Date of Award

1983

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

Keywords

Chemistry, Physical.

Rights

CC BY-NC-ND 4.0

Abstract

The XPS spectra of perfluoromethylgermanes, (CF(,3))(,n)GeX(,4-n): n = 1(--->)4; X=H,F,Cl,Br,I,CH(,3), were studied in order to determine core-level binding energies of all atoms in these molecules. The inductive effect of the CF(,3) group was determined from the chemical shifts to be close to those of bromine and chlorine atoms. The partial charges calculated using the EESOP method correlate well with the binding energies and lend support to the conclusion that the effective electronegativities of the CF(,3) group, chlorine, and bromine are fairly similar in these compounds. The He(I) and He(II) spectra, recorded within the region 8 to 25 eV, were used to study the valence level orbitals in the molecules of the series: Me(,n)GeBr(,4-n); n = 1-3, Me(,2)GeHX, MeGeH(,2)X, MeGeHX(,2), X=Cl,Br, and (CF(,3))(,n)GeX(,4-n); n = 1-4; X=H,F,Cl,Br,CH(,3). The spectral assignments were made on the basis of semi-empirical CNDO/2 calculations, band shapes, relative intensity changes between He(I) and He(II) spectra, and comparisons with the spectra of related molecules. The changes in energy levels within the series showed trends which were rationalized in terms of inductive effects and the changing character of molecular orbitals. These data from photoelectron spectra were compared with the data available from vibrational spectroscopy, force constant calculations, and molecular structure determinations. The Ge-C bonds were found to be relatively weakened in all of the perfluoromethylgermanes with respect to their methyl analogues. The best rationalization of this seems to be that based on inductive effects.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1983 .G679. Source: Dissertation Abstracts International, Volume: 44-03, Section: B, page: 0810. Thesis (Ph.D.)--University of Windsor (Canada), 1983.

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