THE INFRARED SPECTRA OF THIN FILMS OF SIX $HEXAFLUORIDES^{*}$

Abstract

The infrared spectra of thin films of the hexafluorides of sulfur, selenium, tellurium, molybdenum, tungsten, and uranium have been observed from 2 to 15$\mu$. For $UF_{6}$, the observations were extended to 18$\mu$ in order to observe $\sigma_{3}$. The films were deposited on a silver chloride plate chilled by heat conduction through a hollow silver mounting bracket containing liquid nitrogen. $\sigma_{3}$ was found to fall at longer wavelengths in the solid state than in the gas state for all six molecules. $\sigma_{1}+\sigma_{3}$ and $\sigma_{2}+\sigma_{3}$ were observed doubled in the solid state in each case.