Coordination chemistry of perhalogenated cyclyopentadienes and alkynes - XXI. Studies on the substitution reactions of Pt(PPh3)2(C2Cl2) and trans-Pt(PPh3)2(Cl)(C2Cl) with triphenylphosphite

Article abstract of DOI:10.1016/S0277-5387(97)00087-9

The reactions of the Pt(O) π-alkyne complex Pt(PPh₃)₂(Cl C≡CCl) and the Pt^II alkynyl complex Pt(PPh₃)₂(Cl)(C≡CCl) with P(OPh)₃ lead to either the π-alkyne complexes Pt(PPh₃)_n(P(OPh)₃)_2-n(Cl C≡CCl) (n = 0, 1) or the cis and trans isomers of Pt(PPh₃)_n[P(OPh)₃]_2-n (Cl)(C≡CCl) (n = 0, 1), depending on the reaction conditions. The course of the reaction was followed by ³¹P-NMR spectroscopy, from which a plausible mechanism for the oxidative addition reaction can be derived: key steps are phosphine dissociation from the Pt(0) species to a two-coordinate intermediate, which undergoes oxidative addition of a C - Cl bond to give a three-coordinate Pt^II species, which might be stabilized by dimerization.