Ridha Zouari

Crystal structure, DSC, IR and Raman studies in the compound NH3(CH2)5NH3HgCl4

Abstract The penthylene-diammonium tetrachloromercurate (II) salt is triclinic centrosymmetric with the following unit cell dimensions: a= 7.7672(4) A , b= 7.9754(6) A , c= 10.9471(6) A , α = 98.915(2) o , β = 109.363(2) o and γ = 91.463(2) o with Z = 2. The structure consists of disordered penthylene-diammonium chains sandwiched between HgCl 6 octahedral layers. The chloromercurate sheet is packed as a result of hydrogen bonding to 1,5-penthylene diammonium ions. Ammonium groups at the ends of the chains fit into cavities of adjacent HgCl 4 layers and form N-H…Cl hydrogen bonds. Thermal analysis indicates a hysteresis phenomenon characteristic of a first order phase transition. The Raman and IR spectra of polycrystalline samples of NH 3 (CH 2 ) 5 NH 3 HgCl 4 investigated at room temperature illustrate the conformational and statistical disorder of the organic chain. The system progressively gets ordered at low temperature, as the disorder of organic chains is due to a thermal effect.

A New Mononuclear Complex: Structure, Vibrational (FT-IR and Raman), Hirshfeld Surfaces Analysis, Electrical Properties and Equivalent Circuit

The present paper aims to develop the synthesis, crystal structure, and properties of Zn(C7H5NO4)Cl2.H2O compound investigated by vibrational study, thermal analysis and dielectric measurements. The single crystal X-ray diffraction investigation reveals that the studied compound crystallizes in the orthorhombic system with space group Pnna according to the following lattice parameters: a=13.8816(4) A, b=10.3602(3) A, c=7.8967(2) A and Z=4. The presence of the key functional groups in the molecule has already been confirmed by Fourier transform infrared (FT-IR) analysis. Thermal behaviour of this sample, studied by TGA and DSC exhibit two anomalies at 345 and 386K. The hydrogen bonding plays a significant role in the stabilization of the structure. Such a parallel displaced structure has also a contribution from π-σ non-covalent interactions (C-H…π and C-O…π stacking between the C-H groups and C-O groups with the benzene rings). The dipicolonic acid (2,6-pyridinedicarboxylic acid) ligand coordinated to the Zn(II) ions through a nitrogen atom of pyridine ring, two oxygen atom of carboxylic group and two chloride atoms as a tridentate ligand. Hirshfeld surface analysis of the intermolecular interactions in crystal structures have been used to scrutinize molecular shapes. The characteristic features of 13C solid state CP/MAS-NMR applications showed five isotropic resonances, confirming the structure determined by XRD. Its dielectric properties as a function of temperature and frequency in the ranges 298-418 K and 209 Hz-5 MHz are measured. The Cole-Cole (Z’ versus Z’’) plots are analyzed by fitting to an equivalent electrical circuit model, consisting of a circuit elements; grain, grain boundary, electrode-solid interface polarization and Warburg resistance. Each circuit elements is formed by a parallel combination resistance (R) and constant phase elements (CPE). The grain conductivity as well as the activation energy depending to of temperature, via impedance technique, besides the activation energy due to relaxation time as function of temperature, have been studied showing two anomalies, which are also detected by the TGA and DSC. They could be explained by not only a phase transition and reorientation hopping between equivalent sites at 343K but also the disappearance of the water molecule of the structure at 388K.

Redetermination of K4[Bi2Cl10]·4H2O

In comparison with the previous refinement of tetrapotassium di-μ-chlorido-bis[tetrachloridobismuthate(III)] tetrahydrate [Volkova, Udovenko, Levin & Shevchenko (1983). Koord. Khim. 9, 356–360], the current redetermination reveals anisotropic displacement parameters for all non-H atoms, localization of the H atoms, and higher precision of lattice parameters and interatomic distances. The crystal structure is built up of edge-sharing [Bi2Cl10]4− double octahedra with the bridging Cl atoms situated on a mirror plane, three K+ counter-cations (two of which are on mirror planes), and two water molecules that are solely coordinated to the K+ cations. These building units are linked into a three-dimensional network structure. Additional O—H⋯Cl hydrogen bonds between the water molecules and the complex anions stabilize this arrangement.

1,3-Propanediammonium Tetrachloromercurate

The title compound, (C3H12N2)[HgCl4], contains layers of tilted corner-sharing chloromercurate octahedra, with Hg—Cl distances ranging from 2.397 (2) to 2.839 (2) A. These layers are interconnected by N—H⋯Cl bonds to the cations, building a three-dimensional network. The cation has a disordered propane chain.

Experimental, Theoretical, Characterization and TD-DFT Analysis of a Complex [Cu(CAP) 2 Cl 2 ]

The present paper work investigates a new complex bis (4-amino-2-chloropyridinium) dichlorocuprate(II) with the formula [Cu(C5H5ClN2)2Cl2] abbreviated as [Cu(CAP)2Cl2]. The sample was characterized by X-ray diffraction, Hirshfeld surface analysis, thermal analysis, FT-IR, FT-Raman and CP/MAS-NMR spectroscopy and optical properties. It was crystallized in the monoclinic system with space group P21/n. The crystal structure was stabilized by the presence of N–H⋯Cl hydrogen bond, forming a three-dimensional network. The Hirshfeld surfaces and the 2D fingerprint plots were analysed in the intermolecular interactions within the crystal network. Solid state CP/MAS-NMR spectra showed five isotropic resonances, 13C confirming the existence of five non-equivalent carbon atoms of the asymmetric unit determined by X-ray diffraction. The density functional theory using B3LYP/LanL2DZ basis sets, showed an excellent overall agreement between the calculated values and the experimental data. The energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital was determined by a time-dependent DFT approach.

Synthesis, structure and Hirshfeld surface analysis, vibrational and DFT investigation of (4-pyridine carboxylic acid) tetrachlorocuprate (II) monohydrate

The new organic–inorganic hybrid compound [C6H6NO2]2CuCl4⋅H2O has been grown from an aqueous mixture by the solvent evaporation method. X-ray diffraction, Hirshfeld surface analysis, FT-IR and FT-Raman spectroscopy were applied to characterize the composition and crystal structure of the complex. It is crystallized in a triclinic system (P1̄

Elaboration, Structural, Vibrational, DSC Investigations and Hirshfeld Surface Analysis of New Organic–Inorganic Hybrid Compound: [H2mela]Cu2Br6

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Crystal structure of potassium bismuth dichloride sulfate, KBiCl2SO4

space group). The structure of this compound might be described as layered with two parallel anionic and cationic layers. The first layer is composed of isolated square planar [CuCl4]2− and the second layer of [C6H6NO2]2+. The water molecule is placed between the layers formed by organic cations along the b axis. Network hydrogen-bonding and π–π interactions lead to the formation of a three-dimensional architecture. Hirshfeld surface analysis for visually analysing intermolecular interactions in crystal structures employing molecular surface contours and 2D fingerprint plots has been used to scrutinize molecular shapes. The vibration properties of this structure were studied by IR spectroscopy and Raman scattering. Vibration spectra were also calculated theoretically by means of Gaussian 03 package of programs within the density functional theory (DFT) framework using the B3LYP/LanL2DZ level of theory. To sum up, good consistency is found between the calculated results on one hand and the IR and Raman spectra and experimental structure on the other. This study confirms the presence of the organic cations [C6H6NO2]2+, the inorganic anions [CuCl4]2− and H2O.

Redetermination of Bis(1,2-ethanediammonium) Dichloride Tetrachloromercurate(II)

The present paper accounts for the synthesis, crystal structure, differential scanning calorimetry and vibrational spectroscopy of a new compound (1,3,5-triazinidium-2,4,6-triamine) hexabromidodicuprate (II) grown at room temperature by slow evaporation of aqueous solution. From X-ray diffraction data collected at room temperature, it is concluded that it crystallizes in the monoclinic system (P21/c space group). The anion and the cation are linked by N–H···Br hydrogen bonds. Furthermore, the room temperature IR and Raman spectra of the title compound were recorded and analyzed. The differential scanning calorimetric has also been investigated. Hirshfeld surfaces were used to confirm the existence of inter-molecular interactions in the compound.

Synthesis, infra-red, MAS-NMR characterization, structural study and electrical properties of the new compound [C5H6ClN2]2Cd3Cl8

0.8556(8) 0.9631(8) 0.4151(4) 0.015(2) 0.019(3) 0.032(4) 0.001(2) 0.003(2) -0.003(3) 0(2) 4a 1.1548(7) 0.8985(9) 0.3234(4) 0.015(2) 0.035(4) 0.028(4) 0.001(3) 0.001(2) 0.001(3) 0(3) 4a 1.1316(9) 0.7520(9) 0.4625(4) 0.023(3) 0.041(4) 0.027(4) 0.001(3) -0.003(3) 0.020(3) 0(4) 4a 0.8818(8) 0.6704(8) 0.3476(5) 0.021(2) 0.019(3) 0.046(4) -0.003(2) -0.001(3) -0.007(3)