Synthetic pathway of 2-fluoro-N,N-diphenylbenzamide with opto-electrical properties: NMR, FT-IR, UV-Vis spectroscopic, and DFT computational studies of the first-order nonlinear optical organic single crystal

Abstract

Abstract 2-Fluoro-N,N-diphenylbenzamide (2FNNDPBA), a natural nonlinear optical (NLO) single crystal, was incorporated from diphenylamine utilizing 2-fluoro benzoyl chloride as a side chain. The single crystals were successfully developed by a slothful evaporation arrangement approach utilizing ethyl acetate as a dissolvable solvent at room temperature. The synthesized compound fragmented ion peak (m/z = 291) was affirmed by gas-chromatographic mass spectrometry investigation. The unit cell dimensions were assessed using single-crystal X-ray diffraction analysis, which reveals that the crystals possess the orthorhombic system with space group Pbca. The existence of proton and carbon in a compound was affirmed by 1H and 13C nuclear magnetic resonance. The functional groups therein of 2FNNDPBA have been identified from FT-IR and FT-Raman studies and amide carbonyl stretching frequency peak appeared at 1,662 cm−1. The lower cut-off wavelength of 2FNNDPBA is found to be 240 nm and the experimental and theoretical optical band gap was calculated as 3.21 and 3.1083 eV. The UV-Visible spectrum of 2FNNDPBA shows two high-flying peaks at 240 and 273 nm. Major weight losses were observed between 160°C and 275°C for the designated compound. The thermal property for 2FNNDPBA was estimated by thermogravimetric analysis/differential thermal analysis investigation, which shows immense thermal strength up to 171°C. Density functional theory method with Gaussian 09 software for theoretical investigations of 2FNNDPBA for Mulliken charge analysis, highest occupied molecular orbital–lowest-lying unoccupied molecular orbital, and molecular electrostatic potential properties has been analyzed. The SHG productivity was proved by Kurtz-Perry powder strategy and has an efficiency 2.22 times that of standard potassium dihydrogen phosphate. The laser damage threshold of 2FNNDPBA crystals was discovered to be 1.18 GW·cm−2. The hyperpolarizability simulations further show that the current material has an excellent NLO activity tendency. The melting point of the developed crystal is 158°C. Graphical abstract