RAMAN AND INFRRED SPECTRAL DATA ASSIGNMENTS, AND CALCULATED WAVE NUMBERS AND THERMODYNAMIC PROPERTIES FOR 1,1 DICHLOROFLUOROETHYLENE$^{\ast}$
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Date
1962
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Raman displacements $\Delta \sigma$ (in cycles/cm), semiquantiative relative intensities I, and quantitative depolarization rations $\rho$ for the liquid; and infrared wave numbers $\sigma$ and estimated intensities $I_{e}$ for both the gas and the liquid; have been obtained for $Cl_{2}C = CHF$ (1,1-dichlorofluoroethylene). The observed $\Delta \sigma(I)\rho$ values for the fundamentals are: $a^{\prime\prime}---206(33)P, 278(100)0.69^{\ast}$, $461(100)0.09, 660(87)0.09, 962(vw), 1138(12)0.35, 1291(16)0.37, 1654(43)0.11$, $3107(8)0.25: a^{\prime\prime}-284(100)^{\ast}, 444 (22)0.85, 801(16)0.79$ (P = polarized, $^{\ast} =$ polarization state uncertain because of the small separation of the two lines, v = very, w = weak). The observed $\sigma(I_{\nu})$ values for the fundamentals are: liquid---655(vvs), 958(vvs), 1137(vvs), 1288(vvs), 1648(vvs), 3107(vs), 799(vvs); gas---663(vs), 966(vvs), 1147(vvs), 1291(s), 1654(vvs), 3107(s), 797(vs) (v = very, s = strong). The probable values of $\sigma_{1}(\sigma_{g}) (\sigma_{g}---\sigma_{l})$ are: $a^{\prime}---3107(3107)0, 1651(1654)3, 1290(1291)1, 1138(1147)9, 960(966)6, 658(663)5, 461(464^{\ast}), 278(281^{\ast}), 206(209^{\ast}); a^{\prime\prime}---800(797) (---3), 444(447^{\ast}), 281(287^{\ast}) (l=$ liquid; g=gas; $^{\ast}$=estimated value = $\sigma_{l}$ plus the average observed value of $\sigma_{g} \sigma_{1}$, or $\sigma_{1}+3 c/cm$). To cheek the assignments, a normal coordinate analysis was made by the Wilson method, using a potential energy function of the Urey-Bradley type and an IBM 1620 electronic digital computer. The calculated $\sigma_{l}$ values are: $a^{\prime}---206, 278, 462, 659, 956, 1139, 1291, 1654, 3107; a^{\prime\prime}---284, 444, 801 c/cm$. The maximum and average deviations of these from the observed values are 0.4 and 0.1 per cent. respectively. The probable values of $\sigma_{g}$ were used to calculate the heat content, free energy, entropy, and heat capacity for 12 temperatures from 100 to $1000^{\circ}K$.
Description
$^{\ast}$Aided by the National Science Foundation. $^{\dagger}$ Present address: Automatic Electric Laboratories. Inc., Northlake, Illinois.
Author Institution: Department of Physics, Illinois Institute of Technology
Author Institution: Department of Physics, Illinois Institute of Technology