The Electronically Excited States of LH2 Complexes from Rhodopseudomonas acidophila Strain 10050 Studied by Time-Resolved Spectroscopy and Dynamic Monte Carlo Simulations. II. Homo-Arrays Of LH2 Complexes Reconstituted Into Phospholipid Model Membranes

Abstract

We performed time-resolved spectroscopy on homoarrays of LH2 complexes from the photosynthetic purple bacterium Rhodopseudomonas acidophila. Variations of the fluorescence transients were monitored as a function of the excitation fluence and the repetition rate of the excitation. These parameters are directly related to the excitation density within the array and to the number of LH2 complexes that still carry a triplet state prior to the next excitation. Comparison of the experimental observations with results from dynamic Monte Carlo simulations for a model cluster of LH2 complexes yields qualitative agreement without the need for any free parameter and reveals the mutual relationship between energy transfer and annihilation processes.