Synthesis and electrochemistry of dimanganese(II) complexes of phenol-based dinucleating ligands with four methoxyethyl chelating arms

Abstract

KEYWORDSDimanganese(II) complexes [Mn2(bonp)(PhCO2)2]PF6 (1) and [Mn2(bocp)(PhCO2)2]PF6 (2) were synthesized with p-nitro-and p-chloro-substituted phenol-based dinucleating ligands bonp -[2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-nitrophenolate anion] and bocp -[4chloro-2,6-bis[bis(2-methoxyethyl)aminomethyl]phenolate anion], respectively, with the aim of controlling the redox potentials of the dimanganese center by changing the p-substituents in the dinucleating ligands. Cyclic voltammograms of 1 and 2 showed quasi-reversible oxidation processes, assigned to Mn II Mn II /Mn II Mn III , at 1.17 and 1.00 V vs. Ag/AgCl, respectively. Compared to the previous p-methyl complex [Mn2(bomp)(PhCO2)2]PF6 (3) [bomp -: 2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-methylphenolate anion] (0.96 V vs.Ag/AgCl), the order of the potentials was 1(-NO2) > 2(-Cl) > 3(-CH3). Thus, the redox potentials of the dimanganese centers were controlled by the p-substituents in the dinucleating ligands. Dimanganese(II) complexDinucleating ligand Electrochemistry p-Substituent DFT Redox potential