Chem. J. Chinese Universities ›› 2009, Vol. 30 ›› Issue (11): 2233.

• Articles • Previous Articles     Next Articles

Linear Relationship Between the Partial Charges of H and O Atoms in Carboxyl of Substituted Benzoic Acid and the Hammett Constants

LI Hua-Yi*, HU You-Liang   

  1. Joint Laboratory of Polymer Science and Materials, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2009-01-05 Online:2009-11-10 Published:2009-11-10
  • Contact: LI Hua-Yi. E-mail: liweike@iccas.ac.cn
  • Supported by:

    国家自然科学基金(批准号: 20334030, 50703044 和 20734002)资助.

Abstract:

The linear dependence between the partial charges of H1, O2 and O3 atoms in carboxyl of substituted benzoic acid and Hammett constants was analyzed by density functional theory(DFT). Different density functional and partial charge computation methods[B3LYP/6-311G*/(NBO, Mulliken), (BLYP, BP, PWC)/DNP/(Hirshfeld, Mulliken)] were used to evaluate the above linear relationship. It was found that BLYP/DNP/Hirshfeld had high accuracy and high computational speed. Seventy substituted benzoic acid compounds were computed. The results show that the linear correlation coefficient between the partial charges of H1, O2 and O3 atoms and σp and σm is higher than 0.98. The best linear relationship occurred between the partial charge of O2 atom and Hammett constant. The partial charge of O2 atom could be used as substitute of Hammett constant in the quantitative structure property analysis and to predict Hammett constant.

Key words: Hammett constant; Density functional theory; Atom charge; Benzoic acid

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