ATHMANI Ali Salah

This study presents a computational investigation of p-phenylenediamine (PPD) interaction with 3,5-dinitrosalicylic acid (DNS) within a PPD/DNS charge-transfer (CT) complex. All calculations are performed at M06-2X/6-311+G(d,p) levels of theory in vacuum, water, and methanol. The EDA analysis is used to control the complexation process and it suggests that electrostatic and dispersion energies contribute greatly to the stabilization of the PPD/DNS CT complex. The results of the energy optimization show that the PPD/DNS CT complex is stable with a negative complexation energy. The obtained geometries reveal that the PPD ammonium group is close to the DNS carboxylate one, enabling the establishment of a large number of interactions. Additionally, different analyses are performed on the obtained optimized structures: TD-DFT, NBO, QTAIM, and NCI. Consequently, NBO, QTAIM and NCI analyses give that the PPD/DNS CT complex is stabilized by the hydrogen bonding and van der Waals interactions.