Etude physico-chimique et minéralogique comparative des attapulgites de Mbodiène (Sénégal) et de Mormoiron (France)

La valorisation des ressources locales constitue un impératif afin d’atteindre des objectifs de développement durable. Cette étude a consisté à évaluer les caractéristiques physiques, chimiques et minéralogiques d’une argile provenant de Mbodiène (Sénégal), l’attapulgite, comparativement avec un médicament antidiarrhéique, constitué d’attapulgite, dénommé Actapulgite®. L’échantillon d’attapulgite brute a été purifié avec une solution de HNO3 1M. Une étude morphologique effectuée par visualisation à la Microscopie Electronique à Balayage a montré pour les deux argiles étudiées, une structure fibreuse caractéristique de la palygorskite, représentant le minéral dominant. L’analyse chimique par la spectrométrie à fluorescence X a donné pour l’attapulgite purifiée : 65,69% Si, 7,89% Al, 5,92% Fe, 17,90% Mg, 0,43% Ca et 0,93% K contre respectivement 63,98 % Si, 12,92% Al, 10,32% Fe, 6,20% Mg, 2,48% Ca et 2,25% K pour l’Actapulgite®. La diffraction aux rayons X a montré une présence de palygorskite, quartz et carbonates dans les échantillons étudiés. L’étude des isothermes d’adsorption a montré une surface spécifique nettement plus élevée pour l’attapulgite purifiée, 138,96 m2.g-1 contre 98,72 m2.g-1 pour l’Actapulgite®. Ces résultats ont montré que l’attapulgite de Mbodiène pourrait être utilisée comme antidiarrhéique orale après lavage à l’eau et séchage.© 2016 International Formulae Group. All rights reservedMots clés: Argile, attapulgite, antidiarrhéique, SénégalEnglish Title: Physico-chemical and mineralogical comparative study of attapulgites Mbodiène (Senegal) and Mormoiron (France)English AbstractThe development of local resources is imperative to achieve sustainable development goals. This study was to assess physical, chemical and mineralogical characteristics of a clay from Mbodiène (Senegal), named attapulgite, compared with Actapulgite® (antidiarrheal drug), composed of attapulgite. A sample of attapulgite from Mbodiène was purified with a 1M HNO3 solution to remove impurities including carbonates. A morphological study using Scanning Electron Microscopy showed for both types of clay studied, a fibrous structure characteristic of palygorskite which represent major mineral. Chemical analysis by XRF spectrometry gave for purified attapulgite: 65.69% Si, 7.89% Al, 5.92% Fe, 17.90% Mg, 0.43% Ca and 0.93% K against respectively 63.98% Si, 12.92% Al, 10.32% Fe, 6.20% Mg, 2.48% Ca and 2.25% K for Actapulgite®. X-ray diffraction showed the presence of palygorskite, quartz and carbonates for both samples studied. The study of adsorption isotherms showed a significantly higher surface area for purified attapulgite, 138.96 m2.g-1 versus 98.72 m2.g-1 for Actapulgite®. These results have shown that Mbodiène attapulgite compared to Actapulgite®, could be used as an oral antidiarrheal after washing with water and drying.© 2016 International Formulae Group. All rights reserved.Keywords: Clay, attapulgite, antidiarrheal, Senega

A new 3-D La(lll)-Cu(ll) Containing Coordination Polymer with High Potential Porosity.

WOSInternational audienceA new 3-D coordination polymer containing both 3d and 4f ions has been designed. Its chemical formula is La2[Cu(pba)]3(H2O)8•8H2O. It crystallizes in the quadratic system, space group I41/a with a = 42.4947(9) Å, c = 16.3378(3) Å, and Z = 16. Its crystal structure can be described as a 3-D molecular framework exhibiting a complex network of interconnected zigzaglike channels. Once crystallization water molecules are removed, this compound presents a high potential porosity and a low density. The porosity has been evaluated using Connolly's algorithm

Poly[[nonaaquabis(μ-5-hydroxybenzene-1,3-dicarboxylato)(5-hydroxybenzene-1,3-dicarboxylato)dicerium(III)] hexahydrate]

In the title coordination polymer, {[Ce2(C8H4O5)3(H2O)9]·6H2O}n, the asymmetric unit is formed by two CeIII atoms, three 5-hydroxybenzene-1,3-dicarboxylate ligands, nine coordinating water molecules and six water molecules of crystallization. The two CeIII atoms are bridged by 5-hydroxybenzene-1,3-dicarboxylate ligands acting in a bis-bidentate coordination mode, generating infinite chains along [101]. Both independent metal atoms are nine-coordinated, one by four O atoms from the carboxylate groups of two bridging 5-hydroxybenzene-1,3-dicarboxylate ligands and five O atoms from water molecules, generating a tricapped trigonal–prismatic geometry. The coordination around the second CeIII atom is similar, except that one of the water molecules is replaced by an O atom from an additional 5-hydroxybenzene-1,3-dicarboxylate ligand acting in a monodentate coordination mode and forming a capped square-antiprismatic geometry

Poly[[octaaqua-μ4-(benzene-1,2,4,5-tetracarboxylato)-dicobalt(II)] octahydrate]

The title polymeric coordination compound, {[Co2(C10H2O8)(H2O)8]·8H2O}n, was obtained by slow diffusion of a dilute aqueous solution of CoCl2 and the sodium salt of benzene-1,2,4,5-tetracarboxylic acid (H4btec) through an agar–agar gel bridge in a U-shaped tube. The two independent Co2+ ions are each situated on an inversion centre and are coordinated in a slightly distorted octahedral geometry by four water O atoms and two carboxylate O atoms from two btec4− ligands (-1> symmetry), forming a layer parallel to (11-1). This layer can be described as a molecular two-dimensional square grid with the benzene rings at the nodes and the CoII atoms connecting the nodes. O—H...O hydrogen-bonding interactions involving the coordinating water molecules, the carboxylate O atoms and lattice water molecules lead to the formation of a three-dimensional network

Synthesis and crystal structure of a new coordination polymer based on lanthanum and 1,4-phenylenediacetate ligands

Reaction in gel between the sodium salt of 1,4-phenylenediacetic acid (Na2C10O4H8–Na2p-pda) and lanthanum chloride yields single crystals of the three-dimensional coordination polymer poly[[tetraaquatris(μ-1,4-phenylenediacetato)dilanthanum(III)] octahydrate], {[La2(C10H8O4)3(H2O)4]·8H2O}∞. The LaIII coordination polyhedron can be described as a slightly distorted monocapped square antiprism. One of the two p-pda2− ligands is bound to four LaIII ions and the other to two LaIII ions. Each LaIII atom is coordinated by five ligands, thereby generating a metal–organic framework with potential porosity properties

Synthesis and crystal structure of a calcium(II)-basedcoordination polymerconstructed from 1,2,4,5-Benzenetetracarboxylic Acid

International audienceThe polymeric compound, [Ca2(btec)(H2O)6]∞ was obtained by slow diffusion of dilute aqueous solutionsof calcium chloride and of the sodium salt of benzene-1,2,4,5-tretracarboxylic acid(H4btec) through an agar-agar gelbridge in a U-shaped tube. This compound crystallizes in the triclinic system, space group P-1 (n° 2) with a = 5.8270 (2)Å, b = 7.7197 (2) Å, c = 9.6763 (3) Å, a = 112,497 (1) °, β = 101.293 (1)°, g = 97.567(2)° and Z = 2. Each Ca2+ ion iscoordinated by three oxygen atoms from coordinated water molecules and five oxygen atoms from three btec4-ligandsthat form a slightly distorted dodecahedron. Ligands also act as μ6-bridging groups between the Ca2+ ions.Thecrystal structure consists of a superimposition of 2D layers that spread parallel to the, plane

Poly[[hexaaquasesqui(μ-benzene-1,2,4,5-tetracarboxylato)dicopper(II)disodium] monohydrate]

In the title compound, {[Cu2Na2(C10H2O8)1.5(H2O)6]·H2O}n, the Cu2+ ion is hexacoordinated by five O atoms from benzene-1,2,4,5-tetracarboxylate (btec4−) ligands and one water molecule. The Na+ ion is also hexacoordinated, by four O atoms from btec4− ligands and two water molecules. One of the two btec4− molecules sits on a crystallographic inversion centre. CuO6 and NaO6 octahedra are connected, forming bi-dimensional layers. These layers, which extend parallel to the ac plane, are further interconnected by μ10- or μ11-bridging btec4− ligands and by O—H...O hydrogen bonds, involving both btec4− ligands and water molecules, forming a three-dimensional network

Synthesis and crystal structure of a new calcium-containing trimesate coordination polymer: [Ca3(btc)2(H2O)12]∞.

International audienceReaction in gel between the sodium salt of 1,3,5-benzenetricarboxylic acid or trimesic (Na3[C6H3(COO)3] hereafter referenced as Na3btc) and calcium chloride has afforded single crystals of a bidimensional coordination polymer with chemical formula [Ca3(btc)2(H2O)12]∞. This compound crystallizes in the monoclinic system, space group C2/c (n° 15) with a = 19.3028 (16) Å, b = 11.4850 (9) Å, c = 13.0435 (12) Å, β = 106.394 (10)° and Z = 4. The crystal structure consists of a superposition of molecular planes that spread parallel to the (a-b) plane

High Brightness and Easy Color Modulation in Lanthanide-Based Coordination Polymers with 5-Methoxyisophthalate as Ligand: Toward Emission Colors Additive Strategy

International audienceReactions in water between lanthanide chlorides and the disodium salt of 5-methoxyisophthalic acid, Na2(mip)·7H2O, lead to the first three series of lanthanide-based coordination polymers based on this ligand. The first series contains only one compound with chemical formula [Ce(mip)3/2(H2O)5·2H2O]∞. The second series has general chemical formula [Ln(mip) (Hmip)(H2O)5·H2O]∞ with Ln = La–Ce. The last family is constituted by compounds with general chemical formula [Ln2(mip)3(H2O)8·4H2O]∞ with Ln = Sm–Er plus Y. Luminescent properties of the compounds that belong to this family have been studied. The Tb-based compound presents one of the brightest luminescences reported to date for a lanthanide-based coordination polymer. The weak intermetallic energy transfer evidenced on the third family of compounds allows easy and predictable color modulation of the heterobimetallic powders through additive colors strategy