Bis-µ-[bis(diphenylphosphino)methane]-bis(halogenoplatinum)(Pt–Pt); dimeric complexes of platinum( I ) containing a platinum–platinum bond

Bis-µ-[bis(diphenylphosphino)methane]-bis(chloroplatinum)(Pt–Pt), [{PtCl(dppm)}2](dppm = Ph2PCH2PPh2), is obtained by treatment of the platinum(II) complex [PtCl2(dppm)] with Na[BH4]–MeOH followed by HCl–C6H6. The corresponding dimeric bromo- and iodo-complexes of PtI are obtained from the chloro-complex by halide exchange. The 1H and 31P n.m.r. and vibrational spectra of these complexes are analysed and strongly support the assigned structure rather than the halogenide-bridged structure proposed earlier. Bands assigned to ν(Pt–Pt) are present in the Raman spectra.