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Biomedical subjects

Catherine Reyé

Publications and source records attributed to Catherine Reyé.

8 recordsLinked to original sources
PubMed2006

Mesoporous materials with an acidic framework and basic pores. A successful cohabitation.

Bifunctional mesoporous material with an acidic framework and basic pores was synthesized via the co-condensation of TEOS, bistrimethoxysilylated precursors with a disulfide core, and 3-tert-butyloxycarbonyl (aminopropyl)triethoxysilane using P123 as surfactant; the reduction of disulfide units to SH groups followed by their oxidation into SO3H and deprotection of amino groups gave rise to a material containing two antagonist functionalities located at the nanometric scale in a successful cohabitation, avoiding their mutual destruction in the presence of aprotic solvent. This kind of material illustrates the large possibilities offered by mesoporous materials and opens new and unsuspected applications.

Journal Article↗
PubMed2006

First direct synthesis of highly ordered bifunctionalized mesoporous silica thin films.

Optically transparent and highly ordered mesoporous organosilica thin films functionalized with two different organic groups in various proportions were synthesized by templated-directed cocondensation of tetraethylorthosilicate (TEOS) and a mixture of two distinct and functional organotriethoxysilanes [NC(CH2)3Si(OEt)3 and O=P(OEt)2(CH2)3Si(OEt)3]. The mesostructured films obtained by evaporation induced self-assembly (EISA) approach were deposited on glass or silicon substrates by dip-coating. They were characterized by Grazing Incidence Small Angle X-ray Scattering (GISAXS) and X-ray reflectivity. We showed that whatever the proportion in organic groups, only 2D hexagonal phase having p6m symmetry was observed for all the materials indicating a good compatibility between the organic groups. The bi-functionalization of the internal pores surface by the organotriethoxysilanes groups was clearly evidenced by using micro-Raman spectroscopy.

Magnetic Resonance Spectroscopy↗
PubMed2005

CO2 as a supramolecular assembly agent: a route for lamellar materials with a high content of amine groups.

The uptake of carbon dioxide on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane 1 and N-(6-aminohexyl)-3-aminopropyltrimethoxysilane 2 afforded a supramolecular network of bis-silylated ammonium carbamate salts, the hydrolytic polycondensation of which gave rise to structured hybrid materials. Subsequent loss of CO2 was readily achieved upon heating, thus generating materials in which the structure was maintained (well-defined lamellar structure from 2) and contains free amino groups. The accessibility of amine-functionalized groups was shown by their ability to complex transition metal or lanthanide salts.

Journal Article↗
PubMed2002

Coordination chemistry in the solid: evidence for coordination modes within hybrid materials different from those in solution.

Two routes of incorporation of europium(III) salts into cyclam-containing hybrid materials have been explored, to elucidate the coordination mode of EuIII in cyclam-containing hybrid materials in a study of the arrangement of cyclam moieties during the solgel process. They were 1) complexation of europium salts by N-tetrasubstituted 1,4,8,11-tetraazacyclotetradecane (cyclam) derivatives bearing four hydrolysable Si(OEt)3 groups, followed by hydrolysis and polycondensation of these complexes; and 2) hydrolysis and polycondensation of N-tetrasubstituted silylated cyclam derivatives, then incorporation of europium salts directly into the hybrid materials. The coordination mode of europium salts within solids is not the same as in solution. In solution, the complexation of EuIII with cyclam is not possible; it requires cyclam derivatives containing N-chelating substituents such as amido groups in an appropriate geometry. In contrast, the incorporation of EuIII into hybrid materials is always possible, whatever the nature of the arms of the cyclam moieties. Thus, EuIII uptake is one EuIII/two macrocycles with cyclam moieties containing N-alkyl substituents. This constitutes the first example of 4N + 4N lanthanide coordination.

Journal Article↗
PubMed1999

Evidence for Nondissociative Ligand Exchange within [4+2]-Coordinate Phosphorus Species in Solution.

[4+2]-Coordinate phosphorus compounds, [bis(8-(dimethylamino)-1-naphthyl)]phenylphosphane, [bis(8-(dimethylamino)-1-naphthyl)]phenylphosphane sulfide, [bis(8-(dimethylamino)-1-naphthyl)]phenylphosphonium bromide, [bis(8-(dimethylamino)-1-naphthyl)]methylphosphane, and [bis(8-(dimethylamino)-1-naphthyl)]phosphane oxide, with two identical bidentate (8-(dimethylamino)-1-naphthyl) ligands have asymmetrical geometries in solution and undergo intramolecular nondissociative ligand exchange as shown by dynamic (1)H NMR studies. The DeltaG() values for this process were found to lie in the range 56.2-61.7 kJ mol(-)(1). The (1)H NMR study for bis[(8-(dimethylamino)-1-naphthyl)]phenylphosphane sulfide has revealed that two hexacoordinate isomers coexist in solution in a solvent dependent ratio. Their interconversion in solution is consistent with an intramolecular 1,2-shift of adjacent ligands.

Journal Article↗