Ultrafast electron transfer between methylene blue and liquid anilines

The charge separation and recombination rate constants for electron transfer between the first excited singlet state of methylene blue and either aniline or N,N-dimethylaniline have been measured over a range of temperature so that the solventʹs longitudinal relaxation rate varies greatly. The observed charge separation and charge recombination rate constants are almost the same over this temperature range. The data are consistent with nuclear tunnelling as the rate-limiting process.