| Fermi resonance is a phenomenon which widely present in the of molecular vibration spectra, especially in multi-atom molecules with complex structure. Due to the Fermi resonance phenomenon, the structure and intensity of the vibration spectrum of polyatomic molecule has changed, and that lead the spectral structure becoming more complicated, bring great difficulties to the attribution of vibration spectrum. By now, biological macromolecules are the main research targets in biological sciences and gene science. Their vibration spectra is more complicated, and the vibration level coupling phenomenon is ubiquitous. It is necessary to understand the attribution of spectrum, that means the research of Fermi resonance is very important.In previous studies, Fermi resonance is studied through infrared spectra of solvent effects, also Raman spectra of solvent concentration, but rarely Raman spectra of solvent effects. In this article, We will do some experimental research of Fermi resonance in CS 2 betweenν1 ? 2ν2 to further verify the solvent effect on Fermi resonance in the Raman spectrum. It is Conducive to further understand the structure of CS 2, solvent effect and Fermi resonance.The quantum theory and the basic theory of solvent effect of Fermi resonance are introduced, and the method of Fermi resonance -- transforming solvents is brought in. According to mechanism of solvent effects and Spectrometry, We study Fermi resonance of Raman spectra in CS 2 betweenν1 ? 2ν2 transforming the concentration of solvent and the solvents; analysis the effect of the solvent dielectric constant, Fermi resonance intensity ratio R and level width. At last we expand the influence of solvent effect on Fermi resonance by theory.This work includes two parts.Part 1:Experimental Study of Fermi resonance of CS 2betweenν1 ? 2ν2 in different solvent.Figure 1 shows Fermi resonance of Raman spectra with CS 2of 100% concentration under the room temperature. We obtained the resonance peaks of (655.862), (796.291), by measuring the CS 2. The mechanism is the symmetric stretching vibration and bending vibration of the multiplier.Figure 2 shows Fermi resonance of Raman spectra with CS 2 in 11 kinds of solvent. By the experiment result, the relation of Fermi resonance intensity ratio and dielectric constant was concluded,Conclusion is consistent with KBM equation. In addition, the relationship betweenΔ0 and R,Δ0 andε, relative variation relations ofΔ0(( )Δ?Δ0 /Δ0) and R are analyzed, correlation curves were obtained as follows. Part 2:Experimental Study of Fermi resonance of CS 2betweenν1 ? 2ν2 in different concentrations.Figure 7 shows Fermi resonance of CS 2 in THF solvent with different concentrations. Figure 8 shows the diagram of relationship between R and the concentration of CS 2. Figure 9 shows the diagram of relationship betweenΔand the concentration of CS 2. Figure 10 shows the diagram of relationship between K and the concentration of CS 2.The relationship between the Raman scattering coefficient and the changing of Fermi resonance of the liquid CS 2 at different concentrations. Figure 7 showed that theυ1 ? 2υ2 Fermi resonance Raman spectra of the pure liquid CS 2 and the liquid CS 2 in THF at different concentrations are different from each other. Especially,in the solution of CS 2 and THF , the values of R decrease with the volume concentration of solution from 10% to 100%,but the values of K,4,W increase,which has been rational explained using the theory of solvent effects. In THF, the CS 2 spectrum intensity of stretching vibrationυ1 is very strong and it is affected by THF. The CS 2 spectrum intensity of bending vibration 2υ2is very weak, and it is not affected by THF. so compared with the intensity ofυ1 and 2υ2has a big change. The analysis shows that dissipation coefficient ofυ1 of CS 2is affected by the concentration of tetrahydrofuran(THF)。...
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