Synthesis, growth, structural and optical studies of organic nonlinear optical material – Piperazine-1,4-diium bis 2,4,6-trinitrophenolate

The polymeric title complex, poly[hexa-μ-aqua-diaquatetra-μ-cyanurato-tetralithium] [Li4(C3H2N3O3)4(H2O)7] n , synthesized at room temperature from an aqueous solution of lithium hydroxide and cyanuric chloride, crystallizes in the triclinic space group P\overline{1}. There are two distinct Li+ cations in the asymmetric unit, one of which, Li1, has distorted trigonal–bipyramidal geometry and is coordinated via oxygen to two cyanurate anions occupying equatorial positions, and three water molecules, two in the axial positions and the third in an equatorial position. One of the axial water ligands and the equatorial water ligand are involved in bridging to a crystallographically equivalent Li1 cation. A centre of inversion lies between the two Li1 cations and the Li1...Li1 distance is 3.037 (5) Å. The remaining axial water ligand bridges to the second Li cation, Li2, which is disordered over two crystallographic sites with approximately equal occupancy, and has an Li1...Li2 distance of 3.438 (7) Å. The terminal Li2 cation is coordinated to three water molecules and an oxygen atom from a cyanuric anion and has a distorted tetrahedral geometry. A three-dimensional network of intermolecular hydrogen bonds involving N—H...O, O—H...O and O—H...N interactions serves to hold the structure together, as confirmed by a Hirshfeld surface analysis. The title compound was further characterized using IR and UV–vis spectroscopy and TG–DTA analysis.

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“…Overall a supramolecular hydrogen-bonded assembly is formed, as seen previously in other systems (Suguna et al, 2014;Jeseentharani et al, 2010).…”

Section: Figuresupporting

confidence: 74%