Discotic liquid crystals of transition metal complexes, Part 30: spontaneous uniform homeotropic alignment of octakis(dialkoxyphenoxy)phthalocyaninatocopper(II) complexes

Six novel octakis(dialkoxyphenoxy)phthalocyaninatocopper(ii) complexes (abbreviated as [(CnO)(2)PhO](8)PcCu (n = 9-14)) have been synthesized. It was found that these derivatives exhibit rich mesophases; Col(h), Col(r1), Col(r2), Col(r3,) Col(tet) and Cub phases. These mesophases were characterized by microscopic observation, DSC measurements and temperature-dependent X-ray diffraction measurements. Temperature-dependent electronic spectra for the thin films of these complexes revealed that roof-top-shaped dimers in the column gradually change into cofacial dimers as the temperature is increased from rt to their clearing points. Furthermore, the phthalocyanine derivatives for n = 11-14 exhibited spontaneous uniform homeotropic alignment for the Col(tet) mesophase, which is the first example in discotic liquid crystalline phthalocyanine compounds.