Photoinduced intermolecular electron transfer in a room temperature imidazolium ionic liquid: An excitation wavelength dependence study

In this work we have reported the photoinduced intermolecular electron transfer reaction from N,N-dimethylaniline to different Coumarin dyes in a neat room temperature imidazolium ionic liquid, 1-ethyl-3-methylimidazolium-bis (trifluoromethylsulfonyl) imide ([Emim][Tf2N]) and observed a difference in electron transfer rate with the variation of excitation wavelengths. We have also observed an excitation wavelength dependent solvation dynamics in this ionic liquid media. The excitation wavelength dependence is attributed to the presence of structural heterogeneity in this neat ionic liquid media. The electron transfer rate vs free energy correlation curve show a retardation in the electron transfer rate at higher free energy region.