Synthesis, spectral, thermal, optical and dielectric studies on 4-dimethylaminopyridinium picrate crystals

Single crystal of 4-dimethylaminopyridinium picrate was grown by slow evaporation solution growth method. The optical properties of the crystal were studied by using UV–vis absorption and transmittance studies. The emission spectrum indicates that the crystal shows green and red fluorescence emissions. The band gap energy of the crystal was calculated and it is found to be 2.05 eV. The thermal stability of the crystal was studied using thermogravimetry-differential thermal (TG-DTA) analyses. The thermal anomalies observed in the differential scanning calorimetry (DSC) heating and cooling cycles indicate the occurrence of a first order phase transition. FTIR spectrum was used to confirm the presence of various functional groups in the crystal. The synthesized crystal shows SHG efficiency 32 times greater than that of potassium dihydrogen phosphate (KDP). The dielectric constant and dielectric loss of the crystal decreases with increases in frequency.