abstract |
The invention relates to new four-ring compounds with negative DK anisotropy of the formula I DOLLAR F1 where R 1, R 2, A 1, A 2, A 3, A 4, Z 1 , Z · 2 · and Z · 3 · have the meaning given in claim 1, their use as components of liquid-crystalline media and liquid-crystal and electro-optical display elements which contain the liquid-crystalline media according to the invention. |