尿素及硫脲及羰基化合物间的氢键相互作用.pdf

物理化学学报(Wuli Huaxue X uebao) 1018 A cta Phys. Chim. Sin., 2007, 23(7) ：1018-1024 July [Article] 素及硫脲与羰基化合物间的氢键相互作用 郑文锐 傅 尧 刘 磊 郭庆祥 (中国科学技术大学化学系, 合肥 230026) 摘要： 利用量子化学二级微扰理论方法对尿素及硫脲衍生 与羰基化合物之间的氢键复合 进行了研究, 在 自然键轨道分析基础上进一步揭示了氢键本质并研究了取代基效应. 结果表明, 羰基化合 中供电子基和共轭 基, 尿素及硫脲中的吸电子基和共轭基均有利于氢键的形成. 结合尿素与硫脲的催化反应过程, 讨论了氢键复合 物两种可能的顺反异构并分析比较了顺反式构象异构体的稳定能大小. 关键词： 氢键; 羰基化合 ; 顺反异构; 尿素; 硫脲 中图分类号： O641 Hydrogen Bonding Interaction between Ureas or Thioureas and Carbonyl Compounds ZHENG Wen Rui FU Yao LIU Lei GUO Qing Xiang (Dep artment of Chemistry, University of Science and Technology of China, Hef ei 230026, P. R. China) Abstract ： The hydrogen bonding interactions between ureas or thioureas and different carbonyl compounds were studied using the Moller Plesset perturbation theory (MP2) method. The natural bond orbital analysis further disclosed the essence of the hydrogen bonding interaction. In addition, the substituent effects were investigated and the results indicated that both the electron withdrawing groups on ureas (thioureas) and electron donating groups on carbonyl compounds can facilitate the hydrogen bonding formation. Two possible hydrogen bonding complex conformations, cis and trans, were discussed and the energy gaps between them were analyzed, in combination with the catalytic reactions. Key Words ： Hydrogen bond; Carbonyl compound; cis trans isomerization; Urea; Thiourea 尿素和硫脲类化合 因具有较强的氢键活性而 aza