Oxidative Addition of Phthaloyl Peroxide to Dimethylplatinum(II) Complexes

Complexes [PtMe2(NN)], with NN = 2,2′-bipyridine (bipy), 4,4′-di-tert-butyl-2,2′-bipyridine (bu2bipy), di-2-pyridylamine (dpa), or di-2-pyridyl ketone (dpk), react easily with phthaloyl peroxide to give a mixture of the chelate complex [PtMe2{κ2-O,O′-1,2-(O2C)2C6H4}­(NN)], which was structurally characterized when NN = bu2bipy, and an oligomer or polymer [PtMe2{μ-κ2-O,O′-1,2-(O2C)2C6H4}­(NN)]n. In the case with NN = dpa, no phthalate chelate complex is formed. These complexes are easily hydrolyzed, and the complexes cis-[PtMe2(OH)­{κ1-O-O2CC6H4-2-CO2H}­(bipy)] and trans-[PtMe2{κ1-O-O2CC6H4-2-CO2H}­(dpkOH)] have been structurally characterized. It is argued that the oxidative addition of phthaloyl peroxide occurs by a polar mechanism and that the hydrolysis is easy because there is no special stability associated with the seven-membered platinum-phthalate chelate ring.