Arsine complexes iridium

A considerable number of the tertiary phosphine and arsine complexes of iridium(III) have been synthesized [4, 8] they generally contain 6-coordinate iridium and are conventionally prepared by refluxing Na2IrCl6 with the phosphine in ethanol or 2-methoxyethanol [154]... 

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphoms, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

C1bHi5As, Arsine, triphenyl-iron complex, 26 61 C H 5OjP, Triphenyl phosphite ruthenium complex, 26 178 CuHijP, Phosphine, triphenyl-cobalt complex, 26 190—197 cobalt-gold-ruthenium, 26 327 gold complex, 26 90, 325, 326 gold-manganese complex, 26 229 iridium complexes, 26 117-120, 122-125, 201, 202... 

An NMR study (597) of ligand exchange in the system (diene)MCl(L) (diene = norbornadiene or 1,5-cyclooctadiene M = Rh or Ir L = tertiary phosphine, arsine, or stibene) shows a first-order dependence of the rate upon both L and the olefin complex in the temperature range from —70° to —10°C. The exchange involves an 8 2 mechanism with the five-coordinate complex (diene)MCl(L)2 as intermediate. The intermediate iridium complexes (l,5-CgHi2)IrCl(L)2 can be isolated from ethanolic solution. The activation energy for the process ranges from 4 to 10 kcal/mole (597). 

In early patents by Halcon, molybdenum carbonyls are claimed to be active catalysts in the presence of nickel and iodide [23]. Iridium complexes are also reported to be active in the carbonylation of olefins, in the presence of other halogen [24] or other promoting co-catalysts such as phosphines, arsines, and stibines [25]. The formation of diethyl ketone and polyketones is frequently observed. Iridium catalysts are in general less active than comparable rhodium systems. Since the water-gas shift reaction becomes dominant at higher temperatures, attempts to compensate for the lack of activity by increasing the reaction temperature have been unsuccessful. 

The complex serves as a useful intermediate for the preparation of other iridium(I) complexes, because the p-toluidine ligand can be readily displaced at room temperature by pyridine or 1,10-phenanthroline.2 An additional carbon monoxide ligand is replaced with triphenylphosphine, -arsine, and -stibine as well as with phosphites and ethylenebis[diphenylphosphine].2... 

A. J. Deeming, B. L. Shaw, Oxidative addition of alkyl ot aryl chloroformates to the complexes [IrCl(CO)L2](L = dimethylphenyl-phoshine ot -arsine, or trimethylphosphine). Iridium-carboxy- complexes, J. Chem. Soc. A. (1969) 443-448. 

C10H15N, Benzenemethanamine, N,N,4-trimethyl-, lithium complex, 26 152 C10H15P, Phosphine, diethylphenyl-, nickel complex, 28 101 platinum complex, 28 135 CioHigAsi, Arsine, 1,2-phenylenebis(dimethyl-, gold complex, 26 89 nickel complex, 28 103 CioHie, 1,3-Cyclopentadiene, 1,2,3,4,5-pen-tamethyl-, 28 317 chromium complex, 27 69 cobalt complexes, 28 273, 275 iridium complex, 27 19 samarium complex, 27 155 titanium complex, 27 62 ytterbium complex, 27 148 CioH,gBrN04S, Bicyclo[2.2.1]heptane-7-methanesulfonate, 3-bromo-1,7-di-methyl-2-oxo-, U.IRHENDO, ANTPi]-, ammonium, 26 24... 

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