Magneto-structural studies of a one dimensional Mn(II) coordination polymer derived from a flexible polydentate ligand

The polydentate ligand LH mu contains bipyridine, hydrazone and oxime functionalities and reacts with Mn (CH3COO)(2)center dot 4H(2)O to afford an alternating one dimensional chain comprising Mn(II) ions, [{Mn-2(LH) (CH3COO)(3)(CH3OH)(2)}center dot CH3OH](n) (1). The structure of 1 contains two Mn(II) ions in the asymmetric unit; Mn-1 adopts an unusual pentagonal bipyramidal coordination geometry comprising an [N3O4] donor set, while Mn-2 adopts a more conventional octahedral geometry coordinated by an [NO5] donor set. The two manganese ions within the dinuclear unit are connected to each either via O-hydrazone and syn-syn O-acetate bridges. These dinuclear units are then linked by anti-anti Oacetate bridges, affording a magnetic 1-D alternating chain topology. Magnetic studies on 1 reveal the presence of weak antiferromagnetic interactions via O-hydrazone and O-acetate bridges. The magnetism of 1 was modelled using a dimer model [(H) over cap = 2J (S) over cap (1) (S) over cap (2)], with inter-dimer exchange modelled using a mean field term (zJ') to afford g = 2.046 +/- 0.002, J/k = -1.03 +/- 0.02 cm(-1) and zJ' = 0.06 +/- 0.01 cm(-1).

Automated summary

A compound containing Mn(II) ions was synthesized, with magnetic studies revealing weak antiferromagnetic interactions between dinuclear units connected by different bridges, forming a magnetic 1-D chain structure.