Quantum chemical modeling, synthesis, spectroscopic (FT-IR, excited States, UV–Vis) studies, FMO, QTAIM, NBO and NLO analyses of two new azo derivatives

Abstract

• Two new azo derivatives were synthesized and FT-IR, UV-Vis and NMR spectra were measured and compared with theoretical calculations. • Detailed structural, physical and chemical properties were studied. • Hyperpolarizability calculations reveal suitability for optoelectronic and photonic applications. In this research, we report the results of experimental and density functional theory (DFT)/time-dependent DFT analyses of two new azo derivatives that absorb light in the visible range: (E)-2-((4-(diethylamino)phenyl)diazenyl)-6-methoxy-3-methylbenzo[d]thiazol-3-ium ( I ) and N,N-diethyl-4-((6-methoxybenzo[d]thiazol-2-yl)diazenyl)aniline ( II ) in the presence of water ( I ) and chloroform ( II ). The molecular geometry and excited states of the compounds were investigated, and their natural bond orbital, frontier molecular orbital, quantum theory of atoms in molecules, and nonlinear optical (NLO) parameters were calculated. In addition, Fourier-transform infrared, nuclear magnetic resonance, and ultraviolet/visible spectral parameters were generated from the derived structures and compared to experimental spectral parameters. The practical applicability of the azo derivatives was investigated by determining their electronic and NLO properties, which demonstrated that both molecules have potential for optoelectronic and photonic applications. A high degree of approximation between the calculated and experimental results was demonstrated.