It has been observed using absorption spectra that some organic dyes self-assemble within a solution to form aggregates. The purpose of this research was to study the pi interactions through Davydov shift observation in a series of merocyanine dyes. 1-methyl-4-[(oxocyclehexadiene)ethylidene]-1,4-dihydropyridine (MOED) and five of its variants were synthesized for this study. A long carbon tail was added to MOED in order to achieve organic solubility for use in high concentration studies. In addition, two MOED molecules were linked by different flexible carbon chains (3-carbon, 4-carbon chains) to mimic high concentrations (BisMOED). In order to mimic dimerization, two 4-carbon chains linked two Bis4MOED molecules. All of these dyes were to be used in concentration studies to determine their pi interactions through Davydov shifts in their absorbencies, as monomers become dimers, trimers, tetramers, etc. Additionally, a pH study, comparison of absorbencies in basic and non-basic solutions, was conducted on MOED and Bis3MOED. This study could allow insights into the solvatochromic behavior of the dye. This study is significant to the understanding of intermolecular forces within a nonlinear optical dye.
Tim Strovas, ’00 Dodge City, KS
Majors: Biochemistry and Molecular Biology, Mathematics
Betsy Campbell, ’99 Jacksonville, IL
Sponsor: Charles Liberko