FERROELECTRIC LIQUID CRYSTALS FOR NONLINEAR OPTICS APPLICATIONS

摘要

PCT No. PCT/US92/03427 Sec. 371 Date Nov. 19, 1993 Sec. 102(e) Date Nov. 19, 1993 PCT Filed Apr. 24, 1992 PCT Pub. No. WO92/20058 PCT Pub. Date Nov. 12, 1992The present invention provides ferroelectric liquid crystal and liquid crystal compounds, among which are compounds which possess large X(2), i.e. second order nonlinear susceptibility and thus make them useful in optical and nonlinear optical applications. The invention includes chiral nonracemic compounds of formula where one of n or m is 1; k is 1 and B is COO or OOC; R' is a straight-chain or branched alkyl or monoalkene group having from 1 to 20 carbon atoms where one or more of the non-neighboring carbon atoms in R', except any unsaturated carbon atoms, can be replaced with O, S or a Si(CH3)2 group; and R' is a chiral nonracemic tail group selected from the group consisting of -O-C*H(CH3)Rc, -O-C*H(CH3)COORd and -O-CH2C*HF-C*HF-R6 in which the * indicates an asymmetric carbon enriched in one stereoconfiguration which for -O-CH2C*HF-C*HF-Re is either the (S,S) or (R,R) stereoconfiguration wherein: Rc is a straight-chain or branched alkyl or monoalkene group having 2 to 15 carbon atoms; Rd is a straight-chain or branched alkyl or monoalkene group having 2 to 13 carbon atoms and Re is a straight-chain or branched alkyl or monoalkene group having 2 to 11 carbon atoms wherein in Rc, Rd or Re one or more non-neighboring carbon atoms, except any unsaturated carbon atoms, can be substituted with an O, S, or Si(CH2)2 group.