Synthesis, structure and magnetic properties of a linear trimanganese(II,III,II) complex with hydroxo and 1,2,4-triazole as bridging ligands

摘要

A mixed valence trinuclear manganese(II,III,II) complex [Mn_3(admtrz)_6(OH)_2(DMF)_2(H_2O)_2]_2(ClO_4)_(10) centre dot 2(admtrz) centre dot 3H_2O (1), (admtrz=4-amino-3,5-dimethyl-1,2,4-triazole) with hydroxo and 1,2,4-triazole as bridging ligands has been isolated, and characterized by X-ray crystallography and magnetic susceptibility measurements. In each cation structure, the central Mn(III) ion lies on an inversion center and is bridged to each of the external Mn(II) ions by one OH~- anion and two admtrz ligands. Each external Mn(II) ion complexes its octahedral surroundings with one admtrz, one DMF and one H_2O molecule. Complex 1 exhibits weak antiferromagnetic coupling. Analysis of variable temperature magnetic susceptibility data (4-300 K) according to a Heisenberg model yields a J value of -4.47 cm~(-1).