Multi-spectroscopic investigation on the inclusion complexation of α-cyclodextrin with long chain ionic liquid.

Host-guest interaction of ionic liquid (IL) 1-decyl-3-methylimidazolium tetrafluoroborate [Dmim][BF4] within α-cyclodextrin (α-CD) has been studied by different spectroscopic techniques and our investigated system is significant in the field of supramolecular chemistry and medicine. Benesi-Hildebrand correlation is used to study the stoichiometry of the host-guest complexation. Here concurrence with FT-IR and dynamic light scattering (DLS) results, it is shown that α-CD interacts with [Dmim][BF4], induces compositional and structural changes. Characterization of the [Dmim][BF4]-α-CD inclusion complex (IC) by 1H NMR spectroscopy provided information about the complexation among the [Dmim][BF4] and α-CD molecules and the structure of the ICs. 1H NMR results confirm the formation of inclusion complex (IC) while UV-vis spectroscopy, DLS and FTIR studies show development of IC with 1:1 stoichiometry. The present study can be highly applicable in the fields of pharmaceutical science, supra-molecular chemistry and material science.