Vibrational resonant coupling of liquid benzene

Abstract The intermolecular vibrational resonant coupling of liquid benzene has been examined by measuring shifts of the vibrational frequencies and changes in the line widths by isotopic dilution for the infrared-active ν 4 , ν 13 , and ν 14 , and the Raman-active ν 2 modes. The resonant coupling for the infrared-active modes is well explained by the transition-dipole-transition-dipole interaction, while the high-frequency shift of the ring breathing ν 2 mode suggests the presence of the charge transfer interaction. From the analysis of the frequency shift of the out-of plane ν 4 mode, it is suggested that the configuration of near neighbors in liquid benzene is similar to that in crystalline benzene.