- Liquid crystal compounds and compositions
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Smetic C liquid crystal compounds, represented by the following formula (1) or (2) are disclosed. R1-O-A1-C≡C-A2-CO-(O)P-R2 (2)wherein R1and R2are C1-18 alkyl groups; A is a cyclic group, such as aubstituted or unsubstituted 1,4-phenylene group, X is direct bond, O or C#IDW#C; Y is -C#IDW#C- or -CH2CH2-; one of A1and A2is 1,4-phenylene group and the other is, 2,3-difluoro-1,4-phenylene group; and p is 0 or 1. These compounds can provide ferroelectric liquid crystal composition of low viscosity, and are useful as a component giving negative dielectric anisotropy and enlarging a temperature range showing smetic C phase.
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- Liquid crystal compounds and compositions
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Liquid crystal naphtalene compounds, represented by the following formula (1) are disclosed. R-Z-A-NAP-Z?-R? (1)In the formula (1), R is an alkyl group containing 1 to 18 carbon atoms; R? is an alkyl group containing 1 to 21 carbon atoms; NAP represents 2,6-naphthylene group; A, Z and Z? are as follows: 1) A is Pyr> and (a) Z is - or and Z? is O, or (b) Z is - and Z? is COO; 2) if A is Pym>, (a) Z is - and Z? is O, or (b) Z is O and Z? is -, O or ; 3) A is FPhF and (a) Z is - or O and Z? is -, O or COO, (b) Z is OCO and Z? is - or O, or (c) Z is and Z? is O; 4) A is PhF and (a) Z is - or and Z? is O, (b) Z is O and Z? is -, or (c) Z is - and Z? is COO; 5) A is FPh and (a) Z is O and Z? is-, (b) Z is -, O, or OCO and Z? is O, or (c) Z is O and Z? is COO; 6) A is Pyr and Z is -, O or and Z? is O; or 7) A is Ph and one of Z and Z? is - and the other is O; As a component of liquid crystal compositions showing chiral smectic C phase, these compounds can provide liquid crystal compositions of improved orientation and free from zigzag deffects, and liquid crystal display elements of high contrast ratio.
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