Generation and Coordinating Properties of a Carbene Bearing a Phosphorus Ylide: An Intensely Electron‐Donating Ligand

A generous giver: Rh and Pd complexes of an ylide-substituted carbene were synthesized. The carbonyl stretching vibration of the Rh complex (see picture; Rh purple, C turquoise, N blue, O red, P orange, Cl green) was observed at the lowest wavenumber of all cis-[RhCl(CO)2(carbene)] complexes known to date, which indicates that this is the strongest known electron-donating carbene.