Late-Transition-Metal Complexes as Tunable Lewis Bases

Syntheses of the first heteroleptic N-heterocyclic carbene (NHC)-phosphane platinum(0) complexes and formation of the corresponding Lewis acid base adducts with aluminum chloride is reported. The influence of N-heterocyclic carbenes on tuning the Lewis basic properties of the metal complexes was judged from spectroscopic, structural, and computational data. Conclusive experimental evidence for the enhanced Lewis basicity of NHC-containing complexes was provided by a transfer reaction.