Synthetic and structural studies of NHC-Pt(dvtms) complexes and their application as alkene hydrosilylation catalysts (NHC = N-heterocyclic carbene, dvtms = divinyltetramethylsiloxane)

The synthesis and structural characterization of a series of platinum complexes, hearing N-heterocyclic carbenes (NHC) and divinyltetramethylsiloxane (dvtms) as supporting ligands, are described. The reaction of commercially available Karstedt's catalyst (Pt-2{(eta(2) -ViSiMe(2))(2)O}(3)) with in situ generated NHC leads to monomeric platinum(O) complexes in which one NHC is bound to the metal center, as indicated by spectroscopic analysis and single-crystal X-ray diffraction studies. The relative reactivity trend for these complexes as catalysts for the hydrosilylation of alkenes is discussed in terms of NHC ligand steric properties. (c) 2005 Elsevier B.V. All rights reserved.