Individual tuning of solvent parameters – from organic solvents to ionic liquids

Alexander Wankmüller, Martin Georg Berghold, Stephan Landgraf*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


For more than 20 years, we have investigated electron transfer reactions of various types and under various conditions. According to the Marcus theory, solvent parameters have a significant influence on the observed kinetics. Temperature-dependent measurements, such as those used to obtain activation parameters, are especially strongly affected by these influences. Typically, all solvent parameters (e.g., viscosity, density, refractive index, dielectric constant) change systematically as the temperature changes. Therefore, the analysis of kinetic data is difficult. One way to overcome this difficulty is to apply solvent mixtures. In this paper, a detailed description is provided of how one single solvent parameter can be changed while the all others are kept nearly constant. Three different approaches were taken: First, the viscosity was altered at a constant temperature while maintaining the refractive index and dielectric constant. Second, dielectric constant was altered at a constant temperature while maintaining a constant viscosity and refractive index. Finally, all parameters were maintained while the temperature was varied. The latter approach offers the possibility to study activation parameters, e.g., by applying the Arrhenius equation, regardless of the viscosity changes that occur when the reaction temperature increases.

Original languageEnglish
Article number115880
Number of pages9
JournalJournal of Molecular Liquids
Publication statusPublished - 1 Jul 2021


  • Electron transfer
  • Ionic liquids
  • Solvent mixtures
  • Solvent properties
  • Solvents

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry
  • Atomic and Molecular Physics, and Optics
  • Spectroscopy

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

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