Show simple item record

dc.creatorDecius, J. C.en_US
dc.creatorTurrell, George C.en_US
dc.creatorJones, W. D.en_US
dc.descriptionAuthor Institution: Department of Chemistry, Oregon State Collegeen_US
dc.description.abstractThe infrared spectrophone, a device similar to certain commercial gas $analyzers^{**}$ dependent upon infrared absorption, was first employed by $Slobodskaya^{1}$ for the determination of vibrational relaxation times in $CO_{2}$. Slobodskaya’s results indicated: (i) relaxation times approximately 200-fold smaller for collisions of two $CO_{2}$ molecules than for collisions of $CO_{2}$ with air molecules, (ii) relaxation times of the same order of magnitude for the 668 and $2350 cm^{-1}$ modes. Neither of these results is in agreement with the theory of Schwartz, Slawsky, and $Herzfeld^{2}$ which predicts relaxation times of approximately $10^{-5}$ sec and $10^{-4}$ sec for the 668 and 2350 modes for $CO_{2}-CO_{2}$ collisions, and somewhat shorter times for $CO_{2}$-air collisions. These discrepancies may be due to: (i) relaxation of the $2350 cm^{-1}$ mode by a complex process, (ii) the presence of impurities of low molecular weight, (iii) breakdown of a simple connection between the observed delay time and the true vibrational relaxation time. Experiments have been performed indicating that the effective relaxation times for the high-frequency modes in $CO_{2}, N_{2}O$, and CO are indeed much shorter than indicated by the $theory^{2}$ for a simple process. In the case of carbon monoxide the observed order of the relaxation time ($10^{-4}$ sec) is, however, explained by the presence of about 1% $H_{2}$ impurity. The theory of the relation between phase shifts in the spectrophone and the relaxation time will be discussed briefly; it will be shown that under the normal experimental conditions the relation is not always simple.en_US
dc.format.extent138323 bytes
dc.publisherOhio State Universityen_US

Files in this item


Items in Knowledge Bank are protected by copyright, with all rights reserved, unless otherwise indicated.

This item appears in the following Collection(s)

Show simple item record