon, CL. Painting, J. Hamblin, A. Jackson and W. Errington, Chem. Commun., 1997, 1807-1808.

Chiral supramolecular arrays may be produced as shown in J. Hamblin, L.J. Childs, N.W. Alcock and M.J. Hannon, J. Chem. Soc, Dalton Trans., 2002, 164-169 and Chem. Commun., 2001, 1078-1079

Spacer Control of Directionality in Supramolecular helicates is shown in Angew. Chem. Int. Ed. 1999, 38, No. 9, 1277-8.

Polymeric Helical and Helical arrays may be produced as shown in a paper F. Tuna, J. Hamblin, G. Clarkson, W. Errington, N.W. Alcock and M. J. Hannon, Chem., Eur. J., 2002, 8, 4957-4964.

The supramolecular compounds produced may be purified by chromatographic resolutions, see Chem. Commun., 2001, 1078-1079. In the process, paper chromatographic or cellulose chromoatography using saline solution as an element affords the two enantiomers.

Further synthetic examples Synthesis of ligand L³

6-Formyl-nicotinic acid methyl ester. 6-Methyl-nicotinic acid methyl ester (5.00 g, 33.1 mmol) was mixed with iodine (8.40 g, 33.1 mmol) and a small amount of DMSO was added to promote mixing. After addition of DMSO (5ml), this solution of added to a heated solution of DMSO (15 ml) at 130°C The temperature of the mixture is then slowly raised to 160°C and stirred at this temperature for 15 minutes. After cooling down the solution, a small amount of a saturated aqueous solution of Na₂CO₃ is added. Extraction of the product with diethyl ether. Crude compound used without further purification.

Η NMR (400 MHz, CDC1₃, 298K) δ 10.00 (s, IH, CHO), 9.22 (d, ³J(H,H)=1.5 Hz, 1 H, ArH), 8.34 (dd, ³J(H,H)=6.0Hz; 2.0 Hz, 1 H, ArH), 7.90 (d, ³J(H,H)=8.0 Hz, 1 H, ArH), 3.87 (s, 3 H, CHa).

6-[l,3]Dioxolan-2-yl-nicotinic acid methyl ester. 6-Formyl-nicotinic acid methyl ester (300 mg, 1.82 mmol) was dissolved in toluene (25 ml) and ethylene glycol (0.33 ml, 5.92 mmol) and p-toluenesulfonic acid (cat) were added. The mixture is refluxed with a dean-stark for 7.5 hours. The solvents are evaporated and the crude product was purified by column chromatography (SiO₂, CH₂Cl₂/MeOH =99/1). The protected aldehyde was obtained as a white solid (310 mg, 81%).

'H NMR (400 MHz, CDC1₃, 298K) δ 9.18 (d, ³J(H,H)=1.8 Hz, 1 H, ArH), 8.31 (dd, ³J(H,H)=8.2Hz; 2.2 Hz, 1 H, ArH), 7.59 (d, ³J(H,H)=8.0 Hz, 1 H, ArH), 5.87 (s, IH, CH), 4.16-4.05 (m, 4 H, CHa), 3.93 (s, 3 H, CH₃).¹³C NMR (100 MHz, CDCI3, 298K) δ 165.5 (C=O), 161.0 (ArC), 150.5 (ArCH), 138.0 (ArCH), 126.2 (ArC), 120.3 (ArCH), 103.1 (CH), 65.7 (CHa), 52.5 (CH₃).

6-[l,3]dioxolan-2-yl-nicotinate sodium salt. 6-[l,3]Dioxolan-2-yl-nicotinic acid methyl ester (78 mg, 0.38 mmol) was dissolved in MeOH (1 ml) and an IM aqueous solution of NaOH (1 ml) was added while the mixture was kept in a water bath. The mixture was stirred for 2 hours at room temperature before the solution was evaporated to dryness. The crude was used without further purification.

Η NMR (400 MHz, D₂O, 298K) δ 8.93 (d, ³J(H,H)=2.0 Hz, 1 H, ArH), 8.29 (dd, ³J(H,H)=8.2Hz; 2.2 Hz, 1 H, ArH), 7.67 (d, ³J(H,H)=8.0 Hz, 1 H, ArH), 5.92 (s, IH, CH), 4.20-4.13 (m, 4 H, CHa).

N-α-benzyl-glycine. Glycine (1.88 g, 25 mmol) and p-toluenesufonic acid (4.65 g, 25.5 mmol) were added to a solution of benzyl alcohol (10 ml) in toluene (35 ml). The mixture was refluxed with a dean-stark for 3 h and cooled to room temperature. Diethyl ether (25 ml) was added and the mixture was cooled in an ice-bath. The white precipitate was filtered and washed with diethyl ether. Crude as p-TsOH salt is used without further purification.

•H NMR (400 MHz, D₂O, 298K) δ 7.66 (d, ³J(H,H)=8.3 Hz, 2 H, ArH),7.42 (s, 5 H, Ph), 7.33 (d, ³J(H,H)=8.0 Hz, 2 H, ArH)5.27 (s, 2 H, CHa), 3.92 (s, 2 H, CHa), 2.36 (s,

Compound 1. 6-[l,3]dioxolan-2-yl-nicotinate sodium salt (80 mg, 0.42 mmol) was suspended in acetonitrile (5 ml) and a suspension of glycine in acefronifrile (10 ml) was added. HBTU (180 mg, 0.50 mmol) and DIPEA (0.36 ml, 2.08 mmol) were added to the mixture. The mixture is stirred for 1 hour before the white solid is filtered off. Evaparation of the solvent gave yellow oil, which was dissolved in CH₂C1₂ (5 ml) and washed with H₂O (two times). The organic layer was dried on MgSO₄ and evaporated to dryness. The yellow oil was purified by column chromatography (SiO₂, CH₂Cl₂/MeOH =99/1 followed by CH₂Cl₂/MeOH =98/2). The protected aldehyde was obtained as a white solid (66 mg, 48 %).

Η NMR (400 MHz, CDCL₃, 298K) δ 9.00 (d, ³J(H,H)=2.1 Hz, 1 H, ArH), 8.18 (dd, ³J(H,H)=8.1 Hz; 2.1 Hz, 1 H, ArH), 7.63 (d, ³J(H,H)=8.1 Hz, 1 H, ArH), 7.36 (s, 5H, Ph), 6.78 (br s, IH, NH), 5.89 (s, IH, CH), 5.22 (s, 2H, CHa), 4.29 (d, ³J(H,H)=5.1 Hz, 2 H, CHa),4.18-4.03 (m, 4 H, CHa).

Compound 2. Compound 1 (100 mg, ) was dissolved in a mixture of acetone (19 ml) and H₂O (2 ml) and p-TsOH (200 mg, ) was added. The mixture was refluxed overnight and the solvents were evaporated. The solid is redissolved in CH2C1₂ and washed with H₂O (3 times). The compound is obtained as a white solid (60 mg, ) •H NMR (400 MHz, CDC1₃, 298K)δ 10.02 (s, 1 H, CHO), 9.12 (d, ³J(H,H)=1.5 Hz, 1 H, ArH), 8.23 (dd, ³J(H,H)=8.0 Hz; 2.0 Hz, 1 H, ArH), 7.91 (d, ³J(H,H)=7.6 Hz, 1 H, ArH), 7.37 (d, ³J(H,H)=5.0 Hz, 1 H, NH), 7.30-7.17 (m, 5 H, Ph), 5.22 (s, 2 H, CHa), 4.20 (d, ³J(H,H)=5.3 Hz, 2 H, CHa).

Compound 3 (ligand L²) Compound 2 (39 mg, 0.13 mmol) and 4,4 '-methylene dianiline (10 mg, 0.050 mmol) were dissolved in ethanol (10 ml) and the mixture was stirred for 1 hour. The ligand was obtained by filtration as an off-white solid. Η NMR (300 MHz, OMSO-d₆, 298K) δ 9.35 (s, 1 H, NH), 9.14 (s, 1 H, ArH/CH), 8.68 (s, 1 H, ArH/CH), 8.36 (d, ³J(H,H)=10.2 Hz, 1 H, ArH), 8.26 (d, J(H,H)=7.9 Hz, 1 H, ArH), 7.41-7.30 (m, 9 H, Ph; ArH), 5.18 (s, 2 H, CHa), 4.14-4.03 (m, 4 H, CHa).

[Cu₂L² ₂]Cl₂. Ligand L² (4.0 mg, ) was suspended in MeOD-d₄ (0.50 ml) and CuCl (0.5 mg, 0.005 mg) in MeOD-dn (0.5 ml) was added. The resulting pink mixture was stirred for 0.5 hour.

Η NMR (400 MHz, MeOD-rf₄, 298K) δ 9.47 (s, 1 H, Ar/CH), 9.03 (s, 1 H, ArH/CH), 8.65 (d, ³J(H,H)=6.5 Hz, 1 H, ArH), 8.30 (d, ³J(H,H)=8.3 Hz, 1 H, ArH), 7.50-7.21 (m, 10 H, Ph; ArH; NH), 5.21 (s, 2 H, CHa), 4.63 (d, ³J(H,H)=4.6 Hz, 2 H, CHa), 4.20 (s, 2 H, CHa).

Ligand L¹

Ligand L¹. 6-Formyl-nicotinic acid methyl ester (30 mg, 0.18 mmol) and 4,4 '-methylene dianiline (17 mg, 0.086 mmol) were dissolved in ethanol (10 ml) and the mixture was stirred for 3 hours. The ligand was obtained by filfration as a white-yellow solid (33 mg, %). FAB-MS Calcd for Ca₉Ha₄N4θ₄ m/z= 492.2, Found m/z = 493.1 [M=H].

Η NMR (400 MHz, CDC1₃, 298K) δ 9.28 (d, IH, ³J(H,H)=1.5 Hz ArH), 8.67 (s, IH, CH), 8.39 (d, ³J(H,H)=8.3 Hz; 2.0 Hz, 1 H, ArH), 8.28 (d, ³J(H,H)=7.8 Hz, 1 H, ArH), 7.30-7.22 (m, 4H, ArH), 4.05 (s, IH, CHa), 3.98 (s, 3H, CH₃).

[Cua lCU. Ligand L¹ (10 mg, 0.020 mmol) was suspended in MeOH (10 ml) and CuCl (2 mg, 0.020 mg) in MeOH (5 ml) was added. The mixture was stirred for 2 hours at room temperature followed by 4 hours at 65 °C. Solution was cooled down and filtered through cotton wool. Evaporation gave the crude complex as a dark red solid. Η NMR (400 MHz, CDC1₃, 298K) δ 9.31 (s, IH, ArH), 9.24 (s, IH, CH), 8.65 (d, ³J(H,H)=8.0 Hz, 1 H, ArH), 8.47 (d, ³J(H,H)=8.0 Hz, 1 H, ArH), 7.41 (d, ³J(H,H)=7.8 Hz, 1 H, ArH), 7.21 (d, ³J(H,H)=7.8 Hz, 1 H, ArH), 3.95 (s, IH, CHa), 3.90 (s, 3H, CHa).

[AgzlΛjCb. Ligand L¹ (20 mg, 0.041 mmol) was suspended in MeOH (15 ml) and Ag(acetate) (6.8 mg, 0.041 mg) in MeOH (5 ml) was added. The mixture was refluxed for 3 hours, followed by filtration over celite. Metanolic ammonium hexafluorophosphate was added, the resulting yellow precipitate was collected by vacuum filtration (5.8 mg, 19 %)

Η NMR (400 MHz, CDC1₃, 298K) δ 9.28 (d, ³J(H,H)=2.0 Hz, 1 H, ArH), 8.97 (s, 1 H, CH), 8.62 (dd, ³J(H,H)=8.0 Hz; 2.0 Hz, 1 H, ArH), 8.14 (d, ³J(H,H)=8.0 Hz, 1 H, ArH), 7.43 (d, ³J(H,H)=8.3 Hz, 1 H, ArH), 7.31 (d, ³J(H,H)=8.3 Hz, 1 H, ArH), 4.02 (s, IH, CHa), 3.98 (s, 3H, CHa).

Treatment of Cancer Cells

As stated above, the cationic, metal ion assembled, supramolecular architectures (including but not limited to bi- and poly- metallo- double- and triple-helicates) may be used as agents for anti-tumour and anti-viral treatment alone or in combination with biomolecules or synthetic agents.

Cell line testings were carried out on human ovarian cancerous cells (A2780 normal and A2780 cisplatin resistant cells) These are available from European Collection of Cell Cultures (ECACC) - ECACC 93112517 and ECACC 93112519. The cisplatin resistant cell line is also cross resistant to melphan, adriamycin and irradiation, but is a useful model because of its resistance to cisplatin. The Compound tested was that disclosed in Meistermann et al. (PNAS 2002, 99. Pages 5096-5074).

Cell survival was evaluated using a system based on the tetrazolium compound MTT, which is reduced by living cells to a formzan product that can be detected colourimetrically at 520nm. Cells were plated at a density of 4000 cells/well in sterile 96-well plates in 200 μl of media and allowed to attach overnight. The media was removed and replaced with media containing final concentrations from 0 to 1 mM. Seventy-two hours later, 20 μl of a fresh MTT solution in PBS at a concentration of 1 mg / ml was added to the cells and the plate incubated for 4h at 37°C in a humidified atmosphere of 5% CO2 where purple crystals ofthe formazan product were produced. The media was removed carefully by aspiration and 25 μl of Sorenson Buffer (0.1M gylcine, 0.1M NaCl, 0.1M NaOH, pH 10.5) and 200 μl of DMSO were added to lyse the cells and dissolve the formazan product, respectively. The absorbance was measured at 520nm. Curves constructed from a plot of (%) cell survival versus drug concentration were used to determine the IC50 (compound concentration required to produced 50% cell growth inhibition). Results using supramolecular agent racemic [Fe₂(C₂5H₂oN )₃]Cl₄:

A2780 IC50 =8 M

A2780 cisplatin resistant IC50 =190 μM using supramolecular agent (-)- [Fe₂(C₂₅H₂oN₄)3]Cl₄:

A2780 IC50 =20μM

A2780 cisplatin resistant IC50 =89 μM

using supramolecular agent (+)- [Fe2(C25H₂oN₄)₃]Cl :

A2780 IC50 =13 μM

A2780 cisplatin resistant IC50 =36 μM

Further cancer cell lines

HBL-100 (epithelial breast cancer) and T47D (epithelial ductal carcinoma ofthe breast) cells were cultured in RPMI (Roswell Park Memorial Institute) 1640 media, supplemented with FCS (10 %), L-glutamine (1%), non-essential amino acids (1%), sodium pyruvate (1%), antibiotic / antimycotic (1%) and HEPES (1%) in an atmosphere of 95% air and 5% CO₂ at 37°C.

HBL-100 IC₅o = 1.3 micromolar + / - 0.05 micromolar T47D IC50 = 4.2 micromolar + / - 1.0 micromolar

Protein Synthesis Assay

General 96well flat bottomed plates were obtained from Nuclon (Gibco-BRL, Glasgow, UK). FBS (foetal calf serum) and DMEM (Dulbeccos modified Eagle's medium) was from Gibco (Glasgow, UK). ³⁵S-methionine , non-essential amino acids, L-glutamine, sodium pyruvate, HEPES (4-(2-hydroxyethyl)-l-piperazineethanesulfonic acid), antibiotic / antimycotic suspension were obtained from Sigma (Poole, UK). Scinillation fluid was obtained from Fisher (Loughborough, UK).

Cell Culture Conditions HeLa (epitheloid carcinoma ofthe cervix) cells were cultured in DMEM, supplemented with FCS (10 %), L-glutamine (1%), non-essential amino acids (1%), sodium pyruvate (1%), antibiotic / antimycotic (1%) and HEPES (1%) in an atmosphere of 95% air and 5% COa at 37°C.

Protein Synthesis Assay Protein synthesis was determined using a ³⁵S-methionine incorporation assay. HeLa cells were seeded at a density of 10⁴ cells/well in 200 μl of medium and were allowed to attach overnight. The Iron triple helicate [Fe₂(Ca5H₂oN₄)3]Cl₄ was added to final concentrations 0 - 1 mM in a volume of 200 μl media per well. Twenty-four hours later, the media was removed and the plates washed twice with PBS (phosphate buffered saline). To each well was added one curie of ³⁵S-methionine in 100 ml of media and the cells incubated for 1 hour at 37°C in a humidified atmosphere of 5% CO₂. The radioactivity was removed and the cells treated with trifluroacetic acid to precipitate proteins and the plates washed 3x with PBS. Scintillation fluid (100 μl) was added to each well and incorporated radioactivity counted using a scintillation counting performed using a direct counting method. Results were standardised according to ³⁵S-methionine incorporation/ 10⁴ cells to standardize results to cell number

Results IP₅o (Inhibition of 50% of protein synthesis) = 118 mM

Experiment to confirm the anti-bacterial growth effects of a supramolecular agent

The growth rate of Synechocystis sp. PCC 6803 was assessed in the presence of varying concentrations of the purple supramolecular agent [Fe₂(C25H₂oN4)₃]Cl4 (0-10. ImM). Synechocystis sp. PCC 6803 cultures were grown in 20ml BGII medium contained in 50ml conical flasks and at constant illumination of 30 microEinsteins m^sec^"1. Cell density was measured at 750nm using uninnoculated BG11 media as a blank. The cells stain visibly purple at lOμM and cell growth is stopped above this concentration.

The results are shown in Figure 4

RNA binding experiment

Compounds ofthe invention have also unexpectedly been found to bind to RNA, thus indicating an alternative mode of action ofthe compounds

Circular dichroism (CD) spectra were collected in 1 cmpathlength cuvettes using a Jasco J-715 spectropolarimeter. Spectroscopic titrations were performed in which CD and UV/Vis absorbance spectra were collected. Titrations were carried out using supramolecular agents [Fe₂(C25H2oN )₃]Cl or [Fe₂(CaιHι₈N₆)3]Cl4 and conducted at constant concentrations of Poly(G)-poly(C) RNA (300 μM), NaCl (20 mM) and sodium cacodylate buffer (1 mM). The RNA: supramolecular agent ratio was varied during the titration series while retaining constant RNA concentration and incrementing the concentration of supramolecular agent in the cuvette from 0 - 38 μM. In both cases induced CD signals appeared in the MLCT region ofthe supramolecular agents at ~550nm for [Fe₂(C₂₅H₂₀N₄)₃]Cl4 and between 450-600nm for [Fe₂(C₂ιH₁₈N₆)3] CU. The appearance of these bands confirms binding ofthe supramolecular agent to the RNA.

This lead compound used in the toxicity, antibacterial and protein synthesis study is a tetracationic cylinder and forms a triple helicate. Similar structures with substitutions are expected to have similar properties. Many of structures described above have similar dimensions, cationic properties, metal binding sites etc. and are also expected to have such properties.

Claims

1 A method of inhibiting tumour, microbial or viral growth comprising contacting a tumour, microbe or virus with an effective amount of a supramolecular compound, or a pharmaceutically acceptable salt, derived from a ligand (L) of formula I or a ligand of formula II,:

Formula I

Wherein:

Each X for formula I may the same or different and may be C or N, wherein when X=N, there is no R group attached to X; or

Formula II:

wherein X in formula II may be the same or different and may be C or N, or X can be NH, S, O, in which case the R group is absent; and wherein

Rl to R8 may be independently selected from H, OAlkyl, OAryl, CHaOAlkyl, CHzOAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSOaAryl, O₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

Z = CH, CAlkyl, CAryl, or CNH₂and may be the same or different

Y may be present or not present and may be selected from:

Wherein:

R may be selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

A = NH, S, SO₂, 0, (CH₂)„, CHR, CR₂, or NR and R is as defined above

n = an integer 1, 2, 3, 4, 5, ... 20

coordinated to at least 2 metal ions

2) A method of treating a tumour, a microbial infection or a viral infection comprising the step of administering a pharmaceutically effective amount of a supramolecular compound, or a pharmaceutically acceptable salt, derived from a ligand (L) of formula I or a ligand of formula II,: Formula I

Wherein:

Formula II:

Rl to R8 may be independently selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CHaSAiyl, OSO₂Alkyl, OSO₂Aryl, O₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

Z = CH, CAlkyl, CAryl, or CNH₂ and may be the same or different

Y may be present or not present and may be selected from:

Wherein:

R may be selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

A = NH, S, SO₂, O, (CH₂)„, CHR, CR₂, or NR and R is as defined above.

n = an integer 1, 2, 3, 4, 5, ... 20 coordinated to at least two metal ions

3) A supramolecular compound, or a pharmaceutically acceptable salt, derived from a ligand (L) of formula I or a ligand of formula II,: Formula I

Wherein:

Formula II:

wherein X in formula II may be the same or different and may be C or N, or X can be NH, S, O, in which case the R group is absent; and wherein Rl to R8 may be independently selected from H, OAlkyl, OAryl, CHaOAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, O₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

Z = CH, CAlkyl, CAryl, or CNH₂and may be the same or different

Y may be present or not present and may be selected from:

Wherein:

R may be selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO₂H, CO₂Alkyl, CO₂Aryl, O- , CH2O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

A = NH, S, SO₂, 0, (CH₂)_n, CHR, CR₂, or NR and R is as defined above.

n = an integer 1, 2, 3, 4, 5, ... 20

coordinated to at least two metal ions for use as a therapeutic agent more preferably for use to treat a tumour, a microbial infection or a viral infection.

4) Method or compound according to any preceding claim, wherein the ligand of Formula I or Formula II is coordinated to a metal ions are selected from one or more of selected from Fe²⁺, Fe³⁺, Ni²⁺, Co²⁺, Co³⁺, Cu⁺, Cu²⁺, Ag⁺, Cd²⁺, Zn²⁺, Ru²⁺, Ru ⁺, Rh³⁺, Mn²⁺, Mn³⁺, Ir⁺, hA, Ir³⁴, Os²⁺, Os³⁺, Pd²⁺ , Pd³⁺, Pd⁴+, Pt²+, and Pt⁴+.

5) Method or compound according to any preceding claim, wherein the compound comprising the Ligand coordinated to the metal ions is defined by the general formula : Mn Lm where n and m are integers of 2 to 20, preferably 2, 3, 4 or 5 and n and m may be the same or different.

6) Method or compound according to any preceding claim, wherein the compound is in combination with a pharmaceutically acceptable carrier, adjuvant or vehicle.

7) A supramolecular compound, or a pharmaceutically acceptable salt, derived from a ligand (L) of formula I or a ligand of formula II, : Formula I

Wherein:

Formula II:

Rl to R8 may be independently selected from H, OAlkyl, OAryl, CH∑OAlkyl, CHzOAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO2H, CO₂Alkyl, CO₂Aryl, O- , CH2O-, CO2-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, O₂Aryl, SO₂Me, N(Alkyl)2 and Alkyne;

Z = CH, CAlkyl, CAryl, or CNH₂ and may be the same or different

Y may be

Wherein:

A = NH, S, SO₂, O, (CH₂)_n, CHR, CR₂, or NR and R is as defined above.

n = an integer 1, 2, 3, 4, 5, ... 20

coordinated to at least two metal ions, in combination with a pharmaceutically acceptable carrier, adjuvant or vehicle

8) A disinfectant formulation comprising a supramolecular compound, or a pharmaceutically acceptable salt, derived from a ligand (L) of formula I or a ligand of formula II, coordinated to at least two metal ions : Formula I

Wherein:

Formula II:

Rl to R8 may be independently selected from H, OAlkyl, OAryl, CH₂OAlkyl, CH₂OAryl, CH₂OC(O)Alkyl, CH₂OC(O)Aryl, OC(O)Aryl, OC(O)Alkyl, OH, CH₂OH, CO2H, CO₂Alkyl, CO₂Aryl, O- , CH₂O-, CO₂-, Alkyl, Aryl, BR, Cl, I, F, CN, NO₂, CF₃, SAlkyl, SAryl, CH₂SAlkyl, CH₂SAryl, OSO₂Alkyl, OSO₂Aryl, O₂Aryl, SO₂Me, N(Alkyl)₂ and Alkyne;

Z = CH, CAlkyl, CAryl, or CNH₂ and may be the same or different Y may be present or not present and may be selected from:

Wherein:

A = NH, S, SO₂, 0, (CH₂)_n, CHR, CR₂, or NR and R is as defined above.

n = an integer 1, 2, 3, 4, 5, ... 20

coordinated to at least two metal ions

9) A combination or formulation according to claim 7 or claim 8, wherein the ligand of Formula I or Formula II is coordinated to a metal ions are selected from one or more of selected from Fe²⁺, Fe³⁺, Ni²⁺, Co²⁺, Co³⁺, Cu⁺, Cu²⁺, Ag⁺, Cd²⁺, Zn²⁺, Ru²⁺, Ru³⁺, Rh³⁺, Mn²⁺, Mn³⁺, Ir⁺, Ir²*, Ir³*, Os²⁺, Os³⁺, Pd²⁺ and Pd³⁺.

10) A combination or formulation according to claim 7 or claim 8„ wherein the compound comprising the Ligand coordinated to the metal ions is defined by the general formula : Mn Lm

where n and m are integers of 2 to 20, preferably 2, 3, 4 or 5 and n and m may be the same or different.

11) A method, compound or formulation according to any preceding claim, wherein the ligand is selected from a ligand shown in Figure 1 or Figure 2

12) A compound for use in the production of a supramolecular compound, selected from a compound shown in Figure 5

13) A supramolecular compound comprising a ligand selected from a compound shown in Figure 5 coordinated to at least two metal ions.