| Autor: |
N. A. Shirokov, V.V. Mazurek |
| Rok vydání: |
1976 |
| Předmět: |
|
| Zdroj: |
Polymer Science U.S.S.R.. 18:3068-3072 |
| ISSN: |
0032-3950 |
| DOI: |
10.1016/0032-3950(76)90418-4 |
| Popis: |
The initiating activity for the methyl methacrylate (MMA) anionic polymerization by tris-τ-allyl chromium (CrA3) rises sharply as a result of its reaction with pyridine at room temperature. Hydrolysing the reaction mixture after several days storage does not cause liberation of propylene, which indicates that there are no allyl groups linked to the chromium. The magnetic moment (3–7 boron magnetons) typical of a d3 electronic configuration of tervalent chromium is not lost during storage. The hydrolysate has been found to contain 2-propylpyridine which was identified by PMR and GLC in comparisons with a standard. Our results lead to the conclusion that the coordination sphere forming as a result of the pyridine coordination during the τ-δ transition of the allyl group is subject to a rearrangement in which chromamide derivatives of allyl-dihydropyridine are produced. These derivatives are assumed to be the carriers of the catalytic activity for the MMA polymerization. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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