Dibenzofuran derivatives, dibenzothiophene derivatives and fluorene derivatives

摘要

The present invention relates to compounds of the formula I where Y, X1, X2, X3, R1, R2, A1, A2, Z1, Z2, m and n are as defined in Claim 1, to the use thereof as components in liquid-crystalline media, and to electro-optical display elements containing the liquid-crystalline media according to the invention.