New iminophosphonamide chromium(II) complexes as highly active polymer-free ethylene oligomerization catalysts
| Autor: | Khalid Al-Bahily, Zeeshan Y. Ahmed, Ece Koç, Sandro Gambarotta, Robbert Duchateau, Ilia Korobkov |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
MECHANISM
Ethylene SELECTIVE TRIMERIZATION Stereochemistry OXIDATION-STATE chemistry.chemical_element Medicinal chemistry Divalent Catalysis Inorganic Chemistry chemistry.chemical_compound Chromium Deprotonation ROUTE Active polymer Physical and Theoretical Chemistry ETHENE TRIMERIZATION OLEFINS TRIAZACYCLOHEXANE COMPLEXES TETRAMERIZATION chemistry.chemical_classification Ligand Organic Chemistry Monomer chemistry LIGANDS |
| Zdroj: | Organometallics, 30, 6022-6027. American Chemical Society Organometallics, 30(21), 6022-6027. AMER CHEMICAL SOC INC |
| ISSN: | 0276-7333 |
| DOI: | 10.1021/om2008474 |
| Popis: | The reactions of the deprotonated form of cis-{[(mu-N)(t-Bu)](2)PN(H) (o-OMeC6H4)](2)} (a) with either CrCl2(THF)(2) or CrCl3(THF)(3) afforded the corresponding dimeric Cr(II) and monomeric Cr(III) complexes {cis-[(mu-N)(t-Bu)](2)[PN (o-MeOC6H4)](2)Cr}(2) (1a) and cis-[(mu-N)(t-Bu)](2)[PN-2-MeOC6H4](2)CrCl (2a). By replacing the ligand's o-OMeC6H4 groups with less-crowded CH2CH2N(i-Pr)(2) functionalities and reacting the deprotonated form of cis-{[(mu-N)(t-Bu)](2)[PN(H)CH2CH2N(i-Pr)(2))](2)} (b) with CrCl2(THF)(2), the dimetallic, divalent {cis-[(mu-N)(t-Bu)](2)[PNCH2CH2N(i-Pr)(2))](2)Cr}(2) (1b) was obtained in crystalline form. Upon activation with MAO, both la and 1b afforded highly active, polyethylene-free ethylene oligomerization catalysts. Complex 2a is instead catalytically inactive. |
| Databáze: | OpenAIRE |
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