Seven-coordinate Manganese(II) Complex Formed with the Tripodal Tetradentate Ligand Tris(N-methylbenzimidazol-2-ylmethyl)amine

Abstract

A seven-coordinate manganese(II) complex with the tripodal tetradentate ligand tris(N-methylbenzimidazol- 2-ylmethyl)amine (Mentb), with composition [Mn(Mentb)(α-methacrylate)(DMF)]- (ClO4) · (DMF), was synthesized and characterized by elemental analysis, electrical conductivity, and IR and UV/Vis spectral measurements. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. The MnII cation is bonded to a Mentb ligand, an α-methacrylate ligand and a DMF molecule through four N atoms and three O atoms, resulting in a seven-coordinate geometry. Cyclovoltammograms of the complex indicate a quasireversible Mn3+/Mn2+ couple. The X-band EPR spectrum of the complex exhibits a six-line manganese hyperfine pattern with g = 2, A = 91, and confirms that the material is high-spin Mn(II).