Electrochemical and optical studies of model photosynthetic systems

Technical Report · Wed Jan 15 00:00:00 EST 1992

DOI:https://doi.org/10.2172/5698105· OSTI ID:5698105

The objective of this research is to obtain a better understanding of the relationship between the structural organization of photosynthetic pigments and their spectroscopic and electrochemical properties. Defined model systems were studied first. These included the least ordered (solutions) through the most highly ordered (Langmuir-Blodgett (LB) monolayers and self-assembled monolayers) systems containing BChl, BPheo, and UQ. Molecules other than the photosynthetic pigments and quinones were also examined, including chromophores (i.e. surface active cyanine dyes and phtahlocyanines) an redox active compounds (methyl viologen (MV) and surfactant ferrocenes), in order to develop the techniques needed to study the photosynthetic components. Because the chlorophylls are photosensitive and labile, it was easier first to develop procedures using stable species. Three different techniques were used to characterize these model systems. These included electrochemical techniques for determining the standard oxidation and reduction potentials of the photosynthetic components as well as methods for determining the heterogeneous electron transfer rate constants for BChl and BPheo at metal electrodes (Pt and Au). Resonance Raman (RR) and surface enhanced resonance Raman (SERR) spectroscopy were used to determine the spectra of the photosynthetic pigments and model compounds. SERRS was also used to study several types of photosynthetic preparations.

• Research Organization: Nebraska Univ., Lincoln, NE (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-84ER13261
• OSTI ID: 5698105
• Report Number(s): DOE/ER/13261-6; ON: DE92010657
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
PHOTOSYNTHESIS
PIGMENTS
RAMAN SPECTROSCOPY
CHLOROPHYLL
DYES
PROGRESS REPORT
REDOX REACTIONS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DOCUMENT TYPES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LASER SPECTROSCOPY
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYTOCHROMES
PORPHYRINS
PROTEINS
SPECTROSCOPY
SYNTHESIS
400500* - Photochemistry
400102 - Chemical & Spectral Procedures