Compound having perfluoroalkyl terminal group and CF2O bonding group, liquid crystal composition and liquid crystal display device

Abstract

The subject is to provide a liquid crystal compound satisfying at least one of physical properties such as a high stability to heat or light, a high clearing point (or a high maximum temperature), a low minimum temperature of a liquid crystal phase, a small viscosity, a suitable optical anisotropy, a large dielectic anisotropy, a suitable elastic constant and an excellent compatibility with any other liquid crystal compound, a liquid crystal composition including this compound and a liquid crystal display device including this composition. The compound is represented by the following formula (1a): ##STR00001##
wherein R.sup.1 is alkyl having 1 to 15 carbons or the like; ring A.sup.1, ring A.sup.2, ring A.sup.3 and ring A.sup.4 are independently 1,4-phenylene, naphthalene-2,6-diyl or the like; Z.sup.1 and Z.sup.2 are independently a single bond or the like; o and p are independently 0, 1 or 2; and n is an integer from 2 to 10.

Claims

1. A compound represented by formula (1a): ##STR00145## in formula (1a), R.sup.1 is alkyl having 1 to 15 carbons, and in the alkyl at least one CH.sub.2 may be replaced by O or S and at least one CH.sub.2CH.sub.2 may be replaced by CHCH; ring A.sup.1, ring A.sup.2 and ring A.sup.3 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 2,6,7-trioxabicyclo[2.2.2]octane-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and in these rings at least one hydrogen may be replaced by fluorine or chlorine; ring A.sup.4 is 1,4-phenylene or naphthalene-2,6-diyl, and in these rings at least one hydrogen may be replaced by fluorine or chlorine; Z.sup.1 and Z.sup.2 are independently a single bond, CH.sub.2CH.sub.2, CHCH, CC, COO, OCO, CH.sub.2O, OCH.sub.2, CF.sub.2O, OCF.sub.2 or CFCF; o and p are independently 0, 1 or 2, and the sum of o and p is 0, 1 or 2; and n is an integer from 2 to 10.

2. The compound according to claim 1, wherein in formula (1a) according to claim 1, ring A.sup.3 is 1,4-phenylene, 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl or naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine.

3. The compound according to claim 1, wherein the compound is represented by formula (1b): ##STR00146## in formula (1b), R.sup.1 is alkyl having 1 to 15 carbons, and in the alkyl at least one CH.sub.2 may be replaced by O and at least one CH.sub.2CH.sub.2 may be replaced by CHCH; ring A.sup.1 is 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl or 2,6,7-trioxabicyclo[2.2.2]octane-1,4-diyl; ring A.sup.2 is 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl or naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine; ring A.sup.3 is 1,4-phenylene, 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl or naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine; Z.sup.1 and Z.sup.2 are independently a single bond, CH.sub.2CH.sub.2, CHCH, CC, COO, OCO, CH.sub.2O, OCH.sub.2, CF.sub.2O, OCF.sub.2 or CFCF; L.sup.1 and L.sup.2 are independently hydrogen, fluorine or chlorine; o and p are independently 0, 1 or 2, and the sum of o and p is 0, 1 or 2; and n is an integer from 2 to 10.

4. The compound according to claim 3, wherein in formula (1b) according to claim 3, R.sup.1 is alkyl having 1 to 15 carbons, alkoxy having 1 to 14 carbons, alkenyl having 2 to 15 carbons or alkenyloxy having 2 to 14 carbons; and Z.sup.1 and Z.sup.2 are independently a single bond, CH.sub.2CH.sub.2, CHCH, CF.sub.2O or COO.

5. The compound according to claim 1, wherein the compound is represented by any one of formulas (1-1) to (1-4): ##STR00147## in formulas (1-1) to (1-4), R.sup.1 is alkyl having 1 to 15 carbons, alkoxy having 1 to 14 carbons, alkenyl having 2 to 15 carbons or alkenyloxy having 2 to 14 carbons; ring A.sup.1 is 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; ring A.sup.2 is 1,4-cyclohexylene, 1,4-phenylene or 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl or naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine; ring A.sup.3 is 1,4-phenylene or 1,4-phenylene in which at least one hydrogen has been replaced by fluorine or chlorine, naphthalene-2,6-diyl or naphthalene-2,6-diyl in which at least one hydrogen has been replaced by fluorine or chlorine; Z.sup.1 and Z.sup.2 are independently a single bond, CH.sub.2CH.sub.2 or CHCH; L.sup.1 and L.sup.2 are independently hydrogen or fluorine; and n is an integer from 2 to 10.

6. The compound according to claim 5, wherein in formulas (1-1) to (1-4) according to claim 5, R.sup.1 is alkyl having 1 to 15 carbons or alkenyl having 2 to 15 carbons.

7. The compound according to claim 1, wherein the compound is represented by any one of formulas (1-5) to (1-37): ##STR00148## ##STR00149## ##STR00150## ##STR00151## ##STR00152## in formulas (1-5) to (1-37), R.sup.1 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons; L.sup.1 and L.sup.2 are independently hydrogen or fluorine; Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4, Y.sup.5 and Y.sup.6 are independently hydrogen or fluorine; Z.sup.1 is a single bond, CH.sub.2CH.sub.2 or CHCH; and n is an integer from 2 to 10.

8. The compound according to claim 1, wherein the compound is represented by any one of formulas (1-38) to (1-45): ##STR00153## in formulas (1-38) to (1-45), R.sup.1 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons; L.sup.1 and L.sup.2 are independently hydrogen or fluorine; Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4 and Y.sup.5 are independently hydrogen or fluorine; and n is an integer from 2 to 10.

9. The compound according to claim 8, wherein in formulas (1-38) to (1-45) according to claim 8, R.sup.1 is alkyl having 1 to 10 carbons; L.sup.1 and L.sup.2 are fluorine; and Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4, Y.sup.5 and Y.sup.6 are independently hydrogen or fluorine.

10. A liquid crystal composition including at least one of compounds according to claim 1.

11. The liquid crystal composition according to claim 10, further including at least one compound selected from the group of compounds represented by formulas (2) to (4): ##STR00154## in formulas (2) to (4), R.sup.11 and R.sup.12 are independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and alkenyl at least one CH.sub.2 may be replaced by O and at least one hydrogen may be replaced by fluorine; ring B.sup.1, ring B.sup.2, ring B.sup.3 and ring B.sup.4 are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene or pyrimidine-2,5-diyl; and Z.sup.11, Z.sup.12 and Z.sup.13 are independently a single bond, CH.sub.2CH.sub.2, CHCH, CC or COO.

12. The liquid crystal composition according to claim 10, further including at least one compound selected from the group of compounds represented by formulas (5) to (7): ##STR00155## in formula (5) to (7), R.sup.13 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and alkenyl at least one CH.sub.2 may be replaced by O and at least one hydrogen may be replaced by fluorine; X.sup.11 is fluorine, chlorine, OCF.sub.3, OCHF.sub.2, CF.sub.3, CHF.sub.2, CH.sub.2F, OCF.sub.2CHF.sub.2 or OCF.sub.2CHFCF.sub.3; ring C.sup.1, ring C.sup.2 and ring C.sup.3 are independently 1,4-cyclohexylene, 1,4-phenylene in which at least one hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl; Z.sup.14, Z.sup.15 and Z.sup.16 are independently a single bond, CH.sub.2CH.sub.2, CHCH, CC, COO, CF.sub.2O, OCF.sub.2, CH.sub.2O or (CH.sub.2).sub.4; and L.sup.11 and L.sup.12 are independently hydrogen or fluorine.

13. The liquid crystal composition according to claim 10, further including at least one compound selected from the group of compounds represented by formula (8): ##STR00156## in formula (8), R.sup.14 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and alkenyl at least one CH.sub.2 may be replaced by O and at least one hydrogen may be replaced by fluorine; X.sup.12 is CN or CCCN; ring D.sup.1 is 1,4-cyclohexylene, 1,4-phenylene in which at least one hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl; Z.sup.17 is a single bond, CH.sub.2CH.sub.2, CC, COO, CF.sub.2O, OCF.sub.2 or CH.sub.2O; L.sup.13 and L.sup.14 are independently hydrogen or fluorine; and i is 1, 2, 3 or 4.

14. The liquid crystal composition according to claim 10, further including at least one compound selected from the group of compounds represented by formulas (9) to (15): ##STR00157## in formulas (9) to (15), R.sup.15 and R.sup.16 are independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and alkenyl at least one CH.sub.2 may be replaced by O and at least one hydrogen may be replaced by fluorine; R.sup.17 is hydrogen, fluorine, alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and alkenyl at least one CH.sub.2 may be replaced by O and at least one hydrogen may be replaced by fluorine; ring E.sup.1, ring E.sup.2, ring E.sup.3 and ring E.sup.4 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene in which at least one hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl or decahydronaphthalene-2,6-diyl; ring E.sup.5 and ring E.sup.6 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl or decahydronaphthalene-2,6-diyl; Z.sup.18, Z.sup.19, Z.sup.20 and Z.sup.21 are independently a single bond, CH.sub.2CH.sub.2, COO, CH.sub.2O, OCF.sub.2 or OCF.sub.2CH.sub.2CH.sub.2; L.sup.15 and L.sup.16 are independently fluorine or chlorine; S.sup.11 is hydrogen or methyl; X is CHF or CF.sub.2; and j, k, m, n, p, q, r and s are independently 0 or 1, the sum of k, m, n and p is 1 or 2, and the sum of q, r and s is 0, 1, 2 or 3, and t is 1, 2 or 3.

15. The liquid crystal composition according to claim 10, further including at least one additive selected from the group of a polymerizable compound, a polymerization initiator, a polymerization inhibitor, an optically active compound, an antioxidant, an ultraviolet light absorber, a light stabilizer, a thermal stabilizer, a coloring matter and an antifoaming agent.

16. A liquid crystal display device including the liquid crystal composition according to claim 10.

Description

EXAMPLES

(1) The invention will be explained in more detail by way of Examples (including Synthetic Examples and Use Examples). The invention is not limited to Examples. The invention includes a mixture of the composition in Use Example 1 and the composition in Use Example 2. The invention also includes a composition prepared by mixing at least two compositions in Use Examples.

(2) 1. Examples of Compound (1a)

(3) Compound (1a) was prepared according to the procedures described below. Compounds prepared herein were identified by methods such as NMR analysis. The physical properties of compounds or compositions and the characteristics of devices were measured by the methods described below.

(4) NMR Analysis: A model DRX-500 apparatus made by Bruker BioSpin Corporation was used for measurement. In the measurement of .sup.1H-NMR, a sample was dissolved in a deuterated solvent such as CDCl.sub.3, and measured under the conditions of room temperature, 500 MHz and the accumulation of 16 scans. Tetramethylsilane was used as an internal standard. In the measurement of .sup.19F-NMR, CFCl.sub.3 was used as an internal standard, and 24 scans were accumulated. In the explanation of the nuclear magnetic resonance spectra, the symbols s, d, t, q, quin, sex, m and br stand for a singlet, a doublet, a triplet, a quartet, a quintet, a sextet, a multiplet and line-broadening, respectively.

(5) Gas Chromatographic Analysis: A gas chromatograph Model GC-2010 made by Shimadzu Corporation was used for measurement. The column used was a capillary column DB-1 (length 60 meters, bore 0.25 millimeters, film thickness 0.25 micrometers) made by Agilent Technologies, Inc. The carrier gas was helium (1 milliliter per minute). The sample injector and the detector (FID) were set to 300 C. A sample was dissolved in acetone to give a 0.1% solution by weight, and 1 microliter of the solution was injected into the sample injector. A recorder used was Model GC Solution System made by Shimadzu Corporation or the like.

(6) HPLC Analysis: Model Prominence (LC-20AD; SPD-20A) made by Shimadzu Corporation was used for measurement. A column YMC-Pack ODS-A (length 150 millimeters, bore 4.6 millimeters, particle size 5 micrometers) made by YMC Co., Ltd. was used. Acetonitrile and water were properly mixed and used as eluent. A detector such as a UV detector, a RI detector or a Corona detector was properly used. The measurement wavelength was 254 nanometers when the UV detector was used. A sample was dissolved in acetonitrile to give a 0.1% by weight solution, and then 1 microliter of the solution was injected into the sample injector. Model C-R7Aplus made by Shimadzu Corporation was used as a recorder.

(7) Ultraviolet and Visible Spectrophotometric Analysis: Model PharmaSpec UV-1700 made by Shimadzu Corporation was used for measurement. Wavelengths in the range of 190 nm to 700 nm were used for the detection. A sample was dissolved in acetonitrile, giving a 0.01 mmol/L solution, which was placed in a quartz cell (optical path length: 1 cm) and measured.

(8) Sample for measurement: A compound itself was used as a sample when the phase structure and the transition temperature (a clearing point, a melting point, a starting temperature of polymerization or the like) were measured. A mixture of the compound and mother liquid crystals was used as a sample when physical properties such as the maximum temperature of a nematic phase, viscosity, optical anisotropy and dielectric anisotropy were measured.

(9) When a sample was prepared by mixing a compound and mother liquid crystals, the measurement was carried out according to the following method. The sample was prepared by mixing 20% by weight of the compound and 80% by weight of the mother liquid crystals. Extrapolated values were calculated from the measured values of the sample by means of an extrapolation method represented by the following equation, and their values were reported. [Extrapolated value]=(100[Measured value of sample][% by weight of mother liquid crystals][Measured value of mother liquid crystals])/[% by weight of compound].

(10) When crystals (or a smectic phase) deposited at 25 C. even at this ratio of the compound to the mother liquid crystals, the ratio of the compound to the mother liquid crystals was changed in the order of (15% by weight: 85% by weight), (10% by weight: 90% by weight), (5% by weight: 95% by weight) and (1% by weight: 99% by weight). The physical properties of the sample were measured at the ratio in which the crystals (or the smectic phase) did not deposit at 25 C. Incidentally, the ratio of the compound to the mother liquid crystals was (20% by weight: 80% by weight), unless otherwise noted.

(11) Mother liquid crystals (i) composed of the following fluorine-containing compounds were used as mother liquid crystals. The ratio of each component is expressed as a percentage by weight.

(12) ##STR00067##

(13) Measurement method: The physical properties were measured according to the following methods. Most of them are described in the JEITA standards (JEITA-ED-2521B) which was deliberated and established by Japan Electronics and Information Technology Industries Association (abbreviated to JEITA). A modified method was also used. No TFT was attached to a TN device used for measurement. (1) Phase structure: A sample was placed on a hot plate of a melting point apparatus (Hot Stage Model FP-52 made by Mettler Toledo International Inc.) equipped with a polarizing microscope, and the phase conditions and their changes were observed with the polarizing microscope while the sample was heated at the rate of 3 C. per minute, and the type of phase was specified. (2) Transition temperature ( C.): A differential scanning calorimeter, a Diamond DSC System made by PerkinElmer Inc. or a X-DSC7000 high sensitivity differential scanning analyzer made by SII NanoTechnology Inc. was used for measurement. A sample was heated and then cooled at the rate of 3 C. per minute, and the starting point of an endothermic peak or an exothermic peak caused by the phase change of the sample was obtained by means of the extrapolation, and thus the transition temperature was determined. The melting point and a starting temperature of polymerization of a compound were also measured by use of this apparatus. The transition temperature of a compound from solid to a liquid crystal phase such as a smectic phase or a nematic phase may be abbreviated to the minimum temperature of a liquid crystal phase. The transition temperature of a compound from a liquid crystal phase to liquid may be abbreviated to a clearing point.

(14) The symbol C stood for crystals. When the type of crystals was distinguishable, each was expressed as C.sub.1 or C.sub.2. The symbols S and N stood for a smectic phase and a nematic phase, respectively. When a smectic A phase, a smectic B phase, a smectic C phase or a smectic F was distinguishable in the smectic phases, it was expressed as S.sub.A, S.sub.B, S.sub.C or S.sub.F, respectively. The symbol I stood for a liquid (isotropic). Transition temperatures were expressed as, for example, C 50.0 N 100.0 Iso, which means that the transition temperature from crystals to a nematic phase was 50.0 C., and the transition temperature from the nematic phase to a liquid was 100.0 C. (3) Compatibility at low temperatures: Samples were prepared by mixing a compound with mother liquid crystals so that the ratio of the compound became 20% by weight, 15% by weight, 10% by weight, 5% by weight, 3% by weight and 1% by weight, and placed in glass vials. After these glass vials had been kept in a freezer at 10 C. or 20 C. for a certain period of time, they were observed as to whether or not crystals (or a smectic phase) deposited. (4) Maximum temperature of a nematic phase (T.sub.NI or NI; C.): A sample was placed on a hot plate in a melting point apparatus equipped with a polarizing microscope and was heated at the rate of 1 C. per minute. The temperature was measured when part of the sample began to change from a nematic phase to an isotropic liquid. The symbol T.sub.NI means that the sample was a mixture of compound (1a) and mother liquid crystals. The symbol NI means that the sample was a mixture of a compound (1a) and a compound such as component B, C and D. A higher limit of the temperature range of a nematic phase may be abbreviated to the maximum temperature. (5) Minimum temperature of a nematic phase (T.sub.c; C.): A sample having a nematic phase was placed in a glass vials and kept in freezers at temperatures of 0 C., 10 C., 20 C., 30 C. and 40 C. for 10 days, and then the liquid crystal phases were observed. For example, when the sample maintained the nematic phase at 20 C. and changed to crystals or a smectic phase at 30 C., T.sub.c was expressed as <20 C. A lower limit of the temperature range of a nematic phase may be abbreviated to the minimum temperature. (6) Viscosity (bulk viscosity; ; measured at 20 C.; mPa.Math.s): An E-type viscometer made by Tokyo Keiki Inc. was used for measurement. (7) Viscosity (rotational viscosity; 1; measured at 25 C.; mPa.Math.s): Measurement was carried out according to the method described in M. Imai, et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37 (1995). A sample was poured into a TN device in which the twist angle was 0 degrees and the distance between the two glass substrates (cell gap) was 5 micrometers. A voltage in the range of 16 to 19.5 volts was applied stepwise to the device with an increment of 0.5 volts. After a period of 0.2 seconds with no voltage, a voltage was applied repeatedly under the conditions of only one rectangular wave (rectangular pulse; 0.2 seconds) and of no voltage (2 seconds). The peak current and the peak time of the transient current generated by the applied voltage were measured. The value of rotational viscosity was obtained from the measured values and the calculating equation (8) on page 40 of the paper presented by M. Imai, et al. The value of dielectric anisotropy necessary for this calculation was obtained by use of the device that had been used for the measurement of rotational viscosity, according to the method that will be described below. (8) Optical anisotropy (refractive index anisotropy; An; measured at 25 C.): Measurement was carried out using an Abbe refractometer with a polarizing plate attached to the ocular, using light at a wavelength of 589 nanometers. The surface of the main prism was rubbed in one direction, and then a sample was placed on the main prism. The refractive index (n) was measured when the direction of the polarized light was parallel to that of the rubbing. The refractive index (n) was measured when the direction of polarized light was perpendicular to that of the rubbing. The value of the optical anisotropy (n) was calculated from the equation: n=nn. (9) Dielectric anisotropy (; measured at 25 C.): A sample was poured into a TN device in which the distance between the two glass substrates (cell gap) was 9 micrometers and the twist angle was 80 degrees. Sine waves (10 V, 1 kHz) were applied to this device, and the dielectric constant () in a major axis direction of liquid crystal molecules was measured after 2 seconds. Sine waves (0.5 V, 1 kHz) were applied to the device and the dielectric constant () in a minor axis direction of the liquid crystal molecules was measured after 2 seconds. The value of dielectric anisotropy was calculated from the equation:
=. (10) Elastic constant (K; measured at 25 C.; pN): A LCR meter Model HP 4284-A made by Yokokawa Hewlett-Packard, Ltd. was used for measurement. A sample was poured into a homogeneous device in which the distance between the two glass substrates (cell gap) was 20 micrometers. An electric charge of 0 volts to 20 volts was applied to the device, and the electrostatic capacity and the applied voltage were measured. The measured values of the electric capacity (C) and the applied voltage (V) were fitted to the equation (2.98) and the equation (2.101) in page 75 of the Ekisho Debaisu Handobukku (Liquid Crystal Device Handbook, in English; The Nikkan Kogyo Shimbun, Ltd., Japan) and the values of K.sub.11 and K.sub.33 were obtained from the equation (2.99). Next, the value of K.sub.22 was calculated from the equation (3.18) in page 171 and the values of K.sub.11 and K.sub.33 thus obtained. The elastic constant K was expressed as an average value of K.sub.11, K.sub.22 and K.sub.33. (11) Threshold voltage (Vth; measured at 25 C.; V): An LCD evaluation system Model LCD-5100 made by Otsuka Electronics Co., Ltd. was used for measurement. The light source was a halogen lamp. A sample was poured into a TN device having a normally white mode, in which the distance between the two glass substrates (cell gap) was 4.45/An (micrometers) and the twist angle was 80 degrees. Voltage to be applied to the device (32 Hz, rectangular waves) was stepwise increased in 0.02 V increments from 0 V up to 10 V. The device was vertically irradiated with light simultaneously, and the amount of light passing through the device was measured. A voltage-transmittance curve was prepared, in which the maximum amount of light corresponded to 100% transmittance and the minimum amount of light corresponded to 0% transmittance. The threshold voltage was expressed as voltage at 90% transmittance. (12) Voltage Holding Ratio (VHR-1; measured at 25 C.; %): A TN device used for measurement had a polyimide-alignment film, and the distance between the two glass substrates (cell gap) was 5 micrometers. A sample was poured into the device, and then the device was sealed with an adhesive curable on irradiation with ultraviolet light. A pulse voltage (60 microseconds at 5 V) was applied to the device and the device was charged. A decreasing voltage was measured for 16.7 milliseconds with a high-speed voltmeter, and area A between a voltage curve and a horizontal axis in a unit cycle was obtained. Area B was an area without the decrease. The voltage holding ratio was a percentage of area A to area B. (13) Voltage Holding Ratio (VHR-2; measured at 80 C.; %): The voltage holding ratio was measured by the method described above, except that it was measured at 80 C. instead of 25 C. The resulting value was represented by the symbol VHR-2. (14) Specific Resistance (; measured at 25 C.; cm): A sample of 1.0 milliliter was poured into a vessel equipped with electrodes. A DC voltage (10 V) was applied to the vessel, and the DC current was measured after 10 seconds. The specific resistance was calculated from the following equation: (specific resistance)=[(voltage)(electric capacity of vessel)]/[(DC current)(dielectric constant in vacuum)]. (15) Response Time (; measured at 25 C.; millisecond): An LCD evaluation system Model LCD-5100 made by Otsuka Electronics Co., Ltd. was used for measurement. The light source was a halogen lamp. The low-pass filter was set at 5 kHz. A sample was poured into a TN device having a normally white mode, in which the distance between the two glass substrates (cell gap) was 5.0 micrometers and the twist angle was 80 degrees. Rectangular waves (60 Hz, 5 V, 0.5 seconds) were applied to this device. The device was vertically irradiated with light simultaneously, and the amount of light passing through the device was measured. The transmittance was regarded as 100% when the amount of light reached a maximum. The transmittance was regarded as 0% when the amount of light reached a minimum. Rise time (r; millisecond) was the time required for a change from 90% to 10% transmittance. Fall time (f; millisecond) was the time required for a change from 10% to 90% transmittance. The response time was expressed as the sum of the rise time and the fall time thus obtained.

(15) Materials: Solmix A-11 (registered trademark) was a mixture of ethanol (85.5%), methanol (13.4%) and isopropanol (1.1%), and was available from Japan Alcohol Trading Co., Ltd.

Synthetic Example 1

Preparation of Compound (No. 2)

(16) ##STR00068##
First Step:

(17) Compound (S-1) prepared by known methods (5.44 g) and THF (100 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was cooled to 70 C. n-Butyllithium (1.59 M; cyclohexane solution; 10.8 ml) was slowly added dropwise. After 1 hour of stirring, iodine (4.98 g) in THF (10 ml) solution was slowly added dropwise, and the reaction mixture was warmed to room temperature. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane). Further purification by recrystallization from solmix gave compound (S-2) (5.35 g; 71%).

(18) Second Step:

(19) Compound (S-2) (5.35 g), 2,2-bipyridine (0.13 g), copper powder (1.63 g), C.sub.5F.sub.11I (18.5 g), dimethylsulfoxide (25 ml) and perfluorobenzene (50 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 90 C. and stirred for 16 hours. The reaction mixture was poured into water, to which toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane). Further purification by recrystallization from solmix gave compound (No. 2) (0.68 g; 10%).

(20) .sup.1H-NMR (ppm; CDCl.sub.3): 6.90-6.86 (m, 2H), 2.08-1.96 (m, 3H), 1.87 (d, J=12.6, 2H), 1.40-1.17 (m, 11H), 0.98-0.87 (m, 5H).

(21) Transition temperature: C 23.0 I.

(22) Maximum temperature (T.sub.NI)=7.4 C.; optical anisotropy (n)=0.053; dielectric anisotropy ()=9.60; viscosity ()=38.6 mPa.Math.s.

Synthetic Example 2

Preparation of Compound (No. 201)

(23) ##STR00069##
First Step:

(24) Compound (S-3) (15.1 g) prepared by known methods and THF (450 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was cooled to 70 C. n-Butyllithium (1.59 M; cyclohexane solution; 25.7 ml) was slowly added dropwise. After 1 hour of stirring, iodine (11.9 g) in THF (50 ml) solution was slowly added dropwise, and the reaction mixture was warmed to room temperature. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane). Further purification by recrystallization from heptane gave compound (S-4) (15.4 g; 77%).

(25) Second Step:

(26) Compound (S-4) (15.4 g), 2,2-bipyridine (0.33 g), copper powder (4.21 g), C.sub.5F.sub.11I (23.8 g) and dimethyl sulfoxide (250 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 120 C. and stirred for 11 hours. The reaction mixture was poured into water, and toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane). Further purification by recrystallization from 2-propanol gave compound (No. 201) (1.18 g; 6%).

(27) .sup.1H-NMR (ppm; CDCl.sub.3): 6.89-6.85 (m, 2H), 2.05-1.96 (m, 3H), 1.89-1.82 (m, 2H), 1.79-1.67 (m, 4H), 1.38-1.25 (m, 4H), 1.20-0.79 (m, 14H).

(28) Transition temperature: C 68.5 N 121.8 I.

(29) Maximum temperature (T.sub.NI)=104.1 C.; optical anisotropy (n)=0.078; dielectric anisotropy ()=11.2; viscosity ()=58.2 mPa.Math.s.

Synthetic Example 3

Preparation of (No. 274)

(30) ##STR00070##
First Step:

(31) Compound (S-5) (15.5 g) prepared by known methods and THF (250 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was cooled to 70 C. n-Butyllithium (1.59 M; cyclohexane solution; 24.9 ml) was slowly added dropwise. After 1 hour of stirring, iodine (11.5 g) in THF (50 ml) solution was slowly added dropwise, and the reaction mixture was warmed to room temperature. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane:ethyl acetate=10:1 by volume). Further purification by recrystallization from a mixed solvent of 2-propanol and ethyl acetate (1:1 by volume) gave compound (S-6) (16.4 g; 81%).

(32) Second Step:

(33) Compound (S-6) (3.57 g), 2,2-bipyridine (0.07 g), copper powder (0.93 g), C.sub.5F.sub.11I (6.60 g) and dimethylsulfoxide (50 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 100 C. and stirred for 16 hours. The reaction mixture was poured into water, and toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane). Further purification by recrystallization from 2-propanol gave compound (No. 274) (0.89 g; 20%).

(34) .sup.1H-NMR (ppm; CDCl.sub.3): 7.51-7.47 (m, 2H), 7.30 (d, J=8.10, 2H), 7.23 (d, J=10.6, 2H), 7.03-6.98 (m, 2H), 2.65 (t, J=7.50, 2H), 1.71-1.65 (m, 2H), 0.97 (t, J=7.40, 3H).

(35) Transition temperature: C 38.7 (S.sub.A 38.0) I.

(36) Maximum temperature (T.sub.NI)=22.6 C.; optical anisotropy (n)=0.118; dielectric anisotropy ()=22.1; viscosity ()=51.5 mPa.Math.s.

Synthetic Example 4

Preparation of Compound (No. 275)

(37) ##STR00071##
First Step:

(38) compound (S-6) (8.27 g), 2,2-bipyridine (0.17 g), copper powder (2.16 g), C.sub.7F.sub.15I (15.3 g) and dimethylsulfoxide (160 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 100 C. and stirred for 16 hours. The reaction mixture was poured into water, and toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane). Further purification by recrystallization from 2-propanol gave compound (No. 275) (1.66 g; 14%).

(39) .sup.1H-NMR (ppm; CDCl.sub.3): 7.49 (d, J=8.15, 2H), 7.30 (d, J=8.15, 2H), 7.23 (d, J=10.7, 2H), 7.00 (d, J=10.4, 2H), 2.65 (t, J=7.50, 2H), 1.72-1.64 (m, 2H), 0.97 (t, J=7.35, 3H).

(40) Transition temperature: C 51.6 S.sub.A 70.9 I.

(41) Maximum temperature (T.sub.NI)=46.8 C.; optical anisotropy (n)=0.120; dielectric anisotropy ()=19.8; viscosity ()=50.3 mPa.Math.s.

(42) Incidentally, a sample in which the ratio of the compound to the mother liquid crystals was 15% by weight: 85% by weight was used for measurement of the maximum temperature, the optical anisotropy, dielectric anisotropy and the viscosity.

Synthetic Example 5

Preparation of Compound (No. 458)

(43) ##STR00072##
First Step:

(44) Compound (S-7) (5.04 g) prepared by known methods and THF (100 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was cooled to 70 C. n-Butyllithium (1.59 M; cyclohexane solution; 6.60 ml) was slowly added dropwise. After 1 hour of stirring, 1,2-dibromo-1,1,2,2-tetrafluoroethane (3.12 g) was slowly added dropwise, and the reaction mixture was warmed to room temperature. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane:ethyl acetate=10:1 by volume). Further purification by recrystallization from a mixed solvent of 2-propanol and ethyl acetate (1:1 by volume) gave compound (S-8) (4.79 g; 82%).

(45) Second Step:

(46) Compound (S-8) (4.29 g), 2,2-bipyridine (0.08 g), copper powder (1.03 g), C.sub.5F.sub.11I (5.82 g) and dimethylsulfoxide (85 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 95 C. and stirred for 15 hours. The reaction mixture was poured into water, and toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane:ethyl acetate=9:1 by volume). Further purification by recrystallization from a mixed solvent of 2-propanol and toluene (1:1 by volume) gave compound (No. 458) (0.97 g; 17%).

(47) .sup.1H-NMR (ppm; CDCl.sub.3): 7.54 (d, J=8.10, 2H), 7.52-7.48 (m, 2H), 7.43 (d, J=12.2, 1H), 7.33-7.25 (m, 4H), 7.02 (d, J=10.3, 2H), 2.65 (t, J=7.45, 2H), 1.74-1.64 (m, 2H), 0.98 (t, J=7.35, 3H).

(48) Transition temperature: C 82.5 S.sub.A 153.2 I.

(49) Maximum temperature (T.sub.NI)=118 C.; optical anisotropy (n)=0.173; dielectric anisotropy ()=27.1; viscosity ()=58.1 mPa.Math.s.

(50) Incidentally, a sample in which the ratio of the compound to the mother liquid crystals was 5% by weight: 95% by weight was used for measurement of the maximum temperature, the optical anisotropy, dielectric anisotropy and the viscosity.

Synthetic Example 6

Preparation of Compound (No. 457)

(51) ##STR00073##
First Step:

(52) Compound (S-9) (10.8 g) prepared by known methods and THF (170 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was cooled to 70 C. n-Butyllithium (1.65 M; cyclohexane solution; 13.2 ml) was slowly added dropwise. After 1 hour of stirring, iodine (6.34 g) in THF (30 ml) solution was slowly added dropwise, and the reaction mixture was warmed to room temperature. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane:ethyl acetate=10:1 by volume). Further purification by recrystallization from mixed solvent of 2-propanol and ethyl acetate (1:1 by volume) gave compound (S-10) (11.2 g; 84%).

(53) Second Step:

(54) Compound (S-10) (5.50 g), 2,2-bipyridine (0.09 g), copper powder (1.19 g), C.sub.3F.sub.7I (5.05 g) and dimethylsulfoxide (110 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 120 C. and stirred to 16 hours. The reaction mixture was poured into water, and toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane:ethyl acetate=20:1 by volume) Further purification by recrystallization from 2-propanol gave compound (No. 457) (1.04 g; 18%).

(55) .sup.1H-NMR (ppm; CDCl.sub.3): 7.54 (d, J=8.10, 2H), 7.51-7.48 (m, 2H), 7.43 (d, J=12.4, 1H), 7.33-7.25 (m, 4H), 7.02 (d, J=10.4, 2H), 2.68 (t, J=7.70, 2H), 1.68-1.60 (m, 2H), 1.44-1.35 (m, 2H), 0.95 (t, J=7.20, 3H).

(56) Transition temperature: C 72.2 S.sub.A 118 N 123 I.

(57) Maximum temperature (T.sub.NI)=93.6 C.; optical anisotropy (n)=0.183; dielectric anisotropy ()=33.6; viscosity ()=80.6 mPa.Math.s.

Synthetic Example 7

Preparation of Compound (No. 459)

(58) ##STR00074##
First Step:

(59) Compound (S-10) (5.50 g), 2,2-bipyridine (0.09 g), copper powder (1.19 g), C.sub.7F.sub.15I (8.47 g) and dimethylsulfoxide (110 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and the mixture was heated to 120 C. and stirred for 16 hours. The reaction mixture was poured into water, and toluene was added. After filtration through Celite, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (heptane: toluene=15:1 by volume). Further purification by recrystallization from a mixed solvent of 2-propanol and heptane (1:1 by volume) gave compound (No. 459) (1.91 g; 25%).

(60) .sup.1H-NMR (ppm; CDCl.sub.3): 7.54 (d, J=8.10, 2H), 7.51-7.48 (m, 2H), 7.43 (d, J=12.5, 1H), 7.32-7.26 (m, 4H), 7.02 (d, J=10.3, 2H), 2.68 (t, J=7.75, 2H), 1.68-1.60 (m, 2H), 1.45-1.37 (m, 2H), 0.96 (t, J=7.45, 3H).

(61) Transition temperature: C 74.7 S.sub.A 169 I.

(62) Maximum temperature (T.sub.NI)=124 C.; optical anisotropy (n)=0.153; dielectric anisotropy ()=25.1; viscosity ()=66.1 mPa.Math.s.

(63) Incidentally, a sample in which the ratio of the compound to the mother liquid crystals was 5% by weight: 95% by weight was used for measurement of the maximum temperature, the optical anisotropy, dielectric anisotropy and the viscosity.

Comparative Example 1

(64) The following compound (C-1) was selected for comparison. This is because this compound is different from the compound of the invention in view of the right-terminal group being fluorine. The compound was prepared according to the description in WO 96/011897 A.

(65) ##STR00075##

(66) .sup.1H-NMR (ppm; CDCl.sub.3): 7.49 (d, J=8.00 Hz, 2H), 7.29 (d, J=8.00 Hz, 2H), 7.21 (d, J=10.5 Hz, 2H), 7.03-6.94 (m, 2H), 2.65 (t, J=7.50 Hz, 2H), 1.75-1.64 (m, 2H), 0.97 (t, J=7.50 Hz, 3H).

(67) Transition temperature: C 46.1 I.

(68) Maximum temperature (T.sub.NI)=17.9 C.; optical anisotropy (n)=0.115; dielectric anisotropy ()=25.7.

(69) The maximum temperatures (T.sub.NI) of compound (No. 274), compound (No. 275) and comparative compound (C-1) are summarized in Table 1 below. As is clear from Table 1, the compound of the invention is superior to the comparative compound in view of the fact that the maximum temperature is high.

(70) TABLE-US-00001 TABLE 1 Comparison of the Maximum Temperature Maximum Examples Compounds Temperature (T.sub.NI).sup.1) Synthetic Example 3 22.6 C. (No. 274) Synthetic Example 4 46.8 C. (No. 275) Comparative Example 1 17.9 C. (C-1) .sup.1)The maximum temperature (T.sub.NI) of a nematic phase was measured using a mixture of the compound and the mother liquid crystals as a sample and calculated by extrapolating from the measured value.

(71) The following compounds (No. 1) to (No. 108), compounds (No. 200) to (No. 349), compounds (No. 400) to (No. 565) and compounds (No. 600) to (No. 675) are prepared according to the synthetic methods of compound (1a) described above and the synthetic procedures described in Synthetic Examples 1 to 7.

(72) ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093## ##STR00094## ##STR00095## ##STR00096##

(73) ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103## ##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111## ##STR00112## ##STR00113##

(74) ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## ##STR00119## ##STR00120## ##STR00121## ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127## ##STR00128## ##STR00129##
2. Examples of the Composition

(75) The invention will be explained in more detail by way of Examples. The invention includes a mixture of the composition in Use Example 1 and the composition in Use Example 2. The invention also includes a mixture prepared by mixing at least two compositions in Use Examples. The compounds described in Examples were expressed in terms of symbols based on the definition in Table 2 described below. In Table 2, the configuration of 1,4-cyclohexylene is trans. A parenthesized number next to a symbolized compound in Example represents the chemical formula to which the compound belongs. The symbol () means any other liquid crystal compound. The ratio (percentage) of a liquid crystal compound means the percentages by weight (% by weight) based on the weight of the liquid crystal composition. Last, physical property-values of the composition are summarized. Physical properties were measured according to the method described above, and the measured value was reported as it was (without extrapolation).

(76) TABLE-US-00002 TABLE 2 Method of Description of Compounds using Symbols R(A.sub.1)Z.sub.1. . . . .Z.sub.n(A.sub.n)R 1) Left-terminal GroupR Symbol C.sub.nH.sub.2n+1 n- C.sub.nH.sub.2n+1O nO C.sub.mH.sub.2m+1OC.sub.nH.sub.2n mOn- CH.sub.2CH V C.sub.nH.sub.2n+1CHCH nV CH.sub.2CHC.sub.nH.sub.2n Vn- C.sub.mH.sub.2m+1CHCHC.sub.nH.sub.2n mVn- CF.sub.2CH VFF CF.sub.2CHC.sub.nH.sub.2n VFFn- 2) Rightterminal Group R Symbol C.sub.nH.sub.2n+1 -n OC.sub.nH.sub.2n+1 On COOCH.sub.3 EMe CHCH.sub.2 V CHCHC.sub.nH.sub.2n+1 Vn C.sub.nH.sub.2nCHCH.sub.2 -nV CmH.sub.2mCHCHC.sub.nH.sub.2n+1 -mVn CHCF.sub.2 VFF F F Cl CL OCF.sub.3 OCF3 OCF.sub.2H OCF2H CF.sub.3 CF3 OCHCHCF.sub.3 OVCF3 CN C C.sub.nF.sub.2n+1 Rfn 3) Bonding Group Z.sub.n Symbol C.sub.nH.sub.2n n COO E CHCH V CH.sub.2O 1O OCH.sub.2 O1 CF.sub.2O X CC T 4) Ring A.sub.n Symbol 0 H B B(F) B(2F) B(F,F) B(2F,5F) B(2F,3F) Py G dh 0 Dh Cro B(2F,3CL) 5) Examples of Description Example 1. 3-HHV Example 2. 3-BB(F,F)XB(F,F)Rf7

Use Example 1

(77) TABLE-US-00003 3-BB(F)B(F,F)XB(F,F)-Rf5 (No. 458) 1% 3-HB-O2 (2-5) 10% 5-HB-CL (5-2) 13% 3-HBB(F,F)-F (6-24) 7% 3-PyB(F)-F (5-15) 10% 5-PyB(F)-F (5-15) 10% 3-PyBB-F (6-80) 9% 4-PyBB-F (6-80) 9% 5-PyBB-F (6-80) 9% 5-HBB(F)B-2 (4-5) 10% 5-HBB(F)B-3 (4-5) 10% NI = 98.7 C.; = 40.1 mPa .Math. s; n = 0.188; = 8.3.

Use Example 2

(78) TABLE-US-00004 4-BB(F)B(F,F)XB(F,F)-Rf3 (No. 457) 2% 5-HXB(F,F)-Rf5 (No. 2) 2% 2-HB-C (8-1) 5% 3-HB-C (8-1) 12% 3-HB-O2 (2-5) 15% 2-BTB-1 (2-10) 3% 3-HHB-F (6-1) 4% 3-HHB-1 (3-1) 8% 3-HHB-O1 (3-1) 5% 3-HHB-3 (3-1) 14% 3-HHEB-F (6-10) 4% 5-HHEB-F (6-10) 4% 2-HHB(F)-F (6-2) 5% 3-HHB(F)-F (6-2) 7% 5-HHB(F)-F (6-2) 7% 3-HHB(F,F)-F (6-3) 3% NI = 99.2 C.; = 19.1 mPa .Math. s; n = 0.102; = 5.1.

Use Example 3

(79) TABLE-US-00005 3-HHXB(F,F)-Rf5 (No. 201) 5% 7-HB(F,F)-F (5-4) 3% 3-HB-O2 (2-5) 7% 2-HHB(F)-F (6-2) 10% 3-HHB(F)-F (6-2) 10% 5-HHB(F)-F (6-2) 10% 2-HBB(F)-F (6-23) 7% 3-HBB(F)-F (6-23) 6% 5-HBB(F)-F (6-23) 16% 2-HBB-F (6-22) 4% 3-HBB-F (6-22) 4% 5-HBB-F (6-22) 3% 3-HBB(F,F)-F (6-24) 5% 5-HBB(F,F)-F (6-24) 10% NI = 87.0 C.; = 26.1 mPa .Math. s; n = 0.112; = 5.9.

Use Example 4

(80) TABLE-US-00006 3-BB(F,F)XB(F,F)-Rf7 (No. 275) 4% 5-HB-CL (5-2) 16% 3-HH-4 (2-1) 12% 3-HH-5 (2-1) 4% 3-HHB-F (6-1) 4% 3-HHB-CL (6-1) 3% 4-HHB-CL (6-1) 4% 3-HHB(F)-F (6-2) 10% 4-HHB(F)-F (6-2) 9% 5-HHB(F)-F (6-2) 9% 7-HHB(F)-F (6-2) 5% 5-HBB(F)-F (6-23) 3% 1O1-HBBH-5 (4-1) 3% 3-HHBB(F,F)-F (7-6) 2% 4-HHBB(F,F)-F (7-6) 3% 5-HHBB(F,F)-F (7-6) 3% 3-HH2BB(F,F)-F (7-15) 3% 4-HH2BB(F,F)-F (7-15) 3% NI = 111.8 C.; = 19.5 mPa .Math. s; n = 0.092; = 4.3.

Use Example 5

(81) TABLE-US-00007 3-BB(F,F)XB(F,F)-Rf5 (No. 274) 5% 3-HHB(F,F)-F (6-3) 9% 3-H2HB(F,F)-F (6-15) 8% 4-H2HB(F,F)-F (6-15) 8% 5-H2HB(F,F)-F (6-15) 8% 3-HBB(F,F)-F (6-24) 20% 5-HBB(F,F)-F (6-24) 19% 3-H2BB(F,F)-F (6-27) 8% 5-HHBB(F,F)-F (7-6) 2% 5-HHEBB-F (7-17) 2% 3-HH2BB(F,F)-F (7-15) 3% 1O1-HBBH-4 (4-1) 4% 1O1-HBBH-5 (4-1) 4% NI = 94.9 C.; = 35.5 mPa .Math. s; n = 0.116; = 9.6.

(82) The helical pitch was 63.9 micrometers when optically active compound (Op-5) was added to the preceding composition in the ratio of 0.25% by weight.

Use Example 6

(83) TABLE-US-00008 3-BB(F,F)XB(F,F)-Rf2 (No. 276) 5% 5-HB-F (5-2) 10% 6-HB-F (5-2) 7% 7-HB-F (5-2) 6% 2-HHB-OCF3 (6-1) 7% 3-HHB-OCF3 (6-1) 7% 4-HHB-OCF3 (6-1) 7% 5-HHB-OCF3 (6-1) 5% 3-HH2B-OCF3 (6-4) 4% 5-HH2B-OCF3 (6-4) 4% 3-HHB(F,F)-OCF2H (6-3) 4% 3-HHB(F,F)-OCF3 (6-3) 5% 3-HH2B(F)-F (6-5) 3% 3-HBB(F)-F (6-23) 10% 5-HBB(F)-F (6-23) 10% 5-HBBH-3 (4-1) 3% 3-HB(F)BH-3 (4-2) 3%

Use Example 7

(84) TABLE-US-00009 3-B(F)B(F,F)XB(F)B(F,F)-Rf5 (No. 654) 1% 3-GB(F,F)XB(F,F)-Rf3 (No. 296) 3% 5-HB-CL (5-2) 11% 3-HH-4 (2-1) 8% 3-HHB-1 (3-1) 5% 3-HHB(F,F)-F (6-3) 7% 3-HBB(F,F)-F (6-24) 20% 5-HBB(F,F)-F (6-24) 14% 3-HHEB(F,F)-F (6-12) 10% 4-HHEB(F,F)-F (6-12) 3% 5-HHEB(F,F)-F (6-12) 3% 2-HBEB(F,F)-F (6-39) 3% 3-HBEB(F,F)-F (6-39) 3% 5-HBEB(F,F)-F (6-39) 3% 3-HHBB(F,F)-F (7-6) 6%

Use Example 8

(85) TABLE-US-00010 4-BB(F)B(F,F)XB(F,F)-Rf7 (No. 459) 2% 3-dhBB(F,F)XB(F,F)-Rf5 (No. 547) 1% 3-HB-CL (5-2) 6% 5-HB-CL (5-2) 4% 3-HHB-OCF3 (6-1) 5% 3-H2HB-OCF3 (6-13) 5% 5-H4HB-OCF3 (6-19) 13% V-HHB(F)-F (6-2) 4% 3-HHB(F)-F (6-2) 5% 5-HHB(F)-F (6-2) 5% 3-H4HB(F,F)-CF3 (6-21) 8% 5-H4HB(F,F)-CF3 (6-21) 10% 5-H2HB(F,F)-F (6-15) 5% 5-H4HB(F,F)-F (6-21) 7% 2-H2BB(F)-F (6-26) 5% 3-H2BB(F)-F (6-26) 10% 3-HBEB(F,F)-F (6-39) 5%

Use Example 9

(86) TABLE-US-00011 3-BB(F)B(F,F)XB(F,F)-Rf5 (No. 458) 1% 4-BB(F)B(F,F)XB(F,F)-Rf3 (No. 457) 2% 5-HB-CL (5-2) 17% 7-HB(F,F)-F (5-4) 3% 3-HH-4 (2-1) 10% 3-HH-5 (2-1) 5% 3-HB-O2 (2-5) 15% 3-HHB-1 (3-1) 8% 3-HHB-O1 (3-1) 4% 2-HHB(F)-F (6-2) 7% 3-HHB(F)-F (6-2) 6% 5-HHB(F)-F (6-2) 6% 3-HHB(F,F)-F (6-3) 6% 3-H2HB(F,F)-F (6-15) 5% 4-H2HB(F,F)-F (6-15) 5% NI = 70.0 C.; = 14.9 mPa .Math. s; n = 0.077; = 3.6.

Use Example 10

(87) TABLE-US-00012 3-HHXB(F,F)-Rf5 (No. 201) 3% 5-HB-CL (5-2) 3% 7-HB(F)-F (5-3) 7% 3-HH-4 (2-1) 9% 3-HH-EMe (2-2) 23% 3-HHEB-F (6-10) 8% 5-HHEB-F (6-10) 8% 3-HHEB(F,F)-F (6-12) 10% 4-HHEB(F,F)-F (6-12) 5% 4-HGB(F,F)-F (6-103) 5% 5-HGB(F,F)-F (6-103) 5% 2-H2GB(F,F)-F (6-106) 4% 3-H2GB(F,F)-F (6-106) 5% 5-GHB(F,F)-F (6-109) 5% NI = 81.0 C.; = 19.9 mPa .Math. s; n = 0.064; = 5.5.

Use Example 11

(88) TABLE-US-00013 3-BB(F,F)XB(F,F)-Rf7 (No. 275) 5% 3-HB-O1 (2-5) 16% 3-HH-4 (2-1) 5% 3-HB(2F,3F)-O2 (9-1) 12% 5-HB(2F,3F)-O2 (9-1) 10% 2-HHB(2F,3F)-1 (10-1) 10% 3-HHB(2F,3F)-1 (10-1) 12% 3-HHB(2F,3F)-O2 (10-1) 11% 5-HHB(2F,3F)-O2 (10-1) 13% 3-HHB-1 (3-1) 6% NI = 83.5 C.; = 35.6 mPa .Math. s; n = 0.091; = 3.1.

Use Example 12

(89) TABLE-US-00014 3-BB(F,F)XB(F,F)-Rf5 (No. 274) 5% 2-HH-5 (2-1) 3% 3-HH-4 (2-1) 15% 3-HH-5 (2-1) 4% 3-HB-O2 (2-5) 12% 3-H2B(2F,3F)-O2 (9-4) 13% 5-H2B(2F,3F)-O2 (9-4) 15% 3-HHB(2F,3CL)-O2 (10-12) 5% 2-HBB(2F,3F)-O2 (10-7) 3% 3-HBB(2F,3F)-O2 (10-7) 8% 5-HBB(2F,3F)-O2 (10-7) 7% 3-HHB-1 (3-1) 3% 3-HHB-3 (3-1) 4% 3-HHB-O1 (3-1) 3% NI = 72.0 C.; = 20.0 mPa .Math. s; n = 0.092; = 3.8.

Use Example 13

(90) TABLE-US-00015 3-BB(F,F)XB(F,F)-Rf2 (No. 276) 4% 2-HH-3 (2-1) 18% 3-HH-4 (2-1) 9% 1-BB-3 (2-8) 9% 3-HB-O2 (2-5) 2% 3-BB(2F,3F)-O2 (9-3) 9% 5-BB(2F,3F)-O2 (9-3) 5% 2-HH1OB(2F,3F)-O2 (10-5) 13% 3-HH1OB(2F,3F)-O2 (10-5) 21% 3-HHB-1 (3-1) 5% 3-HHB-O1 (3-1) 3% 5-B(F)BB-2 (3-8) 2%

Use Example 14

(91) TABLE-US-00016 3-B(F)B(F,F)XB(F)B(F,F)-Rf5 (No. 654) 1% 3-GB(F,F)XB(F,F)-Rf3 (No. 296) 3% 2-HH-3 (2-1) 16% 7-HB-1 (2-5) 10% 5-HB-O2 (2-5) 8% 3-HB(2F,3F)-O2 (9-1) 17% 5-HB(2F,3F)-O2 (9-1) 14% 3-HHB(2F,3CL)-O2 (10-12) 3% 4-HHB(2F,3CL)-O2 (10-12) 3% 3-HH1OCro(7F,8F)-5 (13-6) 5% 5-HBB(F)B-2 (4-5) 10% 5-HBB(F)B-3 (4-5) 10%

Use Example 15

(92) TABLE-US-00017 4-BB(F)B(F,F)XB(F,F)-Rf7 (No. 459) 2% 3-dhBB(F,F)XB(F,F)-Rf5 (No. 547) 1% 1-BB-3 (2-8) 10% 3-HH-V (2-1) 27% 3-BB(2F,3F)-O2 (9-3) 12% 2-HH1OB(2F,3F)-O2 (10-5) 20% 3-HH1OB(2F,3F)-O2 (10-5) 14% 3-HHB-1 (3-1) 8% 5-B(F)BB-2 (3-8) 6%

Use Example 16

(93) TABLE-US-00018 3-BB(F)B(F,F)XB(F,F)-Rf5 (No. 458) 1% 4-BB(F)B(F,F)XB(F,F)-Rf3 (No. 457) 2% 2-HH-3 (2-1) 6% 3-HH-V1 (2-1) 10% 1V2-HH-1 (2-1) 8% 1V2-HH-3 (2-1) 7% 3-BB(2F,3F)-O2 (9-3) 8% 5-BB(2F,3F)-O2 (9-3) 4% 3-H1OB(2F,3F)-O2 (9-5) 6% 2-HH1OB(2F,3F)-O2 (7-5) 7% 3-HH1OB(2F,3F)-O2 (10-5) 19% 3-HDhB(2F,3F)-O2 (10-5) 6% 3-HHB-1 (3-1) 3% 3-HHB-3 (3-1) 2% 2-BB(2F,3F)B-3 (11-1) 11% NI = 85.5 C.; = 22.1 mPa .Math. s; n = 0.111; = 4.2.

Use Example 17

(94) TABLE-US-00019 5-HXB(F,F)-Rf5 (No. 2) 5% 1V2-BEB(F,F)-C (8-15) 5% 3-HB-C (8-1) 18% 2-BTB-1 (2-10) 10% 5-HH-VFF (2-1) 30% 3-HHB-1 (3-1) 3% VFF-HHB-1 (3-1) 8% VFF2-HHB-1 (3-1) 11% 3-H2BTB-2 (3-17) 3% 3-H2BTB-3 (3-17) 4% 3-H2BTB-4 (3-17) 3% NI = 74.3 C.; = 12.3 mPa .Math. s; n = 0.123; = 6.1.

Use Example 18

(95) TABLE-US-00020 3-HHXB(F,F)-Rf5 (No. 201) 5% 5-HB(F)B(F,F)XB(F,F)-F (7-41) 5% 3-BB(F)B(F,F)XB(F,F)-F (7-47) 3% 4-BB(F)B(F,F)XB(F,F)-F (7-47) 5% 5-BB(F)B(F,F)XB(F,F)-F (7-47) 3% 3-HH-V (2-1) 41% 3-HH-V1 (2-1) 7% 3-HHEH-5 (3-13) 3% 3-HHB-1 (3-1) 3% V-HHB-1 (3-1) 5% V2-BB(F)B-1 (3-6) 5% 1V2-BB-F (5-1) 3% 3-BB(F,F)XB(F,F)-F (6-97) 9% 3-HHBB(F,F)-F (7-6) 3% NI = 83.8 C.; = 12.4 mPa .Math. s; n = 0.102; = 5.6.

Use Example 19

(96) TABLE-US-00021 3-BB(F,F)XB(F,F)-Rf7 (No. 275) 4% 3-GB(F)B(F,F)XB(F,F)-F (7-57) 5% 3-BB(F)B(F,F)XB(F,F)-F (7-47) 3% 4-BB(F)B(F,F)XB(F,F)-F (7-47) 5% 5-BB(F)B(F,F)XB(F,F)-F (7-47) 3% 3-HH-V (2-1) 41% 3-HH-V1 (2-1) 7% 3-HHEH-5 (3-13) 3% 3-HHB-1 (3-1) 4% V-HHB-1 (3-1) 5% V2-BB(F)B-1 (3-6) 5% 1V2-BB-F (5-1) 3% 3-BB(F,F)XB(F,F)-F (6-97) 5% 3-GB(F,F)XB(F,F)-F (6-113) 4% 3-HHBB(F,F)-F (7-6) 3% NI = 81.5 C.; = 12.5 mPa .Math. s; n = 0.102; = 6.9.

INDUSTRIAL APPLICABILITY

(97) The liquid crystal compound of the invention satisfies at least one of physical properties such as a high stability to heat or light, a high clearing point (or a high maximum temperature), a low minimum temperature of a liquid crystal phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a suitable elastic constant and an excellent compatibility with any other liquid crystal compound. The compound has an especially high maximum temperature. The liquid crystal composition of the invention includes this compound and satisfies at least one of physical property such as a high stability to heat or light, a high maximum temperature, a low minimum temperature, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance and a suitable elastic constant. The composition has a suitable balance between at least two of physical properties. The liquid crystal display device of the invention includes this composition and has a wide temperature range in which a device can be used, a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life. The device can be used for a liquid crystal projector, a liquid crystal television and so forth, accordingly.