Synthesis and crystal structure of a heterobimetallic cadmium-sodium complex of 1,3,5-triazine-2,4,6-trione, [CdNa2(C3H2N3O3)4(H2O)8].

Heterobimetallic crystals of a cadmium-sodium complex of 1,3,5-triazine-2,4,6-trione, namely, µ-aqua-1:2κ2 O:O-hepta-aqua-1κ3 O,2κ2 O,3κ2 O-bis-(µ-4,6-dioxo-1,4,5,6-tetra-hydro-1,3,5-triazin-2-olato)-1:2κ2 O 2:N 1;2:3κ2 N 1:O 2-bis-(4,6-dioxo-1,4,5,6-tetra-hydro-1,3,5-triazin-2-olato)-1κO 2,3κO 2-2-cadmium-1,3-disodium, [CdNa2(C3H2N3O3)4(H2O)8], were grown by the single gel diffusion technique. The asymmetric unit of the title compound comprises four 1,3,5-triazine-2,4,6-trione ligands, two sodium atoms and one cadmium atom. Of the four ligands, two are monodentately coordinated to two Na atoms. The third ligand is coordinated bidentately to one Na and the Cd atom and the fourth is also coordinated bidentately to the Cd atom and the other Na atom. All the metal atoms are six-coordinate with a distorted octa-hedral geometry. The water mol-ecules bridge the Na atoms, constructing coordination polymer chains along the a axis and hence are linked by two Cd and one Na coordinations through the cyanuric acid ligands present in the coordination polymer chains, generating a two-dimensional coordination polymer in the (110) plane. The polymer formation is further assisted by means of many inter-molecular and intra-molecular N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds between the water mol-ecules and the ligands.

Growth and characterisation of a new polymorph of barium maleate: a metal organic framework.

A new polymorph of barium maleate (BM) with chemical formula C24H14O24Ba5⋅7H2O is grown by modified gel method. Transparent plate like crystals of dimensions 9×4×1 mm(3) were obtained. Single crystal X-ray Diffraction analysis was done to determine the structure and the crystal belongs to triclinic system, P-1 space group with cell dimensions a=7.2929(3) Å, b=10.5454(4) Å, c=14.2837(6) Å, α=102.0350(10)°, ß=99.1580(10)°, γ=102.9170(10)°. Hydrogen bonding stabilises the two dimensional polymeric crystal structure. Fourier Transform Infrared spectroscopic method was utilised for the analysis of various functional groups present in the complex. Elemental analysis confirmed the stoichiometry of the complex. Thermal properties of the crystal were studied by TGA/DTA. The material melts at 368°C. The optical transparency of the crystal was studied using UV-Visible absorption spectra. The optical band gap is found to be 3.35 eV.

Growth and characterisation of crystals of a new organic complex of thiourea with quinine sulphate dihydrate: an NLO material.

An organic complex of thiourea and quinine sulphate dihydrate (TQS) has been grown for the first time by gel method. The structure determination was done by the single crystal XRD technique. The crystal belongs to monoclinic system, P21 space group with cell dimensions a=6.228 (3) Å, b=20.4051 (4) Å, c=11.0600 (6) Å, ß=101.9811(2)°. The crystal structure is stabilized by the hydrogen bonding. The functional groups present in the complex were analysed by the Fourier Transform Infrared spectroscopic method. The stoichiometry of the complex was confirmed by the elemental analysis. Thermal properties of the complex were determined by TGA and DTA methods and the complex melts at 222.53°C. The optical transparency of the crystal was studied using UV-Visible absorption spectra. The optical band gap is found to be 2.5 eV. The SHG conversion efficiency of TQS was investigated using Kurtz and Perry method and found to be higher than that of the reference material, potassium dihydrogen phosphate (KDP).

Crystal structure, spectral, thermal and dielectric studies of a new zinc benzoate single crystal.

Single crystals of zinc benzoate with a novel structure were grown in gel media. Sodium metasilicate of gel density 1.04 g/cc at pH 6 was employed to yield transparent single crystals. The crystal structure of the compound was ascertained by single crystal X-ray diffractometry. It was noted that the crystal belongs to monoclinic system with space group P2(1)/c with unit cell parameters a=10.669(1)Å, b=12.995(5)Å, c=19.119(3)Å, and ß=94.926(3)°. The crystal was seen to possess a linear polymeric structure along b-axis; with no presence of coordinated or lattice water. CHN analysis established the stoichiometric composition of the crystal. The existence of functional groups present in the single crystal system was confirmed by FT-IR studies. The thermal characteristic of the sample was analysed by TGA-DTA techniques, and the sample was found to be thermally stable up to 280°C. The kinetic and thermodynamic parameters were also determined. UV-Vis spectroscopy corroborated the transparency of the crystal and revealed the optical band gap to be 4 eV. Dielectric studies showed decrease in the dielectric constant of the sample with increase in frequency.