Schiff's bases derived from 2-aminothiazole and substituted benzaldehydes were reacted with [RhCI(PPh3)3] or [Rh-(/~-CI)(COD)] 2 (COD = 1,5-cyclooctadiene) in the presence of four equivalents of PPh3 to give Rh m cyclometallated complexes of the type [RhHCI{ (X-benzylidene) thiazole}-(PPh3)2], in which the imine C H added oxidatively to the metal. The complexes were characterized using i.r., u.v. and n.m.r, spectroscopy. The disposition of the hydride ligand was inferred as trans to a N-donor ligand.