Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin.
Femtosecond time-resolved stimulated Raman spectroscopy (FSRS) is used to examine the photoisomerization dynamics in the excited state of bacteriorhodopsin. Near-IR stimulated emission is observed in the FSRS probe window that decays with a 400-600-fs time constant. Additionally, dispersive vibratio...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2005
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| _version_ | 1797089701245485056 |
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| author | McCamant, D Kukura, P Mathies, R |
| author_facet | McCamant, D Kukura, P Mathies, R |
| author_sort | McCamant, D |
| collection | OXFORD |
| description | Femtosecond time-resolved stimulated Raman spectroscopy (FSRS) is used to examine the photoisomerization dynamics in the excited state of bacteriorhodopsin. Near-IR stimulated emission is observed in the FSRS probe window that decays with a 400-600-fs time constant. Additionally, dispersive vibrational lines appear at the locations of the ground-state vibrational frequencies and decay with a 260-fs time constant. The dispersive line shapes are caused by a nonlinear effect we term Raman initiated by nonlinear emission (RINE) that generates vibrational coherence on the ground-state surface. Theoretical expressions for the RINE line shapes are developed and used to fit the spectral and temporal evolution of the spectra. The rapid 260-fs decay of the RINE peak intensity, compared to the slower evolution of the stimulated emission, indicates that the excited-state population moves in approximately 260 fs to a region on the potential energy surface where the RINE signal is attenuated. This loss of RINE signal is best explained by structural evolution of the excited-state population along multiple low-frequency modes that carry the molecule out of the harmonic photochemically inactive Franck-Condon region and into the photochemically active geometry. |
| first_indexed | 2024-03-07T03:07:51Z |
| format | Journal article |
| id | oxford-uuid:b32af15c-7912-46c4-91be-19a8ddd018a2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T03:07:51Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:b32af15c-7912-46c4-91be-19a8ddd018a22022-03-27T04:17:07ZFemtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b32af15c-7912-46c4-91be-19a8ddd018a2EnglishSymplectic Elements at Oxford2005McCamant, DKukura, PMathies, RFemtosecond time-resolved stimulated Raman spectroscopy (FSRS) is used to examine the photoisomerization dynamics in the excited state of bacteriorhodopsin. Near-IR stimulated emission is observed in the FSRS probe window that decays with a 400-600-fs time constant. Additionally, dispersive vibrational lines appear at the locations of the ground-state vibrational frequencies and decay with a 260-fs time constant. The dispersive line shapes are caused by a nonlinear effect we term Raman initiated by nonlinear emission (RINE) that generates vibrational coherence on the ground-state surface. Theoretical expressions for the RINE line shapes are developed and used to fit the spectral and temporal evolution of the spectra. The rapid 260-fs decay of the RINE peak intensity, compared to the slower evolution of the stimulated emission, indicates that the excited-state population moves in approximately 260 fs to a region on the potential energy surface where the RINE signal is attenuated. This loss of RINE signal is best explained by structural evolution of the excited-state population along multiple low-frequency modes that carry the molecule out of the harmonic photochemically inactive Franck-Condon region and into the photochemically active geometry. |
| spellingShingle | McCamant, D Kukura, P Mathies, R Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin. |
| title | Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin. |
| title_full | Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin. |
| title_fullStr | Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin. |
| title_full_unstemmed | Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin. |
| title_short | Femtosecond stimulated Raman study of excited-state evolution in bacteriorhodopsin. |
| title_sort | femtosecond stimulated raman study of excited state evolution in bacteriorhodopsin |
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