Geometrical isomerism arising from oxidative addition of an o-quinone monoimide to IrCl(CO)(PPh3)2

Article abstract of DOI:10.1016/0022-328X(92)80142-K

A suspension of the o-quinone monoimide 1,2-N(C(O)-4-C6H4NO2)O-2,4-C6H2Cl2 and IrCl(CO)(PPh3)2 in CH2Cl2 was stirred for 3 days at room temperature.After careful chromatography two compounds were isolated, both with the empirical formula Ir(1,2-N(C(O)-4-C6H4NO2)O-2,4-C6H2Cl2)Cl(CO)PPh3)2.These were shown by 1H, 13C and 31P NMR and IR spectroscopy to be two of the twelve geometrical isomers possible for this complex.X-Ray crystallography confirmed these structures and showed that one isomer has cis and the other trans triphenylphosphine ligands.