Molecular modeling investigation of para-nitrobenzoic acid interaction in β-cyclodextrin

► Geometry optimizations of para-nitrobenzoic acid (PNBA)/β-cyclodextrin complex were carried out using MM+,PM3 and density function theory B3LYP/6-31G*. ► Calculations were performed upon the inclusion complexation of β-CD with neutral (PNBA1) and anionic (PNBA2) species of para-nitrobenzoic acid. ► The negative enthalpy changes calculated from the statistical thermodynamic calculation suggest that both the inclusion complexation is favored enthalpy-driven process.