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The Remarkable Catalytic Activity of Alkali-Metal Alkoxide Clusters in the Ester Interchange Reaction

Matthew G. Stanton、Michel R. Gagné1997-05-01Journal of the American Chemical Society

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTThe Remarkable Catalytic Activity of Alkali-Metal Alkoxide Clusters in the Ester Interchange ReactionMatthew G. Stanton and Michel R. GagnéView Author Information Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 Ci…

Polyoxometalates: Synthesis and ApplicationsCatalysis and Oxidation ReactionsChemical Synthesis and Reactions

Structure of AgI-Ag2O-2B2O3glasses: A neutron and x-ray-diffraction investigation

Jan Swenson、L. Börjesson、R L McGreevy 等 4 位作者1997-05-01Physical review. B, Condensed matter

The structures of fast ion conducting glasses in the system (AgI${)}_{\mathrm{x}}$-(${\mathrm{Ag}}_{2}$O-${2\mathrm{B}}_{2}$${\mathrm{O}}_{3}$${)}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$ have been investigated using x-ray- and neutron-diffraction techniques. The contrasting scattering cross sections of the two technique…

Luminescence Properties of Advanced MaterialsGlass properties and applicationsPhase-change materials and chalcogenides

Anomalous Attractive Interactions in Polypropylene Blends

Glenn C. Reichart、William W. Graessley、Richard A. Register 等 5 位作者1997-05-01Macromolecules

Some new results on thermodynamic interactions in blends of model polyolefins are reported, including more examples of the anomalous attraction found earlier for polyisobutylene (PIB) blends. Small-angle neutron scattering (SANS) data demonstrate a significant suppression of concentration fluctuations in two polypropy…

Polymer crystallization and propertiesMaterial Dynamics and PropertiesNMR spectroscopy and applications

Living ring‐opening polymerization of lactones using cationic zirconocene complex catalysts

Michiya Hayakawa、Makoto Mitani、Tohru Yamada 等 4 位作者1997-05-01Macromolecular Chemistry and Physics

Abstract Living cationic ring‐opening polymerization of ϵ‐caprolactone (CL), δ‐valerolactone (VL) and 1,3‐dioxepane‐2‐one ( 6 ) was achieved at room temperature by using zirconocene borate complex catalysts. Respective block copolymerization of CL with VL or with cyclic carbonate 6 was also successfully performed. The…

biodegradable polymer synthesis and propertiesSynthetic Organic Chemistry MethodsCarbon dioxide utilization in catalysis

The chemical composition component of the distribution of chain length and long chain branching for copolymerization of olefins and polyolefin chains containing terminal double‐bonds

João B. P. Soares、A. E. Hamielec1997-05-01Macromolecular Theory and Simulations

Abstract An analytical solution for the distribution of molecular weight, long chain branching and chemical composition of polyolefins produced under steady‐state conditions with the mechanism of terminal branching is derived. The model predictions agree well with Monte‐Carlo simulation results. This detailed descript…

Polymer crystallization and propertiesAdvanced Polymer Synthesis and CharacterizationFiber-reinforced polymer composites

Photocatalytic Activities of Na2W4O13 with Layered Structure

Akihiko Kudo、Hideki Kato1997-05-01Chemistry Letters

Abstract Na2W4O13 with a layered structure possessed an energy gap between those of bulky WO3 and polyacid [Si(W3O10)4]4− photocatalysts and was active for photocatalytic hydrogen and oxygen evolution reactions in the presence of sacrificial reagents.

Advanced Photocatalysis TechniquesPolyoxometalates: Synthesis and ApplicationsAdvanced Nanomaterials in Catalysis

Molecular Structures and Energetics of Corrole Isomers: A Comprehensive Local Density Functional Theoretical Study

Abhik Ghosh、Knut Jynge1997-05-01Chemistry - A European Journal

Abstract By using geometry optimizations with local density functional theory and double‐π plus polarization basis sets, an extensive study has been carried out on the molecular structures and stabilities of free‐base and metal‐complexed corrole isomers. The optimized structures of normal metallocorroles have been fou…

Magnetism in coordination complexesPorphyrin and Phthalocyanine ChemistrySurface Chemistry and Catalysis

Naphthopyrans. Structural Features and Photochromic Properties

Barry Van Gemert、Anil Kumar、David B. Knowles1997-05-01Molecular crystals and liquid crystals science technology. Section A, Molecular crystals and liquid crystals/Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals

Structural modifications to photochromic 3H-naphtho[2,1 -b]pyrans and 2H-naphtho[1,2-b]pyrans have produced compounds that have found utility in plastic ophthalmic lens applications. The influence of substituents on color, optical density, and fade rate are reported. Synthetic routes to products and key intermediates…

Photochromic and Fluorescence ChemistryOrganic Chemistry Cycloaddition ReactionsSynthesis of Organic Compounds

Fraction of boroxol rings in vitreous boron trioxide

Jan Swenson、L. Börjesson1997-05-01Physical review. B, Condensed matter

The structure of vitreous boron trioxide (${\mathrm{B}}_{2}$${\mathrm{O}}_{3}$) has been investigated by reverse Monte Carlo modeling using reported neutron and x-ray diffraction data. Structural models with different amounts of borons in boroxol rings were created using coordination and bonding constraints. The struc…

Glass properties and applicationsLanthanide and Transition Metal ComplexesCatalysis and Oxidation Reactions

Surface studies of model supported catalysts: NO adsorption on Rh/CeO2(001)

Steven H. Overbury、D. R. Huntley、David R. Mullins 等 5 位作者1997-05-01Journal of Vacuum Science & Technology A Vacuum Surfaces and Films

The adsorption and reaction of NO on a model catalyst composed of Rh supported on ceria has been studied. CeO2 films were grown epitaxially by laser ablation onto SrTiO3(001) substrates. X-ray diffraction and transmission electron microscopy indicate the films are single crystalline with (001) orientation. Comparison…

Catalytic Processes in Materials ScienceCatalysis and Oxidation ReactionsIndustrial Gas Emission Control

Diffuse phase transition in ferroelectrics with mesoscopic heterogeneity: Mean-field theory

Shao-Ping Li、J. A. Eastman、Robert E. Newnham 等 4 位作者1997-05-01Physical review. B, Condensed matter

The diffuse phase transition in ferroelectrics with mesoscopic heterogeneity has been discussed within the context of a superparaelectric model by using the Ginzburg-Landau formalism. In the Curie region ferroelectrics with mesoscopic heterogeneity are treated as 'superparaelectrics' consisting of a mass of polar clus…

Ferroelectric and Piezoelectric MaterialsMaterial Dynamics and PropertiesAcoustic Wave Resonator Technologies

Macromolecular Engineering of Polylactones and Polylactides. 22. Copolymerization of ε-Caprolactone and 1,4,8-Trioxaspiro[4.6]-9-undecanone Initiated by Aluminum Isopropoxide

Dong Tian、Philippe Dúbois、R. Jérôme1997-05-01Macromolecules

Novel biodegradable and biocompatible polyesters have been prepared by random copolymerization of ε-caprolactone (ε-CL) and 1,4,8-trioxaspiro[4.6]-9-undecanone (TOSUO) initiated by Al(O i Pr) 3 . Copolyesters of molecular weight ( M̄ n ) up to 10 4 and containing up to 90 mol % TOSUO repeating units have been prepared…

Polymer crystallization and propertiesbiodegradable polymer synthesis and propertiesCarbon dioxide utilization in catalysis

Dedensification and Anomalous Grain Growth during Sintering of Undoped Barium Titanate

Marlyse Demartin、C. Hérard、C. Carry 等 4 位作者1997-05-01Journal of the American Ceramic Society

Dedensification (up to 10% of the theoretical density in some instances) occurs at temperatures of .1320°C during the sintering of commercial undoped BaTiO 3 powders. The expansion of the rigid, interconnected network of large, rounded grains that grow by the Ostwald ripening effect can explain the dedensification tha…

Ferroelectric and Piezoelectric MaterialsAdvanced ceramic materials synthesisAdvanced materials and composites

Base Effects on the Formation of Four- and Five-Coordinate Cationic Aluminum Complexes

Jolin A. Jegier、David A. Atwood1997-05-01Inorganic Chemistry

This work was conducted as part of our continuing effort to determine the factors that affect cation formation for organometallic aluminum complexes. In this study, the interactions of R(2)AlX (where R = Me, (i)Bu, (t)Bu; X = Cl, Br, I) with the monodentate bases thf, pyridine, NEt(3), HN(i)Pr(2), H(2)N(i)Bu, H(2)N(t)…

Supramolecular Chemistry and ComplexesMesoporous Materials and CatalysisPorphyrin and Phthalocyanine Chemistry

The effect of a lateral substituent on the mesomorphic properties in a series of ferroelectric liquid crystals with a 2-alkoxypropionate unit

Miroslav Kašpar、Věra Hamplová、S. A. Pakhomov 等 8 位作者1997-05-01Liquid Crystals

A new series of ferroelectric liquid crystal materials containing a lateral methyl group on the aromatic ring of the alkoxybenzoate unit has been synthesized and investigated. These materials exhibit a wide temperature range of ferroelectric SmC* phase on cooling (including supercooling) with a very high spontaneous p…

Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesSurfactants and Colloidal Systems

Physics Study on Direct Use of Spent Pressurized Water Reactor Fuel in CANDU (DUPIC)

Hangbok Choi、Bo Wook Rhee、Hyunsoo Park1997-05-01Nuclear Science and Engineering

Physics studies have been performed for the compatibility of DUPIC fuel design to the existing CANDU-6. The DUPIC fuel is made of spent pressurized water reactor fuel through a dry process, and the bundle design utilizes an advanced CANDU fuel bundle geometry that is mechanically compatible with the current fuel chann…

Nuclear reactor physics and engineeringNuclear Materials and PropertiesNuclear and radioactivity studies

Interdependence of Photoorientation and Thermotropic Self-Organization in Photochromic Liquid Crystalline Polymers

Thomas Fischer、Lutz Läsker、Sylvia Czapla 等 5 位作者1997-05-01Molecular crystals and liquid crystals science technology. Section A, Molecular crystals and liquid crystals/Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals

By irradiation with linearly polarized light optical anisotropy is generated in isotropic films of photochromic LCP's due to a photoorientation process. Generally, the efficiency is much higher in films of polymers with a high content of azobenzene moieties. On the other hand, the photochemically induced orientation o…

Liquid Crystal Research AdvancementsSurfactants and Colloidal SystemsPhotochromic and Fluorescence Chemistry

Hydrogen bonding as the origin of both liquid crystallinity and polymer formation in some supramolecular materials

Chien‐Ming Lee、Anselm C. Griffin1997-05-01Macromolecular Symposia

Abstract The use of lateral substitution on the aromatic rings of the diacid component of diacid/bispyridyl AABB supramolecular LC polymers is effective at retarding crystallization presumably by introducing a ‘carbuncle’ along the chain which interferes with the requisite efficient close packing of molecular units. W…

Advanced Polymer Synthesis and CharacterizationDendrimers and Hyperbranched PolymersSynthesis and properties of polymers

Static structure and ionic transport in molten AgBr and AgCl

Çetin Taşseven、Joaquim Trullàs、Olga Alcaraz 等 5 位作者1997-05-01The Journal of Chemical Physics

The static structure of molten AgBr and AgCl have been calculated using the hypernetted chain theory of liquids (HNC) and molecular dynamics simulations (MD) with effective potentials based on the functional form originally proposed by Vashishta and Rahman [Phys. Rev. Lett. 40, 1337 (1978)] to study α-AgI. The HNC and…

Material Dynamics and PropertiesMolten salt chemistry and electrochemical processesThermodynamic and Structural Properties of Metals and Alloys

A Functional Mimic of the New Class of Tungstoenzyme, Acetylene Hydratase

Jyoti Yadav、Samar K. Das、Sabyasachi Sarkar1997-05-01Journal of the American Chemical Society

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Functional Mimic of the New Class of Tungstoenzyme, Acetylene HydrataseJyoti Yadav, Samar K. Das, and Sabyasachi SarkarView Author Information Department of Chemistry Indian Institute of Technology Kanpur Kanpur-208016, IndiaCite this: J. Am. Chem. Soc. 1997, 119, 18…

Enzyme Structure and FunctionEnzyme Production and CharacterizationPorphyrin Metabolism and Disorders