Open AccessNuclear coherences in photosynthetic reaction centers following light excitation
Author(s) -
Stefan Weber,
J. R. Norris,
T. Berthold,
Ernst Ohmes,
G. Kothe,
Marion C. Thurnauer
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/515524
Subject(s) - deuterium , zeeman effect , chemistry , nuclear magnetic resonance , atomic physics , photosynthetic reaction centre , excitation , photosystem ii , resonance (particle physics) , photosynthesis , physics , magnetic field , biochemistry , quantum mechanics
Transient electron paramagnetic resonance is used to study the secondary radical pair in plant photosystem I. Nuclear coherences are observed in the transverse magnetization at lower temperatures following light excitation. Comparative studies of deuterated and deuterated {sup 15}N-substituted cyanobacteria S. lividus indicate assignment of these coherences to nitrogen nuclei in the primary donor and deuterons in the secondary acceptor. The modulation amplitude of a deuteron matrix line, as a function of the microwave power, reveals a distinct resonance behavior. The maximum amplitude is obtained when the Rabi frequency equals the nuclear Zeeman frequency