TWISTING POWER OF BRIDGED BINAPHTHOL DERIVATIVES - COMPARISON OF THEORY AND EXPERIMENT

The twisting ability of a novel series of bridged binaphthol derivativ es with substituents of various lengths and chemical nature in the 6,6 '-positions, recently synthesized and used as dopants in nematic solve nts, is investigated with the help of the model based upon surface-hel icity tensors. Structures of the low energy conformers of these compou nds have been generated by molecular mechanics calculations. Their ori entational behaviour and the coupling between anisotropy in the alignm ent and molecular chirality, which are at the origin of the helical tw isting power, are analysed on the basis of the anisometry and the chir ality of the shape.