Facile synthesis, spectroscopic, electronic and non-linear optical properties of 1,2–4 triazole-based derivatives: An experimental and DFT approach

• Synthesis of novel triazole-based compounds for NLO materials • Utilization of various spectroscopic techniques for structure elucidation • Study of electronic and NLO properties at M06/6-311G (d,p) functional • Utilization of TD-DFT approach for FMOs and UV-Vis analyses In current study, a novel series of 1,2,4-triazole based compounds ( 7a - 7d ) was synthesized and their structure confirmation was accomplished through different spectroscopic (UV-Visible, FTIR, NMR and HRMS), elemental analysis and physio-chemical methods. Besides, the electronic properties were investigated through the DFT/TD-DFT approaches at M06/6-311G(d,p) functional. All the synthesized compounds showed simulated band gap in the range of 4.931-5.489 eV with absorption spectrain the range of 295-302 nm calculated experimentally. A significant charge transfer was observed with in molecules as supported by TDM and FMOs investigations. Compound 7a showed good NLO characteristics (β tot =1.338 × 10 −29 and <γ>= 7.547 × 10 −53 esu ) among all the synthesized compounds owing to the lowest value of HOMO–LUMO band gap (4.931 eV ). Hence it can be utilized as reasonable optoelectronic material for NLO devices.