Density functional study on the role of electronic factors in variation of polymerization activity for Ziegler-Natta catalyst

被引:8
作者
Mukhopadhyay, S
Kulkarni, SA
Bhaduri, S
机构
[1] VLife Sci Technol Private Ltd, Pune 411007, Maharashtra, India
[2] Reliance Ind Ltd, Swastik Mill Compound VN Purav Marg, Bombay 400071, Maharashtra, India
来源
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM | 2004年 / 673卷 / 1-3期
关键词
density functional; Ziegler-Natta catalyst; activation energy; olefin polymerization; alkoxy/non-alkoxy ligands;
D O I
10.1016/j.theochem.2003.11.042
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The role of electronic factors in the variation of activity of Ziegler-Natta (ZN) catalysts having chloride, alkoxy and other ligands for ethylene and propylene polymerization has been investigated using density functional calculations at B3LYP/LANL2DZ level. The barriers for olefin insertion into [TiCl2CH3](+) for ethylene and propylene are comparable whereas for catalysts with alkoxy and non-alkoxy ligands having varying heteroatoms, the insertion barriers for propylene are about 3-6 kcal/mol higher than the corresponding ethylene insertion barriers. This supports the experimental observation that the propylene polymerization with ZN catalyst having alkoxy and non-alkoxy ligands has very low catalytic activity as compared to that for ethylene polymerization whereas [TiCl2CH3](+) polymerizes both ethylene and propylene. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:65 / 77
页数:13
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