2008 Volume 33 Issue 4 Pages 935-938
Homologous series of 2-oxo-2H-chromen-6-yl 6-alkoxynaphthalene-2-carboxylate (compounds 1) were synthesized and their mesomorphic properties were studied. Compounds 1 showed a nematic (N) phase on cooling process. The isotropic (I)- N transition temperatures of these compounds were estimated to be ea. 140°C on average. We calculated optimized structures of the liquid crystal cores of compounds 1, corresponding benzoate derivatives (compounds 2), and biphenyl-carboxylate derivatives (compounds 3), and found that the N-I transition temperatures seem to have a linear correlation with the core length/width ratio of compounds 1-3. We conclude that the geometrical anisotropy is one of the important factors for the N-I transition temperatures.
