Phase matchable semiorganic NLO material for frequency doubling: L-Arginine tetrafluoroborate

Crystal structures and vibrational spectra of L-argininium(2+) bis(tetrafluoroborate) and L-argininium(2+) bis(perchlorate)

In the present work crystal structures of (L-ArgH₂)(BF₄)₂ (I) and (L-ArgH₂)(ClO₄)₂ (II) isostructural salts have been determined. They crystallize in triclinic system with space group P1 and Z = 1. Structure features of the (I) and (II) were compared with respective data of previously known (L-ArgH)(BF₄) and (L-ArgH)(ClO₄) salts with singly charged L-argininium(+) cation. Infrared and Raman spectra of the (I) and (II) are compared with spectra of (L-ArgH)(BF₄) and (L-ArgH)(ClO₄) salts. The presence of cation and anions and hydrogen bonds between them are reflected in the IR and Raman spectra. The crystals (I) and (II) exhibit second harmonic generation activity.

Two tartratoborates with hybrid anionic groups from unusual condensation reactions

Two novel tartratoborates, namely, K₂[(C₄H₂O₆)(B₃O₄H)](H₂O) (1) and KCu₂[(C₄H₂O₆)₂B](H₂O)_2.5 (2), have been successfully synthesized by solvothermal reactions. They feature different kinds of structural types based on hybrid borate-tartrate motifs. The structure of compound 1 features a 3D network composed of novel [(C₄H₂O₆)₂(B₃O₄H)₂]^4- anionic groups interconnected by K⁺ cations. The [(C₄H₂O₆)₂(B₃O₄H)₂]^4- anion was formed by the condensation of two (B₃O₈H)^6- groups and two tartrate anions, and such condensation reaction has never been reported previously. Compound 2 exhibits a novel 3D network structure in which 2D {Cu₂[(C₄H₂O₆)₂B](H₂O)₂}^- layers are further interconnected via K⁺ ions. The [(C₄H₂O₆)₂B]^5- anion was formed by the condensation of two tartrate anions with a B(OH)₄^- unit. Magnetic measurements reveal a dominant antiferromagnetic interaction between neighboring Cu²⁺ ions in compound 2. Furthermore, UV-vis and infrared spectra and thermal analyses were also performed.

Growth and physicochemical properties of L-phenylalaninium maleate: a novel nonlinear optical crystal

Single crystals of novel organic nonlinear optical material, L-phenylalaninium maleate (LPM) having dimensions up to 10 × 6 × 6 mm(3) were grown by slow evaporation solution growth technique at room temperature. The grown crystals were confirmed by single crystal X-ray diffraction studies and the various functional groups were identified by FT-IR spectroscopic analysis. The optical properties were studied by optical absorption, second harmonic generation (SHG), photoconductivity and photoluminescence (PL) studies and reported for the first time. The optical band gap energy and SHG efficiency were found to be 4.85 eV and 1.5 times higher than KDP crystals. Negative photoconducting nature was confirmed by photoconductivity studies. Photoluminescence studies confirm the suitability of the sample for blue and green radiations. The title compound was also subjected to TG/DTA analysis and dielectric studies. Layer like growth pattern was analyzed by SEM micrograph.