WO1987000343A1

WO1987000343A1 - Film aggregate and new compounds therefor

Info

Publication number: WO1987000343A1
Application number: PCT/FI1986/000067
Authority: WO
Inventors: Paavo Kinnunen; Jorma Virtanen
Original assignee: Ksv-Chemicals Oy
Priority date: 1985-06-28
Filing date: 1986-06-27
Publication date: 1987-01-15
Also published as: BR8606785A; DK95887D0; FI852574A0; AU6134586A; HUT46820A; JPS62503202A; DK95887A; EP0228429A1

Abstract

Film aggregate having electricity conducting characteristics. The film is comprised of a substantially inert support surface carrying one or several monomolecular film layers formed by a surface active material of liquid crystal type having modifiable electrical properties. The film layer is of a sandwich type construction containing at least the folllowing zones: - a spacer-zone (2) containing aliphatic hydrocarbyl groups and which to its electrical characteristics is substantially inert, - a conducting area (3-5) which on the one hand is comprised of a charge-transfer zone (3 or 5) and on the otherhand of a polarizable zone (5 or 3) as well as of a spacer zone (4) between these zones, - a spacer zone (6) which corresponds to the above zone (2), - a hydrophilic zone (7). The invention concerns also new glycerophospholipids and threitolphospholipids to be used in the films, containing in their fatty side chains at least one, but preferably two active groups, i.e. a polarizable group and charge-transfer group. The invention also concerns the fatty acids, alcohols group and amines used for the side chains in the lipids and carrying a polarizable group and a charge-transfer group.

Description

Film aggregate and new compounds therefore

The object of this invention is a film aggregate having electricity conducting properties, which film aggregate comprises a substantially inert substrate or support surface and carried by or on this surface, one or several film layers, each layer being comprised of an organic material which is tailor-made to give specific electrical properties to the film. The invention concerns also new chemical compounds and intermediates which are useful for making the film layer.

The film aggregate according to the invention may be used in a variety of different electronic, electric, electrochemical or photochemical applications, such as in microcircuits, photocells, sensors, microphones, miniature lasers, semiconductor lasers, etc.

From the GB-patent specifications 1 572 181 and 1 572 182 are known film aggregates comprising several monomolecular layers of an organic material, especially a fatty acid derivative, on top of a substrate, the molecule comprising a hydrophilic part, a hydrophobic part and between these a cyclic or an acyclic group, which forms a planar cyclic π -electron system. The conducting area in these film aggregates is formed by one single zone in each layer. The conductive properties of these film aggregates are however not satisfying.

The present invention thus concerns a novel type of film aggregate which more specifically comprises, carried by or on a substantially inert substrate surface, one or several monomolecular film layers of a surface active compound, the conductive properties of which aggregate can be selectively modified as desired, even so as to be superconducting at a temperature of use of -40 to + 80°C. Each film layer has a thickness of only one molecule, which generally means a layer thickness of 15 to 40 Å. The molecules forming the film layer are liquid crystals, i.e. they exhibit the optical and electrical properties of crystals but the mechanical properties of a liquid. They have a strong organizational tendency, wherefore the co-operative degree of orientation of the molecules in the film layer is very high.

Each monomolecular film layer is of sandwich-type construction comprising several individual zones which are parallel to each other and to the substrate surface, each zone corresponding to a specific part or portion of the organic molecule forming the film layer. The film layer is characterized in that it, on the one hand, comprises a so called charge-transfer (CT) zone containing groups capable of forming charge-transfer complexes (electron gas forming) and, on the other hand, a polarizable zone containing polarizable groups interacting electrically with and being located at a distance from the charge-transfer zone and separated therefrom by an electrically neutral, spacertype zone.

The basic unit from which a single film layer is built comprises, on a molecular level, basically a derivative of a fatty acid, fatty alcohol or a fatty amine, preferably constituting a side chain of a larger structural entity such as of a phosphoglycerol or a phosphothreitol.

When the film aggregate according to the invention is formed from a phosphoglycerol or a -threitol both of the hydroxy groups in the glycerol moiety or all three hydroxy groups of the threitol, respectively, are etherified, esterified or amidified by the said basic fatty compound. The said basic fatty compound (acid, alcohol, amine) is a substantially aliphatic, long-chained hydrocarbon contain ing covalently bound in the chain the above mentioned charge-transfer groups and/or polarizable groups. The basic fatty acid, alcohol, and amine compounds containing two active groups, as well as the phosphoglycerols and -threitols substituted thereby, form likewise an object of the invention.

A monomolecular film aggregate of afore mentioned type is shown in the appended Figure 1 in cross-section.

According to the Figure, a single film layer in the embodiment shown is formed from individual parallel zones, which in the figure have been given the reference numerals 2 to 7. As mentioned above, each zone corresponds to a specific part in the molecule from which the film is built. According to a preferred embodiment all the zones 2 to 7 in the film layer are formed from their respective counterparts in one and the same organic molecule, starting from the support surface 1 to the opposite end of the molecule, which in the embodiment shown is the hydrophilic part 7 of the molecule. According to another, similarly advantageous embodiment a single molecule extends only through the zones 3 to 7, in which case the support surface has to be precoated with a compound corresponding to the zone 2, as will be explained in more detail below. The individual zones in the film layer are thus formed by cooperatively acting parts of different molecules or side chains "packed" side by side in a mutually parallel manner, and extending generally perpendicularly to the substrate surface, the said co-operative parts of different molecules/side chains being positioned at substantially the same distance from the support surface or the opposite end of the molecule, respectively.

In the following the specific embodiment according to the invention shown in the Figure is discussed simultaneously referring to the corresponding molecular part in the individual molecule/side chain from which the film layer is formed.

The numeral 1 denotes the support surface of the film aggregate, which support surface is made from a substantially inert material, such as silicon, glass, a suitable plastic or metal, and which may be coated with one or several film layers. The coating of the support surface takes place in a manner known and will be discussed in more detail below.

Adjacent the support surface 1 one of the so-called spacerzones has been given the reference numeral 2, which as regards its electrical properties is substantially inert and which advantageously is formed by an aliphatic or substantially aliphatic straight or branched hydrocarbon group, the length of which may vary considerably and which can have from 1 to 20, but preferably 4 to 16 carbon atoms. This hydrocarbon group may also as a chain member contain a heteroatom, such as oxygen, nitrogen or sulphur, provided that the presence of such a heteroatom does not substantially affect the relatively inert nature of the said group. The spacer-zone 2 corresponds to the hydrophobic end of the basic fatty unit and in a preferred embodiment is formed by the outer ends of the fatty side chains of the phospholipid molecule. However, the spacer-zone 2 may also be formed from a substantially aliphatic hydrocarbon used for precoating the substrate surface. In order to obtain a more stable structure the part of the molecule forming this zone may also exhibit polymerizing properties, for example in the form of double or triple bonds, which may form crosslinks, such as polyacetylene structures with the corresponding parts in the side chains of the same or of an adjacent molecule. Alternatively, this part of the molecule may contain groups, which facilitate the binding of the molecule to the support surface, for example photoactivated diazo groups bonded to an aromatic (benzene) group.

Adjacent the zone 2 of the film layer follows, in a direction away from the support surface, the conductive area of the film, which as a whole is formed by a polarizable zone 3 (or 5), a charge-transfer zone 5 (or 3) and a spacer zone 4 separating these. This area may extend over a distance of from 5 to 30 Å. The mutual position of the polarizable and charge-transfer zones respectively, is not critical, provided that the film layer does contain these two zones and that they are separated by a spacer-type zone. The spacer-zone 4 corresponds to the above defined zone 2, and the substantially aliphatic groups contained therein may also be polymerizable (e.g. over triple bonds) with corresponding groups in adjacent chains.

The conducting properties of the film are believed to result from interaction between the zones 3 and 5, which involves direct electron transfer between the zones, or the polarizable zone may form a kind of a buffer zone to the charge-transfer zone. Irrespective of the reason for the good properties, the result from the standpoint of electrical conductivity is optimal and studies have shown that it is possible to obtain even superconducting properties at high temperature (300°F). The electrical properties of the films can be modified or regulated at two levels: firstly, by suitably choosing the groups to be used in the conducting area, the films may be "tailored" according to intended use, and secondly, the electrical properties of the finished film may, in addition, be subsequently modified, e.g. by means of light or an external electrical field.

Following the conducting area 3-5 of the film, there is again a spacer-zone of above type, which to its structure corresponds to above defined zones 2 and 4. With respect to the support surface the outermost film zone is formed by a hydrophilic group, e.g. the phosphoryl group of the phospholipid molecule. Alternatively, other polar groups may be employed, such as present in sulfo- and arsenolipids.- Depending on the groups contained in the alcohol used for esterifying the phosphoric acid group of the phosphoglycerol or -threitol, also the groups contained in the hydrophilic zone may be modified to exhibit polymerizing properties, for example in the form of double bonds. A typical alcohol ester exhibiting polymerizing properties is also serine, which together with adjacent similar groups forms a polyamide structure.

Groups or pairs of groups forming part of the molecule and suitable for use in the charge-transfer zone of the film layer are known in the art and according to the invention any pair of charge-transfer groups may be used, provided it possible to bind the same covalently to the substantially aliphatic hydrocarbon chain.

The compounds (or groups) capable of forming charge-transfer complexes can generally be characterized as containing conjugated cyclic systems (π- electrons), such as in aromatic rings, for example bridged or fused aryl groups containing generally from 1 to 6 rings, e.g. phenyl, naphtyl, anthryl, phenanthryl, or more complex aromatic systems, such as pyrene, perylene, triphenylene, which groups optionally may be substituted in order to enhance either their donor or their acceptor properties, respectively. Suitable substituents thus are e.g. alkyl (preferably 1-3 C), alkoxy (preferably 1-3 C), cyano, hydroxy, oxo, amino, substituted amino (e.g. by lower alkyl), thio-ether groups etc. An aromatic ring may contain a substituent in any of the free (available) positions, i.e. generally not more than 4 substituents in a ring. The cyclic systems may also contain usually not more than 4, and generally only up to two heteroatoms, such as oxygen, nitrogen, sulphur, and/or selenium as an integral part of the ring, such as in carbazole, phenothiazine, pyrazine, acridine, thianthrene, oxanthrene, tetrathiofulvalene, tetraselenofulvalene, etc., and metal atoms. According to the invention it has also proven possible to use certain compounds which do not belong to the above mentioned general classes, that is for example A-vitamin disclosed below, the chain of which may form the spacer group.

As a typical and applicable class of compounds may be mentioned the quinone type groups and of these quite specifically the pair benzoquinone-hydroquinone, as well as the hydroquinone forms of anthracene and phenanthrene. An applicable pair is also tetracyanobenzene as the acceptor and tetramet hylbenzene as the donor. Further examples of CT-pairs are tetracyanoquinodimethane (TCNQ) and the oxygen of the ester and ether bonds of the diacyl- and dialkylphospholipids. Also e.g. pyrene is capable of forming a charge-transfer type system with another pyrene group.

The following formulas illustrate compounds which are suitable to use in the charge-transfer zone. In some of the formulas possible binding sites to the spacer hydrocarbon chains have been indicated. As already stated, the choice of suitable groups is well within the art, where fore the invention should not be considered restricted to the groups specifically indicated.

Polarizable groups are also known in the art. In fact it is not always possible to differentiate between the applicable CT-groups mentioned above and the polarizable groups, both being characterized as having a π -electron system and electron donor and acceptor properties. Thus for the purposes of the invention the groups mentioned above in connection with suitable CT-groups can come into question also as polarizable groups. As the choice of a suitable polarizable group lies within the skill of the artisan, the invention should not be considered limited to those specifically mentioned.

Advantageous, however, are groups which form excimers and exciplexes, i.e. share an excited electron due to energy exchange mechanisms arising from quantum mechanical wave function interactions. Likewise, polarizable moieties can be parinaric acid, vitamin A, and diphenyltetradiene, -hexatriene and so on.

Further suitable groups for the purposes of the invention comprise the aromatic hydrocarbon groups which also may contain heteroatoms as long as these do not substantially influence the general nature of the compounds. Of these may be again especially mentioned the pyrene and perylene group.

According to one suitable mode of the invention, in the film layer the different zones correspond to molecular parts belonging to the same molecule, possibly excluding the first spacer-zone, i.e. molecule extending from the support surface or conducting area, respectively, to the outermost zone of the film layer. This mode of realization is possible and advantageous when the support surface is to be coated with several similar layers in order to enhance the electrical properties of the film aggregate. A typical compound to be used in the layer is a phosphoglycerol derivative, both substantially aliphatic ether, amide or ester side chains of which contain, possibly at a distance (1 to 20 C- atoms) from the outer end of the side chain, covalently bound a polarizable group, for example a pyrene group, and at a distance therefrom (1 to 20 C-atoms) in one of the aliphatic side chains of the glycerol the one member of a charge-transfer complex pair, for example a benzoquinone group, and in the other side chain the corresponding hydroquinone group. The positions of the polarizable and the charge-transfer groups in the side chains may be reversed whereby the charge-transfer zone in the described embodiment will be closer to the support surface.

If desired, the support surface may, prior to coating the same, be treated in order to modify its surface properties, for example as described in the international application PCT/FI85/00102. Such a pretreated surface may, as was mentioned earlier, be further coated with a monomolecular layer forming the first spacer zone. Further it is possible to provide the outer end of such a compound used for precoating with e.g. a covalently bound member of a charge-transfer pair, or alternatively, a polarizable group, which then will form part of the conducting area (3 to 5) of the film layer. In this embodiment, the outermost substantially aliphatic hydrocarbon moiety in the fatty chain, for example in a fatty side chain of the phosphoglycerol and possibly, in addition, the second member of the charge-transfer complex pair or one or both of the polarizable groups, respectively, will be absent in the film forming compound to be applied onto the pretreated support surface. Essential is that in the film layer formed, irrespective of the method of preparation, the different zones will be uniform both to their structure and to their properties.

For many purposes it is not necessary in order to obtain the desired conducting properties to include an active group covalently into every fatty chain, but e.g. only one of the side chains of the phospholipid may contain e.g. a polarizable group.

The fatty acids, alcohols or amines, which, when part of the film layer, form the respective zones necessary for obtaining the desired electrical properties in the finished film, and which contain covalently bound a polarizable group and/or a group constituting one member of charge-transfer pair, in a substantially aliphatic hydrocarbon chain may be characterized by the general formulas

(la)

(lb)

wherein the zig-zag-symbols mean substantially aliphatic, straight or branched hydrocarbyl groups containing about 1 to 20 C-atoms, preferably from 4 to 16 C-atoms, and which may contain heteroatoms (oxygen, nitrogen, sulphur) provided these do not substantially affect the substantially aliphatic nature of the hydrocarbyl group, A means one member of a charge-transfer pair and B means a polarizable group, the integers n, m and q mean 0 or 1, Y' means a carboxy group -COOH, a hydroxy group -OH or an amine group -NH₂, wherein further either a) n = m = 1 and q is 0 or 1; or b) n or m is 0 and q is 0 or 1 as well as their functional derivates.

The compounds of the formula (la) and (lb) containing two active groups (n=m=1) are to our knowledge new and as such form part of the invention.

As compounds for forming the film layer are preferably used phosphoglycerols wherein both hydroxy groups have been substituted with a compound having either the formula (la) or the formula (lb), or a threitol derivative, wherein at least two of the hydroxy groups have been substituted with either a compound of the formula (la) or with a compound of the formula (lb), thus forming an ester-, ether or amide bond with the compound (la) or (lb) respectively. To our knowledge also such substituted compounds are new and thus also form an object of the present invention.

The phosphoglycerols of the invention may be schematically presented in the following manner.

1

In the formulas (IIA) and (lib) the zig-zag symbols, n, m and q have the meanings given in connection with the formu las la and lb, A and A' mean groups forming a chargetransfer complex, B and B', which may be the same or different, mean a polarizable group, n', m' and q' have the meaning of 0 or 1, Y means the group -O-, -C(=0)-O- and/or -NH- and X is hydrogen, or it is the residue of an alcohol, especially a lower alkanol, amino lower alkanol, serine, choline, 1- or 3-glycerol forming an ester with the phosphoric acid group, with the provision that n+m, and n'+m' are irrespective of each other 1 or 2, and q and q' are irrespective of each other 0 or 1.

The compounds of the formula (Ila) and (lib) thus contain in their fatty side chains either 1, 2 or 3 spacer groups, and one or two active groups, i.e. either both a chargetransfer group as well as a polarizable group, or only one of these groups.

In case a side chain contains only one or two spacer groups, a third spacer zone can be provided by precoating the substrate surface with a corresponding substantially aliphatic hydrocarbon as mentioned earlier. In case in the formula (Ila) one or both of the polarizable groups B and B' is absent (n', n =0) or in the formula (lIb) either one of the CT-groups A and A' is absent (m, m' =0) the compound described above for precoating the substrate may carry the corresponding absent group as well in order to obtain a usable film. - However, such a group may also be provided in the side chain of a differently substituted phospholipid which is used as a mixture with the first mentioned, or in certain instances, in a corresponding fatty acid, alcohol or amine of the formula (la) or (lb), respectively, used as such together with the first mentioned phospholipid.

The expression "substantially aliphatic" means that in the formulas I and II the spacer group may contain also nonaliphatic groups, but that it remains substantially alip hatic in character. The spacer groups may contain double or triple bonds capable of polymerizing, and in the terminal spacer groups additionally groups which bind covalently to the support surface, as mentioned above.

With reference to the different film aggregate embodiments according to the invention and described above, the compounds according to the invention form for example the following sub classes.

In the formulas (Ila) and (IIB): a) n = n' = m = m' = 1; q, q' = 0 or 1;

The compounds (Ila) and (lIb) according to the invention are substantially aliphatic dialkyl-, diacyl-, diamide-, alkyl-amide-, acyl-amide- or alkyl-acyl-phosphoglycerols, containing either about 3 to 60 substantially aliphatic carbon atoms in a side chain thereof (corresponding to three spacer groups), or about 2 to 40 such carbon atoms (corresponding to two spacer groups). Each side chain contains one charge-transfer group (A or A'), as well as a polarizable group (B or B'). If only two spacer groups are present in the chain the support surface can be precoated with a substantially aliphatic hydrocarbon compound corresponding to the hydrophobic outer end, i.e. a spacer group.

b) n and/or n' = 0 m and/or m' = 0, provided that n'+ m'> 0 and n + m> 0. In the compounds of the formula (Ila) (lIb) each side chain contains at least one active group. If in the compound (Ila) a polarizable group B or B' or in the compound (lib) a charge-transfer group A or A' is missing in a side chain, the support surface can be precoated with a compound substituted with a polarizable group B or B or a required charge- transfer group A' or A respectively, and containing from 1 to 20 carbon atoms in a substantially aliphatic chain. A required polarizable or charge-transfer group can also be provided using a mixture of appropritely susbtituted phospholipids.

As already mentioned above applicable film layers are obtained also using threitol derivatives containing in at least two (out of three possible) side chains the afore mentioned fatty acids, alcohols or amines, bound to the treitol frame in a similar manner over ester, ether or amide bonds as in the phospholipids described above.

The threitol derivatives thus correspond to the formula

In the formulas (IIIA) and (Illb) the zig-zag symbols, n, m q, n', m', q', A, A', B, B', X and Y have the meanings given in connection with the formulas Ila and lIb, n", m", and q" mean 0 or 1, A" means a charge-transfer group and B" means a polarizable group, with the provision that n+m, n'+m', and n"+m" are irrespective of each other 1 or 2, but one of these sums can in addition be 0, and q, q' and q" are irrespective of each other 0 or 1.

As in connection with the glycerophospholipids the threitolphospholipids may be used in connection with precoated substrates providing required spacer an optionally polarizable or charge-transfer groups. Similary, for the film formation a mixture of suitably substituted glycerophospholipids and/or threitolphospholipids may be used, for example in order to provide the necessary CT-members, as well as a mode wherein a glycero- or threitolphospholipid is used under carefully controlled conditions together with a free fatty acid, alcohol or amine of the formula (la) or (lb) containing the necessary active groups.

The afore mentioned compounds may be prepared with processes known as such.

They may be prepared, for example, by introducing into a glycerol or D-mannitol, or into threitol, the acyl, amide and/or alkyl side chains which are to be included in the final compound and which carry the desired charge-transfer and/or polarizable groups (M. Kates, Methods in Membrane Biology, Vol. 8, 1977, Plenum Publ.Corp. p. 219-290). Thereafter e.g. the substituted D-mannitol is split and reduced to the corresponding glycerol. The substituted glycerol may thereafter be esterified in its free position in order to introduce the desired phosphoryl group or a derivative thereof.

One applicable method for preparing 1,2-diacyl-sn-glycerols is disclosed in the FI-patent specification 60 700. Into such a compound the phosphoryl-glycerol group may be introduced by reacting a 1,2-diacyl-glycerol with phosphorous oxychloride in the presence of triethylamine. The product obtained is thereafter reacted with 1-trityl-snglycerol in the presence of triethylamine and the hydroxy groups of the phosphoryl-glycerol groups are liberated. In the publication Eibl. H., Proc. Natl. Acad. Sci., (1978) p. 40-74 are disclosed processes for the preparation of phosphoryl-ethanolamine and -choline.

The film aggregate according to the invention may be prepared in a conventional manner for example applying Langmuir-Blodgett-coating techniques. This technique is based on letting the film forming, surface active compound, for instance a phospho- or sulpholipid, orient itself at the interface between two phases, for example the interface between a liquid (water, glycerol, etc) and a gas, such as air, argon, etc., whereby the hydrophilic part of the molecule orients itself towards the liquid, and the hydrophobic part, that is the lipophilic part, orients itself in a direction away from the liquid. The desired compound or mixture of compounds is dissolved in a suitable organic solvent or solvent mixture, e.g. chloroform or cyclohexane. From a film made from such a solution spread as a monomolecular layer onto e.g. a water surface, the solvent evaporates rapidly. When a body forming the support surface is transported, preferably at a constant speed, through the interface, the film is transferred as a monomolecular layer onto the support surface, the lipophilic part towards the support surface if the body is transported through the film in a direction from the air to water, and the hydrophilic part towards the support surface if the body is transported through the film in the opposite direction, i.e. from the water to air. By transporting the body several times through the film the support surface can be coated with practically any number of film layers. - It is naturally also possible to coat the substrate with several layers of film, each one made from a different organic material.

As regards the chemical structure it is necessary to note that the fatty acids, alcohols, amines and their derivatives are often very poorly soluble in the solvents used for the manufacture of Langmuir films at liquid-gas interfaces. According to the invention it has been found that when such insoluble fatty compounds are bound into a structure such as in phospholipids or e.g. as three chains into a threitol compound, the compounds thuε formed are easily dissolved e.g. into chloroform, whereby they may be easily spread as monomolecular layers with controlled compression onto a water surface, which is a requisite for making Langmuir-Blodgett films on solid substrate surfaces.

The film aggregates obtained according to the invention may be used a such or they may be polymerized, for example using light or heat, or alternatively they may in a suitable manner be bonded to the support surface, either the layer as a whole or only sections thereof, depending on the intended use. Non-polymerized or non-bonded film areas may thereafter be removed in a suitable manner, for example by dissolution, whereby a conducting film of desired configuration can be obtained. One suitable area of use is e.g. in microlitography, drawing microcircuits into the film with a laser or electron beam in order to promote polymerisation and/or bonding to the surface, and thereafter removing the untreated areas.

The conductivity of the compounds according to the invention in the film aggregates is best measured using a so called four point measurement system, according to which onto the silicon, glass etc substrate surface is e.g. vacuum deposited metallic conducting electrodes, e.g. of gold. The films may be layered directly onto the substrate surface or the surface can be rendered hydrophobic by alkylation or by using the method disclosed in the Applicants' international application PCT/FI85/00102. A monomolecular layer may then be formed from one type of molecule. Optimal with regard to conductivity is, however, a structure which is comprised of one type of phospholipid derivative, wherein, instead of using a mixture of two different acids, these two acids are interconnected over a common glycerol structure. The voltage is applied between the furthermost electrodes and the conductivity of the film aggregate is measured as a current between the centermσst electrodes. Typical values measured, even in the absence of doping with e.g. iodine vapour, are of the order of 10 S/cm to 1 μS/cm. The frequency dependancy of the current is dependant of the composition of the film. The energy belts and conditions (states) of the film may optically be measured based on the absorption of electromagnetic radiation in the UV and visible area, as well as in IR frequencies. The transmission measurement carried out in the optical and UV area usually requires the use of quartz as the substrate. In some cases additional information is received from fluorescence emission and excitation spectra and the relationship to time of the former allowing for the evaluation of the formation of exitons and their diffusion in the film, as well as the influence on these processes by an external field.

The following examples are intended to illustrate the invention.

Example 1

1-hexadecanoyl-2,5-dimethylbenzene

Into a flask of 1 liter, 68 g of hexadecanoyl chloride, 41 ml of p-xylene and 250 ml of 1,2-dichloroethane was added. The mixture was cooled on ice and 50 g of aluminium chloride was added in ca 2 g portions. The mixture was mixed on the ice bath for 1.5 hours and a further 1.5 hours at room temperature. The reaction mixture was poured into a mixture of ice and hydrochloric acid. The lower phase was separated in a funnel and washed with water, a saturated sodium bicarbonate solution and with water untill neutral. It was evaporated to dryness and crystallized from a mixture containing 400 ml of ethanol and 400 ml of 2-propanol. 81 g (95% of teor.) of crystals were obtained. M.p. 47-50°C.

1-hexadecyl-2,5-dimethylbenzene

Into a flask 81 g of 1-hexadecanoyl-2,5-dimethylbenzene was added together with 250 ml of acetic acid and 90 ml of hydrochloric acid (37%). The reaction mixture was warmed until dissolution and 85 g of zinc powder, which had been amalgamated with 6.4 g of mercury (II)chloride was added. The mixture was boiled for an hour and cooled. 250 ml of water was added and extracted in a funnel with 600 ml of toluene. The toluene solution was washed with water, 100 ml of a 0.5 M sodium bicarbonate solution and water. Drying over sodium sulfate and evaporation to dryness afforded a residue weighing 70 g which according to thin layer chromatography (hexane/ether 19:1 R_f = 0.84)) was pure and used as such in the following step.

4-hexadecyl-2,5-dimethylphenyl-6-keto-hexanoic acid, methyl ester

1-hexadecyl-2,5-dimethylbenzene (70 g) was dissolved into 120 ml of 1,2-dichlorobenzene. The methylesterchloride of hexanoic diacid was added in 100 ml of 1,2-dichloroethane and while stirring on an ice bath 42.3 g of aluminium chloride was added in small portions. The mixture was stirred on the ice bath for 1.5 hours and at room temperature for 1.5 hours. The reaction mixture was poured into a mixture of 250 ml of ice and 110 ml of 0.5 M hydrochloric acid. The mixture was extracted with 400 ml of dichloromethane, and washed with water, 160 ml of saturated sodium bicarbonate solution and with water. Drying over sodium sulfate and evaporation of the solvent gave a residue which was crystallized from 700 ml of ethanol. The crystals were recrystallized from 550 ml of ethanol. 24 g of a product was obtained with a m.p. of 51 - 55°C. The product appeared pure on thin layer chromatography (petrolether/ acetone 9:1, R_f =0.75).

4-hexadecyl-2,5-dimethylphenyl-hexanoic acid, methyl ester

4-hexadecyl-2,5-dimethylphenyl-6-keto-hexanoic acid, methylester (24 g) was dissolved while heating into 60 ml of acetic acid and 25 ml of a 37% hydrochloric acid solution. 21.6 g of zinc powder amalgamated with 1.6 g of mercury chloride was added. The solution was boiled for 1.5 hours and cooled. 70 ml of water and 400 ml of toluene was added. The toluene layer was separated and washed with water and 50 ml of a 0.5M sodium bicarbonate solution and finally with water. The mixture was dried over sodium sulfate and evaporated to dryness. Crystallizing first from 150 ml of ethanol and thereafter again from 80 ml of ethanol gave 7.4 g of crystals with a m. p. of 50-52°C. The product exhibited the desired structure as evidenced with NMR. In the aromatic area there was a singlet of two hydrogen atoms at 6.8 ppm and the methyl groups bonded to the aromatic ring appeared as a singlet at 2.2 ppm.

4-hexadecyl-2,5-dimethylphenyl-hexanoic acid

The ester obtained from the previous step was dissolved while heating into diethylene glycol (50 ml) containing 1.2 g of potassium hydroxide. The mixture was heated for one hour on a water bath. The reaction mixture was poured into a mixture containing 50 g of ice and 12 ml of concentrated hydrochloric acid. 160 ml of ether was added. The ether layer was washed to neutral and dried over sodium sulfate. Crystallization from 60 ml of ethanol afforded 5.8 g of crystals with a m.p. of 73-75°C. This acid was used for preparing the phospholipid.

Example 2

1,4-dimethoxy-2-decanoyl-benzene

Into a 3 liter flask was measured 207 g of 1,4-dimethoxybenzene, 290 ml of decanoyl chloride and 1.2 liters of 1,2-dichloroethane. While stirring on ice 280 g of aluminium chloride was gradually added. The mixture was stirred on the ice bath for 1.5 hours and at room temperature for 4 hours. The reaction mixture was poured into a mixture of ice and hydrochloric acid and 1 liter of dichloromethane was added. The organic layer was washed with water, 500 ml of 0.5 M sodium hydroxide solution and 200 ml of 0.5M hydrochloric acid and with water until neutral. The mixture was dried on sodium sulfate and evaportaed to dryness and purified chromatographically. Silica was used in an amount of 3 kg and the eluent was petrolether/ ethylacetate 19:1. 350 g of an oily product was obtained and was used a such in the next step.

1,4-dimethoxy-2-decyl-benzene

Into a three liter flask was added 350 g of 1,4-dimethoxy-2-decanoyl-benzene, 800 ml of diethylene glycol and 183 ml of hydrazine hydrate. The mixture was slightly heated and 266 g of potassium hydroxide was added. The mixture was boiled for 3 hours, whereafter the hydra zine hydrate was distilled off. When the temperature was 196°C the distillation was stopped and the mixture allowed to cool. The reaction mixture was poured into 1.5 liters of water and 350 ml of a 37% hydrochloric acid solution was added. The product was extracted with 1.8 liters of ether. The product was purified in chromatographic column with 3 kg of silica. The eluent was petrolether/ethylacetate 98:2. 128 g of an oily product was obtained which according to NMR exhibited the desired structure.

1,4-dimethoxy-2-decylphenyl-6-ketohexanoic acid, methyl ester

Into a two liter flask 128 g of 1,4-dimethoxy-2-decylbenzene, 82 g of monomethylester-monochloride of hexanoic diacid and 500 ml of 1,2-dichloroethane was added. While stirring on an ice bath 92 g of aluminium chloride was added. Stirring was continued on the ice bath for 1 hour and at room temperature for 1 hour. The reaction mixture was puored into a mixture containing 650 g of ice and 20 ml of a 37% hydrochloric acid solution. For eluation 650 ml of dichloromethane was used. The dichloromethane solution was washed three times with 400 ml of 1:3-mixture of methanol and water and dried on sodium sulfate. The solution was evaporated to dryness and crystallized from 950 ml methanol. 169 g of a pure product was obtained which according to NMR had the correct structure.

1,4-dimethoxy-2-decyl-phenylhexanoic acid

Into a two liter flask was added the product (169 g) obtained in the previous step, 800 ml of diethylene glycol and 117 ml of hydrazine hydrate. The solution was slightly heated and 170 g of potassium hydroxide added. The mixture was boiled for two hours, thereafter distilled until the temperature reached 196°C. The mixture was allowed to cool and thereafter puored into a mixture containing 950 g of ice and 225 ml of a 37% hydrochloric acid solution. The product was extracted with 1.2 liters of ether and the organic phase was washed until neutral with water. The product was dried over sodium sulfate and evaporated to dryness. Crystallization from 1.1 liters of methanol afforded 126 g of crystals with a m.p. of 54-55°C.

This product was used for the preparation of phospholipids and also for the preparation of quinonehexanoic acid derivatives.

Example 3

3-carbazole-6-ketohexanoic acid, methyl ester

10 g of N-(1-carbomethoxypentanoyl)-carbazole was introduced into a 250 ml flask. 60 ml of o-dichlorobenzene and 8.5 g of aluminium chloride was added. The mixture was heated at 120°C for 6 hours and was allowed to cool slightly whereafter 120 ml of methanol was added. The mixture was boiled for 10 minutes and 120 ml of water, 80 ml of 2M hydrochloric acid solution and 300 ml of ethyl acetate was added. The mixture was washed with water, a 0.5M sodium bicarbonate solution and water. The ethyl acetate solution was contentrated to 100 ml and 100 ml of petrolether was added. 6.8 g of crystals were obtained which were recrystallized by dissolving into a mixture containing 100 ml of trichloroethylene and 10 ml of methanol. In the refrigerator 3.7 g of a product crystallized, which according to thin layer chromatography was pure (R_f=0.1; eluent petrolether/ethyl acetate 7:3).

3-carbazole-hexanoic acid, ethyl ester

The product obtained in the previous step (3.7 g), amalgamated zinc (50 g zinc powder and 3.8 g mercury(II)chloride), 80 ml of a 37% hydrochloric acid solution and 80 ml of acetic acid was introduced into a 500 ml flask. It was boiled for 0.5 hours and filtered while hot. 200 ml of ethyl acetate was added and washed with water, a 0.5M sodiumbicarbonate solution and water. The mixture was evaporated to dryness and immediately esterified by boiling with ethanol (200 ml) and sulphuric acid (0.5 ml). The ester mixture was concentrated, 100 ml. of toluene was added, washed with water and dried over sodium sulfate. The mixture was evaporated and the residue purified chromatographically using as the eluent toluene/ethyl acetate 9:1. The pure fractions were combined and crystallized from toluene. 1.1 g of a product with a melting point of 103-5°C was obtained. - Into the compound obtained a second hydrocarbon chain may be added in a symmetrical position, if desired.

Example 4

12-pyrenyl-dodecanol

Into a one liter flask 100 ml of dried toluene and 2 g of litium aluminium hydride was added. While stirring 21.4 g of 12-pyrenyl-dodecanoic acid ethyl ester was added dissolved in a solution containing 100 ml of toluene and 50 ml of tetrahydrofuran. The mixture was stirred at room temperature for 1.5 hours, whereafter a mixture was added containing 30 ml of ethyl acetate and 60 ml of toluene. 120 ml of 2M hydrochloric acid was carefully added drop- wise. The organic phase was separated and washed with 80 ml of water and 60 ml of 2M sodium hydroxide and with water until neutral. The mixture was evaporated to dryness and fractionated on a 100 g silica column using as the eluent toluene/ethyl acetate 9:1. The pure fractions were crystallized from 140 ml of toluene. 14.4 g of a product having a melting point of 80-1°C was obtained. Example 5

4-(5-carboxypentyl)-2,3,5,6-tetramethyl-6-ketohexanoic acid, methyl ester

2,3,5,6-tetramethylphenylhexanoic acid, methyl ester (29 g) and monomethylester monochloride of hexanoic diacid (23 g) was dissolved into 150 ml of 1,2-dichloroethane. While stirring on ice, 46.8 g of aluminium chloride was added. After an hour the mixture was puored into a mixture of ice/hydrochloric acid and one liter of ether was added. The mixture was allowed to stand and then decanted. The ether solution was washed with water until neutral, dried and evaporated, the residue was purified chromatographically (330 g of silica, eluent toluene/methanol 97:3) and crystallized from toluene. 17.0 g of a pure product was obtained with a melting point of 110-1°C.

This product was transformed to its acid chloride using oxalyl chloride and was bonded to further active groups using a Friedel-Crafts reaction.

Example 6

4-(carbmethoxypentanoyl)-2,4-dimethoxyphenyl-hexanoic acid

Into a one liter flask 32.5 g of 2,4-dimethoxyphenylhexanoic acid, 450 ml of 1,2-dichloroethane and 42.2 g of monomethylestermonochloride of hexanoic diacidwas added. While stirring in ice, 63 g of aluminium chloride was added and the mixture stirred for 2.5 hours and thereafter poured into 400 ml of a ice-water-mixture. The organic layer was washed four times with water and evaporated on a rotavapor and the residue purified in a column of 800 g silica. The pure fractions were crystallized from 75 ml of di-isopropylether. 16.1 g of a product was obtained with a m.p. of 75-7°c. The product was transformed into its acid chloride by heating with oxalyl chloride (6 ml) at 70°C in a trichloroethylene solution for one hour. Finally the solvent was evaporated and the acid chloride used as such.

4-(pyrenyl-6-ketohexyl)-2,4-dimethoxyphenyl-6-ketohexanoic acid, methylester

The acid chloride from the previous step (18 g) was dissolved into 60 ml of 1,2-dichloroethane. 12.0 g of pyrene and in ice, 23.7 g aluminium chloride. The mixture was stirred in ice for 0.5 hours and 2 hours at room temperature. It was poured into a mixture containing 180 g of ice and 90 ml of 2M hydrochloric acid, 120 ml of dichloromethane was added and washed with water, 0.5M sodium hydroxide and 0.5M hydrochloric acid and water. The mixture was fractionated on a silica column using as the eluent a 9:1-mixture of toluene/ethyl acetate. After crystallizing from the eluent in the refrigerator 14.8 g of the desired product was obtained.

4-(pyrenylhexyl)-2,4-dimethoxyphenyl-hexanoic acid

The product from the previous step (8.4 g) was reduced using the Wolf-Kishner method, whereby 3.6 g of a product with a m.p. of 118-118.5°C was obtained.

This product was used for the preparation of phospholipids, but the dimethoxy phenyl moiety was also oxidized to quinone and the quinone moiety transformed to tetracyano-quinone dimethane in a known manner. The afore mentioned acids and corresponding acids may be used for example for the preparation of the following phospholipids:

1-(palmitoyl)-2-(4-pyrenylhexyl-2,4-dimethoxyphenyl- hexanoyl)-sn-glycerol-3-phosphocholine

1-decylquinonehexanoyl-2-(4-pyrenylhexyl-2,4-dihydroxy- phenylhexanoyl-sn-glycerol-3-phosphocholine

1-(4-decyltetracyanoquinonedimethanehexanoyl)-2-pyrene- tetradecanoyl-sn-glycerol-3-phosphocholine and -3'-glycerol

1-(4-decyltetracyanoquinonedimethanehexanoyl)-2-tetramethyl- tetraselenofulvaleneundecanoyl-sn-glycerol-3-phosphocholine and -1'-glycerol and -3'-glycerol

1-pyrenyloctadecanoyl-2-pyrenylhexylpyrenylhexanoyl-sn- glycerol-3-phopshocholine

1-palmitoyl-2-pyrenylhexanoyl-sn-glycerol-3-phospho-1'- glycerol and -3'-glycerol

1-palmitoyl-2-pyrenyltetradecanoyl-sn-glycerol-3-phospho- 1'-glycerol and -3'-glycerol

1-hexylanthracenehexanoyl-2-hexyltetracyanoquinonedimethane- sn-glycerol-3-phosphocholine

1-pyrenyldodecyl-2-decylquinonehexanoyl-sn-glycerol-3- phosphocholine and -methanol

1-pyrenyltetradecanoy1-2,3-di(pyrenylhexanoyl)-L-threitol-4- phosphocholine and -methanol.

As examples of such preparation the following examples are given. Example 7

1-pyrenyldodecanyl-2-decyl-quinonehexanoyl-3-triphenylmethyl

-sn-glycerol

1-pyrenyl-dodecanyl-3-triphenylmethyl-sn-glycerol (6.0 g; prepared by reacting pyrenyldodecanol mesylate with isopropylidene glycerol and hydrolyzing the isopropylidene protection and protecting the liberated primary hydroxy group with a triphenylmethyl group), decylquinone hexanoic acid (3.7 g) and dimethylaminopyridine (210 mg) was dissolved into 50 ml of dichloromethane. 2.1 g of dicyclohexylcarbodi-imide was added. The mixture was allowed to react for 4 hours at room temperature and 50 ml of hexane was added. It was filtered and washed with 0.5M hydrochloric acid, water, 0.5M sodiumbicarbonate and water, dried over sodium sulfate and evaporated. It was purified chromatographically on a 150 g silica column using as the eluent hexane/ethylacetate 99:1 and 98:2. 7.9 g of a product with a melting point of 35-9° C was obtained.

1-pyrenyldodecyl-2-decyl-quinone-hexanoyl-sn-glycerol

The product from the previous step (7.9 g) was dissolved into toluene and added to a 150 g boric acid/silica column and eluted with with 500 ml of toluene and toluene/ethyl acetate 95:5 and 90:10. The product was crystallized from ethanol, whereby 3.7 g of a pure product (m.p. 80-1°C) was obtained which was used for the preparation of phospholipids by introducing a phosphoryl group in a known manner.

Example 8

1,4-di(triphenylmethyl)-L-threitol

Into a flask was measured 4.6 g of L-threitol, 23.4 g of triphenylmethyl chloride and 50 ml of pyridine. The mixture was stirred for 24 hours. 100 ml of water was added and the water layer was decanted away. The mixture was dissolved into 150 ml of toluene and washed with 70 ml of 2M hydrochloric acid, water, 0.5M sodium bicarbonate and water. The product was dried over sodium sulfate and evaporated. It was purified over a 120 g silica column using as the eluent toluene/ethyl acetate 9:1. 12.9 g of a product was obtained which according to thin layer chromatography was pure (R_f = 0.39; eluent hexane/acetone 7:3 ).

1,4-di(triphenylmethyl)-2,3-di(pyrenehexanoyl)-L-threitol

Into a flask 3.0 g of 1,4-di(triphenylmethyl)-L-threitol and 4.75 g of pyrene hexanoic acid and 60 mg of dimethylamino pyridine was added using 15 ml dichloromethane as the solvent. The mixture was stirred at 30°C and 2,6 g of dicyclohexylcarbodi-imide was added. The mixture was stirred for 20 hours, filtered, washed with 2M hydrochloric acid, water, 0.5 M sodium bicarbonate and water. It was purified on a 100 g silica column using as the eluent toluene/ethyl acetate 99:1. 2.1 g of the desired product was obtained and monopyrenehexanoyl compound in an amount of 1.1 g. The last mentioned compound can be used for the preparation of a threitol phospholipid containing three different acids.

2,3-di(pyrenehexanoyl)-L-threitol and 1-triphenylmethyl- 2,3-di(pyrenehexanoyl)-L-threitol

The product obtained in the previous step (2.1 g) was dissolved into toluene and added to a chromatography column which was filled with boric acid/silica gel (21 g). It was eluted with 100 ml of toluene very slowly. The column was further eluted with a toluene/ethyl acetate 95:5 and 90:10 mixture. 0.6 g of 2,3-di(pyrenehexanoyl)-L-threitol (Rf=0.39; eluent chloroform/2-propanol 9:1) and 0.34 g of 1-triphe-nyl-2,3-di(pyrenehexanoyl)-L-threitol (R_f=0.81; eluent chloroform/2-propanol 9:1) was obtained, which both can be used for the preparation of threitol phospolipids in a manner corresponding to the preparation of glycerophospholipids.

Claims

Claims :

1. Film aggregate exhibiting electrically conducting characteristics and comprising a substantially inert support surface carrying one or several monomolecular film layers, c h a r a c t e r i z e d in that the said film layer is formed from a surface active organic material having liquid crystal characteristics and that the film layer is of a sandwich type construction containing, in cross-section through the film, at least the following consecutive parallel zones:

- a spacer-zone (2) which to its electrical characteristics is substantially inert and which may contain polymerizable and/or groups which may be bonded to the support surface,

- a conducting area (3-5) which is comprised on the one hand of a charge-transfer zone (3 or 5) and on the other hand of a polarizable zone (5 or 3) as well as of a spacer zone (4) between these zones which to its electrical properties is substantially inert and which may contain polymerizable groups,

- a spacer zone (6) which corresponds to the above zone (2) and which likewise may contain polymerizable groups,

- a hydrophilic zone (7) which may contain polymerizable groups.

2. Film aggregate according to the Claim 1, c h a r a c t e r i z e d in that the spacer zone (2, 4 and/or 6) contains substantially aliphtic straight or branched hydrocarbon groups containing from 1 to 20, preferably 4 to 16 carbon atoms, which groups as polymerizable groups may contain triple or double bonds.

3. Film aggregate according to the Claim 1 or 2, c h a r a c t e r i z e d in that the charge-transfer zone (3 or 5) comprises as groups forming charge-transfer comple xes quinone derivatives, especially benzoquinone or antraquinone groups and their corresponding hydroquinone groups, or the pair tetracyanobenzene-tetramethylbenzene.

4. Film aggregate according to any one of the Claims 1-3, c h a r a c t e r i z e d in that the polarizable zone contains as polarizable groups aromatic hydrocarbon groups, preferably pyrene and/or perylene groups.

5. Film aggregate according to any one of the Claims 1-4, c h a r a c t e r i z e d in that the hydrophilic zone (7) contains a phosphoric acid group, which optionally is esterified with a lower alkanol, amino-lower alkanol, serine, choline or 1'- or 3'-glycerol, which optionally may be substituted with polymerizable groups.

6. A compound having the formula

~ ~ _(Ia)

~ (lb)

wherein the zig-zag-symbols mean substantially aliphatic, straight or branched hydrocarbyl groups containing about 1 to 20 C-atoms, preferably from 4 to 16 C-atoms, and which may contain heteroatoms (oxygen, nitrogen, sulphur) provided these do not substantially affect the substantially aliphatic nature of the hydrocarbyl group, A means the one member of a charge-transfer pair and B means a polarizable group, the integers n, m and q mean 0 or 1, Y' means a carboxy group -COOH, a hydroxy group -OH or an amine group -NH₂, wherein n = m = 1 and q is 0 or 1, and the functional derivatives thereof.

7. Surface active phospholipids, c h a r a c t e r i z e d in that they comprise a phosphoglycerol or -threitol wherein at least two hydroxy groups have been esterified, etherified and/or amidified by either a compound of the formula (la) or by a compound of the formula (lb) M _/ v (Ia)

(Ib)

wherein the zig-zag-symbols mean substantially aliphatic, straight or branched hydrocarbyl groups containing about 1 to 20 C-atoms, preferably from 4 to 16 C-atoms, and which may contain heteroatoms (oxygen, nitrogen, sulphur) provided these do not substantially affect the substantially aliphatic nature of the hydrocarbyl group, A means the one member of a charge-transfer pair and B means a polarizable group, the integers n, m and q mean 0 or 1, Y' means a carboxy group -COOH, a hydroxy group -OH or an amine group -NH₂. provided that either a) n = m = 1 and q is 0 or 1; or b) n or m is 0 and q is 0 or 1 and the functional derivates thereof.

8. Glycerophospholipids according to the claim 7, c h a r a c t e r i z e d in that they have the formula

wherein the zig-zag symbols, n, m and q have the meanings given in the claim 7, A and A' mean a pair of charge- transfer groups, B and B', which may be the same or different, mean a polarizable group, n', m' and q' have the meaning of 0 or 1, Y means the group -O-, -C( =0)-O- and/or -NH- and X is hydrogen, or it is the residue of an alcohol, especially a lower alkanol, amino lower alkanol, serine, choline, 1- or 3-glycerol forming an ester with the phosphoric acid group, with the provision that n+m, and n'+m' are irrespective of each other 1 or 2, and q and q' irrespective of each other 0 or 1.

9. Threitolphospholipds according to the claim 7, c h a r a c t e r i z e d in that they have the formula

wherein zig-zag symbols, n, m, q, n', m', q', A, A', B, B', X and Y have the meanings given in connection with the formulas Ila and lIb in the claim 8, n", m", and q" mean 0 or 1, A" means a charge-transfer group and B" means a polarizable group, with the provision that n+m, n'+m', and n"+m" are irrespective of each other 1 or 2, but one of these sum may in addition be 0, and q, q' and q" are irrespective of each other 0 or 1.