Electrochemical and spectroelectrochemical behavior of N-methyl-phenothiazinyl meso-substituted porphyrins and their complexes with Ni(II), Cu(II) and Pd(II).

Highlights: [•] SWV were recorded for MPtz x Ph4−xPorph (x =0, 1, 2, 4; M=Ni2+, Cu2+, Pd2+). [•] Ptz and Porph contribute distinctly to the overall redox response. [•] Ptz and M2+ exert opposite effects on the redox activity of the Porph ring. [•] Structure–redox activity correlation obeys Hammett’s free energy relationship. [•] The spectral activity of the investigated compounds is decided by the Porph moiety. [Copyright &y& Elsevier]