Dieter Fenske、Nianyong Zhu、T. Langetepe1998-10-16Angewandte Chemie International Edition
A significant extension of the class of AgSe clusters is achieved with the synthesis of the title compounds. This confirms the concept that attaching organic ligands to the outer surface of the cluster hinders the formation of stable binary selenides. The protecting phosphane ligands have a great influence on the stru…
Magnetism in coordination complexesCrystal Structures and PropertiesNanocluster Synthesis and Applications
Jason S. Patzlaff、Jeffrey A. Moeller、Bridgette A. Barry 等 4 位作者1998-10-16Biochemistry
The lactose permease, encoded by the lacY gene of Escherichia coli, is an integral membrane protein that functions as a proton and lactose symporter. In this study, we have characterized a novel monodisperse, purified preparation of lactose permease, as well as functionally reconstituted lactose permease, using spectr…
Protein Structure and DynamicsEnzyme Structure and FunctionAmino Acid Enzymes and Metabolism
Fang Wang、Weiqun Li、Mark R. Emmett 等 8 位作者1998-10-16Biochemistry
Protein tyrosine phosphatases (PTPase) play important roles in the intracellular signal transduction pathways that regulate cell transformation, growth, and proliferation. Here, solvent accessibility is determined for backbone amide protons from various segments of wild-type Yersinia PTPase in the presence or absence…
Protein Structure and DynamicsMetabolomics and Mass Spectrometry StudiesEnzyme Structure and Function
Andrea Riede、Martin Helmstedt、V. Riede 等 4 位作者1998-10-16Langmuir
Dynamic light scattering was used to study the particle formation in the dispersion polymerization of aniline hydrochloride. The organic polymers poly( N -vinylpyrrolidone) and hydroxypropylcellulose are compared with inorganic silica colloids in their role as steric stabilizers of polyaniline dispersions. The particl…
Advanced Sensor and Energy Harvesting MaterialsConducting polymers and applicationsAnalytical Chemistry and Sensors
José A. Rodríguez、Tomàš Jirsàk、Sanjay Chaturvedi 等 4 位作者1998-10-16Journal of the American Chemical Society
The surface chemistry of SO 2 on polycrystalline Sn, Pt(111), and a ( x )R30°-Sn/Pt(111) surface alloy has been investigated using synchrotron-based high-resolution photoemission and ab initio self-consistent field calculations. Metallic tin has a large chemical affinity for SO 2 . At 100−150 K, SO 2 disproportionates…
Catalytic Processes in Materials ScienceGas Sensing Nanomaterials and SensorsIndustrial Gas Emission Control
H. A. M. Biemans、Alan E. Rowan、A. Verhoeven 等 10 位作者1998-10-16Journal of the American Chemical Society
A new type of porphyrin array has been synthesized by the coupling of six porphyrin moieties to a central benzene core via an ether linkage. The resulting porphryin supermolecule has a diameter up to 80 Å and a mass of 8500 daltons. In solution, the six porphyrins around the central benzene ring arrange themselves int…
Porphyrin and Phthalocyanine ChemistryMolecular Junctions and NanostructuresSurface Chemistry and Catalysis
Vivian Wing‐Wah Yam、Chi-Kwan Li、Chui‐Ling Chan1998-10-16Angewandte Chemie
Zwei vielseitig anwendbare Lumineszenzionensonden für Kaliumionen wurden auf der Grundlage des „Ein- und Ausschaltens”︁ einer Gold-Gold-Wechselwirkung entwickelt. Nach Zugabe von Kaliumionen weisen die Gold(I)-Komplexe [Au2(R2PCH2PR2)(S-benzo[15]krone-5)2] (siehe Bild; R=Ph, Cyclohexyl; M+=K+) eine intensive rote Lumi…
Organometallic Complex Synthesis and CatalysisMolecular Sensors and Ion DetectionNanocluster Synthesis and Applications
Vivekanantan S. Iyer、Kimihiro Yoshimura、Volker Enkelmann 等 6 位作者1998-10-16Angewandte Chemie International Edition
At the limits of analytical investigation one finds the nanodimensional C60 graphite segment 1, which, thanks to its long-chain alkyl substituents, is soluble. Monolayers of 1 on graphite can be characterized by scanning tunneling microscopy.
Graphene research and applicationsMolecular Junctions and NanostructuresFullerene Chemistry and Applications
Liang Liang、Xiangdong Feng、Jun Liu 等 5 位作者1998-10-16Macromolecules
A new, simple, and effective method to modify the surface of glass plate and quartz capillary tube by ultraviolet (UV) photopolymerization of N -isopropylacrylamide (NIPAAm) has been developed. A photosensitizer, silane coupling agent with the dithiocarbamate group, was synthesized by the condensation reaction between…
Surface Modification and SuperhydrophobicityHydrogels: synthesis, properties, applicationsInteractive and Immersive Displays
Silvio Aime、Alessandro Barge、Mauro Botta 等 5 位作者1998-10-16Angewandte Chemie International Edition
A large difference in the exchange rate of the coordinated water molecule is seen in solution for the diastereoisomers M and m of a europium(III) complex with an octadentate, neutral macrocyclic ligand (kex(M)<kex(m)). This finding is of high relevance to the design of more efficient contrast agents for magnetic reson…
Advanced MRI Techniques and ApplicationsMagnetism in coordination complexesLanthanide and Transition Metal Complexes
I. D. L. Albert、Tobin J. Marks、Mark A. Ratner1998-10-16Journal of the American Chemical Society
Computational modeling reveals that, by substitutional modification of interplanar dihedral angles in a series of quinopyrans, both the optical absorption cross section and the first hyperpolarizability can be widely tuned in both frequency and magnitude. This is a promising structural control scheme for modulating mo…
Porphyrin and Phthalocyanine ChemistryNonlinear Optical Materials ResearchSynthesis and Properties of Aromatic Compounds
Douglas S. Shephard、Wuzong Zhou、Thomas Maschmeyer 等 8 位作者1998-10-16Angewandte Chemie International Edition
The “staining” cluster–crown compound [Ru6C(CO)14(η6-C6H4C10H20O6)] verifies that the internal walls of mesoporous silica MCM-41 may be selectively functionalized with propylammonium groups (see picture). By the use of high-resolution transmission electron microscopy the presence and position of the cluster and also o…
Metal-Organic Frameworks: Synthesis and ApplicationsMesoporous Materials and CatalysisPolyoxometalates: Synthesis and Applications
Simon R. Johnson、Stephen D. Evans、Rik Brydson1998-10-16Langmuir
Small aromatic thiol molecules HS−C 6 H 4 −X, where X = OH, COOH, NH 2, and CH 3, have been used to stabilize gold nanosized clusters. The physical properties of the surfactant-coated nanoparticles, both in solution and as thin films, were found to be dependent upon the nature of the functional group X. In particular…
Gold and Silver Nanoparticles Synthesis and ApplicationsQuantum Dots Synthesis And PropertiesNanocluster Synthesis and Applications
Vagelis Harmandaris、Vlasis G. Mavrantzas、Doros N. Theodorou1998-10-16Macromolecules
Well-relaxed atomistic configurations of polydisperse, linear polyethylene (PE) melts, obtained with the end-bridging Monte Carlo algorithm, have been subjected to detailed molecular dynamics simulations in both the canonical ( NVE ) and microcanonical ( NVT ) ensembles. Three different systems have been investigated,…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesRheology and Fluid Dynamics Studies
Virgil Percec、W.-D. Cho、Patrick E. Mosier 等 5 位作者1998-10-16Journal of the American Chemical Society
In 1989, it was predicted that a change in dendritic shape to a nearly spherical one should occur upon increasing the generation number (Naylor, A. M.; Goddard, W. A., III; Kiefer, G. E.; Tomalia, D. A. J. Am. Chem. Soc. 1989, 111, 2339). The absence of long-range order required for X-ray analysis allowed only indirec…
Advanced Polymer Synthesis and CharacterizationChemical Synthesis and AnalysisDendrimers and Hyperbranched Polymers
Arnold Holzwarth、Hans‐Werner Schmidt、Wilhelm F. Maier1998-10-16Angewandte Chemie International Edition
Only about 200 μg of catalyst are required to identify the catalytically active materials on a combinatorial library of heterogeneous catalysts by IR thermography. The procedure is highly sensitive, and temperature differences arising from catalytic activity of hydrogenations and oxidations have been reliably detected…
Catalysis and Oxidation ReactionsMachine Learning in Materials ScienceX-ray Diffraction in Crystallography
J. Martinek、J. Barnas、G. Michalek 等 5 位作者1998-10-16arXiv
Spin dependent single electron tunneling in ferromagnetic double junctions is analysed theoretically in the limit of sequential tunneling. The influence of discrete energy spectrum of the central electrode (island)on the spin accumulation, spin fluctuations and tunnel magnetoresistance is analysed numerically in the c…
Mesoscale and Nanoscale PhysicsMaterials Science
D. A. Gorokhov、R. A. Suris、V. V. Cheianov1998-10-16arXiv
In this work we present a theoretical study of EELS (electron-energy-loss spectroscopy) experiments on the ${\rm C}_{60}$ molecule. Our treatment of the problem is based on the simple two-fluid model originally proposed for the description of plasma oscillations in graphite and fullerenes (see Refs.\cite{14,15,16}). I…
Mesoscale and Nanoscale PhysicsMaterials Science
James E. Bateman、Robert D. Eagling、David R. Worrall 等 5 位作者1998-10-16Angewandte Chemie International Edition
The hydrogen-terminated surface of porous silicon (PS) is sufficiently reactive for the uncatalyzed hydrosilation of alkenes and alkynes. These modifications produce dramatic changes to both the physical and chemical properties of the PS.
TiO2 Photocatalysis and Solar CellsSemiconductor materials and devicesSilicon Nanostructures and Photoluminescence
Tapan K. Jain、Indrajit Roy、Tapas De 等 4 位作者1998-10-16Journal of the American Chemical Society
Novel, injectable, and sprayable nanometer size hydrated silica particles encapsulating high molecular weight compounds such as [ 125 I]tyraminylinulin (mol wt 5 kD), FITC-dextran (mol wt 19.6 kD), and horse radish peroxidase (mol wt 40 kD) have been prepared and characterized. The size of these particles is always be…
Mesoporous Materials and CatalysisPolymer Surface Interaction StudiesInnovative Microfluidic and Catalytic Techniques Innovation