The Effect of High Pressure on the Near Infrared Absorption Spectrum of Certain Liquids

Abstract

Certain absorption bands of liquid water, methyl alcohol, amyl alcohol, and toluene were studied when the liquids were subjected to high pressures. In the case of the first three liquids, pressures up to 5000 kg/${\mathrm{cm}}^2$ were used, and pressures up to 8000 kg/${\mathrm{cm}}^2$ were applied to the toluene. No change was found either in the spectral position or in the intensity of the bands studied. The results are of interest since a change in the polymerization of polar liquids is supposed to take place with increase of pressure. The absorption bands are characteristic of the molecules and hence a change in the position and intensity should accompany the change in polymerization. As no such change was observed, it is concluded that there is no change in polymerization in the pressure range studied. The pressure necessary to solidify toluene at 20°C. was found to lie between 8100 kg/${\mathrm{cm}}^2$ and 8300 kg/${\mathrm{cm}}^2$.