Electrochromism in the octapentyloxy nickel phthalocyanines and related phthalocyanines

Reversible electrochromic behaviour has been shown to exist in the monophthalocyanine [Ni(pc(OCSH11)s)] and poor electrochromic behaviour in [Cu(pc(OCSH11)8)] and [Co(pc(OCSH11)a)], the samples having been prepared as Langmuir-Blodgett films. The latter two were deposited in semi-darkened conditions. Electrochromic behaviour was not observed in phthalocyanines of similar structure, in which there was no oxygen atom present, nor was it observed in compounds in which the metal was not a transition metal.