The standard
electron-transfer heterogeneous rate constant of lithium, potassium, sodium and
caesium amalgams in N,N-dimethylformamide was ascertained employing cyclic
voltammetry in an effort to relate the presence of a non-equilibrium electrode
reaction at the dropping lithium amalgam electrode to the variation of the
lithium amalgam electrode potential with amalgam electrode con- figuration,
i.e. whether streaming, dropping or stationary. Such variations are not
observed at other alkali metal amalgam electrodes. ��� In the dipolar aprotic solvents the
standard electron-transfer heterogeneous rate constant for the Li(Hg) electrode
increases as the solvating power for Li+ decreases, i.e. dimethyl
sulphoxide < di- methylformamide < propylene
carbonate. Water is a much stronger solvator of Li+ than is
propylene carbonate, but the electron transfer is faster in water than in
propylene carbonate; the important role of entropic contributions in ion
solvation is discussed as an explanation.
Role of Proton Diffusion in the Nonexponential Kinetics of Proton-Coupled Electron Transfer from Photoreduced ZnO Nanocrystals
