HOLE-BURNING SPECTROSCOPY OF PHOTOSYNTHETICALLY ACTIVE PIGMENTS OF GREEN SULFUR PHOTOSYNTHETIC BACTERIA

Spectral hole burning al low temperatures was used to study bacterioch lorophylls (BChl) e and d in natural chlorosomal structures as well as in artificially prepared monomeric and aggregated forms. Low-temperat ure (4.2 K) absorption and luminescence spectra were analysed to estim ate spectral positions of different BChls' aggregated states. Excited state lifetimes for monomeric (similar to 30 ns) and chlorosomal (simi lar to 1-2 ps) BChl's were obtained from zero-phonon hole analysis. Hu ang-Rhys factor reflecting electron-phonon coupling was estimated for monomeric (S similar to 1), lower-state aggregated (S vary from S simi lar to 0.7 to S similar to 3 depending on spectral position) and oligo meric (chlorosomal) state (S similar to 5) BChl e.