Lahcen El Ammari
Jackson State University
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Featured researches published by Lahcen El Ammari.
Acta Crystallographica Section E-structure Reports Online | 2013
Najat Abbassi; El Mostapha Rakib; Abdellah Hannioui; Mohamed Saadi; Lahcen El Ammari
In the title compound, C19H21N3O5S·H2O, the central indazole system is essentially planar (r.m.s. deviation = 0.012 Å), while both the benzene ring and the mean plane defined by the non-H atoms of the ethyl propionic ester unit (r.m.s. deviation = 0.087 Å) are nearly perpendicular to the indazole plane, as indicated by the dihedral angles of 82.45 (8) and 75.62 (8)°, respectively. Consequently, the molecule adopts a U-shaped geometry. In the crystal, the water molecule, which is linked to the indazole system by a strong O—H⋯N hydrogen bond, is also involved in two additional N—H⋯O and O—H⋯O interactions, which link the organic molecules into chains along the b-axis direction.
Acta Crystallographica Section E-structure Reports Online | 2013
A. Oukhrib; Ahmed Benharref; Mohamed Saadi; Moha Berraho; Lahcen El Ammari
The title compound, C16H24Br2O, was synthesized from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from the essential oil of the Atlas cedar (Cedrus atlantica). The molecule contains fused six- and seven-membered rings, each linked to a three-membered ring. The six-membered ring has a half-chair conformation, while the seven-membered ring displays a chair conformation. The dihedral angle between the mean planes through the six- and seven-membered rings is 39.55 (12)°. The two three-membered rings, linked to the six- and seven-membered rings, are nearly perpendicular to the six-membered ring, making dihedral angles of 78.6 (2) and 80.5 (2)°, respectively. The absolute structure was established unambiguously from anomalous dispersion effects. In the crystal, each molecule is linked to its symmetry-equivalent partner by C—H⋯O hydrogen bonds, forming zigzag chains parallel to [100].
Acta Crystallographica Section E: Crystallographic Communications | 2015
Jamal Khmiyas; A. Assani; Mohamed Saadi; Lahcen El Ammari
The transition-metal orthophosphate Na1.67Zn1.67Fe1.33(PO4)3 cristallizes in an alluaudite-type structure. The chains characterizing the alluaudite structure are then built up from [M 2O10] (M = Fe/Zn) units alternating with [ZnO6] octahedra. This structure is characterized by a cationic disorder in one tunnel and in the general position.
Acta Crystallographica Section E-structure Reports Online | 2011
A. Assani; Lahcen El Ammari; Mohammed Zriouil; Mohamed Saadi
The title compound, Ag2Ni3(HPO4)(PO4)2, has been synthesized by the hydrothermal method. Its structure is formed by two types of chains running along the b axis. The first chain results from a linear and continuous succession of NiO6 octahedra linked to PO4 tetrahedra by a common vertex. The second chain is built up from two adjacent edge-sharing octahedra (dimers) whose ends are linked to two PO4 tetrahedra by a common edge. Those two types of chains are linked together by the phosphate groups to form polyhedral sheets parallel to the (001) plane. The three-dimensional framework delimits two types of hexagonal tunnels parallel to the a-axis direction, at (x, 1/2, 0) and (x, 0, 1/2), where the Ag atoms are located. Each silver cation is surrounded by eight O atoms. The same Ag+ coordination is found in other phosphates with the alluaudite structure, for example, AgMn3(PO4)(HPO4)2. Moreover, O—H⋯O hydrogen bonds link three PO4 tetrahedra so as to build a three-dimensional network.
Acta Crystallographica Section E-structure Reports Online | 2013
Najia Ourhriss; Ahmed Benharref; Mohamed Saadi; Lahcen El Ammari; Moha Berraho
The title compound, C17H24Cl4, was synthesized from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The molecule is built up from fused six- and seven-membered rings and two three-membered rings from the reaction of β-himachalene with dichlorocarbene. The six-membered ring shows a chair conformation, whereas the seven-membered ring displays a boat conformation.
Acta Crystallographica Section E-structure Reports Online | 2013
Ghaleb Alhakmi; A. Assani; Mohamed Saadi; Lahcen El Ammari
The title compound, lead trimanganese tris(orthophosphate), has been synthesized by hydrothermal methods. In this structure, only two O atoms are in general positions and all others atoms are in the special positions of the Imma space group. Indeed, the atoms in the Wyckoff positions are namely: Pb1 and P1 on 4e (mm2); Mn1 on 4b (2/m); Mn2 and P2 on 8g (2); O1 on 8h (m); O2 on 8i (m). The crystal structure can be viewed as a three-dimensional network of corner- and edge-sharing PO4 tetrahedra and MnO6 octahedra, building two types of chains running along the b axis. The first is an infinite linear chain, formed by alternating MnIIIO6 octahedra and PO4 tetrahedra which share one vertex. The second chain is built up from two adjacent edge-sharing octahedra (MnII 2O10 dimers) whose ends are linked to two PO4 tetrahedra by a common edge. These chains are linked together by common vertices of polyhedra in such a way as to form porous layers parallel to (001). These sheets are bonded by the first linear chains, leading to the appearance of two types of tunnels, one propagating along the a axis and the other along b. The PbII ions are located within the intersections of the tunnels with eight neighbouring O atoms in form of a trigonal prism that is capped by two O atoms on one side. The three-dimensional framework of this structure is compared with similar phosphates such as Ag2Co3(HPO4)(PO4)2 and Ag2Ni3(HPO4)(PO4)2.
Acta Crystallographica Section E-structure Reports Online | 2011
Y. Ouzidan; Youssef Kandri Rodi; Frank R. Fronczek; Ramaiyer Venkatraman; Lahcen El Ammari; El Mokhtar Essassi
The molecular structure of the title compound, C17H20N4O5, contains a central fused-ring system, comprised of six- and five-membered rings. This unit is linked by C2 chains to two 2-oxo-1,3-oxazolidine five-membered rings. The central fused-ring system is essentially planar, with a maximum deviation of 0.008 (1) Å from the mean plane. Both oxazolidine five-membered rings are also nearly planar, with maximum deviations of 0.090 (1) and 0.141 (1) Å.
Acta Crystallographica Section E-structure Reports Online | 2010
Mohamed Moumou; Mohamed Akssira; Lahcen El Ammari; Ahmed Benharref; Moha Berraho
The title compound, C15H20O5 (systematic name: 5-hydroxy-1a,4a-dimethyl-7-methyleneperhydrodioxireno[5,6:9,10]cyclodeca[1,2-b]furan-8-one), was obtained by the reaction of 3-chloroperbenzoic acid with 9β-hydroxyparthenolide. The five-membered ring adopts a twist conformation, whereas the ten-membered ring displays an approximate chair–chair conformation. In the crystal structure, molecules are linked into chains propagating along the b axis by intermolecular O—H⋯O hydrogen bonds.
Acta Crystallographica Section E-structure Reports Online | 2014
Mohamed Zaki; Ahmed Benharref; Lahcen El Ammari; Mohamed Saadi; Moha Berraho
The title compound, C16H24Br2O, was synthesized by three steps from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from essential oil of the Atlas cedar cedrus atlantica. The asymmetric unit contains two independent molecules with almost identical conformations. Each molecule is built up from two fused six-membered rings, one having a chair conformation and the other a boat conformation, and an additional three-membered ring arising from the reaction of himachalene with dibromocarbene. In the crystal, there are no significant intermolecular interactions present. The absolute structure of the title compound was confirmed by resonance scattering.
Acta Crystallographica Section E: Crystallographic Communications | 2016
Elhassan Benhsina; A. Assani; Mohamed Saadi; Lahcen El Ammari
The title transition metal vanadate crystallizes in an alluaudite-type structure. The chains characterizing the alluaudite structure are built up from edge-sharing [FeO6] octahedra linked together by VO4 tetrahedra.