SPECTRAL CHARACTERISTICS OF PRODUCTS FORMED BY REACTION BETWEEN RHACAC(PPH(3))(CO) AND METHYL-IODIDE

C-13, P-31 and H-1 NMR spectra revealed that in reaction mixtures Rhac ac(PPh(3))(CO) and MeI there were present two methylcarbonyl (MC) comp lexes of Rh-III. These were presumably isomers of Rhacac(PPh3)(CO)(Me) I: MC-I (delta C-13 185.3 ppm, (1)J(C-Rh) 64.0 Hz, (2)J(C-Rh-P) 18.1 H z; delta P-31 33.7 ppm, (1)J(P-Rh) 124.4 Hz; delta H-1 (Me-Rh) 1.36 pp m, (2)J(H-C-Rh) 1.9 Hz, (3)J(H-C-Rh-P) 2.1 Hz) and MC-II (delta C-13 1 85.6 ppm, (1)J(C-Rh) 62.5 Hz, (2)J(C-Rh-P) 11.0 Hz; delta P-31 28.4 pp m, (1)J(P-Rh) 117.4 Hz delta H-1 (Me-Rh) 1.65 ppm, (2)J (H-C-Rh) 1.9 H z, (3)J(H-C-Rh-P) 3.8 Hz). The third product is an acetyl complex, pre sumably the dimer [Rhacac(PPh(3))(MeCO)I](2) (delta C-13 212.4 ppm, (1 )J(C-Rh) 28.0 Hz, (2)J(C-Rh-P) similar to 7 Hz; delta P-31 37.6 ppm, ( 1)J(P-Rh) 153.0 Hz; delta H-1 (MeCO) 2.94 ppm, (2)J(H-C-C) 5.9 Hz). Th e MC-I complex is able to transform partially into MC-II. Oxidative ad dition of MeI to Rhacac (AsPh(3))(CO) and to Rhoxq(PPh(3))(CO) (hoxq = s-hydroxyquinoline; oxq its residue) yielded similar methylcarbonyl a nd acetyl complexes. All species present in the reaction mixtures are identified spectroscopically without isolation.