02407nas a2200217   4500008004100000022001400041245015100055210006900206260007300275300001200348490000800360520156700368653001301935653001601948653001401964653002301978100001602001700002402017700001802041856013002059       2007                        eng d  a0926-860X00aChromium-containing small pore mesoporous silicas: synthesis, characterization and catalytic behavior in the liquid phase oxidation of cyclohexane0 aChromiumcontaining small pore mesoporous silicas synthesis chara  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a128-1360 v3183 a<p>Organic-inorganic hybrid mesoporous silica materials containing chromium and various organo trialkoxysilanes (chloropropyl, vinyl, methyl) were prepared by the co-condensation method, in the presence of cetyl trimethyl ammonium surfactants. The hybrid material, containing chromium, retains one X-ray diffractogram (XRD) peak up to a molar ratio of 1: 1 between tetra ethyl orthosilicate (TEOS) and organosilane in the synthesis gel. Small pore mesoporous chromium-silica samples can be prepared from the large pore hybrid mesoporous chromium samples by calcination. By this method, the pore size of the material can be tailored into the supermicroporous region, without changing the chain length of the surfactant used in the assembly process, as judged from the XRD and N-2 sorption isotherms. The shrinkage in pore size is dependent on the nature and percentage of the organic pendant groups, such that the chloro propyl and vinyl pendant mesoporous material show more pore size shrinkage than the smaller methyl pendant units. Because of the tailorable pore size and with better textural characteristics, the chromium samples show better catalytic activity in the aerial oxidation reaction of cyclohexane than the conventional chromium-containing mesoporous material, like Cr-MCM-41, under a solvent free system. Among the porous chromium catalysts, the samples prepared using chloro propyl silane show higher cyclohexane conversion and cyclohexanone selectivity and behave as a true heterogeneous catalyst. (c) 2006 Elsevier B.V. All rights reserved.</p>10achromium10aCyclohexane10aOxidation10asmall pore silicas1 aShylesh, S.1 aSamuel, Prinson, P.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/chromium-containing-small-pore-mesoporous-silicas-synthesis-characterization-and-catalytic01809nas a2200241   4500008004100000020002200041022001400063245014400077210006900221260009900290300001400389490000800403520090400411100001601315700002401331700001901355700001801374700001001392700001201402700001201414700001101426856013001437       2007                        eng d  a978-0-444-53068-4  a0167-299100aEthane bridged hybrid mesoporous silsesquioxanes with sulfonic acid functionalities: synthesis, characterization and catalytic applications0 aEthane bridged hybrid mesoporous silsesquioxanes with sulfonic a  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1899-19040 v1703 a<p>Periodic mesoporous organosilicas having -CH(2)-CH(2)- groups in the framewall positions and sulfonic acid groups in the pore channels were prepared using 1,2-bis(triethoxysilyl) ethane, 3-mercaptopropyltriethoxysilane and cetyltrimethylammonium surfactant, under basic conditions, by a one-pot synthesis method. XRD, N(2) sorption isotherm and TEM analysis revealed that the mesoporous structural ordering is retained after the functionalization of organic groups while solid-state NMR techniques like (13)C CP MAS NMR and (29)Si MAS NMR show the presence of sulfonic acid groups and the stability of the mesoporous framework with integrated ethane moieties as bridging groups. The hybrid material was more active, selective and stable than the conventional sulfonic acid containing mesoporous catalysts in the Claisen-Schmidt condensation of acetophenone with benzaldehyde to form chalcone.</p>1 aShylesh, S.1 aSamuel, Prinson, P.1 aParischa, Renu1 aSingh, A., P.1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/ethane-bridged-hybrid-mesoporous-silsesquioxanes-sulfonic-acid-functionalities-synthesis-001907nas a2200241   4500008004100000022001400041245012600055210006900181260007300250300001200323490000800335520103600343653001701379653001801396653001801414653001901432100001601451700002401467700002001491700001901511700001801530856011701548       2007                        eng d  a1381-116900aSulfonic acid functionalized mesoporous silicas and organosilicas: synthesis, characterization and catalytic applications0 aSulfonic acid functionalized mesoporous silicas and organosilica  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a153-1580 v2743 a<p>Ethane bridged mesoporous organosilicas and MCM-41 having sulfonic acid groups in the pore channels were prepared by co-condensation method as well as grafting method, using 3-mercaptopropyltriethoxysilane (3-MPTS) as the sulfur precursor. TEM and N-2 sorption isotherm analysis revealed that the mesoporous structural ordering is retained after the functionalization and modifications of organic groups while FT-IR, Raman, XPS and solid-state C-13 CP MAS NMR shows the presence of sulfonic acid groups and the stability of the mesoporous framework. The catalytic activity of the developed materials was evaluated in the liquid phase Claisen-Schmidt condensation reaction of acetophenone with benzaldehyde, to probe the effect of mesoporous support surfaces as well as the role of preparation methods. Results showed that sulfonic acid functionalized ethane-silica samples were more active, selective and stable than the conventional sulfonic acid containing mesoporous catalysts. (c) 2007 Elsevier B.V. All rights reserved.</p>10acondensation10aethane-silica10aheterogeneity10asulfonic acids1 aShylesh, S.1 aSamuel, Prinson, P.1 aSrilakshmi, Ch.1 aParischa, Renu1 aSingh, A., P.  uhttps://library.ncl.res.in/content/sulfonic-acid-functionalized-mesoporous-silicas-and-organosilicas-synthesis-002394nas a2200217   4500008004100000022001400041245013600055210006900191260007300260300001200333490000800345520156800353653001101921653001401932653002101946653002701967100001601994700002402010700001802034856012402052       2007                        eng d  a1387-181100aSynthesis of hydrothermally stable aluminium-containing ethane-silica hybrid mesoporous materials using different aluminium sources0 aSynthesis of hydrothermally stable aluminiumcontaining ethanesil  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a250-2580 v1003 a<p>Aluminium-containing ethane-silica hybrid mesoporous materials having ethane groups in the frame wall positions are synthesized using aluminium isopropoxide as well as aluminium nitrate as the aluminium sources. The materials were characterized in detail using powder XRD, N-2 adsorption-desorption, SEM, TEM, TG-DTG, TPD, Si-29, C-13 and Al-27 MAS NMR techniques. Characterization techniques revealed that aluminium isopropoxide was the appropriate source for the synthesis of organo aluminosilicas on considering the structural ordering, acidity as well as the percentage of aluminium incorporation into the ethane bridge. Al-27 MAS NMR displays aluminium as tetrahedrally coordinated in both the aluminium-containing organosilicas. Unlike the conventional EtOH-HCl template extraction process, in the present studies, we had used EtOH-NH4OH as the surfactant-extracting medium and chemical analysis results suggest that using this procedure the extent of dealumination can be greatly reduced. XRD and nitrogen physisorption studies further proved that the materials are hydrothermally stable, that the ordered pore channels retains its structure even after 150 h reflux in boiling water, while the conventional Al-MCM-41 catalyst collapsed its mesostructure after 50 h reflux in water. The improved hydrothermal stability of the hybrid materials, even in presence of sodium ions, is attributed to the thick pore walls as well as due to the presence of hydrophobic bridging ethane groups in the wall positions. (c) 2006 Elsevier Inc. All rights reserved.</p>10aAl-HMM10aAl-MCM-4l10ahybrid materials10aHydrothermal stability1 aShylesh, S.1 aSamuel, Prinson, P.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/synthesis-hydrothermally-stable-aluminium-containing-ethane-silica-hybrid-mesoporous01843nas a2200229   4500008004100000022001400041245008100055210006900136260007500205300001200280490000700292520101700299653001901316653001601335653002901351653003901380100001601419700002401435700002201459700001801481856011401499       2008                        eng d  a1571-101300aPeriodic mesoporous silicas and organosilicas: an overview towards catalysis0 aPeriodic mesoporous silicas and organosilicas an overview toward  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScDEC  a266-2820 v123 a<p>Micelle-templated mesoporous and organic-inorganic hybrid mesoporous materials are important in many fields of material research, especially for hosting catalysts in confined space. Among this class, the recent discovery of periodic mesoporous organosilicas (PMOs) represent an exciting new group of organic-inorganic nanocomposites targeted for a broad range of applications ranging from catalysis to microelectronics. Compared to the earlier generation of organic-inorganic hybrid mesoporous samples, obtained by the cocondensation reaction or by the grafting reaction, PMOs represent the right combination of organic and inorganic groups in the frame wall positions. This article reviews the current state of art in organic-inorganic hybrid mesoporous material research with special emphasis over periodic mesoporous organosilica materials having various redox centers (Ti, V, Cr) suitable for oxidation reactions as well as acidic sites (Al, -SO(3)H) for the organic transformation of bulky molecules.</p>10aAcid catalysis10aepoxidation10aMesoporous organosilicas10aOrganic-inorganic hybrid materials1 aShylesh, S.1 aSamuel, Prinson, P.1 aSisodiya, Sheetal1 aSingh, A., P.  uhttps://library.ncl.res.in/content/periodic-mesoporous-silicas-and-organosilicas-overview-towards-catalysis-0