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گواهی نمایه سازی مقاله A Novel Method for Synthesis of rac-1,2-Ethanediylbis(2-methyl-4-phenylindenyl)zirconium Dichloride as a Useable Complex in Production of Isotactic Olefin Polymerization Catalyst

عنوان مقاله: A Novel Method for Synthesis of rac-1,2-Ethanediylbis(2-methyl-4-phenylindenyl)zirconium Dichloride as a Useable Complex in Production of Isotactic Olefin Polymerization Catalyst
شناسه (COI) مقاله: ISPST10_685
منتشر شده در دهمین سمینار بین المللی علوم و تکنولوژی پلیمر در سال ۱۳۹۱
مشخصات نویسندگان مقاله:

Reza Teimuri-mofrad - Department of Organic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, I. R. Iran
Hamed Farzi - Department of Organic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, I. R. Iran
Ramin Farazmand - Department of Organic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, I. R. Iran
Vahid Lotfi Kalajahi - Department of Organic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, I. R. Iran

خلاصه مقاله:
Metallocenes based on group 4 metals were first synthesized by Wilkinson et al. in 1953 [1]. However, the great utility of these compounds as catalyst precursors for the stereoselectivepolymerization of α-olefins was not realized until the mid- 1980s when two key discoveries were made. The first of thesewas the discovery that alkyl substituents placed on the cyclopentadienyl framework of the metallocene can significantly influence the performance and behavior of the catalyst [2]. The second was the discovery that enantioselectivity in the insertion step of an α-olefin polymerization could result if one made metallocene catalysts with the appropriate chirality and stereorigidity [3]. Ewen first demonstrated a correlation between a catalyst’s molecularsymmetry and the stereoregularity of the polymer produced by studying the two isomers (rac and meso) of the ansametallocene.He found that the C2-symmetric rac form produced polypropylene with moderate isotacticity. Brintzinger and Kamisky demonstrated that a similarmetallocene, C2-symmetric rac-Et(H4Ind)2ZrCl2 was able to produce a much greater yield of iPP. These two discoveries led the way for the development of several different families of symmetry-based metallocene catalysts [3-4].

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