02689nas a2200313   4500008004100000022001400041245011600055210006900171260009500240300001200335490000800347520155000355653003601905653002801941653001101969653003001980653002002010653001802030653000802048100001902056700001702075700001702092700003502109700002702144700003002171700001902201700002602220856012902246       2006                        eng d  a0021-951700aEffect of spacer groups on the performance of MCM-41-supported platinum cluster-derived hydrogenation catalysts0 aEffect of spacer groups on the performance of MCM41supported pla  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcSEP  a332-3390 v2423 a<p>MCM-41 was functionalized with (EtO)(3)SiCH2Cl, (MeO)(3)SiCH2CH2CH2Cl, and (CH3)Cl2SiCH2Cl. The functionalized materials were characterized by solid-state NMR (CPMAS, Si-29 and C-13) and XPS. The NMR data indicate that three new silicon environments were created by(EtO)(3)SiCH2Cl and (MeO)(3)SiCH2CH2CH2Cl, whereas with (CH3)Cl2SiCH2Cl, two new silicon environments were obtained. XPS results from Si 2p core level and the valence band from the material functionalized by (MeO)(3)Si(CH2)(3)Cl was found to be the same as that of the corresponding fresh catalyst (1a), in contrast to that of the materials functionalized by the other two silane reagents. After further functionalization with triethylamine, these materials were used as inorganic anion exchangers to support the cluster anion [Pt-12(CO)(24)](2-). Solid-state NMR (29Si, C-13, N-15) was used to establish the presence of the quaternary ammonium group in the cluster-supported species. Analogous materials were also created using fumed silica as the support, and all of the cluster-supported materials were tested as catalysts for the hydrogenation of methyl pyruvate, acetophenone, nitrobenzene, benzonitrile, ethylacetoacetate, 4-nitrotoluene, cyclohexanone, allyl alcohol, and styrene. The best activity was obtained for the catalyst that had MCM-41 as the support and chloropropyl as the spacer group. TEM showed that the supports and the spacer groups had observable effects on the platinum crystallite size of the catalysts. (c) 2006 Elsevier Inc. All rights reserved.</p>10afunctionalized inorganic oxides10ahydrogenation catalysts10aMCM-4110aplatinum carbonyl cluster10aSolid-state NMR10aspacer groups10aXPS1 aMaity, Niladri1 aBasu, Susmit1 aMapa, Maitri1 aRajamohanan, Pattuparambil, R.1 aGanapathy, Subramanian1 aGopinath, Chinnakonda, S.1 aBhaduri, Sumit1 aLahiri, Goutam, Kumar  uhttp://library.ncl.res.in/content/effect-spacer-groups-performance-mcm-41-supported-platinum-cluster-derived-hydrogenation-101984nas a2200253   4500008004100000022001400041245011600055210006900171260007300240300001200313490000800325520103000333653002401363653002401387653002701411653001101438653002801449100001901477700003501496700003001531700001901561700002601580856012401606       2011                        eng d  a0926-860X00aSelective hydrogenation of chloronitrobenzenes with an MCM-41 supported platinum allyl complex derived catalyst0 aSelective hydrogenation of chloronitrobenzenes with an MCM41 sup  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a117-1250 v3993 a<p>A platinuin precatalyst (1) has been prepared by reacting [(eta(3)-C3H5)(4)Pt4Cl4] with surface functionalized MCM-41 with pendant -(CH2)(3)NH(CH2)(2)NH2 groups. For the hydrogenation of o-, m- and p-chloronitrobenzenes to the corresponding chloroanilines, 1 is found to be a highly active catalyst with good selectivities for them-and p-isomers. Its performance is superior to that of its palladium analogue and far superior to that of commercial (5%) Pt/C or (5%) Pt/Al2O3. Comparison of solid state and solution NMR data and other evidences indicate that on treatment with the functionalized MCM-41 support; [(eta(3)-C3H5)(4)Pt4Cl4] loses the ally! ligand. XPS data show that in the fresh catalyst Pt is present in the 2+ oxidation state. Based on these and analytical data, co-ordination by surface diamine and hydroxo groups to Pt2+ in 1 is suggested. In the used catalyst both Pt2+ and Pt are present but the amount of metallic platinum is similar to 16% of the total. (C) 2011 Elsevier B.V. All rights reserved.</p>10aChloronitrobenzenes10aDehydrohalogenation10aheterogeneous catalyst10aMCM-4110aSelective hydrogenation1 aIndra, Arindam1 aRajamohanan, Pattuparambil, R.1 aGopinath, Chinnakonda, S.1 aBhaduri, Sumit1 aLahiri, Goutam, Kumar  uhttp://library.ncl.res.in/content/selective-hydrogenation-chloronitrobenzenes-mcm-41-supported-platinum-allyl-complex-0