| 摘要 |
The present invention relates to benzo[f]chromene and pyrano[3,2-f]-chromene derivatives of the formula I in which L1, L2, R1, R2, A1, A2, Z1, Z2, m and n are as defined in claim 1, to the preparation thereof, to the use thereof as components in liquid-crystalline media, and to electro-optical display elements which contain the liquid-crystalline media according to the invention. |
