物理化学学报 >> 2010, Vol. 26 >> Issue (06): 1623-1628.doi: 10.3866/PKU.WHXB20100628

量子化学及计算化学 上一篇    下一篇

丁吡吗啉与其苯基类似物的电子结构特征比较

路慧哲, 冯振高, 李畅, 袁会珠, 覃兆海   

  1. 中国农业大学理学院, 北京 100193; 中国农业科学院植物保护研究所, 北京 100193
  • 收稿日期:2009-12-30 修回日期:2010-03-24 发布日期:2010-05-28
  • 通讯作者: 覃兆海 E-mail:qinzhaohai@263.net

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

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摘要：

通过化学合成获得丁吡吗啉及其苯基类似物, 并对其杀菌活性进行了比较. 借助X射线晶体衍射方法, 对丁吡吗啉的结构进行了解析. 进一步选择6-31G(2df, 2pd)基组, 利用密度泛函理论B3LYP方法对丁吡吗啉及其苯基类似物的空间几何结构进行优化, 借助前线分子轨道、Mulliken电荷、自然键轨道(NBO)分析、表观静电势等对丁吡吗啉及其苯基类似物的电子结构与其杀菌活性相关性进行了理论探讨. 结果表明吡啶环取代苯环后, 一方面吡啶环上的N原子是一个负电中心, 有利于与受体分子间形成氢键等相互作用; 另一方面, 吡啶环又是一个缺电子的芳环, 与苯环相比, 在与受体的π-π相互作用中能起到更好的电子接受体的作用. 这两种因素使得丁吡吗啉更容易与受体结合, 因而活性更高.

关键词: 密度泛函理论, 丁吡吗啉, 晶体结构, 电子结构

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