First Example of Hydrogen Bonding to Platinum Hydride

The interaction between various proton donors (indole, CF₃CH₂OH, (CF₃)₂CHOH, (CF₃)₃COH) and (NNC)PtH hydrido complex (NNC-H=6-(1,1'-dimethylbenzyl)-2,2'-bipyridine) was investigated through low-temperature IR and NMR spectroscopy in combination with density functional theory calculations at the M06 level of theory. The experiment shows formation of very weak hydrogen bonded complexes (Δ Hº_HB ca. -1.0 kcal mol^-1), which undergo subsequent proton transfer surprisingly easy. Computational analysis of the hydrogen bonded complexes geometry, electronic parameters (obtained by NBO and AIM analysis), and orbital interaction energies shows that all the complexes are better described as bonded to the metal atom. At that in case of weak alcohols (CH₃OH, TFE) there is also the additional interaction with the hydride ligand. These computational results allow explaining the observed experimental trends and give the first example of hydrogen bonding to a metal atom in the presence of hydride ligand.