| abstract |
Spiro compounds of the formula I. wherein R, R 1 are independently H, F, CN, CF 3 , CF 2 CF 3 , OCF 3 , OCF 2 H, OCF 2 CF 3 , SF 5 , NCS an unsubstituted one simply by CN or CF 3 or at least one halogen-substituted alkyl radical having 1-12 C atoms or alkenyl radical having 2-12 C atoms, where in these radicals also one or more non-adjacent CH 2 groups are each independently of one another denoted by -O-, -S-, -CO- -CO-O-, -O-CO- or -O-CO-O- may be replaced, A, A 1 independently one a) trans-cyclohexane-1,4-diyl radical, in which also one or more non-adjacent CH 2 groups can be replaced by -O- and / or -S-, b) 1,4-phenylene radical, in which also one or two CH groups can be replaced by N, c) radical from the group consisting of 1,4-bicyclo (2,2,2) -octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3 , 4-tetrahydronaphthalene-2,6-diyl, d) cyclohexene-1,4-diyl where the radicals a), b) and d) can be substituted by CN, Cl or F, Z, Z 1, independently of one another, are -CO-O-, -O-CO-, -CH 2 O-, -OCH 2 -, -O-, -CH 2 CH 2 -, -CH = CH-, |