Mesogenic Behaviour of some 1,4,8,11,15,18,22,25-Octa-alkylphthalocyanines

Abstract

Abstract Discotic columnar mesophase behaviour exhibited by ten metal-free and copper 1,4,8,11,15,18,22,25- octa-alkylphthalocyanines has been characterised by optical microscopy, differential scanning calorimetry, x-ray diffraction and electronic absorption spectroscopy. Compounds with side-chains as short as hexyl exhibit one or more mesophases, and a total of three different mesophases are apparent for the series as a whole. The highest temperature mesophase is assigned as Dhd. At lower temperatures, some compounds develop a second mesophase of hexagonal symmetry, whereas others form a mesophase of rectangular symmetry. One example shows all three mesophases.