Dear Editor, Please find enclosed a manuscript entitled:PtII-N-Heterocyclic Carbene Complexes in Solvent-Free Alkene Hydrosilylation.

The structural characterization and catalytic activity of a series of platinum(II) complexes, bearing N-heterocyclic carbenes (NHC) as supporting ligands, are reported. The study presents a structure-activity relationship within a group of pre-catalysts, and mechanistic insights into the catalyst activation step. An exceptional catalytic performance of one of the complexes is presented and an attractive solvent-free and open-to-air alkene hydrosilylation protocol, featuring efficient platinum removal, are disclosed.