Synthesis, growth and characterization of new organic 4-N,N-dimethylamino-4′-N′-methylstilbazolium 2,4-dinitrobenzenesulfonate (DSDNS) single crystal for nonlinear optical applications

A new organic material 4-N, N-dimethylamino-4ꞌ-Nꞌ-methylstilbazolium 2,4-dinitrobenzenesulfonate (DSDNS) is synthesized via Knoevenagel condensation reaction followed by metathesization reaction and DSDNS single crystals are successfully grown from the methanol–acetonitrile medium by low-temperature slow evaporation solution technique (SEST). The FT-IR and FT-Raman spectra disclose the vibrational characteristics of various functional groups present in the DSDNS material. NMR analysis (¹H and ¹³C) reveals that nuclei of respective signals from hydrogen and carbon confirm the molecular structure. The molecular structure of the DSDNS crystal was solved by single crystal X-ray diffraction (SXRD) techniques which confirms that the DSDNS crystal crystallizes in a monoclinic crystal system with the space group C2/c. UV-DRS spectrum displays 90% optical transmittance with the cut-off wavelength λ_max 520 nm and bandgap of 2.39 eV. The luminescence and chromaticity diagram reveals that the DSDNS could be a possible candidate for white light application. The positive photoconductivity nature of DSDNS crystal was confirmed from the calculation of photo and dark current values. The thermal studies reveal its stability up to 273 °C and its high tolerance capacity of 19.4 GW/cm² against 1064 nm from laser damage threshold studies. The third-order properties of NLO from the Z-scan method signify its promising feature towards application in the design of nonlinear optical devices and optical limiting applications.