"A is a C1-C5-alkylene radical which is substituted at any point by a linker L and may bear further substituents, L is a methylene group, p is 0 or an integer from 1 to 6, preferably 0 or 1, M is an n-functional mesogenic group, n is an integer from 1 to 8 and B is a bridging group of the formula (B) where" . . . .