Hemilabile phosphonate-phosphane-RH-catalysts for homogeneous and heterogeneous carbonylation
- Inst. for Applied Chemistry Berlin (Germany)
Mixed bidentate phosphane ligands such as ether-phosphanes, phosphane oxide-phosphanes, phosphanopyridines and amine-phosphanes containing weak O- or N-donor groups and a strongly electron - donating phosphane group, are known to enhance activities or selectivities of Rh-catalyzed carbonylations. Also other transition metals form hemilabile O, P-chelated complexes, which have been extensively reviewed by Lindner. A row of these complexes catalyzed not only carbonylations effectively but also hydrogenation, hydrosilylation, and ethylene polymerization. The assumed function of the heterobidentate ligands in the rhodium catalyzed methanol carbonylation is illustrated. It has been suggested that the oxygen-donating site of the bidentade ligand changes between a coordinated and an uncoordinated state during the catalytic cycle, thus forming chelate and open-chain metal complex structures. The intramolecular generation and occupance of free coordination sites, stabilizing Rh-intermediates of different oxidation states and proceeding faster than according intermolecular processes, is assumed to accelerate rate-determining steps in the carbonylation route. This paper describes studies on the the properties of hemilabile complexes and their properties in slurry and vapor phase methanol carbonylation.
- OSTI ID:
- 433260
- Report Number(s):
- CONF-950402--
- Journal Information:
- Preprints of Papers, American Chemical Society, Division of Fuel Chemistry, Journal Name: Preprints of Papers, American Chemical Society, Division of Fuel Chemistry Journal Issue: 1 Vol. 40; ISSN ACFPAI; ISSN 0569-3772
- Country of Publication:
- United States
- Language:
- English
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