中国物理B ›› 2015, Vol. 24 ›› Issue (9): 93101-093101.doi: 10.1088/1674-1056/24/9/093101

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Covalent intermolecular interaction of the nitric oxide dimer (NO)2

张辉a, 郑桂丽a b, 吕刚c, 耿轶钊a, 纪青a d e   

  1. a School of Science, Hebei University of Technology, Tianjin 300401, China;
    b Changchun Institute of Optics, Fine Mechanics and Physics, Changchun 130033, China;
    c Mathematical and Physical Science School, North China Electric Power University, Baoding 071003, China;
    d Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China;
    e State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2015-03-14 修回日期:2015-05-09 出版日期:2015-09-05 发布日期:2015-09-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 90403007 and 10975044), the Key Subject Construction Project of Hebei Provincial Universities, China, the Research Project of Hebei Education Department, China (Grant Nos. Z2012067 and Z2011133), the National Natural Science Foundation of China (Grant No. 11147103), and the Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Grant No. Y5KF211CJ1).

Covalent intermolecular interaction of the nitric oxide dimer (NO)2

Zhang Hui (张辉)a, Zheng Gui-Li (郑桂丽)a b, Lv Gang (吕刚)c, Geng Yi-Zhao (耿轶钊)a, Ji Qing (纪青)a d e   

  1. a School of Science, Hebei University of Technology, Tianjin 300401, China;
    b Changchun Institute of Optics, Fine Mechanics and Physics, Changchun 130033, China;
    c Mathematical and Physical Science School, North China Electric Power University, Baoding 071003, China;
    d Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China;
    e State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2015-03-14 Revised:2015-05-09 Online:2015-09-05 Published:2015-09-05
  • Contact: Ji Qing E-mail:jiqingch@hebut.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 90403007 and 10975044), the Key Subject Construction Project of Hebei Provincial Universities, China, the Research Project of Hebei Education Department, China (Grant Nos. Z2012067 and Z2011133), the National Natural Science Foundation of China (Grant No. 11147103), and the Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Grant No. Y5KF211CJ1).

摘要: Covalent bonds arise from the overlap of the electronic clouds in the internucleus region, which is a pure quantum effect and cannot be obtained in any classical way. If the intermolecular interaction is of covalent character, the result from direct applications of classical simulation methods to the molecular system would be questionable. Here, we analyze the special intermolecular interaction between two NO molecules based on quantum chemical calculation. This weak intermolecular interaction, which is of covalent character, is responsible for the formation of the NO dimer, (NO)2, in its most stable conformation, a cis conformation. The natural bond orbital (NBO) analysis gives an intuitive illustration of the formation of the dimer bonding and antibonding orbitals concomitant with the breaking of the π bonds with bond order 0.5 of the monomers. The dimer bonding is counteracted by partially filling the antibonding dimer orbital and the repulsion between those fully or nearly fully occupied nonbonding dimer orbitals that make the dimer binding rather weak. The direct molecular mechanics (MM) calculation with the UFF force fields predicts a trans conformation as the most stable state, which contradicts the result of quantum mechanics (QM). The lesson from the investigation of this special system is that for the case where intermolecular interaction is of covalent character, a specific modification of the force fields of the molecular simulation method is necessary.

关键词: nitric oxide dimer, intermolecular interaction, natural orbital, covalent bond

Abstract: Covalent bonds arise from the overlap of the electronic clouds in the internucleus region, which is a pure quantum effect and cannot be obtained in any classical way. If the intermolecular interaction is of covalent character, the result from direct applications of classical simulation methods to the molecular system would be questionable. Here, we analyze the special intermolecular interaction between two NO molecules based on quantum chemical calculation. This weak intermolecular interaction, which is of covalent character, is responsible for the formation of the NO dimer, (NO)2, in its most stable conformation, a cis conformation. The natural bond orbital (NBO) analysis gives an intuitive illustration of the formation of the dimer bonding and antibonding orbitals concomitant with the breaking of the π bonds with bond order 0.5 of the monomers. The dimer bonding is counteracted by partially filling the antibonding dimer orbital and the repulsion between those fully or nearly fully occupied nonbonding dimer orbitals that make the dimer binding rather weak. The direct molecular mechanics (MM) calculation with the UFF force fields predicts a trans conformation as the most stable state, which contradicts the result of quantum mechanics (QM). The lesson from the investigation of this special system is that for the case where intermolecular interaction is of covalent character, a specific modification of the force fields of the molecular simulation method is necessary.

Key words: nitric oxide dimer, intermolecular interaction, natural orbital, covalent bond

中图分类号:  (Electronic structure and bonding characteristics)

  • 31.15.ae
87.15.K- (Molecular interactions; membrane-protein interactions) 31.10.+z (Theory of electronic structure, electronic transitions, and chemical binding)