Bridging Rhodium–Iron Borataaminocarbyne Complexes Formed by Intramolecular Isonitrile–Borane Coordination

Reaction of [(TXPB)Rh(μ-CO)2Fe(CO)Cp] (1; TXPB = 2,7-di-tert-butyl-5-diphenylboryl-4-diphenylphosphino-9,9-dimethylthioxanthene) with both aryl and alkyl isonitriles formed [(TXPB)Rh(μ-CO)(μ-CNR)Fe(CO)Cp] (R = C6H4Cl-p (2), Xyl (3), n Bu (4); Xyl = 2,6-dimethylphenyl), in which the CNRBR3 unit is best described as a borataaminocarbyne ligand with single bonds between carbon and nitrogen and between nitrogen and boron. The carbon atom of the …