Simulations of the Two-Dimensional Electronic Spectroscopy of the Photosystem II Reaction Center
| Autor: | Charles F. Yocum, K. L. M. Lewis, Jennifer P. Ogilvie, Franklin D. Fuller, Jeffrey Myers, Shaul Mukamel, Darius Abramavicius |
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| Rok vydání: | 2012 |
| Předmět: |
Models
Molecular Photosynthetic reaction centre High energy Photosystem II Protein Conformation Chemistry Spectrum Analysis Diagonal Photosystem II Protein Complex Electron spectroscopy Molecular physics Article Spectral line symbols.namesake Energy Transfer Computational chemistry symbols Computer Simulation Physical and Theoretical Chemistry Excited state absorption Hamiltonian (quantum mechanics) |
| Zdroj: | The Journal of Physical Chemistry A. 117:34-41 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp3081707 |
| Popis: | We report simulations of the two-dimensional electronic spectroscopy of the Q(y) band of the D1-D2-Cyt b559 photosystem II reaction center at 77 K. We base the simulations on an existing Hamiltonian that was derived by simultaneous fitting to a wide range of linear spectroscopic measurements and described within modified Redfield theory. The model obtains reasonable agreement with most aspects of the two-dimensional spectra, including the overall peak shapes and excited state absorption features. It does not reproduce the rapid equilibration from high energy to low energy excitonic states evident by a strong cross-peak below the diagonal. We explore modifications to the model to incorporate new structural data and improve agreement with the two-dimensional spectra. We find that strengthening the system-bath coupling and lowering the degree of disorder significantly improves agreement with the cross-peak feature, while lessening agreement with the relative diagonal/antidiagonal width of the 2D spectra. We conclude that two-dimensional electronic spectroscopy provides a sensitive test of excitonic models of the photosystem II reaction center and discuss avenues for further refinement of such models. |
| Databáze: | OpenAIRE |
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