Magnetostructural examination of Mn(III) complexes [Mn(cyclam)X 2] + with strong axial ligands

Abstract

Three novel Mn(III) cyclam complexes, [Mn(cyclam)(NCBH 3) 2](CF 3SO 3), [Mn(cyclam)(NCBPh 3) 2](CF 3SO 3), and [Mn(cyclam)(NCSe) 2](CF 3SO 3) · H 2O, have been synthesized. These complexes are in the high-spin state between 4 and 350 K, and show large zero-field splittings. The crystal structure of [Mn(cyclam)(NCBH 3) 2](CF 3SO 3) was determined where the axial elongation of Mn–N bonds is found to be the largest among the homologue complexes. Ligand field in the [Mn(cyclam)X 2] + complex series was examined by angular-overlap model calculation.