Rafika Bouchene

Bis[4-(di­methyl­amino)­pyridinium] tetra­chlorido­cuprate(II)

The asymmetric unit of the title salt, (C7H11N2)2[CuCl4], comprises half a tetrahedral tetrachloridocuprate anion, being located on a twofold axis, and a protonated 4-(dimethylamino)pyridine cation. The geometry around the CuII ion is highly distorted with the range of Cl—Cu—Cl angles being 94.94 (1)–141.03 (1)°. The crystal structure is stabilized by N—H⋯Cl and C—H⋯Cl hydrogen bonds. In the three-dimensional network, cations and anions pack in the lattice so as to generate chains of [CuCl4]2− anions separated by two orientations of cation layers, which are interlocked through π–π stacking contacts between pairs of pyridine rings, with centroid–centroid distances of 3.7874 (7) Å.

Bis(3-amino­pyrazine-2-carboxyl­ato-κ2N1,O)di­aqua­nickel(II) dihydrate

In the title compound, [Ni(C5H4N3O2)2(H2O)2]·2H2O, the NiII ion lies on an inversion center and is coordinated in an slightly distorted octahedral environment by two N,O-chelating 3-aminopyrazine-2-carboxylate (APZC) ligands in the equatorial plane and two trans-axial aqua ligands. In the crystal, O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds involving the solvent water molecules, aqua and APZC ligands form layers parallel to (010). These layers are linked further via O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds involving the axial aqua ligands, amino groups and the carboxylate groups of the APZC ligands, forming a three-dimensional network.

4-(Dimethyl­amino)­pyridinium tetra­chloridoferrate(III)

The title salt, (C7H11N2)[FeCl4], consists of one essentially planar (the r.m.s. deviation for all non-H atoms being 0.004 Å) 4-(dimethylamino)pyridinium cation and a tetrahedral tetrachloridoferrate(III) anion. The cations and anions are arranged in layers parallel to (010). Besides electrostatic interactions, the crystal packing features N—H⋯Cl and C—H⋯Cl hydrogen bonds between cations and anions, forming a three-dimensional network.

Bis(3-amino-pyrazine-2-carboxyl-ato-κ(2)N(1),O)diaqua-cobalt(II).

In the title compound, [Co(C5H4N3O2)2(H2O)2], the CoII atom is situated on a twofold rotation axis and is N,O-chelated by two 3-aminopyrazine-2-carboxylate anions and additionally bonded to the O atoms of two water molecules, leading to a slightly distorted octahedral coordination environment. The crystal packing is dominated by intermolecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonding involving the water molecules and amino groups as donors and carboxylate O atoms, as well as the non-coordinating heterocyclic N atoms as acceptors, resulting in a three-dimensional network. An intramolecular N—H⋯O hydrogen bond is also observed.

5-Amino-3-carb­oxy-1H-1,2,4-triazol-4-ium nitrate monohydrate

The two-dimensional crystal packing of the title compound, C(3)H(5)N(4)O(2) (+)·NO(2) (-)·H(2)O, results from the stacking of well separated layers (i.e. with nothing between the layers) parallel to the (-113) plane in which adjacent cations adopt a head-to-head arrangement such that two -COOH groups are linked via two water mol-ecules (the water O atom behaves simultaneously as donor and acceptor of hydrogen bonds) and two -NH(2) groups are linked through two nitrate anions. This arrangement leads to alternating hydro-philic and hydro-phobic zones in which O-H⋯O and N-H⋯O hydrogen bonds, respectively, are observed.

A simple hydrated salt with a complex hydrogen-bonding network: tetrakis(5-amino-3-carboxy-4H-1,2,4-triazol-1-ium) hexachloridocadmate(II) tetrahydrate

In the title cadmium chloride salt, (C3H5N4O2)4[CdCl6]·4H2O, the asymmetric unit comprises two N-protonated 5-amino-3-carboxy-4H-1,2,4-triazol-1-ium cations, half a [CdCl6](4-) anion and two molecules of water. The Cd(2+) cation is located on a centre of inversion and is coordinated by six chloride anions, forming a distorted octahedron. In the crystal structure, alternating layers of cations and anions are arranged along the [101] direction, forming a three-dimensional supramolecular network via a combination of hydrogen-bonding and aromatic stacking interactions.

2-Amino-3-carb­oxy­pyridinium chloride hemihydrate

The asymmetric unit of the title compound, C6H7N2O2 +·Cl−·0.5H2O, consists of two protonated 2-amino-3-carboxypyridine cations, two chloride anions and one molecule of water. The crystal packing can be described as alternating layers of cations and anions parallel to (110), which are linked together by Ow—H⋯Cl interactions. In the crystal, four types of classical hydrogen bonds are observed, viz. cation–anion (O—H⋯Cl and N—H⋯Cl), cation–cation (N—H⋯O), cation–water (N—H⋯Ow) and water–anion (Ow—H⋯Cl), resulting in the formation of an infinite three-dimensional network.

Synthesis, X-ray diffraction and Hirshfeld surface analysis of two new hybrid dihydrate compounds: (C6H22N4)[SnCl6]Cl2·2H2O and (C8H24N4)[SnCl6]Cl2·2H2O

Two new organic–inorganic hybrid compounds have been synthesized from the same starting materials. Their crystal structures exhibits alternating inorganic and organic stacking sheets or layers in (II), with Cl− ions and water molecules occupying the space in between.

Selective synthesis of (3-ferrocenylprop-2-en-1-yl)triphenylphosphonium iodide: crystal structure determination of two polymorphs

This work is part of a project studying the reactivity of a new ferrocenyl allylammonium salt, [3-(trimethylazaniumyl)prop-1-en-1-yl]ferrocene iodide, (1+)·I-, with different nucleophiles. With nitrogen-based nucleophiles, different ferrocenyl allylamine isomers have been synthesized successfully in good yield. Optimization of the basicity of the reaction medium has allowed selection of the best operating conditions to obtain the targeted isomer. In a similar way and in order to introduce phosphorus-containing functional groups, the reaction of ammonium salt (1+)·I- with a phosphorus nucleophile, namely triphenylphosphane, was attempted. It was then possible to isolate single crystals of (3-ferrocenylprop-2-en-1-yl)triphenylphosphonium iodide, [Fe(C5H5)(C26H23P)]I, which is shown to crystallize in two concomitant polymorphic forms, viz. a triclinic form, (I), in the space group P-1, and a monoclinic form, (II), in the space group P21/c. In the inter-ion packing of polymorph (I), the cations form bilayer ribbons via C-H...π and π-π stacking interactions. In polymorph (II), where π-π interactions do not occur, adjacent molecules are joined by C-H...π interactions into a one-dimensional helical arrangement along the b axis.

An X-ray study of new hybrid systems of Fe(III) and Cu(II) based anions

Organic-inorganic hybrid compounds represent one of the most important developments in materials chemistry in recent years [1]. The role of weak intermolecular interactions in the stabilization of these hybrid systems is one of the main targets of our investigation in crystal engineering study. In continuation of our research on N-aromatic heterocyclic-metal halide salts, the X-ray crystal structures of 4-dimethylaminopyridinium (HDMAP) cation with tetrachlorocuprate (II) (1) and tetrachloroferrate (III) (2) anions is reported [2,3]. In (1), Cu(II) is situated on a twofold rotation axis (4 e). The [CuCl4]2ions are highly distorted with a mean trans angle of 141.02(1)° as a result of hydrogen bonding interactions with two nearly planar HDMAP cations (0.0295 Å mean deviation). The crystal structure of (1) is stabilized by N—H...Cl and C—H...Cl hydrogen bonds. In the three dimensional network, cations and anions pack in the lattice so as to generate chains of [CuCl4]2anions separated by two orientations of cation layers, which are interlocked through π–π tacking contacts between pairs of pyridine rings, with centroid–centroid distances of 3.7874 (7) Å. In (2), the protonoted 4-(dimethylamino) pyridine cation is essentially planar (the r.m.s deviation for all non-H atoms being 0.004 Å). The packing of the ionic entities is realized by alternating layers of cations and [FeCl4]anions parallel to (010) whereby the cations are oriented in a zig-zag fashion. The crystal packing is stabilized by N—H...Cl and C—H...Cl hydrogen bonds forming a three-dimensional network.