JP2006248988A - Double-decker complex, self-assembled monolayer, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new self-assembled monolayer obtained by regularly arranging a double decker complex comprising an alkyl group-modified phthalocyanine derivative which can be arranged and immobilized on a substrate, another phthalocyanine derivative or a porphyrin derivative, and one rare earth metal ion, on the substrate at a sufficient distance. <P>SOLUTION: The double decker complex is obtained by linking the alkyl group-modified phthalocyanine represented by general formula (I): CnPc-M-P with another phthalocyanine derivative or the porphyrin derivative by a coordinate bond with the rare earth metal ion. The self-assembled monolayer has the double decker complex regularly arranged on the substrate. (In the formula, CnPc is 2,3,9,10,16,17,23,24-octakis(alkyloxy)phthalocyanine; the subscript n in CnPc is the number of carbon atoms of each alkyl group; M is a rare earth metal ion; P is a phthalocyanine derivative or a porphyrin derivative; with the proviso that P can be CnPc). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a double-decker complex in which an alkyl group-modified phthalocyanine derivative that can be immobilized on a substrate and another phthalocyanine derivative or porphyrin derivative are linked by a coordinate bond with a rare earth metal ion. The present invention relates to a self-assembled film having an array immobilized thereon, a method for producing the film, and a method for observing the film.

In recent years, the progress of microfabrication technology has been rapid, and it is now possible to process about 100 nanometers, but it is said that there will be a limit in the next decade. For this reason, it is considered that development of another method is necessary to enable microfabrication at a scale of about 100 nanometers or less. Therefore, what is attracting attention today is the method of assembling atoms and molecules one by one. Once this method is established, it can be applied to a wide range of industries such as materials, IT, and biotechnology, and various products such as molecular devices, high-density recording devices, and nanorobots can be produced.

  In order to assemble elements having such physical properties and functions, intermolecular interactions such as intermolecular forces, hydrogen bonds, and coordinate bonds are used. In recent years, synthesis of rotaxane, catenane (Non-Patent Document 1-2), sandwich porphyrin, or phthalocyanine (Non-Patent Document 3-4) has been reported using these interactions. Furthermore, research on the application of compounds characterized by a mechanical structure to molecular devices has also been reported (Non-patent Document 5).

  In addition, self-assembled films in which molecules having thiol groups are arranged on a substrate and Langmuir-Blodgett films (LB films) that utilize the organization of molecules at the gas-liquid interface have been reported (non-patent documents). Reference 6).

  However, these organized films cannot control the distance between adjacent molecules, and the molecules are assembled or randomly dispersed on the substrate, making it difficult to make individual molecules independent.

  Therefore, it has been expected to develop a method for arranging molecules one by one regularly on the substrate at a constant interval. From this point of view, much research has been conducted on monolayers of porphyrin and phthalocyanine. In particular, for porphyrin and phthalocyanine modified with a linear alkyl group as a substituent, it is reported that a difference in the distance between adjacent molecules occurs by changing the carbon number of the alkyl chain (Non-patent Documents 7-8). ).

If this method is used, it is expected that molecules having physical properties and functions can be regularly arranged at regular intervals. Furthermore, porphyrin and phthalocyanine are known to form double-decker complexes with rare earth metal ions. In this case, it is considered that rotation occurs between the upper and lower molecules centering on the metal ion. When any stimulus is given to a certain molecule, the rotation is used for the molecule at the end via the adjacent molecule. If the response can be detected, it can be considered as a molecular sensor or a molecular automaton. In addition, the central metal ion can be easily changed, and if a material having a large spin number is used, there is a possibility of magnetic expression.
M. Asakawa, T. Ikeda, N. Yui, T. Shimizu, Chem. Lett., 2002,174 M. Asakawa, PR Ashton, V. Balzani, CL Brown, A. Credi, OA Matthews, SP Newton, FM Raymo, AN Shipway, N. Spencer, A. Quick, JP Stoddart, AJP White, DJ Williams, Chem. Eur J., 1999, 5, 860 DKP Ng, J. Jiang, Chem. Soc. Rev., 1997, 26, 433 JE Redman, N. Feeder, SJ Teat, JKM Sanders, Inorg. Chem., 2001, 40, 2486 CP Collier, EW Wong, M. Belohradsky, FM Raymo, JFStoddart, PJ Kuekes, RS Williams, JR Heath, Science, 1999, 285, 391]. P. Samori, H. Engelkamp, P. de Witte, AE Rowan, RJM Nolte, JP Rabe, Angew. Chem. Int. Ed., 2001 40 2348 X. Qiu, C. Wang, Q. Zeng, B. Xu, S. Yin, H. Wang, S. Xu, C. Bai, J. Am. Chem. Soc., 2000, 122, 5550, H. Wang, C. Wang, Q. Zeng, S. Xu, S. Yin, B. Xu, C. Bai, Surf. Interface Anal., 2001, 32, 266

  The present invention, from the background as described above, further develops the knowledge so far, has a symmetrical array structure, unlike a conventional self-assembled film using a thiol compound or LB film, The symmetry can be easily changed by changing the substituent of the phthalocyanine on the substrate side. Unlike porphyrins, it can form a variety of array structures and has higher planarity than porphyrins. An object of the present invention is to provide a novel double-decker complex, a self-assembled film comprising an alkyl group-modified phthalocyanine derivative, and a method for producing the same, enabling formation of a new self-assembled / formed film that is also stable as a film .

  The present inventors have developed a double-decker complex in which an alkyl group-modified phthalocyanine derivative that can be immobilized on a substrate and another phthalocyanine derivative or porphyrin derivative are linked by a coordinate bond with a rare earth metal ion. When used, the present invention finds that a self-assembled film can be obtained in which molecules are arranged and immobilized on a substrate while building symmetry, and molecules distant from the substrate can rotate around metal ions. Was completed.

  That is, according to the present invention, the following inventions are provided.

  First: a double-decker complex in which an alkyl group-modified phthalocyanine represented by the following general formula (I) and another phthalocyanine derivative or porphyrin derivative are linked by a coordinate bond with a rare earth metal ion; A self-assembled film characterized in that a solution is dropped on a substrate to form a film, and a method for producing the film.

(In the formula, CnPc is 2,3,9,10,16,17,23,24-octakis (alkyloxy) phthalocyanine, the subscript n in CnPc is the number of carbon atoms of each alkyl group, and M is a rare earth metal ion. And P represents a phthalocyanine derivative or a porphyrin derivative, respectively.)
Second: A self-assembled film in which a double-decker complex represented by the general formula (I) and an alkyl group-modified phthalocyanine derivative represented by the following general formula (II) are mixed, and a method for producing the same.

(In the formula, CnH ₂ Pc is 2,3,9,10,16,17,23,24-octakis (alkyloxy) 29H, 31H-phthalocyanine, and the subscript n in CnH ₂ Pc is the carbon atom of each alkyl group. Each represents a number.)

The self-assembled film by the double-decker complex of the present invention uses an alkyl group-modified phthalocyanine derivative for immobilization on the substrate. Compared to porphyrin, which has four phenyl groups that can rotate to the meso position, phthalocyanine is planar in its entirety. Therefore, it is immobilized on the substrate more stably than porphyrin. Even when the length of the alkyl chain is short, it is easily immobilized on the substrate, so that the distance between adjacent molecules can be controlled within a relatively wide range. Since a rare earth metal ion having a large ion radius is used as the central metal, it is considered that a double-decker complex is formed and rotation occurs between the upper and lower molecules. Therefore, when a stimulus is applied to one molecule from the outside, if the rotation is transmitted to the terminal molecule through the adjacent molecule and the response can be detected, it can be considered to function as a molecular sensor or molecular automaton. In addition, the central rare earth metal ion can be easily changed. If the spin direction of the central metal ion is aligned by immobilizing molecules on the substrate and applying a magnetic field, there is a possibility of magnetic expression. Further, counter ions can be removed by using +4 valent metal ions, and an electrically neutral complex can be formed. That is, only a double-decker complex exists in the system, and a more stable and uniform self-assembled film can be obtained.

  The present invention has the characteristics as described above, and an embodiment thereof will be described below.

The double-decker complex in which an alkyl group-modified phthalocyanine and another phthalocyanine derivative or porphyrin derivative are linked by a coordinate bond with a rare earth metal ion, which is a molecule of the present invention, has the following general formula:
It is a molecule represented by (I).

(In the formula, CnPc is 2,3,9,10,16,17,23,24-octakis (alkyloxy) phthalocyanine, the subscript n in CnPc is the number of carbon atoms of each alkyl group, and M is a rare earth metal ion. And P represents a phthalocyanine derivative or a porphyrin derivative, respectively.)
In the general formula (I), the alkyl group-modified phthalocyanine represented by CnPc is specifically 2,3,9,10,16,17,23,24-octakis (alkyloxy) phthalocyanine, and CnPc
The subscript n in represents the number of carbon atoms of each alkyl group. Each alkyl group is a straight chain alkane having 4 to 18 carbon atoms. This alkyl group is indispensable for the interaction with the substrate by van der Waals force and the self-assembled film formation based on the interaction between alkyl groups, and at the same time, introduced to control the distance between adjacent molecules. Yes. Specifically, it has the following chemical structure.

2,3,9,10,16,17,23,24-octakis (alkyloxy) phthalocyanine (wherein the subscript n in OC _n H _{2n + 1} represents the number of carbon atoms of each alkyl group)
M used in the general formula (I) is a rare earth metal ion, specifically, lanthanum (III), cerium (III / IV), praseodymium (III / IV), neodymium (III), promethium (III ), Samarium (II / III), europium (II / III), gadolinium (III), terbium (III / IV), dysprosium (III), holmium (III), erbium (III), thulium (III), ytterbium ( II / III) and lutetium (III).

Specific examples of the phthalocyanine derivative or porphyrin derivative represented by P in the general formula (I) include compounds (IV) and (V), but the present invention is limited to the following examples. is not. P may be CnPc.

Phthalocyanine derivatives (where X, X ′, X ″, X ′ ″ are hydrogen atoms, saturated hydrocarbon groups, unsaturated hydrocarbon groups, hydroxyl groups,
A thiol group, an alkyl thiol group, a thioacetyl group, an amino group, a carboxyl group, a carboxy ester group, a nitro group, a nitroso group, a cyano group, and the like can be given. X, X ', X
'', X '''may be the same or partially the same. )

Porphyrin derivatives (where X, X ′, X ″, X ′ ″ are hydrogen atoms, saturated hydrocarbon groups, unsaturated hydrocarbon groups, hydroxyl groups,
A thiol group, an alkyl thiol group, a thioacetyl group, an amino group, a carboxyl group, a carboxy ester group, a nitro group, a nitroso group, a cyano group, and the like can be given. X, X ′, X ″, and X ″ ′ may be the same or partially the same. )
The molecule represented by the general formula (I) obtained in the present invention can be exemplified by the compound (VI) having the following structural formula, but the present invention is limited to the following examples. is not.

(In the formula, subscript n in OC _n H _{2n + 1} represents the number of carbon atoms of each alkyl group, and M represents a rare earth metal ion.)
The molecule of the present invention is produced, for example, by the following method. (1) The compound of the general formula (III) and the rare earth metal ion M are reacted in the presence of a base in a high boiling point solvent, and then reacted with a phthalocyanine derivative or a porphyrin derivative P in the general formula (I). The molecule represented can be produced. As the high boiling point solvent, 1-pentanol, 1-hexanol, toluene and the like are used. The base is 1,8-diazabicyclo [5.4.0] -7-
Undecene or the like is used. (2) Next, the obtained molecule is dissolved in an organic solvent, and the solution is developed on a substrate to form a film.

  In this case, the substrate is not particularly limited, but it is necessary to have an atomically flat surface in order to realize a regular arrangement at the molecular level. Examples thereof include, but are not limited to, graphite, mica, gold, silver, copper, silicon, glass, and plastic.

The self-assembled film by the double-decker complex in the present invention is a novel substance not described in any literature. Alkyl group-modified phthalocyanine derivatives are used to immobilize molecules on the substrate. Compared to porphyrin having four phenyl groups that can rotate to the meso position, phthalocyanine is more stable than porphyrin because it is planar in its entirety. Even when the length of the alkyl chain is short, it is easily immobilized on the substrate. Therefore, the distance between adjacent molecules can be controlled in a relatively wide range, and the symmetry is various. Since a rare earth metal ion having a large ionic radius is used as the central metal in order to form a double-decker complex, it is considered that the upper molecules not fixed to the substrate rotate. Therefore, when a stimulus is applied to one molecule from the outside, if the rotation is transmitted to the terminal molecule through the adjacent molecule and the response can be detected, it can be considered to function as a molecular sensor or molecular automaton. In addition, since the central rare earth metal ion can be easily changed, if an ion having a large spin number is used, if the spin direction of the central metal ion is aligned by applying a magnetic field, the possibility of magnetic expression can be expected.

Specific examples of external stimuli for the molecule represented by the general formula (I) include a scanning microscope probe, steric repulsion due to an adjacent molecule or a self-substituent, collision of molecules, light, magnetic field, and electric field. And so on.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.

[Synthesis of double-decker complex in which two alkyl group-modified phthalocyanine derivatives are linked by coordination bond with cerium]
2,3,9,10,16,17,23,24-Octakis (octyloxy) 29H, 31H-phthalocyanine 78.6 mg
(0.05 mmol) and cerium (III) acetylacetonate hydrate 45.5 mg (0.09 mmol), 1,8-diazabicyclo [5.4.0] -7-undecene 0.5 ml, 1-hexanol 2 ml and toluene 2 ml The mixture was suspended in a solvent and stirred at 150 ° C. for 30 hours. After distilling off the solvent, purification by silica gel column chromatography (extraction solvent: chloroform / hexane) linked two alkyl group-modified phthalocyanine derivatives represented by the following structural formula (VII) by coordinate bond with cerium The obtained double-decker complex was obtained in a yield of 46.5 mg (yield 57%).

Mass spectrometry value (as C ₁₉₂ H ₂₈₈ CeN ₁₆ O ₁₆ )
Calculated value: 3216
Actual value: 3213
The NMR spectrum of this compound is shown in FIG.
¹ H NMR (600 MHz, CDCl ₃ ) δ = 8.467 (phthalocyanine), 4.805-4.794 (alkyl), 4.482-4.472 (alkyl), 2.216-2.183 (alkyl), 1.818-1.782 (alkyl), 1.579-1.381 (alkyl) ), 0.949 (alkyl).

[Synthesis of double-decker complex in which alkyl group-modified phthalocyanine derivative and tetraphenylporphyrin are linked by coordination bond with cerium]
2,3,9,10,16,17,23,24-octakis (octyloxy) 29H, 31H-phthalocyanine 156 mg (0.10 mmol) and cerium (III) acetylacetonate hydrate 82.8 mg (0.17 mmol), 1.0 ml of 1,8-diazabicyclo [5.4.0] -7-undecene was suspended in a mixed solvent of 3 ml of 1-hexanol and 5 ml of toluene and stirred at 155 ° C. for 5 hours. After cooling the reaction solution to room temperature,
63.2 mg (0.10 mmol) of tetraphenylporphyrin was added, and the mixture was stirred at 185 ° C. for 20 hours. After the solvent was distilled off, silica gel column chromatography (extraction solvent: chloroform)
/ Hexane) yields 126 mg (54% yield) of double-decker complex in which alkyl group-modified phthalocyanine derivative represented by the following structural formula (VIII) and tetraphenylporphyrin are linked by cerium coordination bond Got in.

Mass spectrometry value (as C ₁₄₀ H ₁₇₂ CeN ₁₂ O ₈ )
Calculated value: 2289
Actual value: 2288
The NMR spectrum of this compound is shown in FIG.
¹ H NMR (600 MHz, CDCl ₃ ) δ = 8.631 (phthalocyanine), 8.358 (porphyrin), 7.740 (phenyl), 7.580 (phenyl), 7.201 (phenyl), 6.505 (phenyl), 4.810-4.774 (alkyl), 4.568 -4.534 (alkyl), 2.237-2.169 (alkyl), 1.845-1.794 (alkyl), 1.620-1.519 (alkyl), 1.443-1.419 (alkyl), 0.977 (alkyl).

[Synthesis of double-decker complex in which alkyl group-modified phthalocyanine derivative and phthalocyanine are linked by coordination bond with cerium]
2,3,9,10,16,17,23,24-Octakis (octyloxy) 29H, 31H-phthalocyanine 79.3 mg
(0.05 mmol) and cerium (III) acetylacetonate hydrate 39.9 mg (0.08 mmol), 1,8-diazabicyclo [5.4.0] -7-undecene 0.5 ml, 1-hexanol 2 ml and toluene 2 ml The mixture was suspended in a solvent and stirred at 155 ° C. for 5 hours. The reaction solution was cooled to room temperature, 27.0 mg (0.05 mmol) of phthalocyanine was added, and the mixture was stirred at 165 ° C. for 18 hours. After the solvent was distilled off, the residue was purified by silica gel column chromatography (extraction solvent: chloroform / hexane). By purifying the first fraction again with silica gel column chromatography (extraction solvent: chloroform / hexane), the alkyl group-modified phthalocyanine derivative represented by the following structural formula (IX) and phthalocyanine are coordinated with cerium. The linked double-decker complex was obtained in a yield of 23 mg (yield 20%).

Mass spectrometry value (as C ₁₂₈ H ₁₆₀ CeN ₁₆ O ₈ )
Calculated value: 2189
Actual value: 2185
The NMR spectrum of this compound is shown in FIG.
¹ H NMR (600 MHz, CDCl ₃ ) δ = 9.001 (phthalocyanine), 8.305 (phthalocyanine), 8.196 (phthalocyanine), 4.835-4.823 (alkyl), 4.594-4.582 (alkyl), 2.318 (alkyl), 1.926-1.894 ( Alkyl), 1.714-1.646 (alkyl), 1.593-1.557 (alkyl), 1.496-1.474 (alkyl), 1.013 (alkyl).

[Preparation of self-assembled film of compound (VII)]
A 1-phenyloctane solution of the following compound (VII) having an arbitrary concentration (1 mmol or less) was prepared. After this solution was dropped on the graphite, the structure was confirmed by a scanning tunneling microscope (tunnel current: 200 picoamperes, tunnel bias: -650 millivolts). The results are shown in FIG.

[Preparation of self-assembled film of compound (VIII)]
A 1-phenyloctane solution of the following compound (VIII) having an arbitrary concentration (1 mmol or less) was prepared. After this solution was dropped on the graphite, the structure was confirmed with a scanning tunneling microscope (tunnel current: 60 picoamperes, tunnel bias: -1200 millivolts). The results are shown in FIG.

[Preparation of self-assembled film of compound (IX)]
A 1-phenyloctane solution of the following compound (IX) having an arbitrary concentration (1 mmol or less) was prepared. After this solution was dropped on the graphite, the structure was confirmed with a scanning tunneling microscope (tunnel current: 250 picoamperes, tunnel bias: -600 millivolts). The result is shown in FIG.

[Preparation of self-assembled mixed film consisting of compound (VIII) and alkyl group-modified phthalocyanine derivative]
A 1-phenyloctane solution of the compound (VIII) and the following compound (X) mixed at an arbitrary ratio was prepared. After this solution was dropped on the graphite, the structure was confirmed with a scanning tunneling microscope (tunnel current: 10 picoamperes, tunnel bias: -1000 millivolts). The result is shown in FIG.

[Preparation of self-assembled mixed film consisting of compound (IX) and alkyl group-modified phthalocyanine derivative]
A 1-phenyloctane solution of the compound (IX) and the following compound (X) mixed at an arbitrary ratio was prepared. After this solution was dropped on the graphite, the structure was confirmed with a scanning tunneling microscope (tunnel current: 30 picoamperes, tunnel bias: -800 millivolts). The result is shown in FIG.

Compound of Example 1 Figure 2 shows the NMR spectrum of the compound of Example 2. Figure 3 shows the NMR spectrum of the compound of Example 3. Diagram of a self-assembled film composed of compound (VII) observed with a scanning tunneling microscope Figure observed by scanning tunneling microscope of a self-assembled film composed of compound (VIII) Figure observed by scanning tunneling microscope of a self-assembled film composed of compound (IX) Diagram of a self-organized mixed film composed of compounds (VIII) and (X) observed with a scanning tunneling microscope Diagram of a self-organized mixed film composed of compounds (VIII) and (X) observed with a scanning tunneling microscope

Claims (5)

A double-decker complex characterized in that an alkyl group-modified phthalocyanine represented by the following general formula (I) and another phthalocyanine derivative or porphyrin derivative are linked by a coordination bond with a rare earth metal ion.
(In the formula, CnPc is 2,3,9,10,16,17,23,24-octakis (alkyloxy) phthalocyanine, the subscript n in CnPc is the number of carbon atoms of each alkyl group, and M is a rare earth metal ion. And P represents a phthalocyanine derivative or a porphyrin derivative, respectively.)   A self-assembled film, wherein the double-decker complex according to claim 1 is regularly arranged on a substrate. A method for producing a self-assembled film, comprising: dropping a solution of the double-decker complex of claim 1 onto a substrate to form a film. A self-assembled mixed film, wherein the double-decker complex according to claim 1 and an alkyl group-modified phthalocyanine derivative represented by the following general formula (II) are mixed and arranged on a graphite substrate.
(In the formula, CnH ₂ Pc is 2,3,9,10,16,17,23,24-octakis (alkyloxy) 29H, 31H-phthalocyanine, and the subscript n in CnH ₂ Pc is the carbon atom of each alkyl group. Each represents a number.) A method for producing a self-assembled mixed film, characterized in that a solution in which the double-decker complex of claim 1 and the alkyl group-modified phthalocyanine derivative represented by the general formula (II) are mixed is dropped onto a substrate to form a film. .