Isolation of the first ferromagnetically coupled Mn(iii/iv) complex

Abstract

Binuclear manganese complexes Mn₂(III/IV)(dtsalpn)₂DCBI, 1, Mn₂(III/III)(dtsalpn)₂HDCBI, 2, containing the ligand dicarboxyimidazole (DCBI) have been prepared in order to address the issue of imidazole bridged and ferromagnetically coupled Mn sites in high oxidation states of the OEC in Photosystem II (PS II). Temperature dependent magnetic susceptibility studies of 1 indicates that the interaction between the two Mn(III)/Mn(IV) ions is ferromagnetic (J = + 1.4 cm⁻¹). Variable temperature EPR spectra of 1 shows that a g = 2 multiline is as an excited state signal corresponding to S =1/2.