Dinuclear manganese(II) complexes of an acyclic phenol-based dinucleating ligand with four methoxyethyl chelating arms: synthesis, structure, magnetism and electrochemistry

Dinuclear manganese(II) complexes [Mn-2(bomp)(PhCO2)(2)]BPh4 (1), [Mn-2(bom p)(MeCO2)(2)]BPh4 (2), and [Mn-2(bomp)(PhCO2)(2)]PF6 (3) were synthesized w ith a dinucleating ligand 2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-methylp henol [H(bomp)]. Dinuclear zinc complex [Zn-2(bomp)(PhCO2)(2)]PF6 (4) was a lso synthesized for the purpose of comparison. X-ray analysis revealed that the complex 1 . CHCl3 contains two manganese ions bridged by the phenolic oxygen and two benzoate groups, forming a mu -phenoxo-bis(mu -benzoato)dima nganese(II) core. Magnetic susceptibility measurements of 1-3 over the temp erature range 1.8-300 K indicated antiferromagnetic interaction (J = - 4 to - 6 cm(-1)). Cyclic voltammograms of 3 showed a quasi-reversible oxidation process at + 0.9 V versus a saturated sodium chloride calomel reference el ectrode, assigned to (MnMnMnMnIII)-Mn-II-Mn-II-Mn-II. (C) 2000 Elsevier Sci ence B.V. All rights reserved.