Reaction of [PtCI2(dppm)](dppm =Ph2PCH2PPh2) with Na[BH4] gives the binuclear cation [Pt2H2(µ-H)-(µ-dppm)2]+ isolated both as its chloride and hexafluorophosphate salts. Reaction of this complex cation with CCl4 or hydrogen chloride affords the related [Pt2(µ-CI)H2(µ-dppm)2]+ and [Pt2CI2(µ-H)(µ-dppm)2]+. The latter cation is also formed by protonation of the Pt-Pt bond in the platinum(I) complex [Pt2CI2(µ-dppm)2]. The 1H and 31P n.m.r. spectra of these complexes are reported. Study of the hydride resonances is shown to be an excellent method of distinguishing between terminal and bridging hydride. The Pt-Cl and Pt-H vibrational bands are in agreement with the proposed structures of these complexes, but vibrational bands due to bridging hydride groups could not be observed.