X-ray structure, magnetic and catalytic properties of a cyclic trinuclear Co-II/Co-III/Co-III complex with a mu(3)-hydroxy anion

The mixed-valent cyclic trinuclear cobalt(II)/cobalt(III)/cobalt(III) compl ex tris (dibenzoylmethanato-1 kappa O-2,O';2K(2)O,O';3 kappa O-2,O')(mu (3) -hydroxo-1:2 kappa O-2;1:3 kappa O-2;2:3 kappa O-2)tetrakis(mu -pyrazolato- 1:2 kappa N-4(1) N-2; 1:3 kappa N-2(1);N-2; 2:3 kappa N-2(1) N-2)-1, 2-dico balt-(III)-3-cobalt(II) with four bridging pyrazolate anions and a mu (3)-h ydroxy anion has been synthesized and its molecular structure has been eluc idated on the basis of X-ray crystallographic, magnetic, NMR, and EPR studi es. The remaining coordination sites of the pentacoordinate cobalt(II) and hexacoordinate cobalt(III) centers are occupied by oxygen donor atoms of di benzoylmethanate anions, rendering the complex soluble in most organic solv ents. The complex has been found to effectively catalyze the decomposition of tert-butyl hydroperoxide (TBHP) in chlorobenzene with a short induction period and a half-life of 80 min and to catalyze the oxidation of cyclohexe ne to 2-cyclohexen-1-one with oxygen and to 2-cyclohexen-1-ol with TBHP.