Redox chemistry of metal-catechol complexes in aprotic media. 2. 3,5-Di-tert-butylcatecholato complexes of manganese(IV) and manganese(III)

Article abstract of DOI:10.1021/ic50226a045

When mixtures of manganese(II) and 3,5-di-tert-butyl-o-quinone (DTBQ) with mole ratios of 1:3 and 1:2 are reduced in aprotic solvents, stable Mn^IV(DTBC)₃^2- and Mn^III(DTBC)₂^- complexes are formed, respectively (DTBC represents the dianion of di-tert-butylcatechol). These complexes and their oxidation-reduction products have been characterized by cyclic voltammetry, controlled-potential electrolysis, optical spectroscopy, ESR spectroscopy, and magnetic susceptibility measurements in dimethylformamide, dimethyl sulfoxide, and acetonitrile solvents. On the basis of these results, a self-consistent redox mechanism is presented for the interconversion of the various species of manganese(II)-DTBQ systems with mole ratios of 1:1, 1:2, and 1:3. The catechol complexes of manganese(II), -(III), and -(IV) are versatile electron-transfer agents and should be effective redox catalysts and oxygen activators.