200138-14-3Relevant academic research and scientific papers
Direct synthesis of ordered and highly functionalized organosilicas containing carboxylic acid groups
Mouawia, Rola,Mehdi, Ahmad,Reye, Catherine,Corriu, Robert
, p. 616 - 618 (2007)
A one step synthesis of highly carboxylic acid-functionalized silica, with lamellar structure under acidic conditions, by hydrolysis and polycondensation of a cyanolkyltrialkoxysilane was analyzed. The method consisted of hydrolysis and polycondensation of 1, 2 and 3 in sulfuric acid aqueous solution in order to transform the cyano groups into carboxylic acid groups. The in situ formation of bis-silyalated dimers by hydrogen-bond formation involved the formation of M1, M2 or M3. The hydrolysis of triethoxysilylpropyldiethylphosphonate in 12 M HCI solution was achieved under the conditions of formation of phosphonic acid groups. The longer the alkylene chains, the better the structural order, which rendered easier uptake of Eu III. The results show that these materials with high content of H+ per g can be used for high proton conductivity for fuel cells.
Thiols make for better catalysts: Au nanoparticles supported on functional SBA-15 for catalysis of Ullmann-type homocouplings
Chen, Tianyou,Chen, Ba-Tian,Bukhryakov, Konstantin V.,Rodionov, Valentin O.
, p. 11638 - 11641 (2017)
A strategy for arraying small gold nanoparticles on a mesoporous support modified with single-component or mixed self-assembled monolayers is described. The use of mixed surface modifiers allows easy access to a range of surface chemistries and modalities of interaction between nanoparticles and supports. A combination of thiol groups and linear semifluorinated chains effectively stabilized the nanoparticles against aggregation, while preserving their catalytic activity. The thiol-fluorous-supported catalyst was found active in Ullmann-type homocoupling of aryl halides and showed exceptional selectivity in this reaction.
AROMATIC AMINO SILOXANE FUNCTIONALIZED MATERIALS FOR USE IN CAPPING POROUS DIELECTRICS
-
Paragraph 0127; 0129, (2019/05/15)
The present invention relates to new aromatic-amino functional siloxanes, which are compounds comprising one or two tail groups X2, and a linking group L of structure (2) linking each said tail group to said head group, wherein the head group X has structure (1), containing an optional organic moiety Y,wherein the attachment point of said tail group X2 through said linking group L to the head group X1, may be, at positions a, b, c, d, or e. Another aspect of this invention are compositions containing these novel aromatic amino functional siloxane. A further aspect of this invention are compositions comprised of the above novel aromatic-amino functional siloxanes, and also the composition resulting from the aging of these compositions at room temperature for about 1 day to about 4 weeks. Still further aspects of this invention are processes for forming self-assembled monolayers on a substrate, from the aged composition, and also the processes of coating these aged compositions on patterned porous dielectrics to cap them also the processes of metallization of these capped pattered porous dielectrics.
Organosilica-metallic sandwich materials as precursors for palladium and platinum nanoparticle synthesis
Besnard, Romain,Cambedouzou, Julien,Arrachart, Guilhem,Le Goff, Xavier F.,Pellet-Rostaing, Stéphane
, p. 77619 - 77628 (2015/09/28)
A promising strategy to design highly active catalysts is to use multicomponent catalysts including active metals (such as platinoids) and organosilica as a substrate. In this article, we develop stable OrganoSilica Sandwiches (OSS) consisting of sandwiched metallic layers between organosilica layers. The formation of such a sandwich-like organosilica@platinoid@organosilica material was obtained from bis-silica-alkylammonium carbamate dimers, acting as a template for the immobilization of platinoid salt complexes or metallic nanoparticles in the interlayer space after a reduction treatment. The layered templates and the sandwich structures were investigated by small angle X-ray scattering, coupled thermogravimetric analysis and mass spectrometry, and Raman spectroscopy. It was demonstrated that the meso-structure of the initial template material is not affected by the chemical steps involved in the synthesis of the material and does not depend on the incorporated metal.
Preparation of bifunctional mesoporous silica nanoparticles by orthogonal click reactions and their application in cooperative catalysis
Dickschat, Arne T.,Behrends, Frederik,Bühner, Martin,Ren, Jinjun,Wei?, Mark,Eckert, Hellmut,Studer, Armido
supporting information, p. 16689 - 16697 (2013/03/14)
The synthesis of bifunctional mesoporous silica nanoparticles is described. Two chemically orthogonal functionalities are incorporated into mesoporous silica by co-condensation of tetraethoxysilane with two orthogonally functionalized triethoxyalkylsilanes. Post-functionalization is achieved by orthogonal surface chemistry. A thiol-ene reaction, Cu-catalyzed 1,3-dipolar alkyne/azide cycloaddition, and a radical nitroxide exchange reaction are used as orthogonal processes to install two functionalities at the surface that differ in reactivity. Preparation of mesoporous silica nanoparticles bearing acidic and basic sites by this approach is discussed. Particles are analyzed by solid state NMR spectroscopy, elemental analysis, infrared-spectroscopy, and scanning electron microscopy. As a first application, these particles are successfully used as cooperative catalysts in the Henry reaction. Cooperative clicking: Bifunctional mesoporous silica particles were synthesized by orthogonal surface chemistry. A thiol-ene reaction, a copper-catalyzed 1,3-dipolar cycloaddition and a radical nitroxide exchange reaction were used as orthogonal processes for the introduction of the acid and base functionalities (see scheme). Catalytic activities of these bifunctionalized inorganic/organic hybrid materials were studied on the Henry reaction. Copyright
From simple molecules to highly functionalised lamellar materials
Mouawia, Rola,Mehdi, Ahmad,Reye, Catherine,Corriu, Robert J. P.
experimental part, p. 2028 - 2035 (2009/10/14)
We describe here a new method permitting the one-step synthesis of ordered (lamellar phase) organosilicas highly functionalised with carboxylic acid or phosphonic acid groups. These materials were obtained by hydrolysis and polycondensation of monosilylated precursors cyanoalkyltrialkoxysilane (NC-(CH2)nSi(OR)3) and diethylphosphonatoalkyltriethoxysilane ((EtO)2(O)P-(CH 2)nSi(OEt)3) in acidic media without any structure-directing agent. The hydrolysis of -CN and -P(O)(OEt)2 groups into -COOH and -P(O)(OH)2 involves the in situ formation of dimers by strong hydrogen bonds, which is the crucial step to obtain a solid. The involvement of hydrophobic interactions between alkylene chains was also evidenced. All materials were characterised by X-ray diffraction measurements, elemental analyses and solid-state 13C and 29Si NMR spectroscopies. The accessibility and adsorption capacity of these groups towards lanthanide ions were investigated.
A simple access to ω-aminoalkyltrialkoxysilanes: Tunable linkers for self-organised organosilicas
Pichon, Beno?t P.,Wong Chi Man, Michel,Bied, Catherine,Moreau, Jo?l J.E.
, p. 1126 - 1130 (2007/10/03)
A simple route to ω-aminoalkyltriethoxysilanes with variable alkylene chain lengths, (EtO)3Si(CH2)nNH2 (n = 5, 11) is described. These silyl linkers have been used to prepare urea-based compounds with H-bonding and hydrophobic interactions which enable the self-assembly of the molecules. These molecular precursors are suitable for the obtention of nano-structured hybrid silicas.
