Solvents with Gutmann donor numbers greater than or equal to 17 promote dissociation of axial Cl- from Mn-III(TPP)Cl and Mn-II(TPPCl- producing six-coordinate Mn-III(TPP)(L)(2)(+) and five-coordinate Mn-II(TPP)(L). Systematic changes in the position of the Sorer band and the relative intensities of the Soret, Q(alpha), and Q(beta) bands provide a basis for establishing the stoichiometries of these species.