Record Details
I. Infrared spectra of solid solutions in alkali halide crystals [and] Method for obtaining minimal kinematically complete sets of internal coordinates
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | I. Infrared spectra of solid solutions in alkali halide crystals [and] Method for obtaining minimal kinematically complete sets of internal coordinates |
| Names |
Conant, Donald Robertson
(creator) Decius, J. C. (advisor) |
| Date Issued | 1963-05-15 (iso8601) |
| Note | Graduation date: 1963 |
| Abstract | A study was made of the infrared absorption spectrum for cyanate ion in KCl and KBr host lattices containing small amounts of calcium or barium ion. Both pellets and single crystals were scanned during the course of this study. The spectra of the barium or calcium doped crystals contained many new peaks which do not appear in the spectra of cyanate doped KC1 or KBr crystals having no divalent cations present. The proposal was made that new absorptions arise from calcium ion-cyanate ion pairs in which the strong field of the calcium ion reorients the longitudinal axis of the cyanate ion along the cell edge from the more usual body diagonal orientation of unpaired cyanate ion. This configuration increases the repulsive forces acting on the end atoms of cyanate causing an increase in the vibrational frequencies. The observed frequency shifts in the spectra for crystals with barium ion present indicated, however, that cyanate ion remains in the body diagonal orientation when barium ion is a near neighbor. An additional effect examined was the change of charge distribution within the cyanate ion caused by the presence of calcium or barium ions as near neighbors. The magnitudes of force constant changes, caused by the action of the surrounding lattice upon the cyanate ion and caused by the shift in the cyanate ion charge distribution, were estimated from theoretical calculations. A method for obtaining a minimal kinematically complete set of internal coordinates was proposed. According to this method, once such a set is obtained for a molecule, any additional internal coordinates added to the set to obtain symmetrical completeness are declared redundant, thus facilitating the removal of redundancies from the symmetry G matrix after factorization of the secular equation. A procedure was given for choosing the internal coordinates used in the kinematically complete set which leads to a reduction in redundancies when the set is expanded to obtain symmetric completeness. Several examples illustrating this method were given. |
| Genre | Thesis/Dissertation |
| Topic | Infrared spectra |
| Identifier | http://hdl.handle.net/1957/48931 |
