| 1 | Author
| Hans-Ludwig Krauss, Erich Hums | Requires cookie* | | Title
| Oberflächenverbindungen von Übergangsmetallen, XXII [1] Die Umsetzung von Oberflächen-Chrom(II) auf Silicagel mit Olefinen bei höherer Temperatur. - Zum Mechanismus von Aufbau-, Abbau-, Metathese- und Isomerisierungs-Reaktionen an koordinativ ungesättigten Oberflächen-Metallionen Surface Compounds of Transition Metal, XXII [1] The Reaction of Surface Chromium(II) on Silica with Olefins at Higher Temperature. - A Contribution to the Mechanism of Growth, Degradation, Metathesis and Isomerization on Coordinatively Unsaturated Surface Metal Ions  | | | Abstract
| With chromium(II) supported on silica, at T > 150 °C olefins undergo growth/degra-dation/metathesis reactions by addition/elimination of even and uneven chain fragments including Ci. Simultaneously, catalytic double bond isomerization and C-rearrangements to methyl branched olefins occur. One mechanism is proposed for all these reactions via a pseudo-tetrahedral MC3 intermediate. Polyethylene synthesis at lower temperatures may follow the same way. For growth/degradation/metathesis the formation of a metal carbene unit is postulated as a characteristic step; in case of ethylene, >Cr=CH2 will be formed as a precursor of the final CH4 (resulting from a secondary reaction with support hydrogen). | | |
Reference
| Z. Naturforsch. 34b, 1628—1636 (1979); eingegangen am 23. Juli 1979 | | |
Published
| 1979 | | |
Keywords
| Surface Compounds, Olefin Polymerization/Degradation, Olefin Metathesis, Olefin Isomerization, Carbene Intermediates | | |
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| default:Reihe_B/34/ZNB-1979-34b-1628.pdf | | | Identifier
| ZNB-1979-34b-1628 | | | Volume
| 34 | |
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