Pincer N-heterocyclic carbene complexes of rhodium functionalised with pyridyl and bipyridyl donors

The "pincer"-type carbene complexes Rh(C-N-C)Cl and Rh(C-N-N)Cl [C-N-C = 3,3'-diaryl-1,1'-pyridine-2,6-diylbis(imidazol-2-ylidene), C-N-N = 1-ar-yl-3-(2,2'-bipyridin-6-yl)imidazol-2-ylidenel have been prepared and characterised by spectroscopic and diffraction methods. They bind CO to give cabonic complexes but are inert to H-2. Both oxidatively add CH2Cl2 to give octahedral Rh-III complexes. Theoretical calculations provide insight into the bonding of the Rh(C-N-C)Cl and Rh(C-N-N)Cl complexes. (c) Wiley-VCH Verlag GmbH & Co.