盐-N,N-二甲基甲酰胺/乙醇双溶剂体系的荧光光谱分析

Fluorescence Spectra Analysis of Salt in N,N-Dimethylformamide and Ethanol Binary Solvents

利用荧光光谱和量子化学计算方法研究了LiCl和MgCl2对N,N-二甲基甲酰胺(DMF)/乙醇双溶剂体系的微观结构变化的影响。通过对DMF的N—C O键以及盐与DMF和乙醇相互作用的研究发现,离子溶剂化作用导致溶剂体系结构变化,生成多种具有荧光属性的团簇,且随浓度的变化而变化。结合具有荧光属性的团簇分子跃迁能和可能的配位构型的优化以及热力学性质计算得到,共轭体系越大的团簇分子受盐的影响越小且其跃迁能越小的规律。比较Li+和Mg2+形成配位构型离子簇的稳定性和荧光强度,说明了离子极化对溶剂化的影响。

Effects of salts on the microstructure of the binary solvents （DMF/ethanol） had been investigated using fluorescence spectrophotometry and quantum chemistry method. Through the analysis of N--C = 0 existing in isolated DMF and interaction between salt and the binary solvents,it was found that the clusters with fluorescence properties are formed and changed with salt concentration. Combined with clusters transition energy, optimal configuration and thermodynamic properties calculated by theoretical calculation, it was found that the clusters with larger conjugation system would be less influence by salt. Moreover, the effect of ionic polarization on ion solvation had been discussed by comparing the stability and fluorescence intensity of clusters formed by coordination of solvents with Li ＋ and Mg2＋ .