Homogeneous Line Width of the Different Vibronic Bands of Retinal Absorption in Bacteriorhodopsin by the Hole-Burning Technique

TitleHomogeneous Line Width of the Different Vibronic Bands of Retinal Absorption in Bacteriorhodopsin by the Hole-Burning Technique
Publication TypeJournal Article
Year of Publication1996
AuthorsKamalov, VF, Masciangioli, TM, EL-Sayed, MA
JournalThe Journal of Physical Chemistry
Volume100
Issue8
Pagination2762 - 2765
Date Published1996
ISBN Number0022-3654
Abstract

Using the hole-burning technique, resolved vibrational structure was observed in the retinal absorption spectrum of bacteriorhodopsin (bR) in poly(vinyl alcohol) (PVA) film at 10 K with 556 and 632 nm irradiation. The homogeneous line widths of v = 1 and v = 2 vibronic bands are estimated from the deconvolution of the observed spectrum. The absorption maximum is found to shift by 100?200 cm-1 by using the two excitation wavelengths; resulting from partial site selection due to the contribution of inhomogeneous broadening. The hole width produced by excitation near the zero-phonon band is found to be ?1250 cm-1, which corresponds to a homogeneous width of ?600 cm-1, and the low limit of dephasing time can be estimated as 20 fs. This width is found to be independent of the vibronic band observed.Using the hole-burning technique, resolved vibrational structure was observed in the retinal absorption spectrum of bacteriorhodopsin (bR) in poly(vinyl alcohol) (PVA) film at 10 K with 556 and 632 nm irradiation. The homogeneous line widths of v = 1 and v = 2 vibronic bands are estimated from the deconvolution of the observed spectrum. The absorption maximum is found to shift by 100?200 cm-1 by using the two excitation wavelengths; resulting from partial site selection due to the contribution of inhomogeneous broadening. The hole width produced by excitation near the zero-phonon band is found to be ?1250 cm-1, which corresponds to a homogeneous width of ?600 cm-1, and the low limit of dephasing time can be estimated as 20 fs. This width is found to be independent of the vibronic band observed.

URLhttp://dx.doi.org/10.1021/jp952971k
DOI10.1021/jp952971k
Short TitleJ. Phys. Chem.