Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes of Iridium(III) and Rhodium(III) of the Type [(Η5- C5Me5)MX2]2

The synthesis, spectroscopic characterization and crystal structures of new C-nitrosoaryl complexes of iridium(III) and rhodium(HI) are reported. The reactions of the mu(2)-halogenido-bridged dimers [(eta(5)-C5Me5)IrX2](2) [X = Cl (1a), Br (1b), I (1c)] and [(eta(5)-C5Me5)RhCl2](2) (2a) with N,N-dimethyl- (3) and N,N-diethyl-4-nitrosoaniline (4) yield the mononuclear complexes [(eta(5)-C5Me5)MX2(3)] [M = Ir, X = Cl (5a), Br (5b), I (Sc); M = Rh, X = Cl (7a)] and [(eta(5)-C5Me5)MX2(4)] [M = Ir, X = Cl (6a), Br (6b), I (6c); M = Rh, X = Cl (8a)]. All new compounds were characterized by their melting points, NMR, IR and mass spectra as well as in selected cases by UV/Vis spectroscopy. The X-ray structure analyses revealed a slightly distorted pseudo-octahedral configuration ("three-legged pianostool") and sigma-N coordination of the C-nitroso ligand.