Open AccessFinal Technical Report for USDOE Grant No. DE-FG02-96ER14675 Supermolecular Photosynthetic Arrays: Construction, Characterization, Exploration and Utilization
Author(s) -
James R. Norris
Publication year - 2009
Language(s) - English
Resource type - Reports
DOI - 10.2172/1097273
Subject(s) - electron paramagnetic resonance , rhodobacter sphaeroides , bacteriochlorophyll , electron transfer , chemistry , ferricyanide , photochemistry , radical , molecular wire , photosynthesis , nuclear magnetic resonance , molecule , physics , inorganic chemistry , organic chemistry , biochemistry
Biological processes provide paradigms for the development of solar energy devices of practical utility. In nature, the light harvesting -complexes (LHCs) are not chemically active. However, with unnatural chemical oxidation by potassium ferricyanide, cation free radicals of bacteriochlorophyll (BChl) can be formed in the light harvesting complex 1 (LH1) of Rhodobacter sphaeroides. Based on EPR studies, the site of the BChl{sup +} cations move rather freely about the LH1 complex as in a molecular wire. These molecular wires function in the frozen, solid state. This work seeks to understand better how nature controls electron transfer in some of its molecular wires. To investigate the nature of electron-hole transfer we have e.onducted both electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) experiments on oxidized LH1 complexes. Progress has been achieved in two main areas: EPR studies of the role of ferricyanide in the molecular wire nature of oxidized LH1; and ENDOR studies of oxidized LH1 at 80K