Ruthenium polypyridyl complexes that utilize azo-dyes to enhance absorption of visible photons

Abstract

Research in the field of dye sensitized solar cells has been growing rapidly. The
challenge in this field is to prepare molecules that absorb in the visible region. An azo
dye ligand based on l,0-phenanthroline, "phen-azo-phenol", was prepared and found to
absorb at 380 nm in MeOH. UV-Vis spectra of this ligand were recorded in different
solvents and in the presence of added acid or base and it appeared that the spectra were
shifted to longer wavelength (around 500 nm) in the presence of base and/or basic
solvents. This was attributed to deprotonation of the phenol portion of the ligand.
Three Ru (II) polypyridyl complexes based on phen-azo-phenol were prepared and
purified by size exclusion chromatography: [(dcbpy)2Run(phen-azo-phenol)]2
\
[(mcbpy)2Run(phen-azo-phenol)]2+ , and [(dmbpy)2Run(phen-azo-phenol)]2\ where
dcbpy = 4,4 '-dicarboxy-2,2 '-bipyridine, mcbpy = 4-methyl-4 '-carboxy-2,2 '-bipyridine,
and dmbpy = 4,4'-dimethyl-2,2'-bipyridine. The complexes were characterized by UVVis
and 1H-NMR. Cyclic voltammetry scans were obtained for the three complexes in
DMF and/or CH3CN using 0.1 M TBAH as the electrolyte.
ii

Date of Award	2012
Original language	American English
Awarding Institution	Eastern Illinois University
Supervisor	Mark E. McGuire (Supervisor)