Professor Rienk van Grondelle
Department of Biophysics and Physics of Complex Systems
Vrije Universiteit Amsterdam
Amsterdam, The Netherlands

Tuesday, February 13, 2001
11:00 am (CT)
3269 Beckman Institute

Abstract

In photosynthetic bacteria solar photons are absorbed by a pigments (carotenoids, bacteriochlorophyll) bound to light-harvesting proteins LH1 and LH2 and transferred to a photosynthetic reaction center (RC), where the energy is used to drive a charge separation. Both LH1 and LH2 are composed of a tightly coupled ring of bacteriochlorophylls and energy transfer in these rings occurs on a timescale of a few hundred femtoseconds. One of the major questions that we have tried to answer concerns the nature of the excited state in LH1 and LH2: localized vs. delocalized. In this talk I will describe femtosecond laser experiments that measure the excited state dynamics in these systems and I will discuss their interpretation in terms of a disordered exciton model.