Xing, Q. and Milius, W. and Krauss, H. L. and Bluemel, J. and Hilbig, H. and Koehler, F. H. and Strauss, W. and Bayreuther, Guenther (1999) Surface compounds of transition metals. XLI - Preparation and properties of organochromium compounds by reaction of Phillips catalysts with ethylene. ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE, 625 (3). pp. 521-529. ISSN 0044-2313,
Full text not available from this repository.Abstract
Reaction of reduced Phillips catalysts with ethylene at 300 degrees C deactivates the catalyst; supported organochromium compounds are formed. These can be cleaved from the silica support by HCl and other acids, and transferred into solution by extraction with CH3OH. Chromatography yields fractions of organochromium compounds which differ by CH2 moieties. XPS, H-1/2 NMR, and mass spectra as well as magnetic measurements prove that an ensemble of (RnCp)CrCl2(CH3OH) (RnCp = alkylated cyclopentadienyl) has been formed. The RnCp ligand results from a chromium-assisted oxidative coupling of the olefin with or without CC-cleavage. According to UV/Vis and mass spectroscopy Cl- and CH3OH can be substituted for other anions and donor molecules. Without a donor dinuclear, Cl-bridged molecules are obtained, of which [(1,2,3-Me3Cp)CrCl2](2) was established by crystal structure analysis. Reaction with O-2 reversibly leads to chromium(V) compounds of the type (R2Cp)Cr(O)Cl-2.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RAY CRYSTAL-STRUCTURE; SILICA-GEL; CYCLOPENTADIENYL COMPLEXES; PARAMAGNETIC METALLOCENES; REDOX REACTIONS; OLEFINS; CHROMIUM(II); POLYMERIZATION; SPECTROSCOPY; TUNGSTENACYCLOBUTADIENE; surface compounds; cyclopentadienyl complexes; organochromium complexes; Phillips catalysts; crystal structure; magnetic measurements; NMR-spectroscopy; reversible oxygen absorption |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Alumni or Retired Professors > Group Günther Bayreuther |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 15 Nov 2022 15:21 |
| Last Modified: | 15 Nov 2022 15:21 |
| URI: | https://pred.uni-regensburg.de/id/eprint/48506 |
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