02178nas a2200217 4500008004100000022001400041245014600055210006900201260007300270300001200343490000700355520136100362653001601723653002701739653001201766653001001778653001301788100001601801700001801817856012501835 2006 eng d a1387-181100aVanadium-containing ethane-silica hybrid periodic mesoporous organosilicas: synthesis, structural characterization and catalytic applications0 aVanadiumcontaining ethanesilica hybrid periodic mesoporous organ aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a127-1380 v943 a

Vanadium-containing ethane-silica hybrid mesoporous silsesquioxane materials (V-HMM) with uniform hexagonal arrangement were prepared using C-18-, C-16- and C-14-alkyl trimethyl ammonium (ATMA) surfactants under basic conditions. The materials were characterized by PXRD, N-2 adsorption-desorption, UV-Visible spectroscopy, Raman, Si-29, C-13 and V-51 solid-state MAS NMR, TEM and SEM techniques. The characterization techniques revealed that the structural ordering, morphology as well as the percentage of metal incorporation depends strongly on the hydrophobic chain length of the surfactant. PXRD, electron microscopy and N-2 adsorptiondesorption analysis confirmed that the original hexagonal structure of the material is maintained after vanadium substitution. UV-Visible, V-51 NMR and Raman analysis certified that vanadium exists in a highly dispersed state and had tetrahedral coordination with the support surface. Liquid-phase epoxidation reaction of styrene using aqueous H2O2 and TBHP as oxidants, showed that the hybrid materials were highly active and more stable than conventional vanadosilicates. The high catalytic activity and improved epoxide selectivity of the V-HMM samples is related to the more hydrophobic environment inside the pore channels than the silica channels in V-MCM-41. (c) 2006 Elsevier Inc. All rights reserved.

10aepoxidation10aorgano vanadosilicates10astyrene10aV-HMM10aV-MCM-411 aShylesh, S.1 aSingh, A., P. uhttp://library.ncl.res.in/content/vanadium-containing-ethane-silica-hybrid-periodic-mesoporous-organosilicas-synthesis-001842nas a2200229 4500008004100000022001400041245008100055210006900136260007500205300001200280490000700292520101700299653001901316653001601335653002901351653003901380100001601419700002401435700002201459700001801481856011301499 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

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.

10aAcid catalysis10aepoxidation10aMesoporous organosilicas10aOrganic-inorganic hybrid materials1 aShylesh, S.1 aSamuel, Prinson, P.1 aSisodiya, Sheetal1 aSingh, A., P. uhttp://library.ncl.res.in/content/periodic-mesoporous-silicas-and-organosilicas-overview-towards-catalysis-001727nas a2200241 4500008004100000022001400041245015700055210006900212260007300281300001200354490000700366520082600373653001601199653002701215653001501242653001701257653001401274653001101288100002201299700001601321700001801337856013001355 2011 eng d a1566-736700aTin incorporated periodic mesoporous organosilicas (Sn-PMOs): synthesis, characterization, and catalytic activity in the epoxidation reaction of olefins0 aTin incorporated periodic mesoporous organosilicas SnPMOs synthe aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR a629-6330 v123 a

Tin incorporated mesoporous organosilicas (Sn-PMO) having uniform hexagonal arrangements were prepared using alkyl trimethylammonium bromide surfactants under basic reaction conditions. Characterization techniques revealed that the structural ordering, morphology, and the percentage of tin incorporation depend critically on the hydrophobic chain length of surfactants. The Sn-PMO samples are thermally stable up to 500 degrees C under air atmosphere and were hydrothermally stable up to 100 h in boiling water. The organotinsilicates showed excellent catalytic activity and reusability in the epoxidation of norbornene and ciscyclooctene than an Sn-MCM-41 due to organic groups in the frame wall positions and the better accessibility of reactants to the active sites. (C) 2010 Elsevier B.V. All rights reserved.

10aepoxidation10aHydrothermal stability10aMesoporous10aOrganosilica10aSn-MCM-4110aSn-PMO1 aSisodiya, Sheetal1 aShylesh, S.1 aSingh, A., P. uhttp://library.ncl.res.in/content/tin-incorporated-periodic-mesoporous-organosilicas-sn-pmos-synthesis-characterization-and-0