Influence of Alkyl Substituent on Optical Properties of Carboxylate-Based Protic Ionic Liquids

The solvation strength of N,N-dialkylethanolammonium based protic ionic liquids (PILs) have been determined by normalised Reichardt's parameter (E-T(N) and molecular polarizability (alpha(P)). The solvation strength depends on the intermolecular interactions which are governed by the functional group and molecular structure of the species. So here in this work, the influence of functional groups such as -OH, -RCOOH and -R, on solvato-chromic parameters of studied PILs have been discussed in terms of experimental results and relevant literature. Further the intermolecular interactions of PILs have been analyzed with the help of temperature dependant experimental refractive index data. Additionally, a positive correlation was obtained between the polarity and the refractive index of the studied PILs.