The Mo-Mo Quintuple Bond as a Ligand to Stabilize Transition-Metal Complexes

Angew Chem Int Ed Engl. 2015 Jul 27;54(31):9106-10. doi: 10.1002/anie.201504414. Epub 2015 Jun 26.

Abstract

Herein, we report the employment of the Mo-Mo quintuple bonded amidinate complex to stabilize Group 10 metal fragments {(Et3P)2M} (M=Pd, Pt) and give rise to the isolation of the unprecedented δ complexes. X-ray analysis unambiguously revealed short contacts between Pd or Pt and two Mo atoms and a slight elongation of the Mo-Mo quintuple bond in these two compounds. Computational studies show donation of the Mo-Mo quintuple-bond δ electrons to an empty σ orbital on Pd or Pt, and back-donation from a filled Pd or Pt dπ orbital into the Mo-Mo δ* level (LUMO), consistent with the Dewar-Chatt-Duncanson model.

Keywords: Group 10 metals; bonding; molybdenum; δ-bond; δ-complex.