Computational investigation of the synthesized new indoline-2,3-dione and their derivatives

Computational studies using DFT incorporating the B3LYP/6-311++G(d,p) level is used to predict the stability of the synthesized 1-(5-phenyl-4H-1,2,4-triazol-3-yl)indoline-2,3-dione and its para-substituted (X: -CH3, -F, -CN, -NO2) in different solvents (acetone, ethanol, and methanol) and gas phases. Energetic properties, atomic charges, dipole moments, natural bond orbital (NBO), molecular electrostatic potential (MEP), and frontier molecular orbital (FMO) analyses are studied. The gauge independent atomic orbital (GIAO) method is used to quantify the nuclear magnetic resonance (NMR) chemical shift of the molecules. NBO analysis was used to assess the stability of the considered molecules, as well as their hyperconjugative relationships and electron delocalization. The charge transfer within the molecules is determined using the HOMO and LUMO analyses. The MEP surface was performed by the DFT method to predict the reactive sites for nucleophilic and electrophilic attacks. FMO analysis revealed that compound 5 (X=NO2) has a lower HOMO-LUMO energy (EHL) gaps in the considered phases, and is thus kinetically more stable in different media. Chemical reactivity indices as NO2 > CN > Cl > H > CH3 that predict the lowest (X=CH3) and highest (X=NO2) activity for the studied compounds. The energy difference derived from EHL gap leads to intramolecular hyperconjugative interactions pi→pi*.