An electrochemical study of the Mnn+ t R,dtc-system in aprotic solvents establishes that the dithiocarbamate ligand forms tris-chelated complexes of manganese in the three oxidation states 11, 111, and IV. Thuq, Mn(R,dtc), undergoes single oneelectron oxidation and reduction steps at a platinum electrode: [MnIV(R,dtc),]+ + e-t Mn111(R2dtc),; MnI"(R,dtc), t e-+ [MnIYR,dtc),]; These redox processes have been examined for 16 different substituents R by normal pulse voltammetry, ac voltammetry, cyclic voltammetry, coulometry, and exhaustive electrolysis. Several Mn(1V) complexes have been isolated and characterized. Tris-chelated Mn(I1) complexes have been characterized in solution. Titrations of %In2' into pyrrolidyldithiocarbamate solutions and vice verw have been monitored by electrochemical means. These experiments show the existence of 1:2 and 1:3 compounds ofMn(II), i.e., Mn(Pyrr(dtc)), and [Mn(Pyrr(dtc))J. A plot of E(red) vs. E(oxid) for the 16 substituents yields a linear relation with a slope of 1.1 over a potential range of approximately 300 mV confirming that the substituent effect of R imposes similar shifts on the oxidation and reduction potentials. The complex with benzyl substituents is hardest to oxidize and easiest to reduce: the dicyclohexyl-substituted complex is easiest to oxidize and hardest to reduce AIC308933