Novel Structures and Magnetic Properties of Two [Mn2] Complexes with 2,4-di-2-pyridyl-2,4-pentanediol as the Ligand

Two ligands, 2,4-di-2-pyridyl-2,4-pentanediol (rD and mD), were employed to synthesize two Mn2 complexes, [Mn2(rD)2Br2] (1) and [Mn2(mD)2(H2O)2]Br2 (2). Compound 1 crystallized in a tetragonal space group, P41212, with a novel hamburger shaped structure. A detailed study indicated that compound 1 did not contain a metal–metal bond, but antiferromagnetic coupling was observed between the Mn(III) ions. Compound 2 crystallized in a monoclinic space group, C2/c, with one Mn(II) and the other with Mn(IV). The two manganese ions were bridged by two alkoxide ligands, resulting in ferromagnetic coupling. Magnetic property studies confirm the above assignments.