Synthesis, Crystal Growth, and Characterization of an Organic Nonlinear Optical Donor-π-Acceptor Single Crystal: 2-Amino-5-nitropyridinium-Toluenesulfonate

A second-harmonic generation (SHG) crystal 2-amino-5-nitropyridinium-toluenesulfonate (2A5NPT) has been synthesized. Good quality single crystal of 2A5NPT was successfully grown by the slow evaporation method with dimensions 16 x 15 x 8 mm(3). The unit cell dimensions were determined from single crystal X-ray diffraction studies. GAUSSIAN 98W has been used to calculate the first-order hyperpolarizability of 2A5NPT. The calculated first-order hyperpolarizability of 2A5NPT is 142 x 10(-30) esu. The structural perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. Fourier transform infrared (FTIR) spectral studies have been performed to identify the functional groups. The optical transmittance window and the lower cutoff wavelength of the 2A5NPT have been identified by UV-vis-NIR studies. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study its thermal properties. Powder test with Nd:YAG laser radiation shows a high second harmonic generation.