Ethylenediaminium di(2-nitrophenolate) single crystals as materials for optical second harmonic generation

An organic second harmonic generation (SHG) active material, ethylenediaminium di(2-nitrophenolate) (EDA2NP) was synthesized through proton transfer reaction. Good quality single crystals of dimension 6×4×2 mm³ were grown by solvent evaporation method using ethanol as a solvent for the first time in literature. The lattice parameters of the grown crystals were determined by X-ray diffraction studies. Fourier Transform Infra Red (FT-IR) spectrum was recorded to identify the presence of various functional groups and the molecular structure was confirmed by nuclear magnetic resonance (NMR) spectrum. Thermal analyses of the grown crystal were carried out using thermo gravimetric–differential thermal analysis (TG–DTA) and differential scanning calorimetry (DSC) curves. Optical (UV–vis–NIR) analysis shows that the grown crystals were found to be transparent (450–2500 nm) in the entire visible region. The existence of second harmonic generation signals was observed by using Nd:YAG laser with fundamental wavelength of 1064 nm