New Metal-Only Lewis Pairs: Elucidating the Electronic Influence of <i>N</i>-Heterocyclic Carbenes and Phosphines on the Dative Pt-Al Bond

The synthesis and full characterization of a new heteroleptic N-heterocyclic carbene (NHC)–phosphine platinum(0) complex and formation of its corresponding alane adduct is reported. The influence of the ligands on the Lewis basic properties was studied via multinuclear NMR-spectroscopy, X-ray analyses, and density functional theory (DFT) calculations. Consistently, the effect of changing the halogens upon the Lewis acid properties of aluminum halides was studied by X-ray analysis and DFT calculations.