The thermodynamic, quantum, AIM and NBO study of the interaction of pyrazinamide drug with the pristine and transition metal-doped B12P12

In this work, the interaction of pyrazinamide (Pyr) drug with pristine, Sc, Ti, V and Cr-doped B12P12 nanocage is investigated by using density functional theory (DFT) at the cam-B3LYP/Lanl2DZ level of theory. From optimized structure, the adsorption energy, deformation energy, thermodynamic parameters, quantum parameters, reduced density gradient (RDG), natural bond orbital (NBO) and atom in molecule (AIM) parameters are calculated at the above level of theory. The calculated results demonstrate that with doping Ti atom the adsorption and deformation energy of Pyr/BP nanocage complex increase significantly from original values. The thermodynamic parameters revealed that adsorption of Pyr on the surface of doped models of B12P12 nanocage is more favorable than the pristine model. On the other hand, the ΔΔG(sol) values of water and ethanol solvent for adsorption of Pyr drug on the surface of pristine nanocage is negative and for Sc, Ti, V, and Cr doped B12P12 nanocage models are positive. The band gap of all adsorption models are in range 0.97–2.52 eV and the electrical and optical properties of system alter significantly from pristine models. The values of ▽2ρ and HBCP for all adsorption models are positive and negative respectively, it refers to medium strength or partially covalent bond and this result is an agreement with RDG and NBO outputs. The calculated results demonstrate that the Sc, Ti, V, and Cr doped B12P12 nanocages are a good candidate for deliver Pyr drug in the biological system.