Synthesis and structural characterisation of a new cobalt(II) pentanuclear complex with a tetranucleating pyrazole-derived ligand

Reaction of Co(O2CMe)2·4H2O with HL0 (3,5-bis(6-methyl-2-pyridyl)pyrazole) yielded unexpectedly a new pentanuclear compound Co5(L0)2(O2CMe)8(H2O)2. The complex has been characterised by elemental analyses, IR and single-crystal X-ray diffraction. The molecular structure is unusual and consists of a centrosymmetrical pentanuclear Co(II) complex containing two 3,5-bis(6-methyl-2-pyridyl)pyrazole ligands, eight MeCOO− anions and two H2O molecules, all co-ordinates.