Synthesis, molecular structure, and racemate-meso interconversion for rac-(Me2Si)2{η5-C5H-3-(CHMe2)-5-Me}2MCl2 (M = Ti and Zr)

被引：23

作者：

Miyake, S

Henling, LM

Bercaw, JE ^{[1
]}

机构：

[1] CALTECH, Arnold & Mabel Beckman Labs Chem Synthesis, Pasadena, CA 91125 USA

[2] Japan Polyolefins Co Ltd, Oita 87001, Japan

来源：

ORGANOMETALLICS | 1998年 / 17卷 / 25期

关键词：

D O I：

10.1021/om980505m

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Doubly [SiMe2]-bridged group IV metallocenes, rac-(Me2Si)(2){eta(5)-C5H-3-(CHMe2)-5-Me}(2)MCl2 (M = Ti, Zr), have been synthesized, and a crystal structure of rac-(Me2Si)(2){eta(5)-C5H3-(CHMe2)-5-Me}(2)TiCl2 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){eta(5)-C5H-3-(CHMe2)-5-Me}(2)TiCl2 meso-(Me2Si)(2){eta(5)-C5H-3-(CHMe2)-5-Me}(2)TiCl2. Measurements of the kinetics of the approach to equilibrium reveal Delta H double dagger = 18(1) kcal.mol(-1) and Delta S double dagger = -7(2) eu. The corresponding zirconium compound is configurationally stable.

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页码：5528 / 5533

页数：6

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