N,N-二甲基乙酰胺与醇分子间相互作用的理论研究

采用密度泛函理论在B3LYP/6-311＋G*水平上对乙醇、丙醇、丁醇、戊醇与N,N-二甲基乙酰胺形成的1∶1氢键复合物进行计算研究. 结果表明: 醇与N,N-二甲基乙酰胺形成的复合物存在强的氢键, 表现为羰基氧原子的孤对电子与醇羟基反键σ轨道的相互作用. 振动分析显示, 分子间C＝O…H—O氢键的形成使C＝O和H—O伸缩振动频率明显红移. 溶剂对氢键产生较大的影响, 随着溶剂极性的增加, 复合物氢键有蓝移趋势.

Theoretical Studies of Molecular Interaction between Alcohols and N,N-Dimethylacetamide

Theoretical studies on molecular interaction between N,N-dimethylacetamide and alcohols were carried out at B3LYP/6-311＋G* level using the density functional theory to obtain optimized equilibrium structures. The results show that the 1∶1 complexes have been formed by strong hydrogen-bonding interaction of lone pairs of oxygen atom with the s* (H—O) anti-bonding orbitals of alcohols. Spectroscopic analysis indicates that the formation of the C＝O…H—O hydrogen bond makes H—O and C＝O stretching vibration frequencies red-shifted. The influence of solvent on the hydrogen bond was found, and the hydrogen bond has a blue-shift trend as the polarity of the solvent becomes greater.