Excitation wavelength dependent fluorescence behavior of the room temperature ionic liquids and dissolved dipolar solutes

Room temperature ionic liquids are novel media for a variety of studies and applications. In this article, the excitation wavelength dependent fluorescence behavior of imidazolium ionic liquids and dipolar solutes dissolved in these liquids is highlighted. We discuss the origin of the unconventional fluorescence behavior of the ionic liquids and also of the dipolar systems, most of which show no excitation wavelength dependence in the conventional solvents. The implications of these observations in fluorescence studies involving the ionic liquids are discussed. (c) 2006 Elsevier B.V. All rights reserved.