First hexanuclear manganese(II) μ6-Cl centered carboxylate anion: Synthesis, structure and magnetic properties

Reaction of manganese(II) polymer [Mn5Cl(OH)(Piv)8(MeCN)(HPiv)(H2O)]n (1, HPiv is pivalic acid) and 2-benzoylpyridine (L) in MeCN produces the ionic complex [Mn3(Piv)5L2(MeCN)]+[Mn6Cl(Piv)12]− · MeCN (3) containing the unusual hexanuclear {Mn6(μ6-Cl)} anion. An analogous anion was also observed in the complex [Mn6Cl(Piv)12]−(NEt4)+ · 5MeCN (4) prepared by the reaction of the polymer [Mn(Piv)2(EtOH)]n (2) with NEt4Cl in MeCN. Complexes 3 and 4 were characterized by the X-ray diffraction and magnetic susceptibility.