Molecular structures and optical properties of Schiff bases derived from pyrrole alkyl ketones and 1-aminophethalazine: DFT calculations

Abstract

The density functional theory (DFT) method at the B3LYP/6-311++G (2d, 2p) level was used to compute the optimized structures of 1-aminophethalazine (I) derived Schiff bases of pyrrole alkyl ketones (II). In these Schiff bases (III, IV) each of the CN bonds has two geometrical isomers (E and Z). The relative stability of these isomers has been calculated. Based on the optimized structures dipole moments, optical properties, UV–visible analysis, and frontier orbitals of these Schiff bases were computed. The values of electron density (ρ), Laplacian (∇2ρ), and potential energy density (V(r)) at the critical points (BCPs) of the carbon–nitrogen double bond (CN) and intramolecular interaction were investigated. This is the first reported case of the molecular structures and optical characteristics of these Schiff bases using DFT calculations. The findings showed that these compounds had an almost identical magnitude of β value for p-nitroaniline, indicating good nonlinear optical characteristics.