Hammouda Chebbi

Crystal structure of 1-cyclohexylpiperazine-1,4-diium dichromate(VI)

Single crystals of 1-cyclohexylpiperazine-1,4-diium dichromate(VI), (C10H22N2)[Cr2O7], were obtained by slow evaporation at room temperature from an aqueous solution of potassium dichromate, hydrochloric acid and 1-cyclohexylpiperazine. (C10H22N2)[Cr2O7] is triclinic (P

Spectroscopic characterization and room-temperature structure of bis(4-aminopyridinium) dichromate

\bar 1

Structure cristalline, caractérisation spectroscopique, calcul DFT et analyse de surface Hirshfeld du perchlorate de p-toluidinium

) with a = 10.351(2) Å, b = 12.766(3) Å, c = 6.111(1) Å, α = 91.50(2)°, β = 104.26(3)°, γ = 94.91(2)°, V = 778.8(3) Å3, and Z = 2. The structure determination performed from single crystal X-ray diffraction data leads to R1/wR2 reliability factors of 0.032/0.078. The asymmetric unit of the title salt C10H22N22+·Cr2O72−, consists of one 1-cyclohexylpiperazine-1,4-diium dication and one dichromate dianion. These entities are linked together by N–H···O hydrogen bonds to form {(C10H22N2)[Cr2O7]}n infinite chains lying parallel to the (100) plane and running along the c axis. The intermolecular N–H···O hydrogen bonds link these chains into a two-dimensional network structure consolidated through C–H···O weak interactions.

Theoretical and Experimental Study of the Reaction of 2-Guanidinobenzimidazole on a Series of meta -Substituted Benzaldehydes

A new organic chromate, ethylenediammonium chromate, [NH3(CH2)2NH3][CrO4], has been isolated. Its structure is built up from organic cations and chromate anions, which pack in columns parallel to the a axis. The cohesion and stability of the ionic arragement result from a three-dimensional network of N—H⋯O hydrogen bonds.

Structure cristalline et analyses thermique et de surface Hirshfeld du diperchlorate de 4-aza­niumyl-2,2,6,6-tétraméthylpipéridin-1-ium

Crystals of bis(4-aminopyridinium) dichromate (C5H7N2)2[Cr2O7] (1) were isolated via slow solvent evaporation and characterized by energy dispersive spectroscopy (EDS), infrared (IR) and ultratviolet-visible (UV-Vis) spectroscopy, and single crystal X-ray diffraction. The room-temperature (RT; 298 K) phase of 1 crystallizes in the monoclinic space group P21/m. Its asymmetric unit consists of two crystallographically independent 4-aminopyridinium cations (A and B) and two halves of symmetry-independent dichromate anions (A and B). Cations and anions are linked with the aid of several moderate N–H⋯O hydrogen bonds and weak C–H⋯O interactions resulting in a three-dimensional supramolecular network. The crystal structure is further stabilized by extensive π–π stacking interactions between adjacent pyridine rings. A comparison of the structure of the RT phase of 1 and that of the low temperature (LT; 150 K) phase is described.

Crystal structure of Na4Co7−xAl0.67x(As1−yPyO4)6 (x = 1.60; y = 0.116)

The title compound, 4-ammonio-2,2,6,6-tetramethylpiperidinium chromate dihydrate, (C9H22N2)[CrO4]*2H2O, crystallizes in the monoclinic system with one organic cation and one chromate anion in the asymmetric unit, together with three independent sites for water molecules, two of which have their O atoms located on twofold axes. The structure is composed of layers built up from CrO4(2-) tetrahedra and water molecules alternating with C9H22N2(2+) cations and additional water molecules. Two types of hydrogen bonds, O-H...O and N-H...O, ensure the cohesion and stability of the structure.

4-Aza-niumyl-2,2,6,6-tetra-methyl-piperidin-1-ium dinitrate.

A new organic perchlorate, C7H10N+·ClO4 −, was synthesized by slow evaporation at room temperature and its crystal structure was determined. This compound was characterized by powder XRD, IR, and UV–Vis spectroscopy. The DFT optimized structure at the B3LYP/6–311++G (d,p) level was compared with the experimentally determined molecular structure in the solid state. Hirshfeld surface and fingerprint plots are presented and discussed.

Chromate de 2,2-diméthylpropylènediammonium

The syntheses of a variety of 1,3,5-triazinebenzimidazoles obtained by the cyclocondensation reaction of 2-guanidinobenzimidazole with a series of meta-substituted benzaldehydes were reported. The prepared compounds were fully characterized by IR and NMR spectroscopies. Based on the density functional theory(DFT) calculations method, quantum chemical calculations were performed by Gaussian 09 set of programs. All possible transition states, reactants and products were fully optimized at the hybrid density functional B3LYP level using the 6-311+G(d,p). The geometries of five possible tautomers of 2-amino-4-aryl[1,3,5]triazino[1,2-a]benzimidazoles were optimized in ethanol, using conductor like polarizable continuum(CPCM) in the gas phase. The energetic diagrams of tautomeric equilibrium showed that form A is the most stable tautomer which proved to be in accordance with the X-ray diffraction structure analysis. In order to interpret the reaction mechanism, the chemical reactivity was studied using local and global reactivity indexes.