Citation | Graham Fleming is distinguished for his outstanding contributions to the application of ultrafast spectroscopy to problems in chemistry and biology and to our understanding of the influence of solvent on molecular motion and on reaction dynamics. He clearly separated solvent properties and reactant molecule properties in the determination of the observed rate and succeeded in finding the Kramers turnover in the rate. He discovered transient birefringence in polarization spectroscopy and carried out a general analysis of level kinetics and molecular motion. He constructed an amplified femtosecond laser system which generates 100 fs white light and developed the technique of single photon counting to impove time resolution by two orders of magnitude. In application of his work to problems in biological systems, he made the first correct determination of fluorescence decay kinetics of chloroplasts. Using mutants to simplify the light harvesting system he showed how to divide the observed fluorescence kinetics between photosystem I and photosystem II. Comparing his results with models he showed that energy transfer takes place on a few hundred femtosecond time scale and that several (PSI) or many (PSII) visits take place before electron transfer occurs. His publications include 'the' definitive monograph on Ultrafast Spectroscopy. |