PRESSURE EFFECTS OF THE ARE SUPPRESSOR GAS, $SF_{6}$, ON GAS PHASE ELECTROCHROMISM SPECTRA

Abstract

The effect of increasing pressure of the are suppressor gas, $SF_{6}$, on the electrochromism spectra of medium sized polyatomic molecules has been measured. The Rydberg absorptions of molecules have been shown to be particularly sensitive to the pressure of surrounding $gases.^{1}$ Even for moderate pressures of a few atmospheres, subtle changes in intensity and shape of these bands have been noted. These absorptions of gas phase samples also show a change in total electrochromic effect when subjected to increasing pressures. The net change is, however, greater than was expected and is thought to be the result of variations of the internal electric field as a result of varying pressure. The pressure range of interest is from ca. 1 to 15 atmospheres. The discussion will demonstrate how these effects may be taken into account when calculating excited state properties and how they relate to solvatochromic effects.