Gao Shu-qin, He Jia-ning, Li Rong-fu, Zuo Jian, Li Zhao-kai, Cao Biao, Li Zuo-wei
Department of Physics, Jilin University, Changchun 130023, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Oct;27(10):2042-4.
Fermi resonance is a very common phenomenon in molecule vibration spectra, especially in polyatomic molecule with complex structure. Fermi resonance appears when a fundamental vibration frequency lies closely to an overtone or combination frequencies. One can observe two peaks coming from Fermi resonance and the energy transfer also occurs between the two peaks. Fermi resonance phenomenon appears in both infrared spectrum and Raman spectrum. The Raman spectrum of CCl4 was measured. The frequency separation between the two peaks in a Fermi resonance doublet was observed and the integrated intensities were calculated with the software of Origin Pro 7.5. Fermi resonance interaction was caused by the CCl4 C-Cl f-symmetrical stretching fundamental nu3 coupling. The combination frequency (nu1 + nu4) of C-Cl a1-symmetrical stretching nu1 and band C-Cl2 f-symmetrical bending nu4 was calculated. Based on Bertran's theory, Fermi coupling coefficient W was calculated and the theoretical value nu3(0) of nu3 was estimated. The present article provided good reference for better understanding of the relationship between molecular vibration frequency and molecular structure.
费米共振是分子振动光谱中一种非常常见的现象，尤其在结构复杂的多原子分子中。当一个基频与一个泛频或组合频率相近时，就会出现费米共振。人们可以观察到来自费米共振的两个峰，并且两个峰之间也会发生能量转移。费米共振现象同时出现在红外光谱和拉曼光谱中。测量了CCl4的拉曼光谱。观察到费米共振双峰中两个峰之间的频率间隔，并用Origin Pro 7.5软件计算了积分强度。费米共振相互作用是由CCl4的C-Cl f对称伸缩基频ν3耦合引起的。计算了C-Cl a1对称伸缩ν1和C-Cl2 f对称弯曲ν4的组合频率（ν1 + ν4）。基于伯特兰理论，计算了费米耦合系数W，并估计了ν3的理论值ν3(0)。本文为更好地理解分子振动频率与分子结构之间的关系提供了很好的参考。
