Growth and characterization of organic 4-chlorobenzaldehyde-N- methyl 4-stilbazolium tosylate crystal: A promising material for nonlinear optical device applications

The organic crystal 4-chlorobenzaldehyde-N-methyl 4-stilbazolium tosylate (CMST) was grown from acetonitrile and methanol mixed solvent using slow cooling method for the first time. The optimum growth conditions based on different solution concentrations were investigated. The crystal atomic packing and bond length alternation (BLA) of CMST were identified through single crystal X-ray diffraction analysis, the calculated BLA value 0.1475 angstrom is close to optimum value for nonlinear optical (NLO) response. The composition and different functional groups of CMST compound were determined by H-1 NMR and FT-IR studies. Moreover, the thermal stability and melting point were obtained through TG/DTG and DSC analyses. Important optical parameters such as optical transmittance, cut-off wavelength, absorption coefficient, band gap energy and refractive index were ascertained through UV-vis-NIR study, the low cut-off wavelength and wide optical transmittance of CMST crystal are favorable to optical device fabrication. The dielectric constant has been investigated. Green emission occurred at 521 nm was found through photoluminescence excitation study. These encouraging results suggest that the CMST crystal is a promising candidate for nonlinear optical device applications.