Evidences for Inclusion and Encapsulation of an Ionic liquid with β-CD and 18-C-6 in Aqueous Environments by Physicochemical Investigation.

Abstract

The interface between pyrrolidinium-based ionic liquid, i.e., 1-ethyl-1-methylpyrrolidinium bromide, with β-cyclodextrin and 18-crown-6 solution have been compared and explored by means of density, viscosity, refractive index, electrical conductance and surface tension, FTIR, 1H nuclear magnetic resonance, 2D ROESY NMR, and high resolution mass spectroscopy studies. Limiting apparent molar volumes (ϕV0), experimental slopes (SV*) interpreted in terms of inclusion and interaction (ion-solvent, ion-ion). Establishment of binding affinity were discussed in molecular terms supported this inclusion complexation and encapsulation interaction process. The result shows that the stability of the resulting complexes of β-cyclodextrin:[EMPyrr]+ and 18-crown-6:[EMPyrr]+ is based on the geometrical and spectrometric data. Host guest chemistry of the five-membered nitrogen containing cation with two different macro cyclic hosts is supported by studying NMR. HRMS has been used to support the complexation process with the proper stoichiometry ratio. The solid complex formations were established by Fourier transform infrared study.