DFT方法研究基于脲及硫脲衍生物的阴离子受体  

DFT study on anion receptors based on urea and thiourea derivatives

作　　者：耿玮宏 王亚茹[1] 李夏[1] 张瑞红[1] 王炳强[1] 

机构地区：[1]山西师范大学化学与材料科学学院,山西临汾041000

出　　处：《化学研究》2017年第1期19-26,共8页Chemical Research

基　　金：山西师范大学大学生创新创业训练项目(SD2014CXXM-45)

摘　　要：采用密度泛函理论(DFT)模拟了两个基于脲和硫脲衍生物的受体分子对卤素阴离子的识别过程.结构优化表明基于脲衍生物的受体分子1最稳定构象为"反反"构象,分子内部形成稳定的C~α-H…O=C分子内氢键;而基于硫脲衍生物的受体分子2,不能形成分子内氢键,最稳定构象为"反顺"构象.受体1、2与卤素阴离子F^-、Cl^-可形成稳定的双氢键复合物,在此过程中,受体2经历了由"反顺"构象到"反反"构象的异构化过程.结构和能量分析表明,1、2受体分子与F^-离子间的氢键强度远大于其与Cl^-离子间的氢键;另一方面,受体2与阴离子间的氢键明显强于受体1,这是由于硫脲基N-H键具有更强的酸性.此外,对受体分子、氢键复合物及去质子化产物的吸收光谱计算结果表明,受体与F^-离子作用可产生明显的吸收光谱红移,而与Cl^-离子的作用对光谱影响较小.Anion recognition process of two receptors based on the urea and thiourea derivatives was studied using density functional theory（ DFT）. The urea derivative（ receptor 1） is a ＂trans,trans＂conformer bearing two Cα-H…O = C intramolecular hydrogen bonds. Otherwise,for the thiourea derivative（ receptor 2）,the ＂trans,cis＂conformer is the most stable due to absence of intramolecular hydrogen bonds. The receptors 1 and 2 both form double hydrogen bonds with F^-and Cl^-,and meanwhile the receptor 2 would change its conformer from ＂trans,cis＂to ＂trans,trans＂. Moreover,the hydrogen bonds of F^-anion are significantly stronger than those of Cl^-anion,and the hydrogen bonds of thiourea donor group are stronger than those of urea group. Finally,a formation of hydrogen bonds and the deprotonation process with F^-cause a large red-shift of absorption spectra,however the interaction with Cl^-has a small effect on the spectra.

关 键 词：脲 硫脲 阴离子受体 密度泛函理论 

分 类 号：O641[理学—物理化学]