Synthesis and Properties of Some New Double-Metal Aroxide Complexes

Abstract A new series of double-metal aroxocobaltate(II) tetra-hydrofurane complexes of the type ˙ nTHF (X = o-NO2, o-Cl, o-Br, m-Cl, p-Br, 2,4-dichloro, 2,6-dichloro and 2,4-dimethyl; n = 1,3,4 or 5) was synthesized by the reaction of anhydrous CoBr2 with the sodium salt of the corresponding phenol (abbreviated as NaOAr) as a monodentate ligand. The blue violet crystalline and very airsenstive compounds show good solubilities in some organic solvents, eliminate THF in vacuo at a temperature between 80 and 120°C/0.8 torr to yield the corresponding THF-free complexes. Electronic spectra (VIS and NIR) and magnetic measurements at 297°K point to a prefered tetrahedral configuration of cobalt(II) in these complexes.