Bulk size crystal growth, spectroscopic, dielectric and surface studies of 4-N,N-dimethylamino-4-N'-methylstilbazolium m-nitrobenzenesulfonate (DSMNS): A potential THz crystal of stilbazolium family

Analysis of the growth and physicochemical properties of the newly developed stilbazolium derivative 4-N,N-dimethylamino-4-N-methyl stilbazolium 2-formyl benzene sulfonate (DSFS) single crystal: an effective material for nonlinear optical applications

A novel ionic stilbazolium derivative single crystal of 4-N,N-dimethylamino-4-N-methyl stilbazolium 2-formyl benzene sulfonate (DSFS) was successfully cultivated with methanol as the solvent by using the slow evaporation technique. Structural confirmation was done using single-crystal X-ray diffraction (SCXRD), and the obtained results reveal that the DSFS crystal crystallized in a centrosymmetric pattern with P1̄ space group. The presence of different vibrational modes in the DSFS crystal is affirmed via Fourier transform infrared (FTIR) spectroscopy. Linear optical constants such as cut-off wavelength, bandgap, extinction coefficient, Urbach energy, electrical conductivity and optical conductivity of the titular crystal were found from ultraviolet–visible–near infra-red spectroscopy (UV-Vis-NIR). The emission wavelength of the title crystal lies in the red region (620 nm), which was confirmed from the photoluminescence spectroscopy (PL). The surface nature of the grown ionic crystal was examined through the etching and atomic force microscopy (AFM) technique. With a He–Ne laser as the source, Z scan analysis was carried out to study the third-order nonlinear properties of the DSFS crystal.

The newly grown stilbazolium derivative 4-N,N-dimethylamino-4-N-methyl stilbazolium 2-formyl benzene sulfonate (DSFS) single crystal can be used for multiple applications such as optoelectronics, photonics and nonlinear applications.

Growth, structural, thermal, dielectric and optical studies on HBST crystal: A potential THz emitter

The efficient organic nonlinear optical material 4-hydroxy benzaldehyde-N-methyl 4-stilbazolium tosylate (HBST) was grown from methanol by slope nucleation method combined with slow cooling (SNM-SC) for the first time. The optimum growth conditions based on the cooling rate was further investigated. The single crystal X-ray diffraction (XRD) revealed that the chromophores of HBST crystal make an angle of about 33° with respect to the a-axis, which is close to the optimum of Terahertz (THz)-wave generation and electro-optics applications. NMR and FT-IR spectral studies have been performed to ascertain various functional groups present in the sample. Futhermore, the thermal stability and decomposition stages were analyzed through TG-DTA and DSC techniques. The dielectric constant and dielectric loss of HBST crystal have been studied. Critical optical properties like the absorption coefficient, refractive index, cut-off wavelength and band gap energy were calculated. Photoluminescence (PL) exication studies indicated green emission occured at 507nm. All the results of HBST crystal make it a promising candidate in the fields of optoelectronic and the generation of THz.