Energetics of electron-transfer reactions in soft condensed media

Acc Chem Res. 2007 Apr;40(4):294-301. doi: 10.1021/ar7000167. Epub 2007 Mar 17.

Abstract

The coupling of electronic transitions within molecules to condensed-phase media involves a complex hierarchy of spatial and dynamical scales. Thermodynamics of activation is related to the length scale of microscopic interactions reflected in the non-Arrhenius reaction kinetics. Solvent dynamics make a particularly strong impact on the activation barrier when the time scale of the reaction is comparable to the relaxation time of the solvent, and the reaction barrier becomes nonergodic. Finally, molecular polarizability is responsible for complex nonparabolic free energy surfaces for electron transfer. We discuss the application of these ideas to soft condensed solvents such as supercooled liquids, liquid crystals, and photosynthetic reaction centers.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Algorithms*
  • Electron Transport*
  • Energy Transfer*
  • Kinetics
  • Liquid Crystals / chemistry
  • Oxidation-Reduction
  • Photosynthetic Reaction Center Complex Proteins / chemistry
  • Solvents / chemistry*
  • Thermodynamics

Substances

  • Photosynthetic Reaction Center Complex Proteins
  • Solvents