Non-Peripheral 1,1′-thiobis(naphthalen-2-oxy) Substituted Mononuclear Ball-Type Precursor and Binuclear Ball-Type Metallophthalocyanines: Synthesis, Structural Characterization, and Electrochemical, In Situ Spectroelectrochemical and Electrocatalytic

Novel alpha-substituted mononuclear ball-type precursor and binuclear ball-type metallo (Cu, Mn, and Ni) phthalocyanines were synthesized by using 3,3′-((thiobis(naphthalene-1,2-diyl))bis(oxy))diphthalonitrile, characterized with UV– vis , FT-IR and MALDI-TOF mass spectroscopy. The rich electron transfers through ring and/or metal-based reductions/oxidations, accompanied by distinct spectral and color changes, had been recorded for the complexes, highlighting their potential applicability in various technological applications. Hydrodynamic voltammetry studies were conducted under conditions similar to polymer electrolyte membranes and direct methanol fuel cells to test the electrocatalytic performances of catalyst inks prepared with the complexes. The positive effect of the studied substituents on catalytic activity was revealed for mononuclear complexes, and the relative changes in activity for the ball-type structures are discussed. Furthermore, by using Mn complexes as co-catalysts, the oxidative activity of the Pt particles was effectively suppressed, and their performance was exceptionally preserved in the presence of methanol, demonstrating the applicability of the prepared catalyst mixtures in direct methanol fuel cell applications.