中国物理B ›› 2018, Vol. 27 ›› Issue (4): 43102-043102.doi: 10.1088/1674-1056/27/4/043102

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

High-level theoretical study of the evolution of abundances and interconversion of glycine conformers

Fan Liu(刘凡), Jing Yu(于静), Yan-Ru Huang(黄艳茹)   

  1. College of Science, Liaoning Shihua University, Fushun 113001, China
  • 收稿日期:2017-11-13 修回日期:2018-02-01 出版日期:2018-04-05 发布日期:2018-04-05
  • 通讯作者: Yan-Ru Huang E-mail:huangganen12@sina.cn
  • 基金资助:
    Project supported by the Young Scientists Funds of the National Natural Science Foundation of China (Grant Nos. 11404154 and 11304136).

High-level theoretical study of the evolution of abundances and interconversion of glycine conformers

Fan Liu(刘凡), Jing Yu(于静), Yan-Ru Huang(黄艳茹)   

  1. College of Science, Liaoning Shihua University, Fushun 113001, China
  • Received:2017-11-13 Revised:2018-02-01 Online:2018-04-05 Published:2018-04-05
  • Contact: Yan-Ru Huang E-mail:huangganen12@sina.cn
  • Supported by:
    Project supported by the Young Scientists Funds of the National Natural Science Foundation of China (Grant Nos. 11404154 and 11304136).

摘要: The relative conformer energies of glycine are evaluated by using a focal point analysis expressed as (HF →MP2 →MP3 →CCSD →CCSD(T)). The conformer abundances at various temperatures (298-500 K) are calculated based on the relative energies and Boltzmann statistical thermostatistical analysis with and without considering internal hindered rotations. A comparison between the available Raman spectrum and the electron momentum spectrum confirms that the influence of rigid-rotor hindered rotation on the conformational proportions of glycine is considerable, especially for the Ⅲp structure. The conformational interconversions are discussed. It is found that with increasing temperature, the mole fraction of Ⅱn keeps constant and Ip structure can convert into IVn and Ⅲp, leading to the decrease in the weight of Ip and the increase in the weights of IVn and Ⅲp conformers, which is in accordance with experimental observations.

关键词: glycine, conformation, abundance, interconversion

Abstract: The relative conformer energies of glycine are evaluated by using a focal point analysis expressed as (HF →MP2 →MP3 →CCSD →CCSD(T)). The conformer abundances at various temperatures (298-500 K) are calculated based on the relative energies and Boltzmann statistical thermostatistical analysis with and without considering internal hindered rotations. A comparison between the available Raman spectrum and the electron momentum spectrum confirms that the influence of rigid-rotor hindered rotation on the conformational proportions of glycine is considerable, especially for the Ⅲp structure. The conformational interconversions are discussed. It is found that with increasing temperature, the mole fraction of Ⅱn keeps constant and Ip structure can convert into IVn and Ⅲp, leading to the decrease in the weight of Ip and the increase in the weights of IVn and Ⅲp conformers, which is in accordance with experimental observations.

Key words: glycine, conformation, abundance, interconversion

中图分类号:  (Calculations and mathematical techniques in atomic and molecular physics)

  • 31.15.-p
33.15.-e (Properties of molecules) 33.15.Bh (General molecular conformation and symmetry; stereochemistry) 31.15.xr (Self-consistent-field methods)