Conversion of the carbonyl group in chorocarbonyl((o-diphenylphosphino)-N, N-dimethylaniline)iridium(I) and chorocarbonyl((o-diphenylphosphino)-N, N-dimethylbenzylamine)iridum(I) into carbon dioxide by reaction wiht molecular oxygen
✍ Scribed by D.M. Roundhill; G.H. Allen; R.A. Bechtold; W.B. Beaulieu
- Book ID
- 104138054
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- English
- Weight
- 158 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0020-1693
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✦ Synopsis
Recently we showed by a single crystal structure determination that the complex chlorocarbonyl-((odiphenylphosphino)-N,Ndimethylaniline)iridium-(I), IrCl(CO)PN has a planar geometry and a stereochemistry with mutually trans dimethylamino and carbonyl ligands [I]. Furthermore, from spectroscopic comparisons we concluded that the same stereochemistry was adopted for the complex chlorocarbonyl ((odiphenylphosphino)-N,Ndimethylbenzylamine)iridium(I), IrCl(CO)PCN. We now report that these complexes react with oxygen under ambient conditions with complete loss of carbonyl ligand. The reaction is not reversible and yields carbon dioxide and a blue hydroxy-bridged iridium complex. Previous reports of the oxidation of a coordinated carbonyl group are rather few, especially under conditions where water or hydroxide ions are absent [2-41.
When oxygen is passed through a yellow solution of IrCl(CO)PCN or IrCl(CO)PN in benzene or dichloromethane solvent a bule-green compound is gradually formed over a period of 3-6 hours in 90% yield. The complexes precipitate from benzene solution, or they can be isolated from dichloromethane solvent by addition of diethyl ether. The following data have been found for compounds [Ir(OH& (PCN)] sCls (I) and [Ir(OH)O,(PN)] sCls(II): Anal. (I); Found: C, 42.2; H, 4.09; N, 2.02; Cl, 6.56%; Calcd. C, 42.3; H, 3.89; N, 2.35; Cl, 5.95%. v(OH) 3550 cm-', 6(OH) 1650 cm-'. M. pt. Decomposes at 140 "C. Anal. (II); Found: C , 39.6; H, 3.65; N, 2.37; Cl, 5.95; 0, 9.17%; Calcd. C 41.3; H, 3.64; N, 2.41; Cl,.09; 0, 8.25%. y(OH) 3450 cm-', 6(OH) 1650 cm-r. M.pt. Decomposes at 190 "C. h(max.) = 650 mn (e = 104). The products are formed even in benzene dried by distillation from LiAlH4. Indeed, addition of water causes no apparent acceleration of the reaction and introduction of DsO does not lead to changes in the infrared spectra of the