LIQUID-CRYSTALLINE HETEROCYCLIC PHTHALOCYANINE ANALOGS BASED ON THIOPHENE

The syntheses and mesomorphism of novel octaalkoxymethyl-substituted t etra-2,3-thiophenophorphyrazines, heterocyclic phthalocyanine analogue s in which the benzene rings are replaced by thiophene rings, are repo rted. NMR analysis indicates that these materials exist as isomeric mi xtures due to the asymmetry induced by the thiophene ring. Among the a ttractive features of liquid-crystalline 2,3-thiophenophorphyrazines o ver phthalocyanines are their lower mesomorphic and isotropic temperat ures. These features have resulted in liquid crystallinity at room tem perature. Similar to liquid-crystalline phthalocyanine derivatives, me talation with copper raises the transition temperatures.