Synthesis, crystal structure and reactivity of bis­(μ-2-methyl­pyridine N-oxide-κ(2) O:O)bis­[di­bromido­(2-methyl­pyridine N-oxide-κO)cobalt(II)] butanol monosolvate

Reaction of CoBr(2) with 2-methyl­pyridine N-oxide in n-butanol leads to the formation of the title compound, [CoBr(2)](2)(2-methyl­pyridine N-oxide)(4)·n-butanol or [Co(2)Br(4)(C(6)H(7)NO)(4)]·C(4)H(10)O. The asymmetric unit of the title compound consists of one Co(II) cation as well as two bromide anions and two 2-methyl­pyridine N-oxide coligands in general positions and one n-butanol mol­ecule that is disordered around a center of inversion. The Co(II) cations are fivefold coordinated by two bromide anions and one terminal as well as two bridging 2-methyl­pyridine N-oxide and linked by two symmetry-related μ-1,1(O,O) 2-methyl­pyridine N-oxide coligands into dinuclear units that are located on centers of inversion. In the crystal structure, the dinuclear units are also connected via pairs of C—H⋯Br hydrogen bonds into chains that elongate in the b-axis direction. The n-butanol mol­ecules are located between the chains and are linked via 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 n-butanol mol­ecules are removed. PXRD measurements of the residue obtained after n-butanol removal shows that a completely different crystalline phase has been obtained and IR investigations indicate significant structural changes in the Co coordination.