Synthesis, electrochemical characterization of tetra- and octa-substituted dodecyl-mercapto tin phthalocyanines in solution and as self-assembled monolayers

Non-peripherally (α) tetra- (9) and octa-(7) substituted dodecyl-mercapto tin(IV) phthalocyanines were synthesized and their electrochemical behavior studied. Cyclic voltammetry and spectroelectrochemistry show ring-based reductions for 7 and 9, the former shows two ring oxidations, while the latter shows only one ring-based oxidation. The adsorption kinetics of (7) and (9) on gold electrode were investigated by electrochemical impedance spectroscopy (EIS). The equilibrium constant (K) for the adsorption and the Gibbs free energy (ΔGads) of the SAMs were evaluated based on the Frumkin isotherm.