Synthesis, physicochemical properties and electrochemistry of morpholine-substituted phthalocyanines

The synthesis, spectroscopic and electrochemical properties of new phthalocyanines bearing four morpholine and four chloro units is reported. Two-step synthesis involved efficient nucleophilic substitution of 4,5-dichlorophthalonitrile as the key step. The free-base phthalocyanine and its several complexes have been characterized using UV-vis, IR, ¹H NMR, ¹³C NMR and mass spectroscopic data. Voltammetric and spectroelectrochemical studies show that while cobalt phthalocyanine gives both metal- and ring-based, diffusion-controlled, multi-electron and reversible/quasi-reversible redox processes, other complexes give ring-based, multi-electron and reversible/quasi-reversible redox processes.