A novel, rigid diphosphine with an active NHC spacer; di- and trinuclear complexes of d~(10) coinage metals

摘要

A novel N,N'-diphosphanyl-imidazol-2-ylidene acts as a stable, hybrid PC_(NHC)P ligand for M_2 or linear M_3 (M = Cu, Ag, Au) arrays with metallophilic interactions. The coordination of both NHC and P donors to the same metal has led to complexes with superior catalytic properties to their all-NHC or all-P analogues. Although the origins of this synergism are mechanistically diverse and not yet fully understood, advancements can be anticipated by precisely tuning the metal coordination sphere through the use of multidentate P-functionalized NHC ligands, featuring donor atoms in fixed positions relative to each other.