Organoplatinum(IV) tris-chelate complexes, each having a cyclic metallacarbonate ring: synthesis, characterization and kinetic studies of the formation

The complexes Pt(CH2)4](NN)], 1a (NN = 2,2'-bipyridine) and 1b (NN = 1,10-phenanthroline) react with 2,3-epoxypropylphenyl ether in the presence of CO2 to give tris-chelate platina(IV)cyclopentane complexes characterized by 1H and 13C NMR spectroscopy as Pt(CH2)4](CH2CHCH2OPhOCO2)(NN)], 2. The reactions proceed by the SN2 mechanism and the rates were independent of concentration of CO2. It is demonstrated that for 1a, the reaction proceeds 2.32 times faster than the similar reaction in which the dimethyl analog, PtMe2(2,2'-bipyridine)], is used. The analog tris-chelate complex Pt(CH2)4](CH2CHPhOCO2)(phen)], 3a, was similarly synthesized.