Polymeric phthalocyanines and their precursors, 12. Reversible reduction and reoxidation of thin films of octacyanophthalocyanine in polymer matrices

Thin films containing 1–100 μg 2,3,9,10,16,17,23,24‐phthalocyanineoctacarbonitrile (1) and 10–100 μg poly(N‐vinylcarbazole) (2) resp. the polyimide 3 were prepared on gold substrates through casting from solution. Smooth green coloured films were obtained. According to VIS spectra molecules of 1 are aggregated within the polymer matrices. Cyclic voltammetric measurements were carried out in 0,5 M sulfuric acid. Mixed films of 1 and 2 show remarkably stable electrochromic redox behaviour and the charge exchanged in the cathodic and anodic wave, respectively, was found to be between 2,3 and 2,7 F/mol for scan rates up to 400 mV · s−1. For mixed films of 1 and 3 with lower amount of 1 or increasing layer thickness the reduction and reoxidation appears to be a diffusion controlled process.