A Tripodal Ligand Constructed from Mesoionic Carbene Donors

A tripodal ligand constructed solely from mesoionic carbene donors is reported. The donor strength of this ligand is lower than most imidazol-2-ylidene-based tris(carbene)-borate ligands, as measured by IR spectroscopy of {NiNO}(10) and {Mn(Co)(3)}(+) derivatives. The attenuated donor strength is proposed to be due to the collective electron-withdrawing effect of the ligand's aryl substituents.