Nonequilibrium heating in LHCII complexes monitored by ultrafast absorbance transients.

摘要: Evidence of nonequilibrium local heating in transient spectra LHCII, the main light-harvesting complex plants, was studied by using various excitation intensities over a wide temperature range, from 10 K to room temperature. No obvious manifestation found at temperature, whereas K, effect is discernible when more than excitons per LHCII trimer pulse are generated. Under these conditions, major part energy converted into heat as result exciton-exciton annihilation. Initially, allocated on chlorophyll molecules, reaching hundreds degrees highest intensities, which correspond almost 100 generated single pulse. The decay characterized well two exponentials. initial phase cooling, most likely caused spreading protein, corresponds characteristic time constant approximately 20 ps. Later, cooling rate decelerates 200 ps and related transfer solvent.