Molecular structure, HOMO–LUMO, and First Order Hyperpolarizability studies of some quinoxaline 1,4-dioxide derivatives: hybrid computational (HF and DFT) analysis

Abstract

Abstract The theoretical investigation results of quinoxaline-1, 4-dioxide (I), and some of its derivatives (II-VII) were reported in this paper. Quantum chemical calculations were performed on 7 molecules at ab initio/RHF/6-311 + + G (d, p) and DFT/B3LYP/6-311 + + G (d, p) levels of theory. Calculated optimized molecular structures, dipole moments, polarizabilities, and first order hyperpolarizabilities for all molecules were dedicated. Also, the frontier molecular orbitals (FMOs), EHOMO (the highest occupied molecular orbital energy), ELUMO (the lowest unoccupied molecular orbital energy), HOMO-LUMO energy gap (ΔE), and quantum chemical parameters such as chemical potential (Pi), absolute electronegativity (χ), chemical hardness (η), global softness (S), and global electrophilicity (ω) are investigated. 1HNMR spectrum for quinoxaline-1, 4-dioxide (I) was calculated and compared with experimental data. The results of two theoretical methods have been analyzed using the Excel program in the linear regression method.