Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (06): 1623 -1628.doi: 10.3866/PKU.WHXB20100628

• QUANTUM CHEMISTRY AND COMPUTATION CHEMISTRY • Previous Articles     Next Articles

Electronic Structure Comparison between Pyrimorph and Its Phenyl Analog

LU Hui-Zhe, FENG Zhen-Gao, LI Chang, YUAN Hui-Zhu, QIN Zhao-Hai   

  1. College of Science, China Agricultural University, Beijing 100193, P. R. China; Institute of Plant Protection, Chinese Academy of Agriculture Science, Beijing 100193, P. R. China
  • Received:2009-12-30 Revised:2010-03-24 Published:2010-05-28
  • Contact: QIN Zhao-Hai E-mail:qinzhaohai@263.net

Abstract:

Pyrimorph and its phenyl analog were prepared by chemical synthesis and their fungicidal activities were tested against P. infestans and P. capsici.We analyzed the structure of pyrimorph by X-ray diffraction method. Furthermore, the structure of pyrimorph and its phenyl analog were optimized by density functional theory using the 6-31G(2df, 2pd) basis set. Based on the calculated frontier molecular orbitals, Mulliken charges, natural bond orbital (NBO) analysis and surface electrostatic potential, the structure-activity relationships (SARs) of pyrimorph and its phenyl analog were discussed. The results show that when the phenyl ring is replaced by pyridine, hydrogen bond formation with a receptor molecule is favored due to the negative charge center of N in the pyridine ring. In addition, pyridine makes the electron-deficient aryl ring a better electron acceptor for π-πstacking. Considering the two above-mentioned factors, pyrimorph was found to bind more easily with the receptor and possessed better activity than its phenyl analog.

Key words: Density functional theory, Pyrimorph, Crystal structure, Electronic structure

MSC2000: 

  • O641