个人信息Personal Information
教授
博士生导师
硕士生导师
任职 : 大连理工大学膜科学与技术研究开发中心主任
性别:女
毕业院校:中国科学院大连化物所
学位:博士
所在单位:化工学院
学科:化学工程. 膜科学与技术. 生物医学工程
联系方式:hgaohong@dlut.edu.cn
电子邮箱:hgaohong@dlut.edu.cn
DFT study on 1,7-octadiene polymerization catalyzed by a non-bridged half-titanocene system
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论文类型:期刊论文
第一作者:Pan, Yu
通讯作者:He, GH (reprint author), Dalian Univ Technol, Sch Petr & Chem Engn, State Key Lab Fine Chem, Panjin 124221, Peoples R China.
合写作者:Xu, Xiaowei,Wei, Ning-Ning,Hao, Ce,Zhu, Xiaodong,He, Gaohong
发表时间:2016-01-01
发表刊物:RSC ADVANCES
收录刊物:SCIE、EI
卷号:6
期号:74
页面范围:69939-69946
ISSN号:2046-2069
摘要:Polymerization of 1,7-octadiene catalyzed by the (eta(5)-C5Me5) TiCl2(O-2,6-iPr2C6H3)/MAO system exhibited unusual favorable selectivity of repeated insertion. However, the mechanism of selectivity of the insertion mode of non-conjugated dienes has not been reported previously as far as we know. By using the density functional theory (DFT) method, the insertion modes of 1,7-octadiene, especially the selectivity of repeated insertion and intramolecular cyclization, were explored in detail concerning the (eta(5)-C5Me5) TiCl2(O-2-,6-(Pr2C6H3)-Pr-i)/MAO system. At the initiation stage, the 1,2-si-insertion is the optimal pathway among four insertion modes kinetically and thermodynamically. At the chain propagation stage, the competition between repeated insertion and intramolecular cyclization was discussed in detail, concerning the insertion into different growing chains. The computational results indicated that the repeated insertion of 1,7-octadiene showed more kinetically favorable than the intramolecular cyclization in three different situations, with free energy barrier differences between two insertion modes of 3.75 kcal mol(-1), 3.88 kcal mol(-1) and 7.43 kcal mol(-1) respectively. Moreover, the sequential insertion of seven-membered rings exhibited disadvantageous kinetically and thermodynamically, probably due to the steric repulsion effect between two cyclic rings. Those are in good agreement with the experimental data.