dc.creator Decius, J. C. en_US dc.creator Turrell, George C. en_US dc.creator Jones, W. D. en_US dc.date.accessioned 2006-06-15T12:46:04Z dc.date.available 2006-06-15T12:46:04Z dc.date.issued 1955 en_US dc.identifier 1955-N-6 en_US dc.identifier.uri http://hdl.handle.net/1811/7429 dc.description Author Institution: Department of Chemistry, Oregon State College en_US dc.description.abstract The 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.extent 138323 bytes dc.format.mimetype image/jpeg dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title VIBRATIONAL RELAXATION TIMES BY THE SPECTROPHONE $METHOD^{*}$ en_US dc.type article en_US
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