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

Herein, we report the employment of the MoMo quintuple bonded amidinate complex to stabilize Group10 metal fragments {(Et3P)2M} (M=Pd, Pt) and give rise to the isolation of the unprecedented [delta]complexes. X-ray analysis unambiguously revealed short contacts between Pd or Pt and two Mo atoms and a slight elongation of the MoMo quintuple bond in these two compounds. Computational studies show donation of the MoMo quintuple-bond [delta]electrons to an empty σorbital on Pd or Pt, and back-donation from a filled Pd or Pt dπ orbital into the MoMo [delta]*level (LUMO), consistent with the Dewar-Chatt-Duncanson model.