Synthesis, structural, optical, thermal and mechanical properties of 2-amino-4-methylpyridinium 5-sulfosalicylic acid single crystal: an efficient material for optoelectronic applications

Abstract

A novel third-order organic nonlinear optical (NLO) material with promising excellent properties is crucial for NLO applications. For the first time, high NLO active 2-amino-4-methylpyridinium 5-sulfosalicylic acid (2A4MP5SSA) has been rationally designed and single crystals have been grown by the slow evaporation solution growth technique (SEST). X-ray diffraction analysis revealed that 2A4MP5SSA belongs to the category of triclinic system and has a Centro symmetric space group of P1. Remarkably, the grown crystal exhibits competitive and even superior physical properties including high thermal stability and wider transparency than the standard NLO single crystals. The morphology of the as-grown 2A4MP5SSA crystal was equivalent to the theoretically produced morphology. Fourier transform infrared spectroscopy (FTIR) was used to investigate the molecular vibrations of 2A4MP5SSA. The optical characteristics of 2A4MP5SSA recorded using optical transmittance spectrum reveals that the 2A4MP5SSA crystal possesses good optical transparency in the range between ultraviolet (UV) and near-infrared (NIR) regions. Intriguingly, the short cut-off edge of the grown crystal is found to be about 356 nm which is more favourable for developing modern photonic and optoelectronic device applications. The Laser Damage Threshold (LDT), were investigated to understand its effectiveness to be utilized in the area of optoelectronics and photonics. The thermal and mechanical stability of 2A4MP5SSA was tested using Thermo gravimetric Differential Thermal Analysis (TG–DTA) and Vickers hardness test. The third-order nonlinear optical properties of 2A4MP5SSA single crystals were analyzed, which involves studying the absorption coefficient and refractive index behaviour using a continuous wave laser. The grown crystal exhibits outstanding third-order NLO response and wide LDT, which are crucial characteristics for developing practical NLO devices. There are various 2-amino-4-methylpyridine (2A4MP) derivative single crystals available in the literature. However 2A4MP5SSA crystal has not been reported earlier. The findings consequently open a novel path for the logical design of enormous, thermally stable and NLO-active organic complexes for true NLO applications.