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Date of Award


Degree Name

Doctor of Philosophy




High resolution (0.14 (ANGSTROM) FWHM) photoionization efficiency (PIE) measurements of HgCl(,2)('+), HgBr(,2)('+), and HgI(,2)('+) have been obtained by the supersonic molecular beam method. This study has yielded more precise values of the ionization energies (IEs) of the ('2)(PI)(,3/2g), ('2)(PI)(,1/2g), and ('2)D(,(+OR-)5/2) states of HgX(,2)('+) (X = Cl, Br, and I) to within (+OR-) 3 meV. Comparison of Rydberg structure observed in the PIE curves for HgX(,2)('+) by these studies with those resolved in the PIE curve of Hg('+) from Hg shows these structures can be assigned to the transitions; (5d)('10)(sigma)(,g)('2)(sigma)(,u)('2)(pi)(,u)('4)(pi)(,g)('4) (--->) (5d)('9)(sigma)(,g)('2)(sigma)(,u)('2)(pi)(,u)('4)(pi)(,g)('4) ('2)D(,(+OR-)5/2) np;(5d)('10)(sigma)(,g)('2)(sigma)(,u)('4)(pi)(,u)('4)(pi)(,g) (--->) (5d)('9)(sigma)(,g)('2)(sigma)(,u)('2)(pi)(,u)('4)(pi)(,g)('4) ('2)D(,(+OR-)3/2,(+OR-)1/2) np;n (GREATERTHEQ) 6, which are mainly associated with the mercury atom in HgX(,2). Lower resolution (1.4 (ANGSTROM) FWHM) studies of the HgX(,2) fragment ions have been undertaken and values of the binding energies of HgX('+) and HgX have been calculated from the measured appearance energies (AEs) of HgX('+) and X('+). In addition, PIE studies of the CO(,2), N(,2)O, CO, N(,2), NO, and O(,2) dimers and clusters have been performed, yielding the IEs of (CO(,2))(,n=2-4), (N(,2)O)(,2), (CO)(,n=2,3), (N(,2))(,n=2,3), and (NO)(,n=2-6), and the AEs of N(,2)O(,3)('+) from (N(,2)O)(,2), O(,3)('+) from (O(,2))(,2), O(,5)('+) from (O(,2))(,3), and O(,7)('+) from (O(,2))(,4). Analysis of the PIE curves of (CO(,2))(,2)('+) and (N(,2)O)(,2)('+) indicates that electronic predissociation may be an important dissociation mechanism for the CO(,2(n))('*)(.)CO(,2) and N(,2)O('*)(,(n))(.)N(,2)O Rydberg dimers. From the IEs of (NO)(,n), n=1-6, solvation energies of NO('+) by one to five NO molecules have been determined. By analysis of the PIE spectra for O(,3)('+), O(,5)('+), and O(,7)('+), and by comparing their relative intensities, insights concerning the internal energy effects on the ion-molecule half reactions;(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI);have been obtained;*USDOE Report IS-T-1033. This work was performed under Contract W-7405-Eng-82 with the U.S. Department of Energy.



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Steven Howard Linn



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195 pages