Synthesis, crystal structure and thermal properties of dibromidobis(2-methylpyridine N-oxide-κO)cobalt(II)

Abstract

Reaction of CoBr2 with 2-methylpyridine N-oxide in n-butanol leads to the formation of the title compound, [CoBr2(C6H7NO)2] or [CoBr2(2-methylpyridine N-oxide)2]. Its asymmetric unit consists of one CoII cation as well as two bromide anions and two 2-methylpyridine N-oxide coligands in general positions. The CoII cations are tetrahedrally coordinated by two bromide anions and two 2-methylpyridine N-oxides, forming discrete complexes. In the crystal structure, these complexes are linked predominantly by weak C–H...Br hydrogen bonding into chains that propagate along the crystallographic a-axis. Powder X-ray diffraction (PXRD) measurements indicate that a pure phase was obtained. Thermoanalytical investigations prove that the title compound melts before decomposition; before melting, a further endothermic signal of unknown origin was observed that does not correspond to a phase transition.