Synthesis, crystal structure and thermal properties of the dinuclear complex bis-(μ-4-methylpyridine N-oxide-κ2O:O)bis-[(methanol-κO)(4-methylpyridine N-oxide-κO)bis-(thio-cyanato-κN)cobalt(II)

Abstract

Reaction of Co(NCS)2 with 4-methyl-pyridine N-oxide in methanol leads to the formation of crystals of the title compound, [Co2(NCS)4(C6H7NO)4(CH4O)2] or Co2(NCS)4(4-methyl-pyridine N-oxide)4(methanol)2. The asymmetric unit consist of one CoII cation, two thio-cyanate anions, two 4-methyl-pyridine N-oxide coligands and one methanol mol-ecule in general positions. The H atoms of one of the methyl groups are disordered and were refined using a split model. The CoII cations octa-hedrally coordinate two terminal N-bonded thio-cyanate anions, three 4-methyl-pyridine N-oxide coligands and one methanol mol-ecule. Each two CoII cations are linked by pairs of μ-1,1(O,O)-bridging 4-methyl-pyridine N-oxide coligands into dinuclear units that are located on centers of inversion. Powder X-ray diffraction (PXRD) investigations prove that the title compound is contaminated with a small amount of Co(NCS)2(4-meth-yl-pyridine N-oxide)3. Thermogravimetric investigations reveal that the methanol mol-ecules are removed in the beginning, leading to a compound with the composition Co(NCS)2(4-methyl-pyridine N-oxide), which has been reported in the literature and which is of poor crystallinity.