4-Bromoanilinium 4-methylbenzenesulfonate (4BPTS) single crystal was successfully grown from ethanol by slow evaporation method at room temperature. The structure of grown crystal was confirmed by single crystal X-ray diffraction studies. The presence of functional groups of grown crystal was confirmed by the Fourier transform infrared spectroscopy (FTIR) spectral analysis. UVVisible absorption study was performed on the grown crystal to determine the cut-off wavelength. The thermal stability of the grown crystal was investigated from the Thermogravimetric analysis (TGA)/ Differential thermal analysis (DTA) analysis. The mechanical behaviour of grown crystal was studied by using Vicker's microhardness test. The third order non-linear optical properties of 4BPTS were investigated by Z-scan technique with He-Ne laser radiation and the corresponding non-linear refractive index and absorption coefficients were also calculated.

The 1-Iodo-3-Nitrobenzene crystal was grown by the slow evaporation method from ethanol solvent. The crystalline structure was identified by powder X-ray diffraction (PXRD). The presence of various functional group of the title material was examined by FTIR analysis. The UV-Vis absorption was carried out which shows the fundamental cutoff wavelength around 390 nm and there is no absorption in the entire visible region 390 nm to 1100 nm. The mechanical strength of the grown crystal was measured by Vicker’s microhardness tester. The thermal toughness of the grown crystal was observed by TGA-DTA and DSC studies. The electrical conductivity of the grown crystal is confirmed by dielectric measurement. The nonlinear optical character was assessed by Kurtz-Perry powder technique. This would propose that 1-iodo-3-nitro benzene crystal is a potentially capable in nonlinear optical applications.