Preferred Label : Rehm–Weller equation;
IUPAC definition : Empirical correlation found between the observed second-order rate constant, kq, for
an intermolecular electron-transfer reaction and the Gibbs energy of the photoinduced
electron transfer process within the encounter complex (ΔET.Go): \[k_{{q}} \frac{k_{{d}}}{1
\frac {k_{{d}}}{K_{{d}}\, {Z}}\left [ {exp}\left ( \frac{Δ G {\ddagger }}{RT} \right
) {exp}\left ( \frac{Δ_{{ET}} G {o }}{RT} \right ) \right ]}\] with kd and k-d the
rate constant for the formation and separation, respectively, of the encounter (precursor)
complex, Kd kd/k-d, Z the universal collision frequency factor, R the gas constant,
T the absolute temperature and ΔG‡ the activation Gibbs energy of the forward electron
transfer reaction.;
Scope note : in the original formulation of this equation the value kd
kd z 0.25in acetonitrile was used.;
Origin ID : RT07472;
See also
Empirical correlation found between the observed second-order rate constant, kq, for
an intermolecular electron-transfer reaction and the Gibbs energy of the photoinduced
electron transfer process within the encounter complex (ΔET.Go): \[k_{{q}} \frac{k_{{d}}}{1
\frac {k_{{d}}}{K_{{d}}\, {Z}}\left [ {exp}\left ( \frac{Δ G {\ddagger }}{RT} \right
) {exp}\left ( \frac{Δ_{{ET}} G {o }}{RT} \right ) \right ]}\] with kd and k-d the
rate constant for the formation and separation, respectively, of the encounter (precursor)
complex, Kd kd/k-d, Z the universal collision frequency factor, R the gas constant,
T the absolute temperature and ΔG‡ the activation Gibbs energy of the forward electron
transfer reaction.
