THE CARBON-13 SHIFT IN THE BENZENE $a_{2}$ MODE AND THE INFRARED EXCITION SPECTRUM OF THE NATURAL ABUNDANCE BENZENE CRYSTAL

Abstract

The benzene $C^{13}$ shift for the gas phase $a_{20}$ vibrational mode was calculated and found to be $0.37 cm^{-1}$. This value was combined with data from the exciton density-of-states and exciton interaction parameters for the isotopically pure $C_{6}H_{6}$ $crystal^{1}$ to calculate the density-of-states and spectral absorption functions for the natural abundance crystal. These calculations will be compared with recent experimental $data.^{2,3}$