Solute-solvent interaction and adsorption studies of sulpha drug derivative: A DFT study

The adsorption of (E)-2-hydroxy-5-(((4-sulfamoyl phenyl) imino) methyl) benzoic acid (5FSANI) on various metal clusters and chemical descriptors was investigated on the basis of the solvation effects by using frontier molecular orbital (FMO), molecular electrostatic potential (MEP), and wave function analyses. In this study two basis sets (mixed basis set) such as cc-pVDZ and Lan-L2DZ with B3LYP functional level were used. The Lan-L2DZ basis set was used for metal atoms and cc-pVDZ basis set was used for other atoms like, C, H, N, S, and O respectively. The adsorption energy of 5FSANI-Pt2-Ru (water) cluster was found to be the highest (-170.78 kcal/ mol), whereas the adsorption energy of 5FSANI-Ru3 (water) cluster was found to be the lowest (-11.94 kcal/ mol). After the addition of the metal clusters, 5FSANI became more electrophilic, as evidenced by the higher electrophilicity index of all metal -drug systems. The results of this study indicated that the solvents had stronger negative solvation energies. The investigation of non-covalent contacts showed the considerable inter and intramolecular interactions. Studies such as electron localized function (ELF), localized orbital locator (LOL), and average localized ionization energy (ALIE) confirmed the electron localization and delocalization energies. The metal frontier molecular orbital and the molecular electrostatic potential of the clusters were calculated by using the density functional theory (DFT) method.