测量了0-15 GPa压强下联苯分子的拉曼光谱.结果表明,随压强增加,分子内和分子间π-π共轭和离域效应增强,谱线的绝对强度变大、蓝移.联苯分子的两费米共振谱线强度比Rva减少,频率差△增加,当压强为8 GPa时,费米共振现象消失,利用Betrnn理论得出了固有频率差△0和耦合系数ω随压强的变化关系,通过高压下相变进行了解释,并探讨了高压下费米共振耦合变弱的机理.%Raman spectra of biphenyl have been obtained under pressures up to 15 GPa. The results indicated that with the increase of pressure, the effect of inter- and intra-molecular π-πconjugation and delocation increases, accompanied by the intensity enhancement of the Raman bands, and blue shift of the frequency. The intensity ratio (Rf/α) of two Fermi resonance bands v'6 + v'1 and v'8 decreases, and the frequency difference Δ increases with the pressure. The Fermi resonance phenomenon disappears when the pressure goos up to 8 GPa. Using J. F. Bertran's theory, we obtained the relationship of the inherent frequency difference Δ0 and coupling coefficient ω with pressure. This phenomenon was explained by high-pressure phase transition. The mechanism of high pressure induced Fermi resonance weakening was also discussed.
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