An unprecedented bonding mode for potassium within a PCP-pincer palladium hydride–K-Selectride® complex

The reaction of (PCP)i-PrPdCl and the commonly-used reductant K-Selectride® solution [K(sec-Bu3BH) in THF] does not yield a simple (PCP)i-PrPdH species, but rather an adduct of the Pd–H that contains bound K(sec-Bu3BH). This adduct has been characterized by X-ray crystallography and shown to be a centrosymmetric dimer in the solid state. The most unique feature of the structure is that the tri-coordinate K+ ion bonds only to the terminal palladium hydride and the two bridging boron hydrides. Despite being prepared in THF, no other donor ligands are bound to K+. This [H3K]+ bonding mode for K+ ions has not been previously reported.