Synthesis of Titanium, Zirconium, and Hafnium Complexes that Contain Diamido Donor Ligands of the Type [(t-BuN-o-C6H4)2O]2- and an Evaluation of Activated Versions for the Polymerization of 1-Hexene
| Autor: | Jonathan T. Goodman, William M. Davis, Rüdiger Stumpf, Robert Baumann, Richard R. Schrock, Steven M. Reid |
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| Rok vydání: | 1999 |
| Předmět: |
chemistry.chemical_classification
Zirconium Ligand Organic Chemistry Trimethylphosphine Inorganic chemistry chemistry.chemical_element Inorganic Chemistry Metal 1-Hexene Trigonal bipyramidal molecular geometry Crystallography chemistry.chemical_compound chemistry Polymerization visual_art visual_art.visual_art_medium Physical and Theoretical Chemistry Alkyl |
| Zdroj: | Organometallics. 18:3649-3670 |
| ISSN: | 1520-6041 0276-7333 |
| Popis: | Titanium, zirconium, and hafnium dialkyl complexes that contain the [(t-Bu-d6−N-o-C6H4)2O]2- ([t-BuNON]2-) ligand have been prepared. Only [t-BuNON]TiMe2 could be isolated, but [t-BuNON]ZrR2 and [t-BuNON]HfR2 complexes could be isolated in which (for example) R = Me, Et, or i-Bu. X-ray studies showed [t-BuNON]MMe2 structures (M = Ti or Zr) to be of the “twisted fac” variety in which two amido nitrogens occupy equatorial positions in a distorted trigonal bipyramid. However, in solution all such species show equivalent alkyl groups on the NMR time scale as a consequence of formation of an intermediate mer structure that contains a planar oxygen donor. In analogous complexes that contain the {[Me(CD3)2CNC6H4][Me(CD3)2CN-2,4-Me2C6H2]O}2- or {[Me(CD3)2CNC6H4][Me(CD3)2N-2-EtC6H3]O}2- ligand the two metal alkyl groups are inequivalent on the NMR time scale. Addition of trimethylphosphine to [t-BuNON]Zr(CH2CH3)2 yields structurally characterized, pseudooctahedral [t-BuNON]Zr(η2-C2H4)(PMe3)2. Addition of B(C6F5)3 ... |
| Databáze: | OpenAIRE |
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