Rhodium aminophosphine chelate complexes as catalysts for asymmetric hydrosilylation

Autor: L. S. Gorshkova, K. N. Gavrilov, E. I. Klabunovskii, E. Yu. Zhorov, V. A. Pavlov
Rok vydání: 1991
Předmět:
Zdroj: Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 40:1303-1304
ISSN: 1573-9171
0568-5230
DOI: 10.1007/bf00961322
Popis: The binuclear structure of complex (IIa) is indicated by the finding of a mass spectral peak with m/z 971 and IR absorption band for the bridging bond VRh_Cl = 294 cm -I. X-ray photoelectron spectroscopy showed bidentate coordination for ligand (IIa). The increase in the energy of the bond energies of the 2p electrons of phosphorus and is electrons of nitrogen upon going from the free ligand (131.0 and 398.6 eV) to the coordinated ligand (132.6 and 400.6 eV) indicates the formation of Rh-P and Rh-N bonds in the solid samples of complex (IIa). The lack of resolution in the iH and 31p NMR spectra of solutions of (IIa) at 20~ and the appearance of a doublet in the 31p NMR spectrum of this complex in CH2CI 2 at -80~ (6P = 33.9 ppm, iJP,Rh = 151.1 Hz) is evidence for rapid dissociation and formation of the Rh-N bond. Analysis of the IH NMR spectrum of complex (IIb) (splittihg of the doublet for the protons of the methyl group bound to the CH group and broadening of the signai for the protons of the methyl groups at the nitrogen atom) and its ~ip NMR spectrum (doublet, 5P = 20.5 ppm, IJP,Rh = 168.0 Hz) suggests coordination of the phosphorus and nitrogen atoms by rhodium'and the existence of two conformers of this complex (IIb) [2].
Databáze: OpenAIRE
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