Accession Number:

ADA160456

Title:

Spectroscopic Studies of Carbon Disulfide at High Pressure.

Descriptive Note:

Annual rept. 1 Apr 84-31 Mar 85,

Corporate Author:

LOS ALAMOS NATIONAL LAB NM

Personal Author(s):

Report Date:

1985-07-01

Pagination or Media Count:

11.0

Abstract:

Recent work on the transient absorption spectra induced by the dynamic shock-loading of carbon disulfide has shown a shock-induced shift of the UV absorption edge up to a pressure of 8.0-9.0 GPa followed by irreversible chemistry in which the CS2 becomes opaque. This document describes the spectroscopic link between shock-induced and the static high pressure experiments for CS2. We have used diamond-anvil cells and a combination of Raman, infrared, and UV-vis-NIR absorption spectroscopies to analyze the behavior of CS2 in the pressure range 0.2-10.0 GPa and have compared one of these spectroscopic observables, the UV-absorption edge shift prior to the onset of irreversible chemistry, with that measured in the shock experiment. The absorption-edge shift as a function of high pressure is reported for carbon disulfide for the range 1.8 to 8.3 GPa. The absorption edge shift compares favorably with the isothermal ramp-wave results of other workers. The absorption edge shift with temperature of the step-shock experiments of 220 C versus 350 C predicted on the basis of previous EOS calculations. The libron modes show strong dependence on crystal orientation at high pressure and an irreversible polymerization is noted at 8.3 GPa. The CS2 product shows some of the infrared characteristics of Bridgemans Black, which has been formed at 185 C and 5.5 GPa. The rather small pressure-induced shift of V sub 1 and V sub 3 is explained on the basis of compensating effects involving intermolecular repulsive versus electronic overlap between adjacent CS2s.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE