二元溶液中CH/π作用及费米共振现象的研究

Study of CH/π Interaction and Fermi Resonance in the Binary Solution

利用变换溶液浓度方法,分别测量苯与二氯甲烷、三氯甲烷不同体积浓度二元溶液的拉曼光谱.随着苯的体积浓度逐渐减小,苯的CH伸缩振动模式向高波数方向移动,二氯甲烷和三氯甲烷的CH对称伸缩振动模式随其体积浓度的减小逐渐向低波数方向移动.利用费米共振理论公式,分别计算了苯在二氯甲烷和三氯甲烷二元溶液中不同体积浓度下的费米共振耦合系数,发现苯的费米共振耦合系数不随二元溶液的CH/π作用强弱而发生改变.结合分子间CH/π作用和费米共振原理,对上述实验现象进行了分析并给出了合理的解释.

The Raman spectra of C6H6 in CH）2Cl2and CHCl3 at different volume concentrations were measured.With decreasing the volume concentration of C6H6,the CH stretching mode of C6H6 shifts to higher wavenumbers gradually. Besides,the CH symmetric stretching modes of CH）2Cl2 and CHCl3shift to lower wavenumbers with increasing the volume concentration of C6H6. According to the Fermi resonance theory equations,we calculated the Fermi resonance coupling coefficients of C6H6 in CH）2Cl2and CHCl3 at different volume concentrations. The results indicated that the Fermi resonance coupling coefficients remain practically unchanged when the strength of CH/π interaction in the binary solution changes. We gave a detailed analysis on the experimental results and made an reasonable explanation based on the theory of CH/π interaction and Fermi resonance.