A novel tetranuclear MnII2MnIII2 cluster [Mn4(hmp)6(N3)4]: Synthesis, crystal structure and magnetic properties

A novel tetranuclear mixed-valence manganese(II/III) cluster [Mn4(hmp)6(N3)4] (1) where hmp is the anion of 2-hydroxymethylpyridine, was obtained by the reaction of manganese perchlorate with hmpH and NaN3 in acetonitrile. Complex 1 was characterized by chemical analysis, IR spectroscopy, single crystal X-ray diffraction and variable-temperature magnetic susceptibility studies. Complex 1 crystallizes in triclinic system with space group Pī consisting of mixed-valence Mn ions whose coordination geometry can be described as distorted octahedron. The magnetic properties were studied in the temperature range of 1.9–300 K and the results show that mixed-valence Mn ions are ferromagnetically coupled in the cluster leading to an S = 9 ground state.