Likhtenshtein Gertz I.
Spin exchange, electron transfer, light energy conversion, donor acceptor pairs, albumin, fluorescent-nitroxide probe
Donor-acceptor structures that retain the charge-photoseparated state long enough for secondary chemestry reactions of these charges to occur are of interest for use of light energy. The aspect of fundamental importance for natural and artificial photosynthesis is the role of orbital effects in the mechanism of conversion of light energy into chemical energy in the primary charge photoseparation. The suggested approach is based on an analogy between superexchange in electron transfer (ET) and such electron exchange processes as triplet-triplet energy transfer (TTET) and spin-exchange (SE). This approach allowes to estimate values of the exchange integral (ISE) and rate constant of electron transfer (kET) using experimental data on long distance TTET and SE in bridged nitroxidebiradicals. Probing environment with dual fluorophore-nitroxidesupermolecules (FNS) in which fluorophore is tethered with nitroxide, a fluorescence quencher, opens unique opportunities to quantitative study orbital phenomena, molecular dynamics, micropolarity which affect intramolecular fluorescence quenching, electron transfer, photoreduction and light energy conversion. The estimated values of ISE andkETfor various systems were found to be in good agreement with corresponding experimental data. Suggested equations can be used for calculation of kET in unknown objects of interest.
Cite this paper
Likhtenshtein Gertz I.. (2017) Orbital Factors Affected on Electron Transfer and Light Energy Conversion in Proteins and Model Systems: A Connection Between Spin Exchange and Electron Transfer. International Journal of Biochemistry Research, 2, 1-9