JP2013193956A - Tetrakis-trialkyl or phenylsilylethynyl-substituted phthalocyanine, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide new phthalocyanine and a method for producing the same.SOLUTION: A compound represented by general formula (1) and a method for producing the same are provided. (in the general formula (1), M is Ni, Cu, Co, Zn or two Hs, and R, Rand Rare each independently a 1-6C alkyl group or phenyl group).

Description

  The present invention relates to a tetrakis-trialkyl or phenylsilylethynyl substituted phthalocyanine which is a soluble phthalocyanine and a method for producing the same.

  Phthalocyanine has been used as a pigment for a long time, but in recent years it is a compound that is extremely important as an information recording dye. Since unsubstituted phthalocyanine has extremely low solubility in an organic solvent or the like, a thin film or the like is prepared by a sublimation method. In recent years, therefore, the synthesis of phthalocyanines that are soluble in organic solvents has been actively studied for the purpose of making them available by coating methods. In addition, metal phthalocyanines are actively studied as molecular magnetic materials and molecular light emitting materials.

  In particular, tetrakis- (tert-butyl) phthalocyanine metal complexes synthesized from 4-tert-butylphthalonitrile must be soluble in various organic solvents by reducing the interaction due to π-π stacking of the phthalocyanine ring. As a result, the use of dyes for dye-sensitized solar cells, optical filters, and dyes for optical recording has been actively studied. In connection with this, the present inventors previously filed a patent application for an efficient production method of a novel soluble monosubstituted phthalocyanine having an amino group (Patent Document 1).

  In recent years, research on molecular electronics, in which each molecule has the role of a device such as a transistor or a wire, has attracted much attention in recent years. If the excellent electronic and optical properties of a single molecule can be used, it is expected that limiting elements such as diodes, drain transistors, and lasers using molecular assemblies can be realized by combining them.

  Although the semiconductor industry has been miniaturized by the top-down method so far, the apparatus for performing microfabrication is very expensive and is not suitable for mass production. However, on the other hand, a bottom-up method of assembling from the minimum unit of substances such as atoms and molecules has come to be considered. In the bottom-up approach, the most efficient method when considering mass production is self-organization. Self-assembly of organic supramolecules is caused by interactions such as electrostatic interactions, hydrogen bonds, van der Waals forces, stacking effects, and donor-acceptor effects. These are useful means for constructing nano-sized devices with much smaller energy than conventional top-down methods.

JP 2011-162575 A

  Metal phthalocyanine, which is a macrocyclic complex with large π electrons, forms a columnar structure by overlapping π electrons between the planes when the complexes are stacked and the metal-metal distance is sufficiently short. However, phthalocyanine having such a structure is not soluble due to π conjugation.

  Accordingly, the present invention provides a novel phthalocyanine that is soluble in an organic solvent and capable of creating molecular nanowires by spontaneous self-assembly utilizing π stacking, and a method for producing the same, and a novel method based on a new light emission principle. The purpose is to clarify that luminescent molecules can be constructed.

  The present inventors have added trialkylsilylacetylene or triphenylsilylacetylene to metal phthalocyanine for the construction of a new bulky trialkylsilyl group or triphenylsilyl group in an organic solvent and the construction of a π-conjugated system with an ethynyl group. Introduced and made soluble, and found that it is possible to create molecular nanowires by spontaneous self-assembly using newly generated π stacking, and found that it can be used as a new light emitting device. Was completed.

The present invention is as follows.
[1]
A compound represented by the following general formula (1).
In general formula (1), M is Ni, Cu, Co, Zn, or two H, and R ¹ , R ² , and R ³ are each independently an alkyl group having 1 to 6 carbon atoms or a phenyl group. . The alkyl group having 1 to 6 carbon atoms is, for example, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or an n-hexyl group. Can do. R ¹ , R ² and R ³ may be the same or different groups, but are preferably the same in terms of the production method.

[2]
4-trialkyl or 4-triphenylsilylethynylphthalonitrile represented by the general formula (2) (R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms or a phenyl group) Represented by the general formula (1) according to [1], which comprises reacting by heating in an organic solvent in the presence of a metal salt (where the metal is Ni, Cu, Co or Zn) or ammonia. The manufacturing method of the compound made.

  The compound of the present invention represented by the general formula (1) is a novel phthalocyanine that is soluble and soluble in an organic solvent and capable of creating molecular nanowires by spontaneous self-assembly using π stacking. It has been found that it has novel physical properties that emit fluorescence in the ultraviolet region. In general, it is known that metal phthalocyanines include compounds that do not emit fluorescence with a central metal and compounds that do not. Phthalocyanine whose central metal is nickel is generally known as a molecule that does not emit fluorescence. However, in the present invention, by introducing a trialkylethynyl group, it has become clear that light is emitted at around 400 nm, which is not generally reported.

1H NMR spectrum (in CDCl ₃ ) of Compound 6 is shown. 1 shows a TOF-MS spectrum of Compound 7 . 1 shows an electron micrograph of Compound 7 . 1 shows an electron micrograph (enlarged image) of Compound 7 . 1 shows an AFM image of Compound 7 . 1 shows the UV-vis spectrum of Compound 7 . 1 shows the fluorescence spectrum of Compound 7 .

<Method for Producing Compound Represented by General Formula (1)>
The compound represented by the general formula (1) can be produced by reacting 4-trialkyl or phenylsilylethynylphthalonitrile represented by the general formula (2).

  4-trialkyl or 4-triphenylsilylethynylphthalonitrile represented by the general formula (2) can be synthesized using phthalimide as a raw material. A synthesis example of 4-trimethylsilylethynylphthalonitrile is shown as a scheme below.

In order to synthesize compound 6 as a starting material, phthalimide is first nitrated to give 4-nitrophthalimide ( 1 ). This is amidated to give 4-nitrophthalamide ( 2 ). The compound ( 2 ) is dehydrated, 4-nitrophthalonitrile ( 3 ) is synthesized, and further the nitro group is reduced to obtain 4-aminophthalonitrile ( 4 ). Furthermore, 4-iodophthalonitrile ( 5 ) was synthesized by iodination of the amino group of compound ( 4 ), and trimethylsilylacetylene was introduced into this by using Sonogashira cross coupling. Nitrile ( 6 ) is obtained. Synthetic methods up to compound 6 are known. (For example, reference (1) SM Marcuccio., Et al., Can. J. Chem., 36 , 3057-3069, 1985) Instead of trimethylsilylacetylene, other trialkylsilylacetylene or triphenylsilylacetylene is used. Thus, 4-trialkylsilylethynylphthalonitrile or 4-triphenylsilylethynylphthalonitrile represented by the general formula (2) can be synthesized in the same manner as described above.

The synthesis route of the compound represented by the general formula (1) is shown below by taking the case where the trialkyl group is a trimethyl group as an example.

  The above reaction can be performed by heating 4-trimethylsilylethynylphthalonitrile represented by the formula (6) in an organic solvent in the presence of a metal salt. Although heating temperature can be suitably determined in consideration of the kind of organic solvent and metal salt, it can be set, for example, in the range of 80 to 130 ° C. The reaction time can be appropriately determined in consideration of the organic solvent, the heating temperature, and the type of metal salt, and can be, for example, in the range of 3 to 48 hours. The organic solvent can be appropriately determined in consideration of the reaction temperature. For example, dimethylaminoethanol, quinoline, n-pentan-1-ol and the like can be used. The metal of the metal salt can be appropriately selected from nickel, copper, cobalt and zinc according to M of the compound represented by the general formula (1). The metal salt can be, for example, an organic acid salt, an inorganic acid salt, and the like. The organic acid that forms the organic acid salt can include, for example, acetic acid, and the inorganic acid that forms the inorganic acid salt. Can include hydrochloric acid and sulfuric acid. The amount of the metal salt used for the reaction is suitably equivalent to or more than 4-trimethylsilylethynylphthalonitrile, and can be, for example, in the range of 1 to 50 equivalents. 4-trialkyl or 4-triphenylsilylethynylphthalonitrile other than 4-trimethyl can be synthesized in the same manner as described above.

Further, phthalocyanine having no central metal can be obtained by using ammonia in place of the metal salt under the above reaction conditions. Ammonia can be supplied, for example, by bubbling under heating in an organic solvent containing 4-trimethylsilylethynylphthalonitrile represented by the formula (6) as a gas. Although heating temperature can be suitably determined in consideration of the kind of organic solvent, it can be set as the range of 80-130 degreeC, for example. Although reaction time can be suitably determined in consideration of an organic solvent and heating temperature, it can be set as the range of 3 to 48 hours, for example. The organic solvent can be appropriately determined in consideration of the reaction temperature. For example, dimethylethanol, dimethylaminomethanol, quinoline, n-pentan-1-ol, and the like can be used. For the reaction using ammonia, reference can be made to the following literature (PJ Brach, SJ Grammatica, OA Ossanna, L. Weinberger, J. Heterocycl. Chem., 7 , 1403, 1970). 4-trialkyl or 4-triphenylsilylethynylphthalonitrile other than 4-trimethyl can be synthesized in the same manner as described above.

  After completion of the reaction, the reaction solution is added to water, for example. The tetrakis-trimethylsilylethynyl substituted phthalocyanine represented by the general formula (1) is insoluble in water because it has trimethylsilylethynyl. Therefore, tetrakis-trimethylsilylethynyl substituted phthalocyanine represented by the general formula (1) precipitates, and can be recovered as a solid by solid-liquid separation by a conventional method. The recovered tetrakis-trimethylsilylethynyl-substituted phthalocyanine represented by the general formula (1) can be further purified by a conventional method. Tetrakis-trialkyl or tetrakis-triphenylsilylethynylphthalonitrile other than tetrakis-trimethyl can be recovered and purified as described above.

  Since the tetrakis-trialkyl or tetrakis-triphenylsilylethynyl substituted phthalocyanine represented by the general formula (1) has four trialkyl or triphenylsilylethynyl groups, it is a molecular nanowire by spontaneous self-assembly using π stacking. Can be created. In particular, a compound in which the central metal M is zinc or a compound without the central metal (M = 2H) exhibits a fluorescence emission characteristic around 700 nm, which is typical of a general metal phthalocyanine. A new property of fluorescence emission around 400 nm, which does not normally appear in the metal phthalocyanine, was revealed.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Synthesis of 4- (2-trimethylsilylethynyl) phthalonitrile ( 6 )

Compound 5 (0.508 g, 20 mmol), copper (I) iodide (3.8 mg, 0.02 mmol), bistriphenylphosphine palladium dichloride (14 mg, 0.02 mmol) in a 30 ml two-necked flask equipped with a septum and argon Replace. Further, after replacing the 30 ml two-necked flask equipped with a septum with argon, trimethylsilylacetylene (0.31 ml) and diethylamine (8.0 ml) are added using a syringe, and freeze deaeration is performed three times. After degassing, transfer the solution to the 30 ml two-neck flask prepared earlier using both needles and react at room temperature for 3 hours. After completion of the reaction, the solution was suction filtered, and purified by silica gel column chromatography (eluent = hexane: methylene chloride = 70: 30) to obtain compound 6 .
The structure of compound 6 was determined by the 1H NMR spectrum (in CDCl ₃ ) of compound 6 shown in FIG.

Synthesis of Ni (II) tetrakis- (trimethylsilylethynyl) phthalocyanine ( 7 )

Attach a septum to a 30 ml two-necked flask, add a stir bar, compound 6 (30 mg, 0.13 mmol), nickel chloride hexahydrate (31 mg), and purge with argon. Then add dimethylaminoethanol (2.0 ml) using a syringe and heat and stir at 100 ° C. for 6 hours. After completion of the reaction, the solid is deposited in water. The precipitated solid is suction filtered and purified by alumina column chromatography (eluent = chloroform) to obtain compound 7 . Yield 3.53 mg, Yield 11%
Compound 7 was confirmed by a TOF-MS spectrum of compound 7 shown in FIG.

The synthesized compound 7 in chloroform is naturally dried on a plate to form a self-assembly. 3 and 4 show electron micrographs of the self-assembly produced at that time.
An atomic force microscope (AFM) measurement was performed to clarify that the phthalocyanine ring was self-assembled (FIG. 5). As a result, we succeeded in observing about 13 to 16 mm of compounds derived from the phthalocyanine ring and about 8 mm between the central metals. Further, the UV-vis spectrum of compound 7 is shown in FIG. 6, and the fluorescence spectrum is shown in FIG. As shown in FIG. 7, Compound 7 emits light at around 400 nm, which is not generally reported.

  The present invention can be used as a donor molecule for organic thin-film solar cells and an organic semiconductor element, and can also be used as a molecular conductive material. Moreover, it is useful for the field | area relevant to the fluorescent dye for the forgery prevention of a banknote, and the labeling dye by utilizing the fluorescence characteristic in a near ultraviolet region.

Claims (2)

A compound represented by the following general formula (1).
(In General Formula (1), M is Ni, Cu, Co, Zn, or two H, and R ¹ , R ² , and R ³ are each independently an alkyl group having 1 to 6 carbon atoms or a phenyl group. is there.) 4-trialkyl or 4-triphenylsilylethynylphthalonitrile represented by the general formula (2) (R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms or a phenyl group) Represented by the general formula (1) according to claim 1, comprising reacting by heating in an organic solvent in the presence of a metal salt (wherein the metal is Ni, Cu, Co or Zn) or ammonia. The manufacturing method of the compound made.