A third-order nonlinear optical 4-[2-(4-dimethylamino-phenyl)-vinyl]-1-methyl-pyridinium 2-nitroaniline-4-sulfonate (DSNA) single crystal was successfully grown for the first time by incorporating a novel counter anion in the stilbazolium cation. Characterization results suggest that the DSNA crystal can be used for optoelectronic and optical limiting applications.

Abstract

A novel counter anion group was incorporated with the organic stilbazolium cation (C₁₆H₁₉N₂ ⁺) to yield a new third-harmonic-generation-active single crystal of 4-[2-(4-dimethylamino-phenyl)-vinyl]-1-methyl-pyridinium 2-nitroaniline-4-sulfonate (DSNA). The slow evaporation solution growth technique is employed to obtain DSNA crystals, whose nonlinear responses are analysed through a continuous wave laser Z scan experiment. The thermally induced strong reverse saturation absorption and self-defocusing behaviour of the DSNA crystal suggests that the material could be used as an optical limiting device. Optical characterization shows that the lower absorption edge falls in the visible region (530 nm), with a broad transparency range of 0.53 to 1 μm. Exploration of other optical constants, such as extinction coefficient (k=10⁻⁴), emission wavelength (602 nm – red light), optical (σ_opt=10¹⁰ Ωm⁻¹) and electrical conductivity (σ_elc=10¹¹ Ωm⁻¹) also concludes that the DSNA crystal could be potentially employed in optoelectronic devices. The various bonds and their corresponding lengths and angles involved in the formation of DSNA ionic crystal are evaluated by means of single-crystal X-ray diffraction (SCXRD). Linear and nonlinear optical property findings undoubtedly affirm that the titular DSNA crystal is an effective nonlinear optical (NLO) crystal.