##STR1## The invention describes liquid crystalline compounds or formula (I), where A, D and G are independently selected from phenyl, thiophene, hydrogenated phenyl, chlorinated phenyl and fluorinated phenyl, B and E are independently selected from a single bond C═≢C. C.tbd.C.C00, azoxy and diazo, k and m are independently selected from 1 and 0, such that m+n is 1 or 2, and R
1 and R
2 are independently selected from R, R0, alkynyl, thioalkyl, hydrogen, CN, NCS and SCN; provided that at least one of R
1 and R
2 is selected from CN, NCS and SCN and that at least one of A, D and G is phenyl; and excluding where at least one of R
1 and R
2 is independently selected as CN and one of A, D or G is not thiophene, and where m is 0, A, and D are phenyl, B is a single bond and only one of R
1 or R
2 is NCS. Also described are compounds suitable for inclusion in a device utilizing pretransitional characteristics of liquid crystalline materials in the isotropic phase, of general formula (II) where J and Y are independently selected from phenyl, thiophene, hydrogenated phenyl, chlorinated phenyl and fluorinated phenyl, X is selected from C═≢C. C.tbd.C.COO azoxy and diazo, k is 1 or 0 and R
3 and R
4 are independently selected from R, RO, alkynyl, thioalkyl, hydrogen, CN, NCS and SCN; provided that at least one of R
3 and R
4 is selected from CN, NCS and SCN and that at least one of J and Y is phenyl.