Electrical-field-driven electron self-exchange in a mixed-valent osmium (II/III) bipyridine polymer: Solid-state reactions of low exothermicity

Academic Article

Abstract

  • The dynamics of electrical-field-driven solid-state electron transfers between Os(II) and OS(III) sites in the 1:1 mixed-valent redox polymer poly[Os(III/II) (bpy)2(vpy)2](ClO4)2.5 (bpy = bipyridine; vpy = vinylpyridine) are described. The nonlinear molecular conductivity of the polymer is modeled as an experimentally controllable intersite free energy gradient imposed by the electrical field. Electron self-exchange rates are analyzed as a function of free energy and temperature from 83 to 295 K with both classical and semiclassical electron-transfer theories. The analysis shows that room-temperature electron transfers lie near the high-temperature limit of classical behavior with a thermal barrier of 7-8 kcal/mol, but those at lowered temperature exhibit non-Arrhenius behavior and involve a nuclear tunneling mechanism.
  • Authors

    Published In

    Digital Object Identifier (doi)

    Author List

  • Jernigan JC; Surridge NA; Zvanut ME; Silver M; Murray RW
  • Start Page

  • 4620
  • End Page

  • 4627
  • Volume

  • 93
  • Issue

  • 11