Manganese clusters derived from a 2,6-diacetylpyridine dioximato ligand: structure and magnetic study

Reactions of 2,6-diacetylpyridine dioxime (dapdoH2) with Mn(NO3)2 or Mn(SO3CF3)2 under a variety of conditions or co-ligands yield compounds with the formula [Mn6O2(OMe)2(dapdo)2(dapdoH)4](X)2 in which X = NO3− (1) or SO3CF3− (2), [Mn8O2(dapdo)6(NO3)2]·H2O (3) and [Mn(dapdoH2)(N3)2]n (4). Compounds 1, 3 and 4 were structurally characterized and equivalent structures for 1 and 2 were inferred from spectroscopic and analytical results. Compounds 1 and 2 consist of hexanuclear Mn2IIMn4III complexes whereas 3 consists of an octanuclear Mn6IIMn2III cluster in which the manganese atoms exhibit a rare bicapped elongated octahedral topology. Compound 4 consists of a 1D system bridged by double end-on azido ligands. Variable temperature magnetic studies were performed between 2–300 K, confirming the ground state S = 5 for 1 and 2, S = 0 for 3 and ferromagnetic response for 4.