skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Direct experimental determination of spectral densities of molecular complexes

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4900512· OSTI ID:22310774
 [1];  [2]
  1. Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)
  2. Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need to be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.

OSTI ID:
22310774
Journal Information:
Journal of Chemical Physics, Vol. 141, Issue 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English