Preparation, physicochemical analysis and molecular modeling investigation of 2,2′-Bipyridine: β-Cyclodextrin inclusion complex in solution and solid state

•The 1:1 stoichiometry was confirmed by Benesi–Hideband double reciprocal plots.•FT–IR, Molecular docking studies strongly confirmed the formation of inclusion complex.•In XRD analysis, reduction of crystallinity in inclusion complex was observed.•Life time studies shows that BPY has single and bi-exponential in water and β-CD.

Supramolecular interaction between 2,2′-Bipyridine (BPY) and β-Cyclodextrin (β-CD) has been investigated in solution and solid state. Non-covalent interaction between BPY and β-CD was studied in solution using absorption and fluorescence spectroscopy. Inclusion complex of BPY and β-CD was prepared in solid state by co-precipitation method and it was characterized using Fourier Transform Infra-red spectroscopy (FT–IR), Thermal analysis, Scanning Electron Microscopy (SEM), Powder X-ray diffractometry (XRD) and Atomic Force Microscopy (AFM). Binding constant values and 1:1 stoichiometry of the inclusion complex were calculated using Benesi–Hildebrand plots at 303 K. Using continuous variation method the 1:1 stoichiometry has been confirmed for BPY: β-CD complex. Thermodynamic parameter, ΔG of inclusion complex formation was determined and the negative value indicated that the inclusion process was an exergonic and spontaneous process. The most probable model of BPY: β-CD inclusion complex suggested by molecular docking studies was in good agreement with the results obtained by experimental methods.