A new pyridine-bis-N-heterocyclic carbene ligand and its coordination to Rh: Synthesis and characterization

The new bis(imidazolylidene) tripodal ligand precursor (2-pyridine)bis(3-methylimidazolium-1-yl)methane diiodide, [H2PYBIMMe]I2, has been obtained by a simple method. The molecular structure of this new ligand precursor has been determined by means of X-ray diffraction. The coordination of this ligand to Rh, provides a Rh(III) complex with very low solubility in most solvents, which we attributed to the polymeric nature of the species. Solution of this polymer in DMSO provided a biscarbene Rh(III) complex in which the pyridine fragment remained unbound.

Graphical abstractThe bis-imidazolylidene tripodal ligand precursor(2-pyridine)bis(3-methylimidazolium-1-yl)methane diiodide, [H2PYBIMMe]I2, reacted with [Rh(cod)2](BF4) providing a Rh(III) complex with very low solubility in most solvents, which we attributed to the polymeric nature of the species. Solution of this polymer in DMSO provided a biscarbene Rh(III) complex in which the pyridine fragment remained unbound.Figure optionsDownload full-size imageDownload as PowerPoint slide