Half-sandwich rhodium complexes containing both N-heterocyclic carbene and ortho-carborane-1,2-dithiolate ligands

A new route was used to synthesize half-sandwich rhodium complexes containing both N-heterocyclic carbenes (NHC) and carborane ligands. The rhodium carbene complexes Cp∗Rh(L)[S2C2(B10H10)] (Cp∗ = pentamethylcyclopentadienyl, L = 1,3-dimethylimidazolin-2-ylidene; 4) can be obtained from the reaction of Cp∗Rh(L)Cl2 (2) with Li2S2C2(B10H10) or from the reaction of Cp∗Rh[S2C2(B10H10)] (3) with silver–NHC complex prepared by direct reaction of an imidazolium precursor and Ag2O. Complexes 2 and 4 were characterized by IR, NMR spectroscopy, element analysis and X-ray structure analyses.