LIGHT-GENERATED NUCLEAR QUANTUM BEATS - A SIGNATURE OF PHOTOSYNTHESIS

Light-induced radical pairs in deuterated and deuterated plus N-15-sub stituted Synechococcus lividus cyanobacteria have been studied by tran sient EPR following pulsed laser excitation. Nuclear quantum beats are observed in the transverse electron magnetization at lower temperatur es. Model calculations for the time profiles, evaluated at the high-fi eld emissive maximum of the spectrum, indicate assignment of these coh erences to nitrogen nuclei in the primary donor. Thorough investigatio n of the nuclear modulation patterns can provide detailed information on the electronic structure of the primary donor, providing insight in to the mechanism of the primary events of plant photosynthesis.