A diverse
range of heteromultinuclear NiI/[MCO] clusters
(MCO = CpFe(CO)2, CpRu(CO)2, Cp*W(CO)3) supported by an N-heterocyclic carbene ligand
have been synthesized by reacting the NiI precursor, [IPrNi(μ-Cl)]2, with [MCO]− reagents under
various conditions. Clusters with Ni2Fe2, NiFe2, Ni2Ru, Ni2Ru2, NiRu2, and Ni2W and NiW cores were all characterized
using NMR and IR spectroscopy and X-ray crystallography. The NiI-containing paramagnetic heterobinuclear species IPrNi-Wp*
(7) was further characterized by EPR spectroscopy and
DFT calculations. Notably, unlike previously studied (NHC)CuI-[MCO] derivatives, complex 7 was found to
coordinate Lewis bases such as 3-chloropyridine to produce (IPr)(3‑Clpy)NiWp* (9). Complex 9 further underwent thermolytic C–Cl activation, proposed to
involve NHC-free [(3‑Clpy)Ni(μ-Wp*)]2 (10), to provide the C-arylated N-heterocyclic carbene
product [IPr(py-3-yl)]+[Cp*WCl2(CO)2]− (11).