Excited-state dynamics of protonated retinal Schiff base in solution
- Georgia Inst. of Technology, Atlanta, GA (United States)
The dynamics of all-trans and 13-cis retinal protonated Schiff base (RPSB) were studied in different solvents by means of picosecond transient spectroscopy. The decay time of the excited state absorption was found to be wavelength dependent due to the contribution of the faster decay of stimulated emission. The stimulated emission has a lifetime of a 2.5-4 ps while the excited state absorption decay is biexponential with lifetimes of 2.5-4 and 10-12 ps. The fluorescence quantum yield is strongly temperature dependent but viscosity has a small effect on both excited-state lifetime and fluorescence quantum yield. This leads to the conclusion that there is a {approx}600 cm{sup -1} barrier in the excited-state which results from intramolecular electronic factors and not from the solvent viscosity. The comparison of these results with those for the retinal in rhodopsin and bacteriorhodopsin is discussed in terms of the protein catalysis for the retinal photoisomerization. 31 refs., 8 figs., 2 tabs.
- OSTI ID:
- 437738
- Journal Information:
- Journal of Physical Chemistry, Vol. 100, Issue 47; Other Information: PBD: 21 Nov 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electrostatic Control of Photoisomerization in Channelrhodopsin 2
Model systems for rhodopsins: The photolysis of protonated retinal Schiff bases, cyanine dye, and artificial cyanine-bacteriorhodopsin