Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (18): 1923-1929.DOI: 10.6023/A12070460 Previous Articles     Next Articles


铬族金属氢化物中M-H 键键能的从头计算

唐诗雅, 傅尧, 郭庆祥   

  1. 中国科学技术大学化学系 合肥 230026
  • 投稿日期:2012-07-23 发布日期:2012-08-16
  • 通讯作者: 傅尧,郭庆祥
  • 基金资助:

    项目受国家自然科学基金(Nos. 20832004, 20972148), 中国科学院(KJCX2-EW-J02)和中央高校基本科研业务费资助. 计算工作在中国科大和上海超算中心完成.

Ab Initio Calculation of M-H Bond Dissociation Energies of Cr-Group Metal Hydrides

Tang Shiya, Fu Yao, Guo Qingxiang   

  1. Department of Chemistry, University of Science and Technology of China, Hefei 230026
  • Received:2012-07-23 Published:2012-08-16
  • Supported by:

    Supporting information for this article is available free of charge via the Internet at Project supported by the National Natural Science Foundation of China (Nos. 20832004, 20972148), Chinese Academy of Science (KJCX2-EW-J02) and the Fundamental Research Funds for the Central Universities. Computations were performed at the Supercomputing Center of USTC and Shanghai.

The metal-hydrogen M-H bond homolysis of the Cr-group metal hydrides is a key process in the radical cyclization reactions mediated by these compounds, which directly affects the catalytic efficiency and selectivity of the reactions. Accurate prediction of M-H BDEs (bond dissociation energies) using theoretical methods not only improves our understanding about the structures and properties of the Cr-group metal hydride based catalysts, but also provides important insights into design of new generations of catalysts for radical cyclization reactions. For this purpose, we have calculated the M-H BDEs with different density functional theory methods (including MPW1K, MPW1b95, MPW1PW91, PBE1PBE, B3P86, O3LYP, TPSSH, MPW1KCIS, and TPSS) and compared the theoretical predictions with 14 reliable experimental M-H BDE values recently reported for the Cr-group metal hydrides. It is found that the B3P86/lanl2dz+p method could accurately predict the M-H BDEs with a precision of 1.6 kcal/mol. Using the B3P86/lanl2dz+p method, we next studied the structure-property relationship for the M-H BDEs in Cr-group metal hydrides. As to the periodical trends, we found that the effects of the metals on the M-H BDEs are greater than the effects of the ligands. The M-H BDEs increase in the order:first row metal

Key words: transition-metal hydride, bond dissociation energy, ab initio calculation, hybridization defects