| abstract |
PCT No. PCT/EP96/01989 Sec. 371 Date Nov. 6, 1997 Sec. 102(e) Date Nov. 6, 1997 PCT Filed May 10, 1996 PCT Pub. No. WO96/35672 PCT Pub. Date Nov. 14, 19961,8,8-Trifluoro-5,6,7,8-tetrahydroisoquinoline derivatives, and their use in liquid-crystalline mixtures 1,8,8-Trifluoro-5,6,7,8-tetrahydroisoquinoline derivatives of the formula (I)R1(-M1)a(-A1-M2)b(-A2-M3)c-B(-M4-A3)d(-M5-A4)e(-M6)f-R2(I)in which the symbols and indices have the following meanings: the group B is R1 and R2 are, for example, alkyl radicals having 1 to 20 carbon atoms; M1, M2, M3, M4, M5 and M6 are, for example, -O-, -CO-O-, -O-CO- or a single bond; A1, A2, A3 and A4 are, for example, 1,4-phenylene, pyrimidine-2,5-diyl or trans-1,4-cyclohexylene, and a, b, c, d, e and f are zero or one, with the proviso that the sum of b, c, d and e is 0, 1 or 2. The compounds of the formula (I) are colorless in the pure state and generally form liquid-crystalline mesophases in a temperature range which is favorably located for electro-optical use. They are stable chemically, thermally and to light. |