| abstract |
PCT No. PCT/EP89/00965 Sec. 371 Date Oct. 4, 1989 Sec. 102(e) Date Oct. 4, 1989 PCT Filed Aug. 16, 1989 PCT Pub. No. WO90/02161 PCT Pub. Date Mar. 8, 1990.The invention relates to thermochromic liquid crystalline phases with at least two components, characterized in that at least one component is an optically active compound of the formula I <IMAGE> (I) wherein R1 and R2 are each independently a chiral residue, importing to the phase a tight helical twist. <IMAGE> denotes a 1,4-phenylene group optionally substituted by fluorine, X1 and X2 are each independently O or NH, n is 1, 2 or 3 and m is 0 or 1, which can be used in electro-optic devices, in temperature indicating devices or for color-changing cosmetics. |