A dinuclear Pt-Au cluster showing an unusual bonding situation and dynamics

Resumen del póster presentado al 6th EuCheMS Chemistry Congress, celebrado en Sevilla (España) del 11 al 15 de septiembre de 2016.The study of complexes containing intermetallic interactions between closed or pseudo-closed shell transitions metals (d8, d10, d10s2) is a field which is attracting a considerable attention in chemistry. These M-M interactions are of dative nature and are established between a basic donor metal centre (typically PtII or PdII square-planar complexes) and an acidic acceptor metal fragment. Interestingly, very few examples of PtII→AuI complexes have been reported and fully characterized. From a structural point of view, several binding modes for the coordination of Lewis basic metal fragments to Lewis acidic ones are known. The most frequent consists of a metal-metal interaction in which the bond axis lies perpendicular to the coordination plane of the d8 metal. A less common binding mode shows additional interaction of the acidic metal with one or two of the ligand atoms directly attached to platinum. The interest on these systems has increased recently as species containing this kind of interactions have been proposed to play a central role in cooperative catalysis. However, scarce experimental evidences supporting these intermediates have been provided and the nature and properties of them remain unexplored so far. In this communication we report the synthesis and thorough characterization of a rare heterobimetallic Pt-Au complex having an unusual metal-metal bonding situation and a surprising dynamic behaviour in solution. The synergy between X-ray diffraction techniques, solution NMR spectroscopy and DFT calculations have provided a deep insight into the metal-metal bonding in the complex. Such bonding situation can be regarded as a frozen model -a “snapshot”- of the transmetalation step in a cooperative bimetallic catalytic system.Peer Reviewe