Liquid-Crystalline Heterocyclic Phthalocyanine Analogs Based on Thiophene.

The syntheses and mesomorphism of novel octaalkoxymethyl-substituted tetra-2,3-thiophenoporphyrazines, heterocyclic phthalocyanine analogs in which the benzene rings are replaced by thiophene rings, are reported. NMR anal. indicates that these materials exist as isomeric mixts. due to the asymmetry induced by the thiophene ring. Among the attractive features of liq.-cryst. 2,3-thiophenoporphyrazines over phthalocyanines are their lower mesomorphic and isotropic temps. These features resulted in liq. crystallinity at room temp. Similar to liq.-cryst. phthalocyanine derivs., metalation with Cu raises the transition temps. [on SciFinder(R)]