VIBRATIONAL INTENSITIES OF BENZENE IN THE CONDENSED $PHASE^{*}$

$^{*}$ Financed by a Frederick Gardner Cottrell Grant from the Research Corporation, 1957-9.Author Institution: Department of Chemistry, Kansas State UniversityIn order to test the feasibility of measuring infrared intensities of substances in the liquid phase, the intensities of the infrared absorption bands in benzene have been investigated. In the pure liquid, the intensities of all four all four fundamentals: have been measured. Furthermore, the intensities of the out-of-plane C-H bending vibration has been measured in cyclohexane, 2, 2, 4-trimethyl pentane, methyl formate, and ethyl propionate solutions as a function of mole fractions of benzene The effect of iodine on this intensity has also been investigated in the most dilute simple of each of these solutions. The intensity of this fundamental band was found to be always greater in the solution than in the pure liquid. Furthermore, these solution values appear to approach a common limiting value when the mole fraction of benzene was small, even though the concentration dependences were different. These data suggest that appreciable intermolecular interactions occur in the condensed phases and that intensity measurements in these phases may be a method of investigating such interactions