Date of Award
Doctor of Philosophy
Gerald J. Small
The excited state structure, early time energy and electron transfer dynamics for bacterial photosynthetic reaction centers of Rhodoseudomonas viridis, Rhodobacter sphaeroides and green plant photosynthetic reaction center of Photosystem II (PS II) have been determined by hole burning spectroscopy. Transient hole burned spectra of the bacterial reaction centers reveal a special pair Franck-Condon marker mode progression with a superimposed zero phonon hole. Such progression is found to be absent in green plant Photosystem II which raises the question of structural similarities between the PS II and bacterial reaction centers. The excited state decay times are obtained for all systems and found to be consistent with time domain experiments. Similar temperature dependence of the decay kinetics have been observed for both bacterial and PS II reaction centers;Study of different preparations of reaction center of Photosystem II utilizing hole burning spectroscopy indicates that Triton X-100 detergent significantly affect the absorption and persistent hole burned spectra and disrupts the energy transfer from the accessory chlorophyll to the active pheophytin. The comparison between the bacterial reaction centers and Photosystem II has been presented and discussed in order to understand the difference in their early time dynamics and the excited state structure. A theoretical model has been developed based on the principle of linear electron-phonon coupling and inhomogeneous broadening. Our experimental results are found to be in good agreement with the theoretical calculations.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Tang, Deming, "Excited state structure, energy and electron transfer dynamics of photosynthetic reaction centers: a hole burning study " (1990). Retrospective Theses and Dissertations. 9414.