Quantum mechanical study and spectroscopic (FT-IR, FT-Raman, 13C, 1H, UV) study, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 4-[(4-aminobenzene) sulfonyl] aniline by ab initio HF and density functional method

► 4-[(4-Aminobenzene) sulfonyl] aniline has anti-inflammatory effect. ► We have assigned the fundamental mode on the basis of a group vibrational concept and calculated vibrational wavenumbers. ► 13C and 1H chemical shift calculations of the 4-[(4-aminobenzene) sulfonyl] aniline have been made. ► Overlap between π (CC) and π* (CC) bond orbital. ► The compound has 65 occupied molecular orbitals.