| abstract |
Concerning the compound of the formula (I) n n R 1 , R 3 are each independently, for example, H R 2 , R 4 are each independently, for example, H X 1 , X 2 are each independently H or F M 1 is —CO—O—, —O—CO—, —CH 2 —O—, —O—CH 2 —, —CF 2 —O—, —O—CF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —CH 2 —CH 2 —CO—O—, —O—CO—CH 2 —CH 2 —, —CH 2 —CH 2 —, —CF 2 —CF 2 —, —(CH 2 ) 4 —, —OC(═O)CF═CF— or a single bond A 1 is, for example, 1,4-phenylene, and R 5 has the same possible definitions as specified for R 2 and R 4 , with the exception of -M 1 -A 1 -R 5 , but independently of the particular definitions of R 2 and R 4 with the following provisos: 1) at least one of X 1 , X 2 has to be F 2) R 1 , R 2 , R 3 and R 4 must not at the same time be H 3) at most two of R 1 , R 2 , R 3 and R 4 may be c). |