【摘要】 测量了0—15GPa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Rf/a减少,频率差Δ增加,当压强为8GPa时,费米共振现象消失,利用Betran理论得出了固有频率差Δ0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.更多还原

【Abstract】 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/a) of two Fermi resonance bands υ’6 + υ’1 and υ’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.更多还原