Trismethimazolylhydroborate (Tm) complexes of ruthenium and manganese

A number of new complexes of the tris(methimazolyl)hydroborate (Tm) ligand have been synthesised: [(Tm)RuCl(DMSO)2] (1), [(Tm)Ru(pcymene)]Cl (2), [(Tm)RuCp] (3) and [(Tm)Mn(CO)3] (4). Complexes 2 and 4 have been characterised structurally by X-ray crystallography and a partial crystallographic analysis was obtained for 1. The Tm ligand is found to coordinate as a tripod ligand through its sulphur donors in all complexes except 3, for which there is evidence of bidentate coordination and formation of a 16-electron species.