Oxygen adducts of Schiff's base complexes of cobalt prepared in solution

Abstract

Some 1:2 adducts of oxygen with NN′-ethylenebis(salicylideneiminato)cobalt(II), Co salen, and its ring-substituted analogues are reported. These compounds, which were obtained from solutions of the cobalt(II)–Schiff's base complexes, were found to be substantially diamagnetic from room temperature to 90°K. The magnetic susceptibility of the 1:2 adduct of oxygen with Co salen obtained by the solid-state reaction has been measured from room temperature to 90°K: it is concluded that, when allowance is made for small impurities of unconverted Co salen, this product is substantially diamagnetic. Finally, conditions have been found in which Co 3-methoxysalen gives a 1:1 adduct with oxygen in pyridine as solvent. I.r. and magnetic susceptibility data suggest that the oxygen group in this adduct of formula Co 3-methoxysalen,py,O₂ is symmetrically bonded to cobalt in an ethylene-like type of arrangement.