Cyclometallated compounds .9. Reactions of 2-benzoylpyridine with rhodium(III) trichloride

X-Ray crystallography and n.m.r. spectroscopy have been used to study the products of reactions between rhodium(III) trichloride and 2-benzoylpyridine under various reaction conditions. X-Ray crystal structures have shown that the initial product of reaction in refluxing ethanol is a centrosymmetric isomer, as previously proposed, but that this undergoes aqueous hydrolysis to a C-2-symmetric isomer, rather than the previously proposed C-2v isomer. Reaction in refluxing 2-methoxyethanol produces an unusual complex with one C-N cyclometallated ligand and one N-O coordinated ligand. In Me(2)SO, the non-cyclometallated ligand of this latter compound undergoes solvolysis to produce a complex containing two Me(2)SO molecules, one coordinated through oxygen and the other through sulfur. The X-ray crystal structure of this compound is also reported.