Trinuclear tris-Co(II) and trans-cobaloxime type Co(III) complexes prepared from Co(II) triflate precursor: Synthesis, structure and properties

摘要

Three new coordination compounds, [CO3(DH)(6)]center dot 24H(2)O (I), [Co(DH)(2)Tu(2)]CF3SO3 (II) and [Co(DH)(2)Py-2]CF3SO3 (III) (where DH- = monoanion of dimethylglyoxime, Py = pyridine, Tu = thiourea), were synthesized starting from CO(CF3SO3)(2)center dot 6H(2)O as a substrate. The complexes were characterized by X-ray crystallography, spectroscopic methods (IR, UV-Vis, H-1 and C-13 NMR, MS) and magnetochemistry. Compound I is a neutral, C-3i symmetrical, trinuclear Co(II) complex with two tris-{Co2+(mu-DH)(3)} units connected to the central Co(II) ion via bridging oxygen atoms, saturating the Co(II) octahedral coordination. In the case of II and III, the complex cations have the usual trans-octahedral configuration with two DH-chelating units in the equatorial plane of the Co(III) ion and the apical coordination sites occupied by two neutral monodentate ligands (Py or Tu). (c) 2006 Elsevier Ltd. All rights reserved.