Novel phthalocyanines containing azo chromophores; Synthesis, characterization, photophysical, and electrochemical properties

A series of novel metal-free and zinc (II), copper (II), cobalt (II), and manganese (III) phthalocyanine complexes bearing peripheral 2,6-dimethyl-4-(4-tert-butyl-phenylazo)phenoxy units have been synthesized. Novel phthalonitrile derivative required for the preparation of these phthalocyanine complexes was prepared by a base-catalyzed nucleophilic aromatic nitro displacement of 4-nitrophthalonitrile with 2,6-dimethyl-4-(4-tert-butyl-phenylazo)phenol. The structures of these new compounds were characterized by using elemental analyses, proton and carbon nuclear magnetic resonance, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy and mass spectrometry. The photophysical properties of metal-free and zinc(II) phthalocyanines were studied in tetrahydrofuran. The electrochemical properties of the phthalocyanine complexes were investigated by cyclic and square wave voltammetry.