Excited-State Vibrational Coherence and Anisotropy Decay in the BacteriochlorophyllaDimer Protein B820

Autor:	Bradley J. Homoelle, Maurice D. Edington, William M. Diffey, Warren F. Beck
Rok vydání:	1998
Předmět:	Physics Absorption spectroscopy Dimer Photobleaching Surfaces Coatings and Films chemistry.chemical_compound chemistry Excited state Materials Chemistry Physical and Theoretical Chemistry Atomic physics Ground state Anisotropy Excitation Coherence (physics)
Zdroj:	The Journal of Physical Chemistry B. 102:2776-2786
ISSN:	1520-5207 1520-6106
Popis:	We have employed dynamic absorption spectroscopy to monitor coherent wave packet dynamics and anisotropy decays following impulsive excitation of the B820 subunit of the LH1 light-harvesting complex, which was isolated from Rhodospirillum rubrum G9. When the lower exciton-state transition of the bacteriochlorophyll a dimer is pumped, the time-resolved pump−probe spectrum exhibits contributions from a fully Stokes shifted stimulated-emission spectrum and a nonstationary vibrational character within 40 fs of excitation. Coherent wave packet motion in both the ground state and the excited state is observed via modulations of single-wavelength transients. The photobleaching portion of the spectrum exhibits strong components only at low frequencies, 20−60 and 180 cm-1, and a weaker component is observed at 400 cm-1. The stimulated-emission portion of the spectrum exhibits weak modulation components at 20−60 and 180 cm-1, but strong components are observed at fairly high frequencies: 360, 400, 470, 600, and 73...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::412e903f1152cf779b013e463811b394 https://doi.org/10.1021/jp9723022 Zobrazit plný text záznamu