New bi:phenylyl:ethane cpds. - for use in liq. crystal phases having large optical anisotropy and increased stability

摘要

New biphenylylethane cpds. of formula (I) are claimed where R = alk(en)yl, fluoroalkyl or oxaalkyl; M = 1 or 2; Y = 0, S, CO-0, 0-C0, 0-C0-0, a bond, or, if m = 1, trans-1,4-cyclohexylene; ph = 1,4-phenylene, or 2-fluoro-, 3-fluoro- or 3,5-difluoro-1,4-phenyle-ne; L1, L2, L3, = H, or one may = F; L4 = H or F; X = F, C1, CF3, CN, OCF3, OCHF2, NCS or NO2, and if (a) X = CN, then Y = trans-1,4-cyclohexylene or m = 2 and/or ph-X = 2-fluoro-, 3-fluoro- or 3,5-difluoro-4-cyanophenyl and/or 1 or 2 of the L gps. = F, and (b) if X = NCS, then Y = trans-1,3-cyclohexylene or m = 2 and/or ph-X = 2-fluoro-, 3-fluoro- or 3,5-difluoro-4-isothiocyanatophenyl and/or 1 or 2 of the L gps. = F and/or -Y-R = 1-3C straight-chain alkyl. USE/ADVANTAGE - Use of (I) as components of liq. crystal phases, contg. at least 2 liq. crystal components, one of which is (I), and liq. crystal recording units contg. the multi-component liq. crystal phase, are claimed. The liq. crystal phases are esp. used in displays, partic. in mixts, based on the supertwist effect . (I) are also components for smectic liq. crystal phases, and are intermediates for other substances for use as components of liq. crystal phases. (I) are stable (chemically, termally and to light) liq. crystal or mesogenic cpds. with high double refraction, giving liq. crystal phases with relatively large optical anisotropy, positive dielectric anisotropy, low viscosity and high nematogen-isity, combined with good low temp. behaviour.