| Autor: |
Miyake, S., Henling, L. M., Bercaw, J. E. |
| Zdroj: |
Organometallics; December 7, 1998, Vol. 17 Issue: 25 p5528-5533, 6p |
| Abstrakt: |
Doubly [SiMe2]-bridged group IV metallocenes, rac-(Me2Si)2{η5-C5H-3-(CHMe2)-5-Me}2MCl2 (M = Ti, Zr), have been synthesized, and a crystal structure of rac-(Me2Si)2{η5-C5H-3-(CHMe2)-5-Me}2TiCl2 has been determined by X-ray diffraction methods. Racemate−meso interchange occurs in benzene solution just above room temperature, affording an approximately 1:1 mixture of rac-(Me2Si)2{η5-C5H-3-(CHMe2)-5-Me}2TiCl2 and meso-(Me2Si)2{η5-C5H-3-(CHMe2)-5-Me}2TiCl2. Measurements of the kinetics of the approach to equilibrium reveal ΔH&thermod; = 18(1) kcal·mol-1 and ΔS&thermod; = −7(2) eu. The corresponding zirconium compound is configurationally stable. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
