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
作者:Karlheinz Sünkel、Uwe Birk
DOI:10.1016/s0277-5387(97)00087-9
日期:1997.1
The reactions of the Pt(0) pi-alkyne complex Pt(PPh3)(2)(CI C equivalent to CCl) and the Pt-II alkynyl complex Pt(PPh3)(2)(Cl)(C equivalent to CCl) with P(OPh)(3) lead to either the pi-alkyne complexes Pt(PPh3)(n)(P(OPh)(3))(2-n)(Cl C equivalent to CCl) (n = 0, 1) or the cis and trans isomers of Pt(PPh3)(n)[P(OPh)(3)](2-n) (Cl)(C equivalent to CCl) (n = 0, 1), depending on the reaction conditions. The course of the reaction was followed by P-31-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. (C) 1997 Elsevier Science Ltd.