Synthesis, crystal structure and reactivity of bis-(μ-2-methyl-pyridine -oxide-κ:)bis-[di-bromido-(2-methyl-pyridine -oxide-κ)cobalt(II)] butanol monosolvate.

Reaction of CoBr with 2-methyl-pyridine -oxide in -butanol leads to the formation of the title compound, [CoBr](2-methyl-pyridine -oxide)·-butanol or [CoBr(CHNO)]·CHO. The asymmetric unit of the title compound consists of one Co cation as well as two bromide anions and two 2-methyl-pyridine -oxide coligands in general positions and one -butanol mol-ecule that is disordered around a center of inversion. The Co cations are fivefold coordinated by two bromide anions and one terminal as well as two bridging 2-methyl-pyridine -oxide and linked by two symmetry-related μ-1,1(,) 2-methyl-pyridine -oxide coligands into dinuclear units that are located on centers of inversion. In the crystal structure, the dinuclear units are also connected pairs of C-H⋯Br hydrogen bonds into chains that elongate in the -axis direction. The -butanol mol-ecules are located between the chains and are linked O-H⋯Br hydrogen bonds each to one chain. Powder X-ray diffraction (PXRD) measurements reveal that a pure phase has been obtained. Measurements using thermogravimetry and differential thermoanalysis shows one mass loss up to 523 K, in which the -butanol mol-ecules are removed. PXRD measurements of the residue obtained after -butanol removal shows that a completely different crystalline phase has been obtained and IR investigations indicate significant structural changes in the Co coordination.