I. Infrared Spectra of Monomeric and Polymeric HCL and DCL in Solid Krypton and Xenon. II. Infrared Spectra of NH₂ and ND₂ Produced by Photolysis and X-Radiolysis of Ammonia in Solid Krypton. III. Ultraviolet Spectra of CH Produced by X-Radiolysis of Methane in Solid Argon

Citation

Keyser, Leon Frank (1965) I. Infrared Spectra of Monomeric and Polymeric HCL and DCL in Solid Krypton and Xenon. II. Infrared Spectra of NH₂ and ND₂ Produced by Photolysis and X-Radiolysis of Ammonia in Solid Krypton. III. Ultraviolet Spectra of CH Produced by X-Radiolysis of Methane in Solid Argon. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/735D-4Q28. https://resolver.caltech.edu/CaltechETD:etd-04142003-163123

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. PART I The construction and operation of a low temperature infrared cell is described; the cell is capable of maintaining temperatures between 7 and 50[degrees]K while in the light beam of a Beckman IR-7 spectrophotometer. Infrared spectra of HC1 and DC1 at 0.2 to 2% concentrations in solid krypton and xenon are reported. Fine structure in the region of the (1-0) vibrational transitions of HC1 and DCl is assigned to monomeric and polymeric species of HC1 and DC1. The monomer lines are assigned to vibration-rotation transitions of HC1 and DCl. In krypton the R(0) transition of HC1 occurs at 2872.7, R(1) at 2887, P(1) at 2837.4, and Q(0) at 2852.8 cm[superscript-1]. The R(0) transition of DC1 in krypton occurs at 2078.9, R(1) at 2089, P(1) at 2058, and Q(0) at 2067.5 cm[superscript-1]. In xenon the R(0) transition of HC1 occurs at 2858.2, R(1) at 2872, P(1) at 2825.5, and Q(0) at 2837.8 cm[superscript-1]. The R(0) transition of DC1 in xenon occurs at 2069, R(1) at 2075, P(1) at 2047 and Q(0) at 2058 cm[superscript -1]. Besides a J-independent band origin shift with respect to the gas phase frequencies of -31 cm[superscript-1] in krypton and -44 cm[superscript -1] in xenon, the rotational levels of HCl exhibit J-dependent perturbations of 5 to 10 cm[superscript -1]. The band origin shift of DC1 is -23 cm[superscript-1] in krypton and -33 cm[superscript-1] in xenon; the J-dependent perturbations of the DC1 rotational levels lie between 1 and 3 cm[superscript -1]. Hindered rotation and libration of HC1 and DCl in the rare gas crystals are not suitable descriptions of the J-dependent perturbations. A model based on the interaction of the rotational motion with the localized translational motion of HC1 and DCl at substitutional sites in the rare gas crystals is used to interpret the J-dependent perturbations. The translational frequencies of HC1 and DC1 and the strength of the translation-rotation interaction are treated as parameters. The values of the translational frequencies which give the best fit to the observed rotational spacings are 36 cm[superscript -1] in xenon, 57 cm[superscript -1] in krypton, and 31 cm[superscript-1] in argon. The strength of the translation-rotation interaction as measured by the distance between the center of mass and the center of electrical symmetry in the molecule is 0.13 [...] for HCl and 0.096 [...] for DC1. A mechanism for the induction of a Q branch in the vibration-rotation spectra of monomeric HC1 and DCl in the solid rare gases is discussed. The vibrational spectra of polymeric HC1 and DC1 are discussed in terms of dimeric and trimeric aggregates. PART II The photolysis of ammonia in solid krypton with 1849 [...] light or with X radiation gives rise to new absorption maxima at 1521, 1114, 1289, and 1280 cm[superscript -1] in the infrared. The line at 1521 cm[superscript -1] is assigned to the previously unobserved bending mode of the NHZ radical. Experiments with isotopic ammonia show that the bending mode of NDZ occurs at 1106 cm[superscript -1] in solid krypton. PART III The CH radical is produced by X-radiolysis of methane in solid argon and krypton. The radiolysis mechanism is discussed in terms of energy transfer from the rare gas lattice to methane.

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