01966nas a2200229 4500008004100000022001400041245010400055210006900159260007300228300001000301490000800311520116300319653001401482653001101496653001501507653001401522653001301536100001601549700002601565700001801591856012701609 2005 eng d a1381-116900aInfluence of silica source in the catalytic activity and heterogenity of mesoporous vanadosilicates0 aInfluence of silica source in the catalytic activity and heterog aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a57-630 v2393 a

Vanadium-substituted ordered mesoporous silicates (V-OMS) were synthesized hydrothermally using two common silica sources, viz. fumed silica and tetraethyl orthosilicate, and their surface properties and catalytic activities were evaluated in the liquid phase oxidation of 1-napthol using aqueous H2O2 as an oxidant. The catalysts were characterized by XRD, N-2, adsorption-desorption, DRUV-vis and TPR to evaluate the mesostructural ordering and the local environment of vanadium in the MCM-41 matrix. Characterization data of the fresh calcined catalysts reveal a more ordered hexagonal structure for the V-MCM-41 catalyst prepared by using tetraethyl orthosilicate as the silica source while spent catalyst showed that the material is less stable than the V-MCM-41 catalyst prepared by using fumed silica as the silica source. Further, the observed differences in the selectivity behavior of extracted and calcined forms of both vanadium catalysts shows that the treatment conditions had a decisive role in the formation of extra framework metal species and further in the mesoscopic structural ordering. (c) 2005 Elsevier B.V. All rights reserved.

10a1-napthol10aMCM-4110aMesoporous10aOxidation10aVanadium1 aShylesh, S.1 aMirajkar, Subhash, P.1 aSingh, A., P. uhttp://library.ncl.res.in/content/influence-silica-source-catalytic-activity-and-heterogenity-mesoporous-vanadosilicates-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-002441nas a2200241 4500008004100000022001400041245015000055210006900205260007300274300001200347490000800359520152700367653000801894653003401902653002901936653003501965653001502000653001602015100001702031700001802048700001802066856011502084 2013 eng d a1387-181100aChiral (VO)-O-IV-Sal-Indanol complex over modified SBA-15: an efficient, reusable enantioselective catalyst for asymmetric sulfoxidation reaction0 aChiral VOOIVSalIndanol complex over modified SBA15 an efficient  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a331-3390 v1703 a

A reusable, mesoporous, heterogeneous vanadium complex, (VO)-O-IV-Sal-Ind-SBA-15 has been synthesized first time from (1R,2S)-(+)-Cis-1-amino-2-indanol for enantioselective sulfoxidation reaction. The physico-chemical properties of the functionalized catalyst were analyzed by a series of characterization techniques like XRD, N-2 sorption measurement isotherm, TEM, FT-IR, XPS, EPR, DRS UV-Visible, ICP-OES and solid & liquid state C-13, Si-29 and V-51 NMR spectroscopy. Powder X-ray diffraction patterns, TEM and N-2 physisorption analysis confirmed the retention of mesoporous structure after various modifications. Solid-state NMR (C-13 CP-MAS NMR, Si-29 MAS NMR) and FT-IR analysis certified the integrity of organo-catalyst residing inside the pore channels of the mesoporous support. Further, XPS, EPR, V-51 NMR and DRS UV-Visible analyses help to find out the oxidation state and coordination environment of vanadium in (VO)-O-IV-Sal-Ind-SBA-15. Catalytic evaluation in asymmetric sulfoxidation reaction of sulfides indicated that VOIV-Sal-Ind-SBA-15 exhibited higher catalytic activity, stability, reusability and comparable enantioselectivity than SBA-15, PrNH2-SBA-15, neat (VO)-O-IV-Sal-Indanol complex and without catalyst. The effect of different catalysts, temperature, solvents and substrates on sulfoxidation reaction were examined in order to optimize the conversion and enantioselectivity of thioanisoles to sulfoxides. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.

10a(1R10a2S)-(+)-Cis-1-amino-2-indanol10aAsymmetric sulfoxidation10aHeterogeneous vanadium complex10aMesoporous10aThioanisole1 aLazar, Anish1 aSharma, Priti1 aSingh, A., P. uhttp://library.ncl.res.in/content/chiral-vo-o-iv-sal-indanol-complex-over-modified-sba-15-efficient-reusable-0