Abstract
The binuclear platinum(II) hydride [Pt~2~(dcype)~2~(H)~3~][Cl] (1b) has been isolated in high yields by treatment of Pt(dcype)Cl~2~ with NaBH~4~ (molar ratio 1:2) in ethanol solution at room temperature. This one‐pot synthesis is not straightforward when starting from diphenylphosphanylalkane complexes. The compounds [Pt~2~(dppp)~2~(H)~3~][OH] (3b) and [Pt~2~(dppb)~2~(H)~3~][OH] (4) were isolated by starting from the mononuclear hydrides {cis‐[Pt(P‐P)(H)~2~]} while mixtures of both binuclear {[Pt~2~(dppe)~2~(H)~3~]^+^, 5} and trinuclear {[Pt~3~(dppe)~3~(H)~3~]^+^, 6} trihydrides were obtained with the dppe ligand. Various salts of the cation 1, [Pt~2~(dcype)~2~(H)~3~][X] (X = BF~4~, 1a; OH, 1c; BPh~4~, 1d), were isolated either from [Pt(dcype)(μ‐OH)]~2~[BF~4~]~2~ (2) by a general procedure (1a), or by decomposition of the complex cis‐[Pt(dcype)(H)~2~] in solution (1c), as well as by metathesis reactions (1a, 1c, and 1d). Compounds 1a, 1b, and 1d react with CO under mild conditions to afford the corresponding Pt^I^ binuclear hydrides [Pt~2~(dcype)~2~(μ‐CO)(μ‐H)][X] (X = Cl, 7a; BF~4~, 7b; BPh~4~, 7c). The binuclear core of cation 1 is broken by KCN in methanol solution, yielding the mononuclear complex cis‐[Pt(dcype)(CN)(H)] (8). The complexes 1a−d, 2, 7a−c, and 8 have been characterised by FAB MS, IR, and NMR (^1^H, ^31^P, and ^195^Pt) spectroscopic techniques; the 1 and 7 cations show fluxional behaviour on the NMR timescale. The structure of compound 1d was determined, at 200 K, by single‐crystal X‐ray diffraction. All the hydrido ligands were located. The Pt−Pt separation is 2.696(1) Å and the coordination geometry around each platinum centre can be regarded as distorted square planar. Incoherent Inelastic Neutron Scattering (INS) spectra were obtained for 1a and [Pt~2~(dppe)~2~(H)~3~][BF~4~] (5a); the spectra reflect the different geometries of the two “P~4~Pt~2~(H)~3~” cores as found by single‐crystal structure determinations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)