Surface-enhanced vibrational spectroscopy of diphenyl sulfide and diphenyl disulfide on films and colloids, and the single-molecule detection of perylene dye on silver and gold colloids.

摘要

In this work, colloidal particles of gold and silver are used as enhancing substrates to study behavior of organic sulfides and a perylene derivative butylimido, butyleneamine perylene (nBu-PTCDA-(CH2) 4-NH2) adsorbed on metal particles using surface-enhanced resonance Raman scattering (SERRS) or SERS. In addition, the SERS spectra of the adsorbed species formed by diphenyl disulfide and diphenyl sulfide (DPDS, DPS) on evaporated silver and gold island thin films were obtained. The SERS vibrational spectra of both DPDS and DPS are discussed and the vibrational assignments of the fundamental modes were aided with an ab-initio calculations using Density Functional Theory (DFT) at B3LYP at 6-31G (d) level of theory. The vibrational assignment, breakage or cleavage of the S-S and C-S bonds on metallic nanoparticles is discussed. In particular, the review of the observation and assignment of the Ag-S stretching vibration in the range of 150--250 cm-1 is provided. Three laser lines (514 nm, 633 nm and 780 nm) were used in this work to study the degree of photo dissociation induced by different energies of the incident beam. (Abstract shortened by UMI.)Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses u26 Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .T65. Source: Masters Abstracts International, Volume: 42-02, page: 0590. Adviser: R. Aroca. Thesis (M.Sc.)--University of Windsor (Canada), 2003.