@article {1254,
	title = {Low-temperature retinal photoisomerization dynamics in bacteriorhodopsin},
	journal = {Journal of Physical Chemistry B},
	volume = {102},
	number = {13},
	year = {1998},
	note = {Logunov, SL Masciangioli, TM Kamalov, VF El-Sayed, MA},
	month = {Mar},
	pages = {2303-2306},
	abstract = {Retinal photoisomerization dynamics are studied at both room temperature and 20 K in wild-type bacteriorhodopsin using femtosecond pulses. We were able to resolve the decay at 20 K into two components with the dominant component having a similar lifetime to that observed at room temperature. This strongly suggests that the retinal lifetime at physiological temperature is barrierless. The minor, low-temperature long-lived component is discussed in terms of previous results obtained for fluorescence and transient absorption with lower time resolution, and the origin of this component is discussed in terms of low-temperature glass heterogeneity.},
	isbn = {1089-5647},
	doi = {10.1021/jp972921a},
	author = {Logunov, Stephan L. and Masciangioli, Tina M. and Kamalov, Valey F. and El-Sayed, Mostafa A}
}
@article {864,
	title = {Optical rotation of the second harmonic radiation from retinal in bacteriorhodopsin monomers in Langmuir-Blodgett film: evidence for nonplanar retinal structure.},
	journal = {Biophysical journal},
	volume = {73},
	year = {1997},
	month = {1997 Dec},
	pages = {3164-70},
	abstract = {We observed optical rotation of the plane of polarization of the second harmonic (SH) radiation at 532 nm (in resonance with the retinal absorption) generated in reflection geometry in Langmuir-Blodgett film of bacteriorhodopsin (bR). The analysis of the experimental data showed that this effect arises from the nonvanishing contribution of the antisymmetrical part of the hyperpolarizability tensor. This requires that the dipole moment of the resonant electronic transition, the change of the dipole moment upon electronic excitation, and the long axis of the retinal not be coplanar. Such conditions are satisfied only if the retinal has a nonplanar geometry, a conclusion that could lend support to the heterogeneity model of the origin of the biphasic band shape of the linear CD spectrum of the retinal in bR. On the basis of our theoretical analysis, we were able to estimate the angle between the induced dipole moment and the plan that contains the long axis of the chromophore and the transition dipole moment of the retinal absorption.},
	keywords = {Bacteriorhodopsins, Biophysical Phenomena, Biophysics, Circular Dichroism, Molecular Structure, Optics and Photonics, Retinaldehyde, Spectrophotometry},
	issn = {0006-3495},
	doi = {10.1016/S0006-3495(97)78342-5},
	author = {Volkov, V. V. and Svirko, Y P and Kamalov, Valey F. and Song, Li and El-Sayed, Mostafa A}
}
@article {1269,
	title = {Homogeneous Line Width of the Different Vibronic Bands of Retinal Absorption in Bacteriorhodopsin by the Hole-Burning Technique},
	journal = {The Journal of Physical Chemistry},
	volume = {100},
	year = {1996},
	note = {doi: 10.1021/jp952971k},
	month = {1996},
	pages = {2762 - 2765},
	publisher = {American Chemical Society},
	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.},
	isbn = {0022-3654},
	doi = {doi: 10.1021/jp952971k},
	url = {http://dx.doi.org/10.1021/jp952971k},
	author = {Kamalov, Valey F. and Masciangioli, Tina M. and El-Sayed, Mostafa A}
}
@article {873,
	title = {Picosecond Electronic Relaxation in CdS/HgS/CdS Quantum Dot Quantum Well Semiconductor Nanoparticles},
	journal = {The Journal of Physical Chemistry },
	volume = {100},
	year = {1996},
	note = {doi: 10.1021/jp953708m},
	month = {1996},
	pages = {6381 - 6384},
	publisher = {American Chemical Society},
	abstract = {Subpicosecond photoexcitation of CdS/HgS/CdS quantum dot quantum well nanoparticles at wavelengths shorter than their interband absorption (390 nm) leads to a photobleach spectrum at longer wavelengths (440?740 nm). The photobleach spectrum changes and its maximum red-shifts with delay time. These results are explained by the rapid quenching of the initially formed laser-excited excitons by two types of energy acceptors (traps); one is proposed to be due to CdS molecules at the CdS/HgS interface, and the other trap is that present in the CdS/HgS/CdS well. The results of the excitation at longer wavelengths as well as the formation and decay of the bleach spectrum at different wavelengths support this description.Subpicosecond photoexcitation of CdS/HgS/CdS quantum dot quantum well nanoparticles at wavelengths shorter than their interband absorption (390 nm) leads to a photobleach spectrum at longer wavelengths (440?740 nm). The photobleach spectrum changes and its maximum red-shifts with delay time. These results are explained by the rapid quenching of the initially formed laser-excited excitons by two types of energy acceptors (traps); one is proposed to be due to CdS molecules at the CdS/HgS interface, and the other trap is that present in the CdS/HgS/CdS well. The results of the excitation at longer wavelengths as well as the formation and decay of the bleach spectrum at different wavelengths support this description.},
	isbn = {0022-3654},
	url = {http://dx.doi.org/10.1021/jp953708m},
	author = {Kamalov, Valey F. and Little, Reginald and Logunov, Stephan L. and El-Sayed, Mostafa A}
}
