Title

Vibrational characterization of a series of aromatic quinones.

Date of Award

1999

Degree Type

Thesis

Degree Name

M.Sc.

Department

Chemistry and Biochemistry

First Advisor

Aroca, R.

Keywords

Chemistry, Organic.

Rights

CC BY-NC-ND 4.0

Abstract

The vibrational characterization of a series of molecules: 1,4-anthracenedione, 5,14-pentacenedione, 6,15-hexacenedione, 8,13-benzo[a]naphthacenedione, 7-methyl-8,13-benzo[a]naphthacenedione has been carried out. The synthesis of these materials was carried out in the research laboratory of Dr. P. Dibble of the Department of Chemistry, University of Lethbridge, Lethbridge, Alberta, who provided to us a purified sample of each compound. The inelastic scattering was measured at 1064nm (FT-Raman) and the infrared absorption spectra were measured in the mid-infrared (300--3600 cm-1). The vibrational assignments of normal modes was assisted by semi-empirical quantum calculations with the AM1 and PM3 Hamiltonian. A high level ab initio computation for 5,14-pentacenedione is also reported. The thesis also contributes to the modern field of surface-enhanced vibrational spectroscopy (SEVS). Surface-enhanced Raman scattering (SERS) of vacuum evaporated quinone films and of single LB monolayers were obtained for some members of the series. For the first time, it has been observed that tin island films used in surface-enhanced infrared (SEIR) experiments give rise to an electromagnetic enhancement of the infrared absorption spectrum. The surface-enhancement of the infrared absorption by tin island films is shown for evaporated nanometric films of 5,14-pentacenedione (Q2). The SEIR enhancement was tuned by fabricating tin island films of varying mass thickness to achieve maximum enhancement. The film morphology was determined by transmission electron microscopy. Comparisons were made between the SEIR spectra on rough tin and on rough silver surfaces and the corresponding reflection-absorption infrared spectra (RAIRS) obtained for the same organic molecules on smooth reflecting surfaces of tin and silver.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .P75. Source: Masters Abstracts International, Volume: 43-05, page: 1733. Adviser: Ricardo Aroca. Thesis (M.Sc.)--University of Windsor (Canada), 1999.