JPH10226727A - Optically active organosilicon copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce at a low cost a stable copolymer which has one-way helix, has a structure containing a chiral center and is useful as an enantiomer- recognizing material, particularly as CSP material for use in HPLC and GC, and as a model standard substance for use in investigation on the structure and physical properties of an one-dimensional semiconductor and a quantum wire, by using a poly silane which has a side chain having a structure containing a phenyl derivative. SOLUTION: This is a copolymer of a silane monomer unit (-R3 R*Si-) which has a substituent of a chiral structure having a branched structure at the β-position thereof and a structure containing a phenyl derivative and has a chiral structure of 100% optical purity with an achiral silane monomer unit (-R1 R2 Si-), and is represented by the formula, wherein R1 and R3 are each a group having a structure containing a phenyl derivative group, R2 is an alkyl, aralkyl, aryloxyalkyl or the like, R* is a chiral alkyl group having a branched structure at the β-position thereof, x is a number of 0.001<=x<=0.999 and n is 10 to 100,000. This copolymer is prepared by subjecting to desalt- copolymerization an optically active dihalogenated silane and an optically non-active dihalogenated silane which have a corresponding substituent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermochromism, a piezochromism, an electroluminescence, an enantiomer molecular recognition ability, or a one-dimensional quantum wire semiconductor, an optical system containing a phenyl derivative group which is expected to have physical properties and functions as an exciton substance. It relates to an active organosilicon copolymer.

[0002]

2. Description of the Related Art Many organosilicon compounds are industrially useful. For example, surface treatment agents, water-repellent oils, electric insulators, heating media, and precursors of ceramic materials all have a silicon atom skeleton. Is a polymer contained in a part of In recent years, solvent-soluble organic polysilanes, whose main chain skeleton is composed only of silicon, have been attracting attention as a new type of functional material. Photoresists, optical waveguide materials, precursors of silicon carbide, electrophotographic photosensitive materials Body, nonlinear optical material,
Many examples of research directed to applications, such as light emitting materials, are in progress.

[0003] Organopolysilanes are generally from 300 to 400
In the vicinity of nm, it has an ultraviolet absorption band based on the main chain skeleton peculiar to the Si-Si chain, and since the main chain itself is a polymer composed only of silicon, the main chain is easily decomposed by irradiation with ultraviolet light, and the low molecular weight is low. Conversion or siloxane conversion easily proceeds. Actually, an application example as a photoresist utilizing this is reported. Therefore, organic polysilanes are used for electrophotographic photoreceptors, nonlinear optical materials, luminescent materials, etc.
It is unsuitable for application for light-related functional materials. However, in light of absorption and emission in the ultraviolet region, a polymer soluble in a solvent can be easily obtained by relatively simple chemical synthesis. It is very valuable and attractive as a model material for basic research on electrical properties, and is expected to be marketable as a polymer standard material.

On the other hand, as a polymer material that recognizes enantiomers, the main chain is unidirectional, such as poly (triphenylmethyl methacrylate) and poly (diphenylpyridylmethyl methacrylate) synthesized using spartin-butyllithium as a polymerization initiator. Carbon skeletal polymers having helicity are known [for example, Y. Okamoto
oto) et al., Journal of American Chemical Society (J. Am. Chem. Soc.), 103, 6971 (1981)]. These organic polymers with unidirectional resiliency are actually supported on the silica gel surface,
It is marketed as a column material for high performance liquid chromatography that separates and separates enantiomers [Daicel Chemical Co., Ltd .: product names Chiralpak-OT, Chiralpak-OP]. However, these poly (triphenylmethyl methacrylate) -based materials have a fatal drawback in that the side chains that fix the main-chain helical structure are eliminated and the ability to recognize enantiomers is lost at the same time.

As long as the silicon main chain skeleton and hydrocarbon side chain of the organic polysilane can take advantage of the feature of being resistant to hydrolysis and solvolysis, they are usually used in a dark place and under conditions of deoxygenation. High performance liquid chromatography (HP
It can be used as a column material for gas chromatography (abbreviated as LC) and gas chromatography (abbreviated as GC). Further, it is expected that the resistance to oxygen is further improved as compared with the organic polysilane, if the organic polysiloxane structure is optically active. For example, when the thermodynamically unstable organic polysilane skeleton is oxidized, it is thought that it is ultimately converted into a thermodynamically stable optically active organic polysiloxane, but the chirality of the main chain is still high. The ability to recognize the enantiomer derived from is still retained, and therefore, it can be expected that it has properties that can be practically used for long-term repeated use.

At present, as a means for separation and analysis by HPLC,
Most of the column materials for enantiomer recognition that can be used under reversed-phase conditions are derived from biological substances, and most of them are alkyl derivatives having an amide bond. Therefore, there still remains a problem of column degradation due to hydrolysis. Here, if an optically active organic polysilane derived from a chlorosilane-based material having an optically active substituent or having the helicity of the main chain skeleton itself can be supported on a carrier, an optical isomer separation column for HPLC ( Hereinafter, it can be used as a CSP for GC) or a CSP for GC.

Recently, a single helical (constant winding direction, uniform pitch) polysilane which is thermally very stable in solution has been reported,
At 4 eV (320 nm), the half width is 0.10 eV (8
nm) very steep UV-circular polarization (CD) absorption,
It was reported to exhibit fluorescence spectral properties. Since this single helix polysilane exhibits ideal exciton optical response spectrum characteristics, it is attracting attention as a quantum wire semiconductor (line width 0.5 nm) soluble in organic solvents and as an ideal one-dimensional exciton substance. [For example, M. Fujiki, Journal of American Chemical Society, Vol. 116, pp. 6017 (19
94); Fujiki, Applied Physics Letters (Appl. Phys. Lett.), 65, 325
1 (1994)].

[0008]

However, the side chains of these optically active polysilanes are alkyl groups, aralkyl groups,
It is limited to an aryloxyalkyl group or an alkyl ether group, and its enantiomer recognition ability has not been confirmed at present. Here, if an optically active polysilane having a phenyl derivative group as a side chain can be synthesized,
It is expected that the affinity for the enantiomer to be recognized will be dramatically improved, and the enantiomer recognition ability will be improved.

Further, a special organic dichlorosilane having an enantiomerically pure right-handed ([R] -isomer) or left-handed ([S] -isomer) chiral alkyl group in the side chain is used as a raw material to remove with sodium metal. When a homopolymer obtained by salt condensation is used, the raw material of the [R] -form or the [S] -form is very expensive, so that the production cost increases. Therefore, even if the optical purity is slightly lower or the amount of chiral monomer used is reduced to reduce the manufacturing cost, the unidirectional helical structure with the same exciton optical response spectrum characteristics as the homopolymer is maintained. There was a need to.

It is an object of the present invention to provide an enantiomer-recognizing material, in particular, an organic substituent containing a chiral center, which is useful as a material for a CSP for HPLC or GC, or as a model reference material for studying the properties of one-dimensional semiconductors and quantum wire structures. An object of the present invention is to provide an optically active organosilicon polymer group having a phenyl derivative group having a structure directly bonded to an atom and having a one-way helix stably maintained even in a solution at room temperature, at a lower cost.

[0011]

The optically active organosilicon copolymer of the present invention for achieving the above object has the following general formula (I):

[0012]

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(Wherein R ₁ and R ₃ are the same or different phenyl derivative groups, R ₂ is an alkyl group, an aralkyl group, an aryloxyalkyl group or an alkyl ether group, and R ^* has a branched structure at the β-position. X is 0.001 ≦ x ≦ 0.999,
n is 10 to 100,000. ).

[0014]

DETAILED DESCRIPTION OF THE INVENTION A feature of the present invention is that a silane monomer unit having a chiral structure having an optical purity of 100% having a substituent having a chiral structure having a branched structure at the β-position and a phenyl derivative (ie,- R ₃ R ^* Si—) and an achiral silane monomer unit containing a phenyl derivative group (that is, —R ₁ R ₂ Si—).

In the above general formula (I), R ₁ and R
Examples of the group represented by ₃ include C ₆ H ₅ , o- (CH
_{3) C 6 H 4, m-} (CH 3) C 6 H 4, p- (CH
₃ ) C ₆ H _{4 and the} like.

In the general formula (I), examples of the alkyl group among the groups represented by R ₂ include CH ₃ ,
_{C 2 H 5, n-C} 3 H 7, n-C 4 H 9, n-C 5
_{H 11, n-C 6 H} 13, n-C 7 H 15, n-C 8 H 17, n
_{-C 9 H 19, n-C} 10 H 21, n-C 11 H 23, n-C 12 H
_{25, n-C 13 H 27} , n-C 14 H 20, n-C 15 H 31, n-
_{C 16 H 33, n-C} 17 H 35, n-C 18 H 37, n-C
_{19 H 30, n-C 20} H 41 and the like. Examples of the aralkyl group include CH ₂ CH ₂ Ph (Ph represents a phenyl group; the same applies hereinafter), CH ₂ CH ₂ CH ₂ Ph, CH ₂ C
H ₂ CH ₂ CH ₂ Ph is mentioned. Examples of the aryloxyalkyl group include CH ₂ CH ₂ OPh, CH
₂ CH ₂ CH ₂ OPh, CH ₂ CH ₂ CH ₂ CH ₂ OP
h. Examples of the alkyl ether group include CH ₂ CH ₂ OCH ₂ CH ₂ OC ₂ H ₅ , CH ₂ C
H ₂ O (CH ₂ CH ₂ O) ₂ C ₂ H _{5 and the} like.

In the general formula (I) of the present invention, among the groups represented by R ^* , examples of the group represented by (R) -R include each group represented by the following formula (Formula 5) Is mentioned.

[0018]

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[0019]

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On the other hand, examples of the group represented by (S) -R include the groups represented by the following formula (Formula 6).

[0021]

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[0022]

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The optically active organosilicon copolymer of the present invention comprises
It is synthesized by desalting and copolymerizing an optically active dihalogenated silane having a corresponding substituent and an optically inactive dihalogenated silane with metallic sodium in toluene. At that time, the helical winding property of the obtained copolymer is determined only by the absolute configuration of the optically active dihalogenated silane used. That is, if an optically active dihalogenated silane having a chiral alkyl group of (S) -configuration is incorporated into a part of the copolymer, it can be synthesized only from an optically active dihalogenated silane having a chiral alkyl group of (S) -configuration. It has the same winding property as the polymer.

The above-mentioned optically active dihalogenated silane for synthesizing the optically active organosilicon copolymer of the present invention has a chiral alkyl group having a branched structure at the β-position.

[0025]

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(Wherein, R ₃ and R ^* have the same meanings as above, X is preferably Cl or Br, Y is a halogen atom, preferably Cl, and Et ₂ O is diethyl ether. )). The specific synthesis method of this compound is described in JP-A-6-306087 and JP-A-7-
No. 33784 is described in each specification. In the present invention, optically active dichlorosilane is preferably used. Specific examples of this compound include [(S) -2-methylbutyl-phenyl] dichlorosilane, [(R) -2-
Methylbutyl-phenyl] dichlorosilane, [(S)-
3-methylpentyl-phenyl] dichlorosilane,
[(R) -3-methylpentyl-phenyl] dichlorosilane and the like.

The above-mentioned optically inactive dihalogenated silane for synthesizing the optically active organosilicon copolymer of the present invention is also represented by the following reaction formula:

[0028]

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(Wherein, R ₁ and R ₂ have the same meanings as above, X is preferably Cl or Br, Y is a halogen atom, preferably Cl, and Et ₂ O is diethyl ether. )). In the present invention, optically inactive dichlorosilane is preferably used. For example, (methyl-phenyl) dichlorosilane, (ethyl-phenyl) dichlorosilane, (n
-Propyl-phenyl) dichlorosilane, (methyl-m
-Tolylsilane) dichlorosilane, (ethyl-m-tolylsilane) dichlorosilane, (n-propyl-m-tolylsilane) dichlorosilane, (n-butyl-m-tolylsilane) dichlorosilane, (n-pentyl-m-tolylsilane) dichlorosilane Chlorosilane, (n-hexyl-m-tolylsilane) dichlorosilane and the like can be mentioned.

At this time, the dichlorosilanes containing an optically active organic substituent to be used are free from racemization or rearrangement in the course of sodium desalination and condensation because the branch is at the β-position. Since the degree of steric hindrance between silicon monomers at the time of the reaction is relatively small, high molecular weight optically active chain organic polysilane is easily formed.

In the present invention, low temperature polymerization, preferably about 65
By carrying out the polymerization at ° C., a copolymer having a desired high molecular weight is obtained. Alternatively, in order to obtain the copolymer of the present invention by high-temperature polymerization, preferably at about 130 ° C., it is desirable to carry out the above-mentioned copolymerization component by dropping it into a solvent at once.

[0032]

EXAMPLES Specific examples of the synthesis of the optically active linear organic polysilane copolymer of the present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

(Example 1) A specific synthesis example of poly [((S) -2-methylbutyl-phenylsilane) _0.25 -co (co)-(methyl-phenylsilane) _0.75 ] will be described.

After the inside of the reaction vessel was sufficiently dehydrated and degassed and purged with argon gas, 1.60 g of metallic sodium and 15 ml of dehydrated toluene were placed in a flask. [(S) -2-
1.65 g of methylbutyl-phenyl] dichlorosilane
(25 mol%) and 5.00 g (75 mol%) of (methyl-phenyl) dichlorosilane were placed in a dropping funnel, and then placed in the flask at an oil bath temperature of 130 ° C. in a volume of 0.3%.
g was dropped. This reaction solution was stirred at high speed to break down the sodium in the flask into fine particles. Oil bath temperature 65 ℃
After cooling, the remainder of the dichlorosilane mixture was slowly added dropwise so that the reaction temperature did not exceed 70 ° C., and the mixture was reacted for 1 hour. The reaction mixture was filtered under pressure, and isopropyl alcohol was added to the filtrate. The resulting white precipitate was collected by a centrifugal separator and dried at 110 ° C. under vacuum.

The yield of the organosilicon copolymer thus obtained was 0.46 g, and the yield was 7% in terms of dichlorosilane.
Met. By GPC, the weight average molecule was 1.5 million monomodal. FIG. 1 shows an ultraviolet absorption spectrum and a circular dichroism absorption spectrum of the obtained copolymer. That is, FIG. 1 shows an absorption spectrum of poly [((S) -2-methylbutyl-phenylsilane) _0.25 -co (co)-(methyl-phenylsilane) _0.75 ] and a circular dichroic absorption spectrum obtained in Example 1. It is a figure which shows (in tetrahydrofuran -10 degreeC).

In FIG. 1, the horizontal axis is the photon energy (e
V), the left vertical axis represents the extinction coefficient [ε (Si unit) -1dm ³ c
m ^-1 ] and the vertical axis on the right is the circular two-color absorption coefficient [Δε (Si unit) −
¹ dm ³ cm ^-1 ]. From the comparison of these spectra, the cotton CD absorption band at 3.56 eV was found to be 3.60 eV.
It was clarified that the main-chain absorption band was almost similar in shape and the absorption maximums were almost the same.

At the photon energy at which the circular dichroism absorption spectrum has a maximum value, the asymmetry factor (value obtained by dividing the CD absorption band by the ultraviolet absorption band) which is very sensitive to the helix property is (S) −
The dependence of the body content is shown in FIG. It can be seen that the value of the asymmetry factor is almost saturated at 30%. Also, comparing the value of the asymmetry factor with that of poly [n-hexyl- (S) -2-methylbutylsilane], which gives a unidirectional helix, poly [n-hexyl- (S) -2-methylbutylsilane] 2.3 × 10 ^-4 and 1.8% with 30% copolymer
^0-4 was ^almost the same.

The above results indicate that when 30% or more of (S) -chiral silane is contained in the copolymer, the copolymer becomes
It means that it has the same winding, spiral pitch, and rigid polymer structure as the homopolymer poly [(S) -2-methylbutyl-phenylsilane].

Example 2 A specific example of the synthesis of poly [((S) -2-methylbutyl-phenylsilane) _0.20 -co (co)-(n-hexyl- (m-tolyl) silane) _0.80 ] is shown. .

After the inside of the reaction vessel was sufficiently dehydrated and degassed and purged with argon gas, 1.07 g of metallic sodium and 5 ml of dehydrated toluene were placed in a flask. [(S) -2-methylbutyl-phenyl] dichlorosilane 0.92 g (2
0 mol%) and (n-hexyl-m-tolylsilane)
3.00 g (80 mol%) of dichlorosilane was dropped into the flask at once at an oil bath temperature of 130 ° C.
The reaction was performed for 0 minutes. The reaction mixture was filtered under pressure, and isopropyl alcohol was added to the filtrate. The resulting self-colored precipitate was collected by a centrifuge, and dried at 110 ° C. under vacuum.

The yield of the organosilicon copolymer thus obtained was 0.03 g, and the yield was 0.1 in terms of dichlorosilane.
7%. By GPC, the weight average molecule was 240,000 monomodal. FIG. 3 shows an ultraviolet absorption spectrum and a circular dichroism absorption spectrum of the obtained copolymer. That is,
FIG. 3 shows poly [((S) -2-methylbutyl-phenylsilane) _0.20 -co (co)-(n-
[Hexyl-m-tolylsilane) _0.80 ] and a circular dichroic absorption spectrum (in tetrahydrofuran at -10 ° C).

In FIG. 3, the horizontal axis represents the photon energy (e
V), the left vertical axis represents the extinction coefficient [ε (Si unit) -1dm ³ c
m ^-1 ] and the vertical axis on the right is the circular two-color absorption coefficient [Δε (Si unit) −
¹ dm ³ cm ^-1 ]. From comparison of these spectra, the cotton CD absorption band at 3.58 eV was 3.53 eV.
It was clarified that the main-chain absorption band was almost similar in shape and the absorption maximums were almost the same.

At the photon energy at which the circular dichroism absorption spectrum has a maximum value, the asymmetry factor (value obtained by dividing the CD absorption band by the ultraviolet absorption band) which is very sensitive to the helix property is (S) −
FIG. 4 shows the body content dependence. Comparing the value of the asymmetry factor to that of poly [n-hexyl- (S) -2-methylbutylsilane], which gives a one-way helix, poly [n-hexyl- (S) -2-methylbutylsilane] gives 2 .3 ×
It was 1.6 × 10 ^-4 at 10 ^-4 and 50% copolymer, which was almost the same. The above results indicate that 50% or more of (S) was contained in the copolymer.
The inclusion of chiral silane means that the copolymer has the same winding, helix pitch, and rigid polymer structure as the homopolymer poly [(S) -2-methylbutyl-phenylsilane]. .

[0044]

As shown in the present invention, when a copolymer is synthesized from dichlorosilane having a chiral alkyl group having a branched structure at the β-position and a phenyl derivative group as a raw material, the optical purity is low. 100% purity if the active chiral monomer is contained in a small amount relative to the achiral monomer
It has been shown that it gives almost the same helical structure, main chain absorption, and circular dichroic absorption spectrum characteristics as the homopolymer synthesized from the chiral monomer. That is, industrially, as a raw material for synthesizing a copolymer, a very small amount of a chiral monomer, or an irregular chiral monomer that can be said to be almost racemic, can be used. An organic polysilane containing a phenyl derivative group can be provided at very low cost. Such an optically active organic polysilane is expected to be used as a new type of enantiomer recognition material.

[Brief description of the drawings]

FIG. 1 shows the absorption of poly [((S) -2-methylbutyl-phenylsilane) _0.25 -co (co)-(methyl-phenylsilane) _0.75 ] obtained in Example 1, and the circular dichroic absorption spectrum (tetrahydrofuran) FIG.

FIG. 2. Poly [((S) -2-methylbutyl-phenylsilane) _x -co (co)-(methyl-phenylsilane)
FIG. 2 is a diagram showing the relationship between the content of the (S) -form and the asymmetry factor (in tetrahydrofuran at −10 ° C.) in the [ _1-x ] system.

FIG. 3 shows the poly [((S) -2-methylbutyl-phenylfusilane) obtained in Example 2 _0.20 -co (co)-(n
-Hexyl-m-tolylsilane) _0.80 ] and a circular dichroic absorption spectrum (in tetrahydrofuran at -10 ° C).

FIG. 4 shows the content of the (S) -form in the poly [((S) -2-methylbutyl-phenylsilane) _x -co (co)-(n-hexyl-m-tolylsilane) _1-x ] system, It is a figure which shows the relationship of an asymmetry factor (in tetrahydrofuran, -10 degreeC).

Claims (1)

[Claims] 1. The following general formula (I): (Wherein R ₁ and R ₃ are the same or different phenyl derivative groups, R ₂ is an alkyl group, an aralkyl group, an aryloxyalkyl group, or an alkyl ether group, and R ^* is a chiral group having a branched structure at the β-position. Represents an alkyl group,
x is 0.001 ≦ x ≦ 0.999, and n is 10 to 1
00000. An optically active organosilicon copolymer represented by the formula: