Particulate models of photosynthesis

Technical Report · Sat Jun 01 04:00:00 EDT 1991

OSTI ID:5425306

Seely, G R

A chlorophyll model system for photochemical energy conversion has been developed. When irradiated with red light, reducing equivalents are transferred from hydrazobenzene in the hydrocarbon particles to 5,5{prime}-dithiobis (2-nitrobenzoate) in the aqueous phase. The primary photochemical step is transfer of an electron from singlet excited chlorophyll to a primary oxidant ligated to it, or to another chlorophyll to a primary oxidant ligated to it, or to another chlorophyll molecule, depending on the composition of the system. Evidence for the mode of operation derives from analysis of kinetics and quantum yields of reaction, and of fluorescence spectra, quantum yields and lifetimes. It was found that chlorophyll associates strongly with micelles of N-dodecylpyridinium iodide in toluene, its hydrate is maintained in a dispersed state by dodecylpyridinium alkanoates, and that it reacts with 2,2{prime}-dithiobis(5-nitropyridine) by photoaddition of a nitropyridylthiyl group. Procedures for correcting fluorescence spectra and quantum yields in highly scattering media were worked out and applied to the characterization of the model system. 29 refs., 2 figs.

• Research Organization: Arizona State Univ., Tempe, AZ (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-86ER13620
• OSTI ID: 5425306
• Report Number(s): DOE/ER/13620-4; ON: DE91016842
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
BIOMIMETIC PROCESSES
CARBOXYLIC ACIDS
CATALYSIS
CHEMICAL REACTIONS
CHEMISTRY
CHLOROPHYLL
DOCUMENT TYPES
EFFICIENCY
ELECTRON TRANSFER
EMISSION SPECTROSCOPY
FLUORESCENCE SPECTROSCOPY
FUNCTIONAL MODELS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HETEROGENEOUS CATALYSIS
KINETICS
LIFETIME
MICELLAR SYSTEMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOSYNTHESIS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROGRESS REPORT
PROTEINS
QUANTUM EFFICIENCY
REACTION KINETICS
REDOX REACTIONS
RESEARCH PROGRAMS
SPECTROSCOPY
SYNTHESIS