Premium
Hydrogen Raman linewidths in supercritical water and carbon dioxide
Author(s) -
Rice Steven F.,
Wickham Jessica J.
Publication year - 2000
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/1097-4555(200007)31:7<619::aid-jrs586>3.0.co;2-r
Subject(s) - dephasing , chemistry , raman spectroscopy , carbon dioxide , supercritical carbon dioxide , intermolecular force , supercritical fluid , relaxation (psychology) , compounds of carbon , hydrogen , atomic physics , molecule , condensed matter physics , optics , physics , organic chemistry , chemical reaction , psychology , social psychology
H 2 Raman linewidths provide a probe of intermolecular potentials and have been examined in the past to explore collisional dynamic characteristics in high‐pressure gas mixtures. We report the measurement of H 2 Δ v = 1 Q‐branch lines, Q(0)– Q(5), and pure rotational lines, S(0)– S(5), in supercritical water and high‐pressure carbon dioxide at 450 ° C and pressures up to 50 MPa. The data are analyzed by separating the contributions to the line broadening due to different collisional processes characterized as vibrational dephasing, inelastic J ‐changing and rotational reorientation. The linear broadening coefficients for these different processes are determined. Both water and carbon dioxide are shown to be much more effective at disturbing H 2 rotation than other less polar molecules that have been examined in the past. Water is shown to be much more effective at causing inelastic J ‐changing relaxation than carbon dioxide. Elastic rotational reorientation rates are comparable for both colliders. Copyright © 2000 John Wiley & Sons, Ltd.