Electrochemical behavior of polymeric complexes of monosubstituted squarate ligands. Part 2. Determination of redox species of manganese(II) complexes in the donor solvents, dimethylformamide and dimethylsulfoxide

Abstract

Cyclic and square wave voltammetry (−1500 to 1500 mV) of {Mn[μ-(C 6H 5) 2NC 4O 3] 2[H 2O] 4} n [manganese(II) diphenylaminosquarate] ( 1) and [Mn(μ-C 6H 5C 4O 3)(C 6H 5C 4O 3)(H 2O) 3] n [manganese(II) phenylsquarate] ( 2) at a gold disk electrode in dimethylsulfoxide (DMSO) and dimethylformamide (DMF), reveal several couples attributable to both ligand and metal-based redox processes. For the manganese(II) phenylsquarate in DMF, the metal-based peaks are more numerous and readily discernible than in DMSO. In either of the solvents, the ligand-based peaks always occur at more positive or more negative potentials than the metal-based ones. In 1 and 2, Mn(II)/Mn(0), Mn(III)/Mn(II), Mn(IV)/Mn(III) and Mn(V)/Mn(IV) couples are observed. However, the manganese redox peaks appear at more negative potentials in 1.