JPH05295118A - Amphipathic polysilane derivative - Google Patents

Abstract

PURPOSE:To obtain the objective derivative which has good conductivity and improved solvent and heat resistance, can be formed into a monomolecular film, and is hence useful as an electronic material, by reacting a polysilane comprising repeating units represented by a specific formula with a pyridine derivative. CONSTITUTION:A polysilane comprising repeating units represented by formula I (wherein W is a halogen) is reacted with a pyridine derivative represented by formula II (wherein R2 is an alkyl) to obtain an amphipathic polysilane derivative (a) comprising repeating units represented by formula III (wherein R1 and R2 each is a monovalent hydrocarbon group, R3 is a divalent hydrocarbon group, X is an (in)organic anion which may have a valence, n, of 1 or higher, and the molar ratio of the pyridinium group to X is n:1). An example of the derivative (a) consists only of repeating units represented by formula IV (wherein X and R2 are as defined above). Thus, a pyridinium salt is incorporated into a side chain. The derivative (a) has improved chemical and heat resistance and can be formed into a monomolecular film. It is hence prospective as an electronic material in new applications.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a porasilane derivative. Polysilane is a moldable polymer compound having only silicon atoms as a main chain. Polysilane has conductivity because the σ electrons involved in the silicon-silicon bond move relatively freely in the polymer (σ conjugation). Therefore, application of polysilane as a conductive material, an optical semiconductor, a photoresist, etc. is considered.

[0002]

2. Description of the Related Art Regarding this compound, R. D Mil
Ler, J .; Michl (Chem. Review 8
9p. 1359-1410 (1989)). The side chains of most polysilanes are aliphatic, aromatic or their linking groups, and are limited to hydrophobic hydrocarbon groups and have cation-introduced hydrophilic groups such as quaternary ammonium salts. Things are unknown.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a polysilane derivative having an amphipathic property by quaternization. More specifically, the present invention is represented by the formula:

[0004]

[Chemical 5]

(Wherein R ₁ and R ₂ are monovalent hydrocarbon groups, R
₃ represents a divalent hydrocarbon group, and X represents a monovalent inorganic or organic anion. And an amphipathic polysilane derivative containing a repeating unit represented by the formula (1) and capable of forming a monomolecular film on the water surface by the Langmuir-Blodgett method.

The hydrocarbon group represented by the side chains R ₁ and R ₃ of the polysilane derivative of the present invention is, as is well known, an aliphatic hydrocarbon group such as an alkyl group, an alkylene group or a cycloalkyl group, or a phenyl group. , An aryl group such as a naphthyl group, or a linking group thereof. R ₂ is an alkyl group. Due to the coexistence and harmony of these hydrophobic hydrocarbon group groups and the hydrophilic groups of the quaternized pyridinium salt, the polysilane derivative of the present invention has amphipathic properties and is
A monomolecular film can be formed on the water surface by the blow jet method.

X is SO ₄ ²⁻ , F ⁻ , CrO ₄ ²⁻ , Cr _{2
^{O 7 2-, PO 4 3-,}} CO 3 2-, ClO 4 -, CN -, C
^{l -, Br -, I -} , [Fe (CN) 6] 4-, [Fe
^{_{(CN) 6] 3-, CH}} 3 COO -, NO 3 -, B
It is an anion selected from F ₄ ⁻ , PF ₆ ^−, OH ^{− and the} like.

Further, the polysilane derivative of the present invention may be constituted substantially only by the repeating unit of the formula,
It may be a copolymer with another silane constituent unit.

Since it has an amphipathic property, the present polysilane derivative can easily form a monomolecular film on the water surface by the Langmuir-Blodgett method, and the pyridinium salt can sufficiently increase the melting point. Therefore, it is advantageous for producing a device requiring a heat treatment step, and since the solubility in an organic solvent is improved, the device can be washed with an organic solvent. Further, since it does not lose its conductivity, it is expected to exhibit excellent properties when applied to various electronic materials, films, etc. as a laminated layer of monomolecular films and other molding layers.

In the present invention, a pyridinium ion is selected as the cation, which raises the melting point of the polysilane quaternized salt even when it is an alkylammonium ion.
This is because it is suitable for practical use. Further, the type of anion is appropriately selected because it relates to the melting point and the ability to form a monomolecular film.

The polysilane derivative of the present invention is produced by introducing a pyridine group into the molecule of polysilane and quaternizing. In this method, when a polysilane having a phenyl group is reacted with chloromethyl methyl ether, a corresponding chloromethylphenyl group-containing polysilane is produced (Ban et al., Macromolecule).
s20, p. 1777-1778 (1987)), and reacting this with pyridine to produce an intramolecular pyridinium hydrochloride, and if necessary, converting it to another anion salt. The chloromethyl methyl ether used can be changed to other halogenoalkyl or alkyl ether. According to this method, the molecular weight of the produced polysilane derivative corresponds to the molecular weight of the raw material polysilane.

For example,

[0013]

[Chemical 6]

(In the formula, R2 represents a propyl group or a butyl group, and m represents a degree of polymerization.) Thus, the polysilane derivative of the most preferable formula in the present invention is obtained.

The copolymerized polysilane derivative containing the repeating unit of the formula of the present invention can be obtained by reacting a copolymer of a silane having a phenyl group in the side chain with another silane in the same manner. Those having an alkyl group and / or a cycloalkyl group in the side chain are preferably selected.

The polysilane derivative of the present invention in the form of a monolayer laminated film obtained by the Langmuir-Blodgett (LB) method is suitable as an alignment film for improving the alignment of liquid crystal molecules in a liquid crystal element in the initial state. is there. Since the membrane is conductive,
Provided is a liquid crystal device which is excellent in response speed and bistability of liquid crystal molecules, because even if a ferroelectric liquid crystal is used, it is difficult to generate a partial charge that prevents spontaneous polarization of the liquid crystal molecules. Further, since the heat resistance and solvent resistance of the film are improved, the rubbing is not necessary because it is a monomolecular film which is advantageous in processing and has orientation.

[0017]

【Example】

Reference Example 1 Synthesis of Polyphenylmethylsilane P. Trefonas III (J. Poly, Sc
i. , Polymer Letters. Ed. 21, p
819-822 (1983)) and is obtained by refluxing a toluene solution of phenylmethyldichlorosilane containing sodium. This reaction formula is shown in the following chemical formula.

[0018]

[Chemical 7]

The yield is 13.1% and the melting point is 210 ° C.-2.
The desired product at 20 ° C was obtained.

Reference Example 2 Synthesis of Polychloromethylphenylmethylsilane Next, polychloromethylphenylmethylsilane was synthesized from the obtained polyphenylmethylsilane. For this synthetic method, see H. Ban et al., “Macromol
ecules, 20, p. 1775-1778 (198
7) ”, and tin tetrachloride may be added dropwise to a solution of polyphenylmethylsilane in chloromethyl methyl ether and chloroform, the mixture may be stirred at 5 ° C. for 15 hours and then reprecipitated in methanol to obtain the compound. This reaction becomes like the following chemical formula.

[0021]

[Chemical 8]

The yield is 44.5% and the melting point is 90 ° C. to 1
The target substance at 00 ° C was obtained.

Example 1 Synthesis of tert-butylpyridinium salt of polyphenylmethylsilane Next, 0.6 g (3.7 × 10 ⁻³ mol) of the above polychloromethylphenylmethylsilane was added to DMF (dimethylformamide). Dissolve in 5.2 ml, and then te at room temperature.
5.2 ml of rt-butylpyridine (3.5 × 10 ^-2 mo
1) was added dropwise and stirred for 20 hours. After that, DMF and unreacted t were added by an evaporator and vacuum heating (70 ° C.).
By removing ert-butylpyridine by distillation, tert-butylpyridinium hydrochloride of polyphenylmethylsilane represented by Chemical Formula 9 could be obtained with a yield of 98.0%.

[0024]

[Chemical 9]

FIG. 1 is an NMR spectrum of the above-mentioned tert-butylpyridinium salt in d-dimethyl sulfoxide. The tert-butylpyridinium salt did not show a clear melting point and decomposed at about 300 ° C. ter
A compound obtained by substituting a chloride ion in a t-butylpyridinium salt with a hexafluorophosphate ion has a melting point of 140 ° C., and has almost no solvent resistance in hexane, benzene, isopropyl alcohol, ethanol, methanol, water, etc. It has the property of not melting. Molecular weight is 5,000
It is distributed between 1 and 1,000,000, and has two peaks of high molecular weight and low molecular weight. The average molecular weight is about 200,000 on the high molecular weight side and about 6000 on the low molecular weight side. The alignment film has excellent heat resistance and chemical resistance as well as excellent conductivity.

Example 2 Preparation of Monomolecular Film Next, a method for forming a monomolecular film of a tert-butylpyridinium salt obtained by the above-described synthesis method will be described. First, tert-butylpyridinium chloride 10 ⁻³
0.1 ml of a chloroform solution of M is developed on the lower layer water of potassium hexafluorophosphate (KPF ₆ ) 6 × 10 ⁻⁴ M at 20 ° C., and two-dimensional pressure is constantly applied to form a monomolecular film. FIG. 2 shows a surface pressure-molecule unit occupied area curve in that case. As shown, collapse pressure 5
It can be seen that a monomolecular film of about 0 mN / m is formed. The glass substrate is immersed in the lower layer water in which this monomolecular film is formed, perpendicularly to the surface of the lower layer water, and moved up and down to transfer the monomolecular film of tert-butylpyridinium salt to the glass substrate surface. By this method, a laminated film could be obtained.

[0027]

INDUSTRIAL APPLICABILITY According to the present invention, an amphipathic polysilane derivative containing a pyridinium cation in its side chain is newly provided. This derivative has good conductivity, and has improved solvent resistance and heat resistance. -Application as an ultra-thin film by the projet method is expected.

[Brief description of drawings]

FIG. 1 is a diagram showing an NMR spectrum of an amphipathic polysilane derivative of the present invention obtained in an example.

FIG. 2 is a diagram showing a surface pressure-area curve of a monomolecular film of the amphiphilic polysilane derivative of the present invention obtained in an example.

Claims (6)

[Claims] 1. The formula: (In the formula, R ₁ and R ₂ are monovalent hydrocarbon groups, R ₃ is a divalent hydrocarbon group, X is an inorganic or organic anion, and X is not necessarily monovalent; The valence may be n. The molar ratio of the pyridinium group and X at that time is n: 1.
Also, X does not have to be only one type of ion, X, Y,
It may be a mixture of various ions such as Z. ) An amphipathic polysilane derivative containing a repeating unit represented by the formula (1) and capable of forming a monomolecular film on the water surface by the Langmuir-Blodgett method. 2. The polysilane derivative according to claim 1, which consists essentially of the repeating unit represented by the formula. 3. The repeating unit of the formula has the formula: The polysilane derivative according to claim 1 or 2, wherein X represents an inorganic or organic anion and R ₂ represents an alkyl group. 4. The polysilane derivative according to claim 3, wherein the alkyl group is a tert-butyl group. 5. The polysilane derivative according to claim 1, which is in the form of a monomolecular film. 6. The formula: A polysilane containing a repeating unit represented by the formula (W represents a halogen atom) The method for producing a polysilane derivative according to claim 1, wherein a pyridine compound represented by the formula (wherein R ₂ represents an alkyl group) is reacted.