Abstract
With CH(2)X(2) (X = Cl, Br, I) and CCl(4) the diplatinum(0) complex [(µ-dmpm)(2)Pt(2)(nbe)(2)] (dmpm = bis(dimethylphosphino)methane, nbe = norbornene) undergoes facile cooperative addition of one C-X bond at each Pt centre to yield the methylene-bridged diplatinum(ii) A-frame complexes [(µ-dmpm)(2)Pt(2)X(2)(µ-CY(2))] (Y[double bond, length as m-dash]H, Cl). In contrast, reactions with Me(4-n) SiX (n) (X = Cl, n = 1-3; X = I, n = 1) lead preferentially to transannular oxidative additions of a single Si-X bond over the two metal centres, yielding the complexes [(µ-dmpm)(2){PtX}{Pt(SiMe(4-n) X (n-1))}]. In CH(2)Cl(2) [(µ-dmpm)(2){PtCl}{Pt(SiCl(3))}] undergoes rearrangement to the silylene-bridged [(µ-dmpm)(2)Pt(2)Cl(2)(µ-SiCl(2))], while in CH(2)Br(2) oxidation of the platinum centres to Pt(ii), Cl-Br exchange, and the insertion of a CH(2)Br(2)-derived methylene unit into the Pt-Si bond are observed. Quantum-chemical calculations provide insights into the differences in reactivity between the halomethanes and -silanes.