JPH07228585A - Silacyclohexane compound, its production and liquid crystal composition containing the compound - Google Patents

Abstract

PURPOSE:To obtain a silacyclohexane compound useful as a base material for liquid crystal, effective for lowering the driving voltage, expanding the working temperature range and improving the low temperature performance, etc., to meet the needs for the use on automobiles by carrying out a carbon- carbon bond forming reaction in the presence of a specific transition metal compound. CONSTITUTION:This silacyclohexane compound is a compound expressed by formula I (R and R' are each a 1-10C straight-chain alkyl, a 1-10C mono or difluoroalkyl, a 3-8C branched-chain alkyl, a 2-7C alkoxyalkyl, a 2-8C alkenyl; either one of ring A and ring B is trans-1- or 4-sila-1,4-cyclohexylene having H, F, Cl or CH3 substituent on the Si at 1 or 4-site; zero, one or two X groups are F and the others are H), e.g. trans,trans-4,4'-dio(4-n-pentyl-4-silacyclohexyl) biphenyl. The compound can be produced by a C-C bond forming reaction of an organometallic reagent of formula II [M is MgP (P is a halogen), ZnP or B(OY)2 (Y is H or an alkyl)] in the presence of a transition metal compound of formula III (Q is a halogen) as a catalyst.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel silacyclohexane compound, a method for producing the same, a liquid crystal composition containing the same, and a liquid crystal display device containing the liquid crystal composition.

[0002]

2. Description of the Related Art A liquid crystal display device utilizes optical anisotropy and dielectric anisotropy of a liquid crystal substance, and depending on its display system, TN type (twisted nematic type), STN type (super twisted nematic type). , SBE type (super birefringence type),
There are various types such as a DS type (dynamic scattering type), a guest / host type, a DAP type (aligned phase deformation type), and an OMI type (optical mode interference type). The most common display device is based on the Schut-Helfrich effect and has a twisted nematic structure.

The properties required of the liquid crystal composition used for these liquid crystal display devices are slightly different depending on the display system, but the liquid crystal temperature range is wide, moisture, air, light,
Stableness against heat, electric field, etc. is commonly required in all display systems. Furthermore, the liquid crystal composition is desired to provide a short address time, a low threshold voltage and a high contrast in a cell in addition to having a low viscosity.

At present, there is no substance that satisfies all of these requirements with a single compound, and actually, a liquid crystal mixture obtained by mixing several to several dozen liquid crystal compounds / latent liquid crystal compounds is used. . Therefore, it is important that the constituent components of the liquid crystal composition be easily miscible with each other.

Among the liquid crystal compounds that can be these constituents, one of the basic components that governs the ability to develop a liquid crystal phase at high temperatures, conventionally, is the following cyclohexyl ring-biphenyl cyclohexyl ring structure, so-called CBC. A compound having a structure is known.

[Chemical 6] (See Japanese Patent Publication No. 62-46527)

[Chemical 7] (See Japanese Patent Publication No. 4-28693)

[Chemical 8] (See Japanese Patent Publication No. 4-28693)

[Chemical 9] (See Japanese Patent Publication No. 4-28693)

[0006]

With the recent widespread use of liquid crystal displays, the properties required of liquid crystal compositions are becoming more and more severe. In particular, it has been desired to further improve the characteristics of the conventional liquid crystal composition, such as lowering the driving voltage, widening the temperature range to meet vehicle needs, and improving low-temperature performance.

From this point of view, the present invention is a liquid crystal material newly developed for the purpose of improving the characteristics of the liquid crystal material, and the above-mentioned conventional cyclohexyl ring-biphenyl-cyclohexyl ring structure (CBC structure). It is an object of the present invention to provide a liquid crystal compound having a silacyclohexane ring which is completely different from the liquid crystal compound having a).

[0008]

That is, the present invention is a silacyclohexane compound represented by the following general formula (I).

[Chemical 10]

In the formula, R and R'have 1 to 1 carbon atoms.
0 straight-chain alkyl group, C1-10 mono- or difluoroalkyl group, C3-8 branched chain alkyl group, C2-7 alkoxyalkyl group or C2
Represents the alkenyl group of ~ 8.

[Chemical 11] as well as

[Chemical 12] Is at least one of trans-1- whose silicon at the 1- or 4-position has a substituent of H, F, Cl or CH _3.
Sila-1,4-cyclohexylene group or trans-4-
It represents a sila-1,4-cyclohexylene group. The substituents X on the aromatic ring are F, 0, 1 or 2 are F, and the others are H.

The present invention also relates to an organometallic reagent.

[Chemical 13] (R is the same as in the general formula (I), M is MgP (P is a halogen atom), ZnP or B (OY) ₂ (Y is H or an alkyl group), X is F or H), and halogenated. Aryl compound

[Chemical 14] The silacyclohexane compound according to claim 1, which is based on a carbon-carbon bond-forming reaction with a transition metal compound (wherein R'is the same as in general formula (I) and Q represents a halogen atom) under the catalyst. Is a manufacturing method.

Furthermore, the present invention is a liquid crystal composition containing a compound represented by the general formula (I) and a liquid crystal display device using the same.

Next, the present invention will be described in more detail.

The novel compound represented by the general formula (I) is specifically represented by the following ring structures of [Chemical Formula 15] to [Chemical Formula 22], and at least one of trans-1 or trans- It is a silacyclohexane compound having a ring structure containing a 4-silacyclohexane ring.

[Chemical 15]

[Chemical 16]

[Chemical 17]

[Chemical 18]

[Chemical 19]

[Chemical 20]

[Chemical 21]

[Chemical formula 22]

However, in each formula, R and R'are as follows (a)
~ Represents each group of (e). (A) a linear alkyl group having 1 to 10 carbon atoms, that is,
Methyl group, ethyl group, n-propyl group, n-butyl group,
n-pentyl group, n-hexyl group, n-heptyl group, n
-Octyl group, n-nonyl group or n-decyl group (b) a branched alkyl group having 3 to 8 carbon atoms, that is,
Isopropyl group, sec-butyl group, isobutyl group, 1
-Methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 1-ethylpentyl group, 1
-Methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 1-methylheptyl group, 2-methylheptyl group or 3-methylheptyl group (c) Carbon number 2 ~ 7 alkoxyalkyl group, that is, methoxymethyl group, ethoxymethyl group, propoxymethyl group, butoxymethyl group, pentoxymethyl group, methoxyethyl group, ethoxyethyl group, proxyethyl group, butoxyethyl group, methoxypropyl group, Ethoxypropyl group, propoxypropyl group, methoxybutyl group, ethoxybutyl group, methoxypentyl group or ethoxypentyl group (d) C2-C8 alkenyl group, that is, vinyl group, 1-propenyl group, anyl group, 1- Butenyl group, 3
-Butenyl group, isoprenyl group, 1-pentenyl group, 3
-Pentenyl group, 4-pentenyl group, dimethylallyl group, 1-hexenyl group, 3-hexenyl group, 5-hexenyl group, 1-heptenyl group, 3-heptenyl group, 6-heptenyl group or 7-octenyl group (e) A mono- or difluoroalkyl group having 1 to 10 carbon atoms,
That is, fluoromethyl group, 1-fluoroethyl group, 1-
Fluoropropyl group, 1-fluorobutyl group, 1-fluoropentyl group, 1-fluorohexyl group, 1-fluoroheptyl group, 1-fluorooctyl group, 1-fluorononyl group, 1-
Fluorodecyl group, 2-fluoroethyl group, 2-fluoropropyl group, 2-fluorobutyl group, 2-fluoropentyl group,
2-fluorohexyl group, 2-fluoroheptyl group, 2-fluorooctyl group, 2-fluorononyl group, 2-fluorodecyl group, 3-fluoropropyl group, 3-fluorobutyl group, 3
-Fluoropentyl group, 3-fluorohexyl group, 3-fluoroheptyl group, 3-fluorooctyl group, 3-fluorononyl group, 3-fluorodecyl group, 4-fluorobutyl group, 4-
Fluoropentyl group, 4-fluorohexyl group, 4-fluoroheptyl group, 4-fluorooctyl group, 4-fluorononyl group, 4-fluorodecyl group, 5-fluoropentyl group, 5-
Fluorohexyl group, 5-fluoroheptyl group, 5-fluorooctyl group, 5-fluorononyl group, 5-fluorodecyl group, 6-fluorohexyl group, 6-fluoroheptyl group, 6
-Fluorooctyl group, 6-fluororonyl group, 6-fluorodecyl group, 7-fluoroheptyl group, 7-fluorooctyl group, 7-fluorononyl group, 7-fluorodecyl group, 8-fluorooctyl group, 8-fluororonyl group, 8- Fluorodecyl group, 9-fluorononyl group, 9-fluorodecyl group, 10
-Fluorodecyl group, difluoromethyl group, 1,1-difluoroethyl group, 1,1-difluoropropyl group, 1,1-difluorobutyl group, 1,1-difluoropentyl group, 1,1
-Difluorohexyl group, 1,1-difluoroheptyl group,
1,1-difluorooctyl group, 1,1-difluorononyl group, 1,1-difluorodecyl group, 2,2-difluoroethyl group, 2,2-difluoropropyl group, 2,2-difluorobutyl group, 2,2- Difluoropentyl group, 2,2-difluorohexyl group, 2,2-difluoroheptyl group, 2,2
-Difluorooctyl group, 2,2-difluorononyl group,
2,2-difluorodecyl group, 3,3-difluoropropyl group, 3,3-difluorobutyl group, 3,3-difluoropentyl group, 3,3-difluorohexyl group, 3,3-difluoroheptyl group, 3,3-difluorooctyl group, 3,3-
Difluorononyl group, 3,3-difluorodecyl group, 4,4
-Difluorobutyl group, 4,4-difluoropentyl group,
4,4-difluorohexyl group, 4,4-difluoroheptyl group, 4,4-difluorooctyl group, 4,4-difluorononyl group, 4,4-difluorodecyl group, 5,5-difluoropentyl group, 5,5-difluorohexyl group, 5,5-
Difluoroheptyl group, 5,5-difluorooctyl group,
5,5-difluorononyl group, 5,5-difluorodecyl group, 6,6-difluorohexyl group, 6,6-difluoroheptyl group, 6,6-difluorooctyl group, 6,6-difluororonyl group, 6, 6-difluorodecyl group, 7,7-difluoroheptyl group, 7,7-difluorooctyl group, 7,
7-difluorononyl group, 7,7-difluorodecyl group,
8,8-Difluorooctyl group, 8,8-difluororonyl group, 8,8-difluorodecyl group, 9,9-difluororonyl group, 9,9-difluorodecyl group or 10,10-difluorodecyl group

Practically desirable H, F or CH ₃ for W, W ₁ and W ₂ .

Next, a method for producing these compounds will be described. These compounds are prepared by reacting an organometallic reagent with an aryl halide compound. The details will be described below.

Organometallic reagent

[Chemical formula 23] (R is the same as in the general formula (I), M is MgP (P is a halogen atom), ZnP or B (OY) ₂ (Y is H or an alkyl group), and X is F or H). Halide

[Chemical formula 24] It can be easily prepared from (P is a halogen atom). For example,
You can follow the route below.

[Chemical 25] (P and P'represent a halogen atom.)

In addition,

[Chemical formula 26] (X and X'represent H or F.) and alkyllithium are reacted and directly lithiated to give a compound

[Chemical 27] After synthesizing, it is also possible to follow the synthetic route described above.

Organometallic reagent and aryl halide compound thus prepared

[Chemical 28] React with and in the presence of a transition metal catalyst to give a compound

[Chemical 29] To get

The catalyst is preferably a palladium or nickel compound. Examples of the palladium catalyst include zero-valent palladium compounds such as tetrakis (triphenylphosphine) palladium (0) and di [1,2-bis (diphenylphosphino) ethane] palladium (0), or palladium acetate and palladium chloride. A compound composed of palladium and a ligand such as, or a combination of these with a reducing agent can be used.

Examples of the nickel catalyst include 1,3-bis (diphenylphosphino) propane nickel (II) chloride, 1,2-bis (diphenylphosphino) ethane nickel (II) chloride, and bis (triphenylphosphine) nickel. (II) A divalent nickel compound such as chloride and a zero-valent nickel compound such as tetrakis (triphenylphosphine) nickel (0) can be mentioned.

When the organometallic reagent is a boric acid derivative,
That is, when M is B (OY) ₂ , the reaction is preferably carried out in the presence of a base. As the base, for example, an inorganic base such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide or the like, or an organic base such as triethylamine, tributylamine, dimethylaniline or the like can be used.

The reaction product is purified by a method such as recrystallization and chromatography after a usual post-treatment to obtain the silacyclohexane compound of the general formula (I) of the present invention.

The silacyclohexane compound of the present invention can be mixed with a known compound to obtain a liquid crystal composition.
The compound specifically mixed for producing the liquid crystal composition can be selected from the known compounds shown below.

[Chemical 30]

[Chemical 31]

In addition, in [Chemical formula 30] and [Chemical formula 31], (M) and (N) are the following (a) to (e), respectively.
Represents either (A) one or more F as unsubstituted or as a substituent,
Cl-, Br, CN or trans- having an alkyl group
1,4-Cyclohexylene group (b) One in cyclohexane ring or not adjacent 2
CH ₂ groups are replaced with O and S (c) 1,4-cyclohexenylene group (d) 1 or 2 F, C unsubstituted or substituted
1,4-phenylene group having l, CH ₃ or CN group (e) 1 or 2 Cs in the ring of 1,4-phenylene group
Ring in which H group is replaced by N atom

A ¹ and A ² are --CH ₂ CH _2- ,
-CH = CH -, - C≡C - , - CO 2 -, - OCO
_{-, - CH 2 O -,} - represents a single bond or - OCH _2.

L (el) and m are 0, 1 or 2 (provided that
1 + m = 1, 2 or 3, n = 0, 1 or 2).

R is hydrogen, a linear alkyl group having 1 to 10 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, and 2 to 7 carbon atoms.
Represents an alkoxyalkyl group or an alkenyl group having 2 to 8 carbon atoms.

X is CN, F, Cl, CF ₃ , OCF ₃ ,
It represents OCHF ₂ , R or OR group. Y and Z represent H or F, respectively.

In the above, when 1 (ell) and n are 2, (M) may contain heterocyclic rings, and when m is 2, (N) may contain heterocyclic rings.

The proportion of the silacyclohexane compound of the present invention in the liquid crystal phase is 1 to 50% by weight, preferably 5 to 30% by weight, of one kind or two or more kinds thereof. Further, the liquid crystal composition may contain a polychromatic dye for forming a colored guest-host system, or an additive for changing the orientation of the dielectric anisotropy and the viscosity nematic phase.

Using the liquid crystal composition thus formed, various liquid crystal display devices can be manufactured by a usual method. That is, the liquid crystal composition containing the silacyclohexane compound of the present invention is used as a liquid crystal display device by enclosing it between transparent substrates having electrodes of a desired shape. This element may have various undercoats, alignment control overcoats, polarizing plates, filters, reflective layers, and the like, if necessary. Further, various types such as a multi-layer cell, a combination with another display element, a semiconductor substrate, or a light source can be used.

The driving method of the liquid crystal display device includes a dynamic scattering (DSM) system, a twisted nematic (TN) system, a guest host (GH) system, and the like.
A method known in the liquid crystal display device industry can be adopted.

[0034]

EXAMPLES The present invention will be described in more detail with reference to specific examples.

Example 1 Preparation of trans, trans-4,4'-di (4-n-pentyl-4-silacyclohexyl) biphenyl trans-4- (p-iodophenyl) -1-n-pentyl- 1-silacyclo. Hexane 37.2 g (100 m
mol), tetrakis (triphenylphosphine) palladium (0) 100 mg, and tetrahydrofuran (hereinafter referred to as “THF”) 200 ml in a mixture of trans-4- (p-iodophenyl) -1-n-pentyl-1.
-Organozinc reagent prepared by reacting silacyclohexane with metallic magnesium and then with zinc chloride.
110 ml of 0M THF-toluene (1: 1) solution was added dropwise. The product was subjected to usual post-treatment operations and then purified by chromatography to obtain 36.8 g of the desired product (yield 75%). IR νmax: 2916, 2850, 2100, 14
52,1404,1078,924,885,833
810 ^-1 (KBr tablet method) SI transition point: 168.2 ° C

The following target was obtained in the same manner as in Example 1.

Example 2 Trans, trans-4,4'-di (4-n-propyl-4-silacyclohexyl) biphenyl IR vmax: 2918,2852,2100,19
03,1497,1456,985,810,532 ^-1
(KBr tablet method) S1-S2 transition point: 95.5 ° C S2-I transition point: 173.7 ° C

Example 3 Trans, trans-4- (4-n-pentyl-4-silacyclohexyl) -4 '-(4-n-propyl-4-
Silacyclohexyl) biphenyl IR νmax: 2916, 2850, 2100, 19
02,1497,1460,1005,812,536
^-1 (KBr tablet method) SN transition point: 191.9 ° C NI transition point: 231.9 ° C

Example 4 Trans, trans-4- (4-n-pentyl-4-silacyclohexyl) -4 '-(4-n-propyl-1-
Silacyclohexyl) biphenyl

Example 5 Trans, trans-2-fluoro-4,4'-di (4
-N-pentyl-4-silacyclohexyl) biphenyl

Example 6 Trans, trans-2-fluoro-4- (4-n-pentyl-4-silacyclohexyl) -4 '-(4-n-
Pentylcyclohexyl) biphenyl IR vmax: 2920, 2848, 2100, 14
91, 1404, 1194, 987, 887, 814 ^-1
(KBr tablet method) C-S transition point: 71.3 ° C S-N transition point: 137.2 ° C NI transition point: 225.4 ° C

Example 7 Trans, trans-2'-fluoro-4- (4-n-
Pentyl-4-silacyclohexyl) -4 '-(4-n
-Propylcyclohexyl) biphenyl IR vmax: 2953, 2918, 2850, 21
00, 1491, 1404, 985, 887, 879,
818,582 ^-1 (KBr tablet method) C-S transition point: 51.6 ℃ S-N transition point: 89.9 ℃ N-I transition point: 232.6 ° C.

Example 8 Trans, trans-2'-fluoro-4- (4-n-)
Pentyl-4-silacyclohexyl) -4 '-(4-n
-Pentylcyclohexyl) biphenyl IR vmax: 2953, 2922, 2850, 21
02,1493,1446,1404,986,88
7,814,584 ^-1 (KBr tablet method) C-S transition point: 69.9 ° C SN transition point: 131.2 ° C NI transition point: 230.7 ° C

[Example 9] trans, trans-2'-fluoro-4- (4-n-)
Propyl-4-silacyclohexyl) -4 '-(4-n
-Propylcyclohexyl) biphenyl IR vmax: 2955, 2922, 2850, 20
98,1493,1404,984,887,812 ^-1
(KBr tablet method) C-S transition point: 110.8 ° C S-N transition point: 118.4 ° C NI transition point: 259.3 ° C

Example 10 Trans, trans-2'-fluoro-4- (4-n-
Propyl-4-silacyclohexyl) -4 '-(4-n
-Pentylcyclohexyl) biphenyl IR vmax: 2953, 2922, 2850, 21
00,1493,1446,1404,984,88
7,812 ^-1 (KBr tablet method) C-S transition point: 53.5 ° C S-N transition point: 116.8 ° C NI transition point: 246.5 ° C

Example 11 Trans, trans-2-fluoro-4- (4-n-propyl-4-silacyclohexyl) -4 '-(4-n-
Propylcyclohexyl) biphenyl IR vmax: 2955, 2920, 2848, 21
04, 1491, 1404, 1194, 986, 88
9,814 ^-1 (KBr tablet method) C-S transition point: 112.9 ℃ N-I transition point: 239.8 ° C.

Example 12 trans, trans-2-fluoro-4- (4-n-propyl-4-silacyclohexyl) -4 '-(4-n-
Pentylcyclohexyl) biphenyl IR vmax: 2955, 2922, 2850, 21
10, 1491, 1404, 1194, 986, 88
9,818 ^-1 (KBr tablet method) C-S transition point: 49.6 ° C SN transition point: 104.8 ° C NI transition point: 250.1 ° C

Example 13 Trans, trans-2-fluoro-4- (4-n-pentyl-4-silacyclohexyl) -4 '-(4-n-
Propylcyclohexyl) biphenyl IR vmax: 2955, 2920, 2850, 21
02,1446,1404,1194,987,88
7,814 ^-1 (KBr tablet method) C-S transition point: 79.0 ℃ S-N transition point: 95.0 ℃ N-I transition point: 247.0 ° C.

Example 14 Trans, trans-4- (1-methyl-4-n-pentyl-1-silacyclohexyl) -4 '-(4-n-pentylcyclohexyl) biphenyl

Example 15 Trans, trans-4- (4-isopentyl-4-silacyclohexyl) -4 '-(4-n-pentylcyclohexyl) biphenyl

Example 16 Preparation of trans, trans-4- (4-n-propyl-4-silacyclohexyl) -4 '-(4-n-propylcyclohexyl) biphenyl trans-4- (p-iodophenyl) ) -1-n-Propyl-1-silacyclohexane 34.4 g (100 mm
ol) and 12.0 g of triethylamine (119 mmo
l), 100 mg of tetrakis (triphenylphosphine) palladium (0) and N, N-dimethylformamide 2
To a mixture of 00 ml, trans-4- (4-n-propylcyclohexyl) phenylboric acid (prepared by reacting a corresponding Grignard reagent with trimethylboric acid and then hydrolyzing with 10% hydrochloric acid) 24.7 g (100 mmol) Was added and reacted at 100 ° C. for 3 hours. The product was subjected to usual post-treatment operations and then purified by chromatography to obtain 26.0 g of the desired product (yield 62%). IR νmax: 2918, 2104, 1902, 14
97,1444,984,810,532cm ^-1 (KB
r tablet method) SN transition point: 191.6 ° C NI transition point: 274.7 ° C

The following compounds were obtained in the same manner as in Example 11.

Example 17 Trans, trans-4- (4-n-pentyl-4-silacyclohexyl) -4 '-(4-n-propylcyclohexyl) biphenyl IR vmax: 2918, 2102, 1903, 14
97, 1446, 986, 812, 536cm ^-1 (KB
r tablet method) S-N transition point: 197.9 ° C NI transition point: 252.2 ° C

Example 18 Trans, trans-4- (4-n-pentylsilacyclohexyl) -4 '-(4-n-pentylcyclohexyl) biphenyl IR vmax: 2956, 2920, 2850, 21
04, 1498, 1456, 985, 887, 812c
m ^-1 (KBr tablet method) SN transition point: 203.7 ° C NI transition point: 214.1 ° C

Example 19 Trans, trans-4- (4-n-propyl-4-silacyclohexyl) -4 '-(4-n-pentylcyclohexyl) biphenyl IR vmax: 2920, 2102, 1903, 14
97, 1446, 986, 812, 536cm ^-1 (KB
r tablet method) S-N transition point: 177.9 ° C NI transition point: 210.4 ° C

Example 20 Trans, trans-4- (4-n-propyl-4-silacyclohexyl) -4 '-{4- (4-fluoropropylcyclohexyl)} biphenyl

Example 21 Trans, trans-4- {4- (4-fluoropentyl-4-silacyclohexyl) -4 '-(4-n-pentylcyclohexyl) biphenyl

Example 22 Trans, trans-4- {4- (5-methoxypentyl) -4-silacyclohexane} -4 '-(4-n-propylcyclohexyl) biphenyl

Next, the compounds of the present invention obtained in the above Examples were added to existing liquid crystal compositions to prepare liquid crystal compositions of the present invention.

Example 23 2- (trans-4-n-pentylcyclohexyl)-
1- (3,4-difluorophenyl) ethane 34%,
1,2-Difluoro-4- [trans-4- (trans-4-n-propylcyclohexyl) cyclohexyl]
Benzene 15% and 2- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] -1
A liquid crystal mixture consisting of 51% of-(3,4-difluorophenyl) ethane shows a nematic liquid crystal phase in the temperature range of -17 to 63 ° C. A liquid crystal mixture consisting of 85% of this mixture and 15% of trans, trans-4- (4-n-propylsilacyclohexyl) -4 ′-(4-n-propylcyclohexyl) biphenyl obtained in Example 11 was -24.
It exhibits a nematic liquid crystal phase in an extended temperature range of ~ 94.8 ° C.

[0061]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a liquid crystal compound having a nematic liquid crystal phase, which has not been known until now, and which has Si as a ring-constituting element and has been expanded to a high temperature range. be able to. By using this compound as a constituent of a liquid crystal composition, the liquid crystal can be expanded to a high temperature range.

The liquid crystal compound of the present invention can be widely used as a base material constituting the main part of the liquid crystal phase, as in the conventional CBC structure liquid crystal compound having a similar hydrocarbon ring, depending on the selection of the substituent. Specifically, a liquid crystal phase for display based on dynamic scattering (DS) or deformation of aligned phase (DAP effect), a liquid crystal phase for use in a display device based on twisted nematic cell or colosteric-nematic phase transition Useful for manufacturing.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location G02F 1/13 500 (72) Inventor Takaaki Shimizu 28, Nishi-Fukushima, Nakakubiki-gun, Niigata prefecture 1 Shin-Etsu Chemical Co., Ltd., Synthetic Technology Laboratory (72) Inventor Tsutomu Ogihara 28, Nishi-Fukushima, Kikugi-mura, Nakakubiki-gun, Niigata Prefecture 1 Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory (72) Inventor Ryuichi Saito Niigata 28, Nishi-Fukushima, Chubiki-gun, Nakakubiki-gun, Shinagawa Prefecture Synthetic Technology Laboratory, Shin-Etsu Chemical Co., Ltd. (72) Inventor Hideshi Kurihara 3-2-1 Sakado, Takatsu-ku, Kawasaki City, Kanagawa Shin-Etsu Chemical Co., Ltd. Inside the collector-center

Claims (4)

[Claims] 1. A silacyclohexane compound represented by the following general formula (I): [Chemical 1] In the formula, R and R ′ are linear alkyl groups having 1 to 10 carbon atoms, mono- or difluoroalkyl groups having 1 to 10 carbon atoms, branched alkyl groups having 3 to 8 carbon atoms, and 2 to 2 carbon atoms.
7 represents an alkoxyalkyl group having 7 or an alkenyl group having 2 to 8 carbon atoms. [Chemical 2] And Is at least one of trans-1- whose silicon at the 1- or 4-position has a substituent of H, F, Cl or CH _3.
Sila-1,4-cyclohexylene group or trans-4-
It represents a sila-1,4-cyclohexylene group. The substituents X on the aromatic ring are 0, 1, or 2 are F, and the other are H.
Represents 2. An organometallic reagent (R is the same as in the general formula (I), M is MgP (P is a halogen atom), ZnP or B (OY) ₂ (Y is H or an alkyl group), X is F or H), and halogenated. Aryl compound The silacyclohexane compound according to claim 1, which is based on a carbon-carbon bond-forming reaction with a transition metal compound (wherein R'is the same as in general formula (I) and Q represents a halogen atom) under the catalyst. Manufacturing method. 3. A liquid crystal composition comprising the silacyclohexane compound according to claim 1. 4. A liquid crystal display device comprising the liquid crystal composition according to claim 3.