02353nas a2200229   4500008004100000022001400041245008700055210006900142260009500211300001000306490000800316520148500324653002101809653002301830653004101853653002201894653003301916100001901949700001701968700001801985856012002003       2006                        eng d  a0021-951700aFe-Zn double-metal cyanide complexes as novel, solid transesteritication catalysts0 aFeZn doublemetal cyanide complexes as novel solid transesteritic  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcJUL  a34-440 v2413 a<p>Fe-Zn double-metal cyanide complexes are currently used as catalysts for the ring-opening polymerization of epoxides, as well as the coupling of epoxides and CO2 for the production of polycarbonates. We report their novel application as highly efficient solid catalysts for the transesterification reactions of carbonates. The catalysts were prepared from aqueous solutions of ZnCl2 and K4Fe(CN)(6) in the presence of tert-butanol (complexing agent) and tri-block copolymer EO20PO70EO20 (average molecular weight, 5800; co-complexing agent). They were characterized by chemical analysis, XRD, thermal analysis, N-2 adsorption, magnetic susceptibility, SEM, and FTIR, diffuse reflectance UV-visible, EPR, and X-ray photoelectron spectroscopies. Their acidity was determined from the IR spectra of adsorbed pyridine and the temperature-programmed desorption of NH3. Catalyst samples prepared with both complexing and co-complexing agents were found to be more acidic and catalytically active than those prepared without these agents. These catalysts are more active/selective than other solid catalysts hitherto reported. Dimethyl carbonate, for example, could be synthesized with 100% selectivity and an isolated yield of &gt;86% by the reaction of propene carbonate with methanol. The catalysts can be recycled without significant loss in activity. Lewis acidic Zn ions are the possible active sites for the transesterification reaction. (c) 2006 Published by Elsevier Inc.</p>10acyclic carbonate10aDimethyl carbonate10adouble metal cyanide Fe-Zn complexes10aorganic carbonate10atransesterification catalyst1 aSrivastava, R.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/fe-zn-double-metal-cyanide-complexes-novel-solid-transesteritication-catalysts-002200nas a2200289   4500008004100000022001400041245008000055210006900135260007300204300001200277490000800289520115000297653003401447653001401481653001801495653003201513653003901545653002801584653002901612653002601641653004201667100003801709700001901747700001701766700001801783856010901801       2006                        eng d  a0926-860X00aHydrophobic, solid acid catalysts for production of biofuels and lubricants0 aHydrophobic solid acid catalysts for production of biofuels and   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a148-1590 v3143 a<p>A novel application of Fe-Zn double-metal cyanide (DMC) complexes as solid catalysts in the preparation of fatty acid alkyl esters (biodiesel/biolubricants) from vegetable oils is reported. The catalysts are hydrophobic (no H2O adsorption at reaction temperatures) and contain only Lewis acidic sites (NH3 and pyridine adsorption). Bronsted acid sites are absent (absence of 1546 and 1639 cm(-1) bands on adsorption of pyridine). Basic sites are also absent (no CO2 adsorption). Unlike the homogeneous or other solid catalysts (like ZnO-Al2O3, for example), the Fe-Zn, DMC catalysts are highly active even for the simultaneous transesterification of triglycerides and esterification of the free fatty acids (FFA) present in unrefined and waste cooking oils as well as non-edible oils. They are also tolerant of water, probably, due to their surface hydrophobicity. A relationship between the transesterification activity and the concentration of strong Lewis acid sites has been observed. Coordinatively unsaturated Zn2+ ions in the structure of the Fe-Zn complex are the probable active sites. (c) 2006 Elsevier B.V. All rights reserved.</p>10aalcoholysis of vegetable oils10aBiodiesel10aBiolubricants10adouble-metal cyanides (DMC)10aesterification of free fatty acids10afatty acid alkyl esters10afatty acid methyl esters10asolid Fe-Zn catalysts10atransesterification of vegetable oils1 aSreeprasanth, Pulinthanathu, Sree1 aSrivastava, R.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/hydrophobic-solid-acid-catalysts-production-biofuels-and-lubricants-002138nas a2200241   4500008004100000022001400041245009000055210006900145260007300214300001200287490000700299520131000306653001801616653002201634653001201656653001601668653001601684653002101700100001901721700001701740700001801757856012101775       2006                        eng d  a1566-736700aSites for CO2 activation over amine-functionalized mesoporous Ti(Al)-SBA-15 catalysts0 aSites for CO2 activation over aminefunctionalized mesoporous TiA  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a314-3260 v903 a<p>{Activation of CO and its utilization in the synthesis of chloropropene and styrene carbonates over functionalized, mesoporous SBA-15 solids, have been investigated. The surface basicity of SBA-15 was modified with nitrogen-based organic molecules of varying basicity viz., alkyl amines (-NH2), adenine (Ade), imidazole (Im) and guanine (Gua). The surface of SBA-15 was also functionalized with Ti4+ and Al3+ species. The acid-base properties of these modified SBA-15 materials were investigated by temperature-programmed desorption (TPD) and diffuse-reflectance infrared Fourier transform (DRIFT) spectroscopy. NH3 and pyridine were used as probe molecules for acid sites, while CO, was used to characterize the basic sites. CO was activated at the basic amine sites forming surface carbamate species (IR peaks: 1609 and 1446 cm(-1)). The latter reacted further with epoxides adsorbed on the acid sites forming cyclic carbonates. A correlation between the intensity of the IR peak at 1609 cm(-1) and cyclic carbonate yield has been observed. The cyclic carbonate yields were higher when both the acid and base functionalities were present on the surface. The Ti- and Al-SBA-15 functionalized with adenine exhibited the highest catalytic activity and selectivity. There is an optimal dependence (''</p>10aaromatization10aGa-based zeolites10apropane10aSi/Al ratio10aSi/Ga ratio10azeolitic factors1 aSrivastava, R.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/sites-co2-activation-over-amine-functionalized-mesoporous-tial-sba-15-catalysts-101626nas a2200265   4500008004100000022001400041245013300055210006900188260010600257300001400363490000700377520063300384653001501017653003101032653001701063653002201080653002701102653001101129653001901140653001801159100001901177700001701196700001801213856012901231       2006                        eng d  a0040-403900aSyntheses of polycarbonate and polyurethane precursors utilizing CO2 over highly efficient, solid as-synthesized MCM-41 catalyst0 aSyntheses of polycarbonate and polyurethane precursors utilizing  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN  a4213-42170 v473 a<p>As-synthesized MCM-41 was used as a reusable, heterogeneous catalyst for the eco-friendly synthesis of cyclic carbonate precursors of polycarbonates via a cycloaddition reaction of CO2 with epoxides. This catalyst is also efficient for the synthesis of alkyl and aryl carbamate precursors of polyurethanes via the reaction of amines, CO2 and alkyl halides. Both these reactions were carried out under mild conditions and without using any solvent or co-catalyst. CO2 is utilized as a raw material replacement for toxic phosgene in the conventional synthesis of these chemicals. (c) 2006 Elsevier Ltd. All rights reserved.</p>10acarbamates10acarbon dioxide utilization10aCO2 fixation10acyclic carbonates10aeco-friendly processes10aMCM-4110apolycarbonates10apolyurethanes1 aSrivastava, R.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/syntheses-polycarbonate-and-polyurethane-precursors-utilizing-co2-over-highly-efficient-002068nas a2200253   4500008004100000022001400041245006600055210006600121260009500187300001200282490000800294520115700302653004301459653002401502653002901526653005201555653001601607653001401623100001901637700002201656700002101678700001801699856009701717       2007                        eng d  a0021-951700aActivation and reactivity of epoxides on solid acid catalysts0 aActivation and reactivity of epoxides on solid acid catalysts  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcDEC  a148-1600 v2523 a<p>The aminolysis of epoxides over novel solid catalysts (Bronsted-acidic SBA-15 functionalized with propylsulfonic acid and Lewis-acidic Ti-MCM-41) is reported. The acidic properties of these catalysts were determined by FTIR spectroscopy and temperature-programmed desorption of pyridine and NH3, respectively. The mesoporous solid acids of the present study are reusable and exhibit significantly higher catalytic activities than known catalysts for opening of the oxirane ring with nitrogen (aromatic and aliphatic amines)-containing and oxygen (alcohols)-containing nucleophiles. A range of beta-amino, alcohols with high regioselectivity and stereoselectivity were synthesized. Adsorption studies as well as the sigmoid shape of the conversion- versus-time plots show that the epoxide and amine compete for adsorption on the acidic sites (-SO3H or Ti4+) on the catalyst surface. Epoxide adsorption and activation on acid sites are the more critical processes. Catalytic activity decreases with increasing basicity of the amines and/or the alcohol, as well as the dielectric constant of the solvent. (C) 2007 Elsevier Inc. All rights reserved.</p>10aaminolysis and alcoholysis of epoxides10abeta-Amino alcohols10aring opening of epoxides10aSBA-15 functionalized with propylsulfortic acid10aSolid acids10aTi-MCM-411 aSaikia, Lakshi1 aSatyarthi, J., K.1 aSrinivas, Darbha1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/activation-and-reactivity-epoxides-solid-acid-catalysts-001492nas a2200217   4500008004100000020002200041022001400063245011200077210006900189260009900258300001400357490000800371520069100379100001701070700001801087700001001105700001201115700001201127700001101139856012401150       2007                        eng d  a978-0-444-53068-4  a0167-299100aChemoselective alkane oxidations by reactive superoxovanadium(V) species in vanadosilicate molecular sieves0 aChemoselective alkane oxidations by reactive superoxovanadiumV s  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1205-12120 v1703 a<p>Unlike their titanium analogs, vanadosilicate molecular sieves catalyze the oxidation of the terminal (primary) C-H bonds in paraffins. This dissimilarity is attributed to differences in the type of reactive superoxo species generated on contact with oxidant. The latter were identified and characterized by in situ EPR and DRUV-vis spectroscopic techniques. By a suitable choice of silicate structure (VS-1 or V-MCM-41), solvent and oxidant (H(2)O(2), tert.-butyl hydroperoxide or H(2)+O2()), the V-O bond covalency and mode of O-O bond cleavage in the oxo-species and thereby, the chemoselectivity in the oxidation of the terminal carbon atoms in paraffins could be controlled.</p>1 aSrinivas, D.1 aRatnasamy, P.1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/chemoselective-alkane-oxidations-reactive-superoxovanadiumv-species-vanadosilicate-001262nas a2200229   4500008004100000022001400041245010100055210006900156260007300225300001200298490000800310520038700318653002700705653003700732653001400769653003600783100002800819700001900847700002100866700001800887856012700905       2007                        eng d  a0926-860X00aRegio- and stereoselective synthesis of beta-amino alcohols over titanosilicate molecular sieves0 aRegio and stereoselective synthesis of betaamino alcohols over t  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a145-1510 v3303 a<p>A novel application of titanosilicate molecular sieves in the synthesis of P-amino alcohols via aminolysis of epoxides, at mild and solvent-free conditions, is reported, for the first time. A range of beta-amino alcohols with nearly 100% regio- and stereoselectivity was produced over these reusable solid catalysts in high yields. (C) 2007 Elsevier B.V. All rights reserved.</p>10aAminolysis of epoxides10asynthesis of beta-amino alcohols10aTi-MCM-4110atitanosilicate molecular sieves1 aSatyarthi, Jitendra, K.1 aSaikia, Lakshi1 aSrinivas, Darbha1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/regio-and-stereoselective-synthesis-beta-amino-alcohols-over-titanosilicate-molecular-002595nas a2200253   4500008004100000022001400041245011600055210006900171260007300240300001200313490000800325520158500333653003301918653002001951653003201971653001602003653005302019653003502072653003902107653003002146100001702176700001802193856013002211       2007                        eng d  a1387-181100aSpectroscopic and catalytic properties of SBA-15 molecular sieves functionalized with acidic and basic moieties0 aSpectroscopic and catalytic properties of SBA15 molecular sieves  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a170-1800 v1053 a<p>SBA-15, grafted with Lewis acidic Ti4+ ions and basic amines (imidazole, guanine or adenine) exhibited high catalytic activity in the cycloaddition of CO2 to epoxides yielding selectively cyclic carbonate precursors of polycarbonates. In the second class of materials, the surface of SBA-15 was grafted with thiol or sulfonic acid functionalities. Mn(Salen)Cl was, then, covalently bound to these acidic groups. The resulting catalysts show enhanced chemo-, regio- and stereo-selective catalytic activity in the epoxidation of terpenes such as R-(+)limonene, alpha-pinene and Delta-carene with molecular oxygen. The acid-base properties of these modified SBA- 15 materials were investigated by temperature-programmed desorption and diffuse-reflectance infrared Fourier transform spectroscopy. Ammonia and pyridine were used as probe molecules for acidic sites and CO2 for basic sites. Acidic Ti sites activated epoxides and the grafted basic amines activated CO2. The simultaneous presence of both acidic and basic sites on amine/adenine-functionalized Ti-SBA-15 enabled synergistic enhancement in catalytic activity in the cycloaddition reaction of CO2 to epoxides. When Mn(Salen)Cl was immobilized on thiol or sulfonic acid-functionalized SBA-15, the oxidation state of Mn decreased from +3 to +2. The organo-acidic functional groups (thiol or sulfonic acid) axialk, coordinated to Mn ions modified the electronic structure of Mn ions enhancing the activity and selectivity of Mn(Salen) complexes in aerial oxidation reactions. (C) 2007 Elsevier Inc. All rights reserved.</p>10aaerial oxidation of terpenes10aCO2 utilization10acyclic carbonates synthesis10aepoxidation10afunctionalization with acidic and basic moieties10aimmobilization of Mn complexes10aorgano-functionalization of SBA-1510asolid acid-base catalysts1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/spectroscopic-and-catalytic-properties-sba-15-molecular-sieves-functionalized-acidic-and-001523nas a2200253   4500008004100000022001400041245012700055210006900182260005700251300001000308490000800318520054500326653002400871653003100895653004400926653003500970653003001005100001901035700002201054700002401076700002101100700001801121856013001139       2008                        eng d  a1011-372X00aDouble metal cyanides as efficient solid acid catalysts for synthesis of beta-amino alcohols under solvent-free conditions0 aDouble metal cyanides as efficient solid acid catalysts for synt  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUN  a24-310 v1233 a<p>A novel application of Fe-Zn double metal cyanide complexes as solid, acid catalysts for regioselective synthesis of beta-amino alcohols under solvent-free conditions via ring-opening of epoxides with amines is reported for the first time. The conversion of epoxides to beta-amino alcohols is nearly 100%. In the reaction with styrene oxide, regioselective beta-amino alcohol formation is higher with aromatic than with aliphatic amines. Strong Lewis acidic Zn(2+) ions in the catalyst are probably the active sites in this reaction.</p>10abeta-Amino alcohols10adouble metal cyanide (DMC)10aregioselective ring-opening of epoxides10aSingle crystal x-ray structure10asolid Lewis-acid catalyst1 aSaikia, Lakshi1 aSatyarthi, J., K.1 aGonnade, Rajesh, G.1 aSrinivas, Darbha1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/double-metal-cyanides-efficient-solid-acid-catalysts-synthesis-beta-amino-alcohols-under-001304nas a2200241   4500008004100000022001400041245010700055210006900162260005700231300001200288490000800300520042400308653002800732653003000760653003300790653001100823653002700834100001900861700001500880700002100895700001800916856012800934       2010                        eng d  a1011-372X00aRegiospecific oxyhalogenation of aromatics over SBA-15-supported nanoparticle group IV-VI metal oxides0 aRegiospecific oxyhalogenation of aromatics over SBA15supported n  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUL  a190-2010 v1373 a<p>TiO(x), VO(x), MoO(x) and WO(x) supported on SBA-15 exhibit efficient catalytic activity for oxyhalogenation of aromatics with the H(2)O(2)-halide ion system. Unlike the hitherto known solid catalysts, these reusable catalysts yield the para-halogenated product with 100% selectivity at 298 K and moderate acidic pH (3-5). The catalytic activity was enhanced by five orders of magnitude when supported on SBA-15.</p>10aHaloperoxidase activity10aOrdered mesoporous silica10aOxyhalogenation of aromatics10aSBA-1510aSupported metal oxides1 aSaikia, Lakshi1 aRajesh, M.1 aSrinivas, Darbha1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/regiospecific-oxyhalogenation-aromatics-over-sba-15-supported-nanoparticle-group-iv-vi-001830nas a2200229   4500008004100000022001400041245008300055210006900138260007300207300001200280490000800292520099600300653003301296653001801329653001601347653004201363653002401405100002201429700001701451700001801468856011401486       2011                        eng d  a0926-860X00aHydrolysis of vegetable oils and fats to fatty acids over solid acid catalysts0 aHydrolysis of vegetable oils and fats to fatty acids over solid   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a427-4350 v3913 a<p>Solid Fe-Zn double-metal cyanide (DMC) complexes exhibit high catalytic activity for hydrolysis of edible and non-edible vegetable oils and animal fat. In a batch reaction, complete conversion of vegetable oil triglycerides to fatty acids with selectivity greater than 73 wt% was obtained at temperatures as low as 463 K, autogenous pressure and with 5 wt% of catalyst. Catalytic activity of DMC was superior to Amberlyst (TM) 70, SAPO-11, H-beta, HY, MoO(x)/Al(2)O(3) and sulfated zirconia. Rates of hydrolysis were greatly enhanced when solvents (tetrahydrofuran or N,N-dimethylformamide), phase transfer agents (tetrapropyl ammonium bromide) and products (a mixture of mono-/diglycerides and fatty acids) or fatty acid was added to the feed. Surface hydrophobicity which enables high wettability and activation of glycerides on active, acidic sites of reusable DMC is attributed to be the major cause for its superior catalytic activity. (C) 2010 Elsevier B.V. All rights reserved.</p>10aDouble-metal cyanide complex10aFat splitting10aFatty acids10aHydrolysis of vegetable oils and fats10asolid acid catalyst1 aSatyarthi, J., K.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/hydrolysis-vegetable-oils-and-fats-fatty-acids-over-solid-acid-catalysts-0