Helical twisting power of chiral titanium complexes in nematic compounds

We report the use of chiral bis-chelated imine-alkoxytitanium complexes as dopants for the conversion of a nematic into a cholesteric phase. High helical twisting power (HTP) is obtained in the liquid crystalline mixture ZLI-1695 (Merck, Darmstadt). Enlargement of the HTP is achieved by novel analogues of the titanium complexes, whose synthesis is described.