Spectroscopic and electrochemical properties of mononuclear Mn(III) complex and of binuclear di-μ-oxo bridged Mn(III) and Mn(IV) complex with isocyclam

trans-[MnIIIisocyclamCl2]Cl·2H2O and [MnIIIMnIV(μ-O)2isocyclam2](ClO4)3·2H2O (isocyclam = 1,4,7,11-tetraazacyclotetradecane) were synthesised and analysed. Coordination geometry of both of these complexes was estimated with IR and electronic spectroscopy as trans-pseudo-octahedral for the first one and cis-pseudo-octahedral with two oxygen bridges for the other one. Magnetic properties of complexes were characterised as high-spin and antiferromagnetic, respectively. Cyclic voltammetry measurements of neutral aqueous solutions showed the possibility of oxidation of both complexes to [MnIVMnIV(μ-O)2isocyclam2]4+. Mechanism of oxidation of mononuclear complex including its isomerisation process was proposed. Formal potentials and transfer coefficients were calculated.