Vibrational spectra, linear and nonlinear optical investigations on 3‑chloro 4-fluoro aniline and 2-iodo aniline for optical limiting applications
Detailed investigations on the linear and nonlinear optical properties of 3‑chloro 4-fluoro aniline (CFA) and 2-iodo aniline (IA) have been carried out to understand their applicability. Natural Bond Orbital (NBO) analysis reveals the potential nonlinearity of CFA and IA by virtue of their π-conjugations in the carbon-ring systems and the n→σ* and n→π* hyperconjugations. Vibrational spectra of the molecules, investigated using the FT-IR and FT-Raman analyses, manifest the incidence of Fermi interaction and Evans hole in IA. The UV-vis spectral analysis brings out the fine photo response of CFA and IA in the visible region.The optical absorption technique has been employed to analyze the optical band gap of the title crystals, through the investigation of the absorption edge, to assess their effectiveness in optical devices.The z-scan measurement brings to light the remarkable third order nonlinearity in IA, with an extraordinary drop in normalized transmittance down to 39% at high laser fluences, which is a clear sign of its potential use as an optical limiter. A study of the molecular docking postures of CFA and IA ligands binding at the active sites of the target proteins reveal them suitable for use as therapeutic agents having anti-inflammation and anti-cancer activities against target proteins.