Advanced conjugated polymer - Helical polyacetylene

Helical polyacetylene [(CH)(x)] thin films were synthesized in chiral nemat ic (N*) liquid crystal (LC) solvents. The N*LC was prepared by adding a chi ral titanium complex as a chiral dopant to a mixture of two nematic LCs. Th e titanium complexes induced the N* phase when dissolved in nematic LCs and they were catalytically active for acetylene polymerization. Positive or n egative Cotton effect was observed in the region of pi --> pi* transition o f polyene chain in circular dichroism (CD) spectra for the (CH), thin films synthesized under the N* LC. Spiral fibrillar morphology was observed thro ugh SEM measurement of the helical (CH)(x)film. Copyright (C) 2000 John Wil ey & Sons, Ltd.