【作者】 朱元成； 李志锋； 李会学；

【Author】 Zhu YuanCheng~* Li ZhiFeng Li HuiXue College of Life Science and Chemistry,Tianshui Normal University,Tianshui 741001,China

【机构】 天水师范学院生命科学与化学学院；

【摘要】 采用密度泛函B3LYP/6-31+G^*方法对多巴胺DA的构象异构及其稳定性进行了研究.结果表明,势能面上存在6种稳定构象和8种构象转换过渡态,构象之间主要通过C1-O7[二面角T₁:H15O7ClC6],C2-O8[二面角T₂:H16O8C2C3]和C9-C10[二面角T₃:N11C10C9C5]单键旋转而相互转化.频率及NBO分析表明,分子内存在红移O…H-O及蓝移N…H-C两类氢键,氢键中电子转移类型均为LP₁（X）→σ^*（H-M）[X=O,N;Y=O,C],二级稳定化能E²对稳定构象有3.6 kJ.mol^-1～9.3 kJ·mol^-1的稳定化贡献.分子中的原子理论（AIM）分析表明,构象中O…H-O及N…H-C键的电子密度ρ（r）和Laplacian量▽²ρ（r）分别在0.0094～0.0171和0.0307～0.0798之间.采用极化连续模型（polarized continuum model,PCM）对体系进行了溶剂化效应计算,结果表明,DA的构象转换主要在水相中进行.更多还原

【Abstract】 The DFT（B3LYP/6-31+g^*） method was used to study the conformations stable and isomerization of dopamine.The results show that there are six stable conformations and eight translate states on the energy surface.Conformations can be convert to the other by the rotation of the C1O7[dihedral angle T1:H15O7C1C6],C2-O8[dihedral angle T2:H16O8C2C3]and C9-C10[dihedral angle T3:N11-C10-C9-C5]single bond.NBO analysis show that the O…H-O and N…H-C hydrogen bonds exist in the conformation and the electron transfer are all LP₁（X）→σ*（H-M）[X=O,N;Y=O,C]which provide 3.6 kJ·mol^-1～9.3 kJ·mol^-1 energy to the corresponding conformation.The AIM results indicate that theρ（r） and▽²ρ（r） range at the hydrogen bond O…H-O and N…H-C BCP are 0.0094～0.0171 and 0.0307～0.0798.The solvent effect have studied by polarized continuum model（PCM）.The calculated results implied that the conversion mainly occurred in the aqueous solution.更多还原