Crystal growth, structure and characterization of diglycine zinc dipicrate: Centrosymmetric crystal exhibiting second harmonic generation efficiency

<p></p> <p>Single crystals of diglycine zinc dipicrate (DZD) were grown by the slow evaporation solution growth technique from ethanol at room temperature. The structure is elucidated by single crystal XRD analysis and it belongs to the triclinic system with centrosymmetric space group P_ī. The crystallinity of the material was confirmed by powder X-ray diffraction analysis. The functional groups present in the molecule are identified by FT-IR analysis and the band gap energy is estimated using diffuse reflectance data by the application of Kubelka–Munk algorithm. Investigation of the intermolecular interactions and crystal packing <i>via</i> Hirshfeld surface analysis, based on single-crystal XRD, reveals the close contacts associated with molecular interactions. Fingerprint plots of the Hirshfeld surfaces were used to locate and analyze the percentage of hydrogen-bonding interactions.The data are analysed by combined results of single crystal XRD and electronic structure calculations. Theoretical calculations done by density functional theory(DFT) gives an idea about structure-function relationship. The second harmonic generation efficiency (SHG) is estimated using the Kurtz and Perry technique and it reveals second order nonlinearity. The observation of a centrosymmetric crystal exbiting NLO character is rationalized.</p

Synthesis, crystal growth, structural characterization and theoretical investigations of bis(benzene-1,2-dicarboxylato)bis(thiourea)zinc

<p></p> <p>Single crystals of bis(benzene-1,2-dicarboxylato)bis(thiourea)zinc (ZTP) were successfully grown by slow evaporation solution growth technique and characterized by means of single-crystal X-ray diffraction analysis. The compound C₁₈H₁₈N₄O₈S₂Zn crystallizes at monoclinic system with centrosymmetric space group C2/<i>c</i> and its structure is built up from tetrahedral (ZnO₂S₂) linked to each other through the phthalate and thiourea groups. The good crystallinity of the as-synthesized specimen is confirmed by the powder X-ray diffraction pattern. The band gap energy is estimated using diffuse reflectance data by the application of Kubelka – Munk algorithm. Photoluminescence exhibits fluorescent emission of ZTP in the solid state at room temperature. The scanning electron microscopy (SEM) images reveal the surface morphology and the presence of Zn(II) in the specimen is further confirmed by the energy dispersive X-ray spectroscopy. Theoretical calculations were performed using density functional theory (DFT) method to derive the optimized geometry, dipole moment and polarizability.</p