Particulate models of photosynthesis. Final technical report

Technical Report · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6363835

Seely, G R

The work during the past year or so has been concentrated in two areas. First, a number of amphiphiles have been synthesized that not only ligate chlorophyll, but also contain oxidizing moieties which could accept an electron from photoexcited chlorophyll. The absorption and fluorescence spectra of chlorophyll, adsorbed to particles together with these amphiphiles, do indeed indicate that they ligate chlorophyll, and fluorescence is quenched as it should be if an electron is transferred. Second, particles containing chlorophyll and these oxidizing amphiphiles have been employed in photochemical reactions involving a number of oxidants and reductants. It was found that in order to produce permanent charge separation, i.e., long-lived photo products, it was necessary to include a secondary acceptor and a reductant in addition to the oxidizing amphiphile which acted as a primary acceptor. Our major, and much-sought-after conclusion from this year's work is that the same particle, in which chlorophyll fluorescence is quenched apparently by electron transfer, are capable of sustaining an active photochemistry, which by implication should be driven by energy not wasted in fluorescence or non-radiative internal conversion. Some details of this work are presented below. We also report further on the interpretation of low-temperature fluorescence spectra, and on the investigation of dimyristylindigo as a photochemical probe for heterogeneous systems. 7 figures.

• Research Organization: Battelle-Charles F. Kettering Research Lab., Yellow Springs, OH (USA)
• DOE Contract Number: AC02-82ER12039
• OSTI ID: 6363835
• Report Number(s): DOE/ER/12039-6; ON: DE85005969
• 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
ABSORPTION
ABSORPTION SPECTRA
AMIDES
CARBONYLS
CARBOXYLIC ACIDS
CHEMICAL PREPARATION
CHEMISTRY
CHLOROPHYLL
ELECTRON TRANSFER
ENERGY LEVELS
EXCITED STATES
FLUORESCENCE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LIGANDS
LUMINESCENCE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARTICLES
PHOTOCHEMISTRY
PHYTOCHROMES
PIGMENTS
PORPHYRINS
SPECTRA
SYNTHESIS