Non linear optical property of 4-aminopyridinium 2-chloro-5-nitrobenzoate

A centro-symmetric crystal of 4-aminopyridinium 2-chloro-5-nitrobenzoate (4A2Cl5NB) has been grown by the slow evaporation method, and its molecular structure has been confirmed by powder X-ray diffraction using GSAS software; Hirshfeld surface analysis has been carried out to analyze the intermolecular interaction through hydrogen bonding in the molecular structure; and vibration frequencies have been assigned by FTIR spectral studies. UV visible absorption occurs at the lower cut-off wavelength of 266 nm, and the optical band gap was found to be E_g = 4.1 eV. A broad emission band was observed at 482 nm in the luminescence spectrum. Thermo-gravimeter and differential thermal (TG–DTA) analysis were carried out. Micro-hardness studies of grown crystals are discussed. A dielectric study reveals a low dielectric constant and loss at higher frequencies, attesting to nonlinear optical activity. Cyclic Volta-metric studies were also analyzed. The second harmonic generation efficiency of the (4A2Cl5NB) crystal is 4.8 times superior to that of the KDP crystal.