Raman Spectrum of Benzene Crystal

The Raman spectrum of the benzene crystal has been observed at 77° and 195°K. All the gas-phase-allowed fundamentals have been found. Only the Raman band ν7(e2g) has been found to split into two bands in the crystal, while all the other fundamentals have shown no splitting due to the crystal field. The splitting of ν7(e2g) indicates invalidity of the dipole-dipole coupling model for the benzene crystal. The interpretation by Mair and Hornig about the doublet structure of several infrared combination bands involving ν10(e1g) has been revised from the result of the direct observation of the Raman fundamental ν10(e1g). A weak Raman band at 1012 cm−1 is difficult to give a reasonable interpretation. It has been suggested that it is due to the fundamental ν12(b1u) appearing in the Raman spectrum in violation of the selection rule.