N-甲基甲酰胺在水溶液中的氢键动力学行为

摘要

The ground-state geometric optimizations of the isolated N-Methylformamide and the hy-drogen-bonded NMF-nH2 O(n=1 ,2 ,3) complexes considered here were carried out using the density functional theory (DFT ) method with B3LYP hybrid functional and the 6-31+ + G basis set .The time-dependent density functional theory (TDDFT ) method with B3LYP hybrid functional was used to calculate the electronic transition energies and corresponding oscillation strengths as well as the absorption spectra of all the isolated N-Methylformamide and the hydrogen-bonded NMF-nH2 O(n=1 ,2 ,3)complexes .Form the TDDFT method result ,we depicted the changes of different hydrogen-bonded complexes the electronic absorption spectra shift and hydrogen-bonding dynamics ,hydrogen bond strengthening can bring the relative electronic absorption spectra redshift ,the electronic absorp-tion spectra redshift is consistent with the mechanism of the hydrogen bond strengthening .%在B3LYP/6-31＋＋G 水平下，利用密度泛函理论方法优化了N-甲基甲酰胺单体和氢键体系NMF-nH2 O（n＝1，2，3）的基态几何构型；用含时密度泛函理论方法计算了N-甲基甲酰胺单体和氢键体系NMF-nH2O（n＝1，2，3）在不同电子激发态的跃迁能、振子强度和电子吸收光谱。结果表明，随着结合水分子个数的增加，氢键强度是加强的。分子间氢键引起电子吸收光谱发生红移，光谱红移程度与氢键加强的程度一致。