Spectroscopic, quantum-chemical and X-ray diffraction studies of Piperidinium p-Hydroxybenzoate-combined experimental and theoretical studies on a novel NLO crystal.

Large size and high quality single crystals of organic nonlinear optical material Piperidinium p-Hydroxybenzoate (PDPHB) have been grown by solution growth method. This crystal belongs to monoclinic system with a noncentrosymmetric space group of Cc. To confirm its structure and compositions this material was subjected to single and powder X-ray diffraction and microanalysis studies. Fourier transform infrared (FTIR), UV-VIS-NIR, photoluminescence and nuclear magnetic resonance spectra have been recorded and extensive spectroscopic investigations have been carried out. Frequency conversion property of the crystal was tested by using Kurtz and Perry powder technique and the relative conversion efficiency was about 19 times greater than that of KDP. Static and dynamic hyperpolarizability values were calculated to confirm the suitability of the crystal for nonlinear optical applications. In addition, frontier molecular orbital (FMO), Mulliken charge and molecular electrostatic potential (MEP) analyses were performed by density functional theory (DFT) at the B3LYP/6-31G (d) basis set.