Imidazolium salts and [Pt(cod)]: from NHC hydrido complexes to the unprecedented olefinic tetrahedral cluster [Pt(μ-H)(cod)]BF.

Whereas the bis(imine)imidazolium salt 1·Cl is a potential precursor to a NCN pincer-type ligand, it reacted with [Pt(cod)] to give the Pt NHC hydrido complex 3, in which chloride coordination and CN chelation is preferred over pincer formation. Unexpectedly, reaction of 1·BF with [Pt(cod)] afforded the unprecedented, 56 CVE tetrahedral cluster [Pt(μ-H)(cod)]BF (7), which was fully characterized. Imidazolium salts are ubiquitous sources of the much studied NHC ligands and not expected to lead to the formation of metal clusters.