Novel 4-(2-(benzo[d]thiazol-2-yl)phenoxy) substituted phthalocyanine derivatives: Synthesis, electrochemical and in situ spectroelectrochemical characterization

In this study, the new tetra peripherally 4-(2-(benzo[d]thiazol-2-yl)phenoxy)-substituted metal-free (4), zinc(II) (5), lead(II) (6), cobalt(II) (7) and copper(II) (8) phthalocyanine derivatives, which are organo-soluble, have been synthesized for the first time and their structures characterized by using electronic absorption, infrared spectroscopy, nuclear magnetic resonance spectroscopy, elemental analysis and mass spectra. Voltammetric characterization of the phthalocyanine derivatives (4–7) was performed with cyclic voltammetry and square wave voltammetry. Cobalt phthalocyanine (7) gave metal based electron transfer reactions in addition to the phthalocyanine ring based reduction and oxidation reactions. Although lead phthalocyanine (6) illustrated reversible reduction process during the voltammetric measurements, it was de-metallized and thus it turned back to the metal free phthalocyanine during the in situ spectroelectrochemical measurements under the applied potentials. Spectroelectrochemical measurements were performed to assign the redox processes and spectroscopic responses of the electrogenerated species.