曲景平

个人信息Personal Information

教授

博士生导师

硕士生导师

性别:男

毕业院校:日本东京大学

学位:博士

所在单位:化工学院

电子邮箱:qujp@dlut.edu.cn

扫描关注

论文成果

当前位置: 中文主页 >> 科学研究 >> 论文成果

DFT Studies on the Methane Elimination Reaction of a Trinuclear Rare-Earth Polymethyl Complex: (sigma-Bond Metathesis Assisted by Cooperation of Multimetal Sites

点击次数:

论文类型:期刊论文

发表时间:2014-03-10

发表刊物:ORGANOMETALLICS

收录刊物:SCIE、Scopus

卷号:33

期号:5

页面范围:1126-1134

ISSN号:0276-7333

摘要:DFT studies have been performed for the process of methane elimination via an intramolecular C-H bond activation of the polymethyl trinuclear rare-earth-metal complex [(eta(5)-C5Me4SiMe3)Tm(mu(2)-CH3)(2)](3). It has been found that intermetallic cooperation plays an important role in achieving such an intramolecular C-H bond activation process, and the cooperation of trimetallic centers makes the C-H bond activation kinetically easier in comparison with that of bimetallic centers. The methane elimination reaction occurs through rearrangement of Tm-CH3 connections and subsequent C-H bond activation. The C-H bond activation is the rate-determining step of the whole process, and the corresponding transition state is characterized by a sigma-bond metathesis assisted by cooperation of multimetal sites. Such a C-H bond activation step was accomplished by a change in the coordination manner (from mu(2) to mu(3) fashion) of a methyl group and a subsequent hydrogen transfer, and the two events are asynchronous concerted processes. The computational results also suggest that the reactivity of the CH bond of the metal-connected CH3 group follows the order mu(3)-C(H-2)-H > mu(2)-C(H-2)H > mu(1)-C(H-2)-H. This is unlike the case of a metal-CH3 bond, where the terminal methyl (monometal-connected mu(1)-CH3) is generally more reactive than multimetal-connected methyls. In addition, the effect of 4f electrons of such trinuclear organolanthanide compounds on the geometry and energy profile studied here is also discussed.