Anion radicals of bacteriochlorophyll a and bacteriopheophytin a. electron spin resonance and electron nuclear double resonance studies

Journal Article · Wed Jun 08 04:00:00 EDT 1977 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00454a037· OSTI ID:7312651

Fajer, J; Forman, A; Davis, M S; Spaulding, L D; Brune, D C; Felton, R H

Chemical, electrochemical, and photochemical reductions of bacteriopheophytin a (BPh) and deuterated BPh yielded stable anion radicals which were characterized by electron spin resonance and electron-nuclear double resonance techniques. Radicals of the model bacteriochlorin compound, 5,10,15,20-tetraphenyl-2,3,12,13-tetrahydroporphyrin, selectively deuterated, were prepared to guide the interpretation of the BPh data and the experimental results compared with self-consistent field-molecular orbital calculations. ESR and ENDOR results for bacteriochlorophyll a (BChl) and deuterated BChl are also assigned with the aid of a model, zinc tetraphenyltetrahydroporphyrin, and molecular orbital calculations. These data thus help define the electronic profile of the BPh and BChl anions, the radical species presently postulated to result, within picoseconds, from the primary charge separation of bacterial photosynthesis.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 7312651
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 99:12; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHLOROPHYLL
ELECTRON SPIN RESONANCE
ENDOR
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
MAGNETIC RESONANCE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
RADICALS
REDUCTION
RESONANCE
SYNTHESIS