PROTONATION STUDIES OF ELECTROPHILIC PLATINUM(II) ALKYL COMPLEXES - SYNTHESIS AND CHARACTERIZATION OF (DFEPE)PT(ME)X (X=O2CCF3, OSO2CF3, OSO3H)

The platinum methyl complexes (dfepe)Pt(Me)X (dfepe = (C2F5)(2)PCH2 CH2P(C2F5)2(,) X = O2CCF3, OSO2CF3, OSO3H) have been prepared by the reaction of (dfepe)Pt(Me), with an excess of the corresponding acid, HX. These compounds have been characterized by H-1, F-19 and P-31 NMR data. (dfepe)Pt(Me)(2) and (dfepe)Pt(Me) (OSO2CF3) have also been characterized in the solid state by X-ray diffraction. Both of these compounds exhibit short Pt-Me bonds, consistent with the highly electrophilic nature of the (dfepe)Pt moiety. In contrast to analogous donor phosphine systems (R(3)P)(2)Pt(Me)(2), which undergo complete protonolysis and methane loss by HX at -78 degrees C to give (R(3)P)(2)Pt(X)(2), (dfepe)Pt(Me)X complexes are remarkably stable to further protonolysis even in neat strong acid media. In dichloromethane, treatment of (dfepe)Pt(Me)(OSO2CF3) with excess CF3SO3H results in the association of one equivalent of acid with the bound triflate ligand to form (dfepe)Pt(Me)((OTf)(2)H).