Sustenance of Inclusion Complexes of Ionic Liquid with Cyclic Oligosaccharide Molecules in Liquid and Solid Phases by Diverse Approaches

Abstract The water soluble inclusion complexes of pyridinium based hydrophobic ionic liquid (IL) were prepared and characterised successfully. The inclusion complexes of sparingly soluble IL prepared with α‐ and β‐cyclodextrin in the mixed solvent medium and in solid state were studied by different physicochemical methodologies. Comparison of the chemical shift of the pure CDs, guest and complexes formed in 1‐H NMR spectra, appearance of the cross peaks in 2D‐ROESY spectra and shift in the band positions in FT‐IR spectra confirmed the formation of inclusion complexes. Surface tension and conductance studies in the mixed solvent system indicated the 1:1 stoichiometric ratio of inclusion complex. Job's plot obtained from UV‐Vis study and the spectra obtained from mass spectrometric study supported the formation as well as the stoichiometry of inclusion complexes. The high binding constant values and calculated values of thermodynamic parameters such as Gibb's free energy, enthalpy and entropy supported the high stability and feasibility of formation of the inclusion complex.