Calculated solvent reorganization entropies, free energies, and fluctuations of the energy gaps for intramolecular electron transfer and excitation of the solvatochromic dye B30

William W Parson; Clemens Burda

doi:10.1063/5.0164136

Calculated solvent reorganization entropies, free energies, and fluctuations of the energy gaps for intramolecular electron transfer and excitation of the solvatochromic dye B30

J Chem Phys. 2023 Oct 21;159(15):154505. doi: 10.1063/5.0164136.

Authors

William W Parson¹, Clemens Burda²

Affiliations

¹ Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA.
² Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA.

PMID: 37861297
DOI: 10.1063/5.0164136

Abstract

Intramolecular electron transfer between two biphenyl groups linked by an androstane spacer and excitation of the pyridinium-N-phenolate betaine dye B30 to the first excited singlet state are studied by quantum/classical molecular-dynamics simulations at temperatures between 150 and 300 K in solvents with a range of polarities. Temperature dependences of the solvent reorganization energies, free energies, entropies, and the inhomogeneous broadening of B30's absorption band are examined. The variances of fluctuations of the energy gap between the reactant and product states do not have the direct proportionality to temperature that often is assumed to hold. An explanation for the observations is suggested.