文档介绍：
Recent Trends in the Polymerization of a-Olefins
Catalyzed plexes of Early
Transition Metals
Kazushi Mashima, Yuushou Nakayama and Akira Nakamura *
Department of Chemistry, Graduate School of Engineering Science, Osaka
University, Toyonaka, Osaka 560, Japan
Department of Macromolecular Science, Graduate School of Science, Osaka
University, Toyonaka, Osaka 560, Japan. *E-mail: ******@-
This review article describes recent progress in the field of anometallic catalysts for
olefin polymerization and focuses on the metal-carbon bonding character of the transition metal
complexes used as catalysts. Most catalysts of this kind are based on metallocene derivatives of
Group 4 metals, their catalytic behavior (such as activity and stereospecificity) and the molecular
weights of the resulting polymers are surveyed on the basis of the molecular structure of the catalyst
precursors. Advanced mechanistic studies on the catalyst systems are also summarized. Some
examples of the related polymerization of functionalized olefins are also presented. Not only the
Group 4 metal catalysts but also the polymerization catalysts of many other early transition metals
and late transition metals are reviewed including our recent study on the mono(cyclopenta-
dienyl)mono(diene) complexes of Group 5 metals.
1 Introduction .................................. 3
2 General Features plexes of Early Transition
Metals ..................................... 3
3 Olefin Polymerization plexes .......... 7
Cationic plexes as Active Species
for a Metallocene/MAO System . . . . . . . . . . . . . . . . . . . 7
Neutral Group 3 plexes as Catalysts
of Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Gas-Phase Reaction of Cationic d pounds of Group 4
Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Propagation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Termi