LAUSR

Abstract This report discusses crystal structure, molecular arrangements, vibrational analysis, UV-Vis-NIR spectrum, fluorescence emission and second harmonic generation (SHG) efficiency of piperazinium l -tartrate (PPZ 2+ ·Tart 2− ) crystals with the support of theoretical analysis. A good optical quality PPZ 2+ ·Tart 2− crystals were grown from slow evaporation of aqueous solution. The PPZ 2+ ·Tart 2− crystal belongs to monoclinic system with non-centrosymmetric space group P2 1 . The charge transfer from donor to acceptor moieties and corresponding changes in the bond lengths and bond angles have been observed. The observed functional group vibrations in the experimental FTIR and the Raman spectrum were assigned and compared with theoretical wavenumbers of PPZ 2+ ·Tart 2− .The electron distribution on the donor and acceptor in PPZ 2+ ·Tart 2− has been clearly visualised using molecular electrostatic potential map. Compared with l -tartaric acid, red shift was observed in absorption and fluorescence spectrum. The low value of dielectric constant and dielectric loss at the higher frequency and its high second harmonic efficiency suggest PPZ 2+ ·Tart 2− crystal is less defect free and suitable for NLO applications.