Metallophthalocyanines

Abstract

Phthalocyanines (from the Greek naphtha and cyanide, rockoil and dark blue) are dyes that have been known for many years. The first phthalocyanine was produced accidentally in 1907 during a study of the properties of 1,2-cyanobenzamide. On heating an alcoholic solution of the benzamide a highly insoluble blue product precipitated [129]. Twently years later, a copper phthalocyanine was obtained during an attempted preparation of 1,2-dicyanobenzene from dibromobenzene and CuCN [130]. But it was Linstead and coworkers in the 1930’s who fitted these earlier observations into a systematic scheme showing that a vast range of phthalocyanines were all based on the one structure shown in Fig. III. 1 [131]. A huge number of different metallophthalocyanines (abbreviated as PcM) has been produced and studied, with a concomitantly large literature of several thousand publications. Apart from their intrinsic use as dyes the PcM’s show a number of special properties which account for the great interest they have always aroused.