Acta Phys. -Chim. Sin. ›› 2018, Vol. 34 ›› Issue (3): 303-313.doi: 10.3866/PKU.WHXB201708302

Special Issue: 密度泛函理论中的化学概念特刊

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Understanding the Isomerization of Monosubstituted Alkanes from Energetic and Information-Theoretic Perspectives

Aiguo ZHONG*(),Rongrong LI,Qin HONG,Jie ZHANG,Dan CHEN   

  • Received:2017-07-19 Online:2018-03-15 Published:2017-12-18
  • Contact: Aiguo ZHONG E-mail:zhongaiguo@tzc.edu.cn
  • Supported by:
    the Natural Science Foundation of Zhejiang Province, China(LY15B030001);the Natural Science Foundation of Zhejiang Province, China(LY15B060001);Zhejiang Province Undergraduate Student Innovation Project, China(2017R430014)

Abstract:

A unified explanation for the relative stability of linear and branched alkanes is still lacking, and research in this direction is ongoing. Unlike the conventional orbital-based description, we have employed the density functional theory (DFT) based on the total energy and its components as well as a newly proposed energy partitioning scheme [Liu, S. B. J. Chem. Phys. 2007, 126, 244103]. Taking monosubstituted hydrocarbons CnH2n+1―R (n = 3, 4, 5, 6; R = OH, OCH3, NH2, NO2, F, Cl, CN, CHO) as examples, we have investigated the molecular origin and nature within the framework of the DFT. Our computational results revealed that no such a single energy component that dictates the transformation of the mono-substituted alkane derivatives. By the binary fit of the electrostatic potential and steric hindrance from the new energy decomposition scheme, we unraveled that isomerization is mainly governed by the electrostatic potential, while the steric effect has a minor influence. Moreover, we established a linear relationship between the Shannon entropy difference and the Fisher information difference, which is accordance with previous findings. Further, there was no linear relationship between Ee and the Fisher information or Shannon entropy.

Key words: Molecular stability, Steric hindrance, Density functional theory, Energy component

MSC2000: 

  • O641