DISCOTIC LIQUID-CRYSTALS OF TRANSITION-METAL COMPLEXES .18. DISCOTIC LIQUID-CRYSTALLINE BEHAVIOR IN PHTHALOCYANINE COMPOUNDS SUBSTITUTED BY STERIC HINDRANCE GROUPS AT THE CORE

Phthalocyanine compounds substituted with steric hindrance groups have been synthesized: octakis(2-ethyl-hexyl)phthalocyanine (1b) and bis[octakis(4-octadecyloxyphenyl)phthalocyaninato]lutetium(III) complex (2d). These compounds exhibit a wide temperature range of discotic liquid-crystalline properties. Each of these compounds shows a discotic tetragonal disordered columnar mesophase (D(tet.d)) or a discotic plain rectangular disordered columnar mesophase [D(rd)(P2m)] with a lattice very close to tetragonal. This D(rd)(P2m) phase is a novel discotic mesophase that has not been reported to date. It was found that the introduction of the steric hindrance groups, 2-ethylhexyl (b) and 4-octadecyloxyphenyl (d), tend to induce the appearance of the D(tet.d) phase.