Synthesis and characterization of β-cyclodextrin inclusion complex containing di(8-hydroxyquinoline)magnesium

The β-cyclodextrin (β-CD) inclusion complex containing di(8-hydroxyquinoline)magnesium was prepared. The product was characterized by NMR, IR, differential thermal thermogravimetric analysis (DT-TGA), spectrofluorimetry, and elemental analysis, indicating the formation of inclusion complex in which the quinoline rings of the guest were encapsulated within the β-CD cavities. The Job's method provided 2:1 stoichiometry for the inclusion complex between β-CD and di(8-hydroxyquinoline)magnesium. The association constant calculated with the modified Benesi–Hildebrand equation at 25 °C was determined. And the mean association constant was 3577 (L/mol)2, R.S.D. was 2.58%. The thermal stability and solubility of di(8-hydroxyquinoline)magnesium were improved when forming inclusion complex.