Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTProgrammed Assembly of DNA Functionalized Quantum DotsGregory P. Mitchell, Chad A. Mirkin, and Robert L. LetsingerView Author Information Department of Chemistry, Northwestern University 2145 Sheridan Rd., Evanston, Illinois 60208 Cite this: J. Am. Chem. Soc. 1999, 121…
A mixture of the 8-O-beta-D-glucopyranoside of omega-hydroxyxanthorin 1-O-methyl ether (3) and the 8-O-beta-D-gentiobioside of xanthorin 1-O-methyl ether (4) was isolated from the water-soluble extractives of the Australian toadstool Dermocybe sp. WAT 22963. Compounds 3 and 4 were identified by characterization of the…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationA Pyropheophorbide Dimer with Single Pyrrole π Overlap and a Low-Energy Q AbsorptionSpencer Knapp, Buwen Huang, Thomas J. Emge, Suzie Sheng, Karsten Krogh-Jespersen, Joseph A. Potenza, and Harvey J. SchugarView Author Information Department of Chemistry RutgersThe State Un…
The two-dimensional phase behavior of mixed-monolayers composed of poly(amidoamine) (PAMAM) dendrimers and n -alkylthiols adsorbed to Au(111) surfaces was studied using tapping mode atomic force microscopy (TM-AFM). Mixed-monolayers were prepared by sequential immersion of Au(111) substrates into ethanolic solutions o…
The influence of stereoregularity of polypropylene on the miscibility with the ethylene−1-hexene copolymer (EHR) whose 1-hexene content is 57 mol % was studied by means of viscoelastic measurements, electron microscopic observation, and so on. In this study, two types of polypropylenes were used; one is an isotactic p…
The mixed-valence diiron centers of nitrosyl derivatives of deoxy hemerythrin have been studied by variable-temperature variable-field Mössbauer spectroscopy. The adduct formed by the reaction of deoxy hemerythrin (deoxyHr) with nitric oxide (deoxyHrNO) produced spectra consistent with a binuclear center of the form F…
Two new conjugated oligoquinolines, 2,2‘-bis(4-phenylquinoline)-1,4-phenylene (2a) and 2,2‘-bis(4-phenylquinoline)-4,4‘-biphenylene (2b), were synthesized and found to crystallize in a monoclinic lattice with different unit cell parameters and space groups. Single-crystal X-ray crystal structures revealed intermolecul…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTIn Situ Observation of a Surface Chemical Reaction by Fast X-Ray Photoelectron SpectroscopyAdam F. Lee, Karen Wilson, Ruth L. Middleton, Alessandro Baraldi, Andrea Goldoni, Giorgio Paolucci, and Richard M. LambertView Author Information Department of Chemistry, Univers…
The paper examines the interaction of a carbon fiber surface, surface-treated by galvanostatic electrochemical oxidation in nitric acid solution, with poly(vinyl alcohol) (PVA). The surface chemistry of the fiber before and after interaction was examined by core and valence band X-ray photoelectron spectroscopy (XPS),…
In this work we study experimentally the lifetime of oil droplets pressed by buoyancy against a large oil/water interface, in a system containing protein (bovine serum albumin). The stability of the drops depends strongly on their size, which can be explained with the hydrodynamics of thinning of the gap region. Two d…
Epitaxial electrodeposition was used to crystallize a 0.5 μm thick film of Cu2O onto single-crystal Au(100) from an alkaline copper lactate solution at room temperature. The film showed strong out-of-plane and in-plane orientation, with no rotation of the respective crystallographic directions of the Cu2O overlayer re…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTEvidence for Sulfur-Based Radicals in Thiolate Compound I IntermediatesMichael T. GreenView Author Information Department of Chemistry and Beckman Institute California Institute of Technology 1200 East California, Pasadena, California 91125 Department of Chemistry and…
Three different methods are described for uniformly anchoring metal colloids (Pt, Pd, and Au) onto the surface of polystyrene microspheres (PSMS). The first method we have employed is electrostatic deposition of preformed anionic colloidal particles onto a polycationic surface. In this method the functional groups on…
A remarkable property of one-dimensional all-dielectric periodic structures has recently been reported, namely a one-dimensional lattice can totally reflect electromagnetic wave of any polarization at all angles within a prescribed frequency region. Unlike their metallic counterpart, such all-dielectric omnidirectiona…
Helium atoms are strongly attracted to the interstitial channels within a bundle of carbon nanotubes. The strong corrugation of the axial potential within a channel can produce a lattice gas system where the weak mutual attraction between atoms in neighboring channels of a bundle induces condensation into a remarkably…
The log k cat values for the dismutation of O 2 • - by a series of monohydroxoiron(III) and aquamanganese(III) porphyrins, including ortho, meta, and para isomers of 5,10,15,20-tetrakis( N -alkylpyridiniumyl)porphyrins, were found to vary linearly with the metal-centered redox potentials ( E 1/2 ) for the M(III)/M(II)…
Obwohl sie schon seit fast 35 Jahren bekannt sind, wurde erst jetzt erkannt, daß N-substituierte Corrole chiral sind. In einer einfachen Zweischrittsynthese wurden mehrere dieser Verbindungen hergestellt; ihre Trennung in die Enantiomere gelang durch HPLC. Vom abgebildeten Corrol wurde auch der Zink(II)-Komplex synthe…
Right- and left-handed homochiral domains segregate in a fluid smectic phase of the racemic (R*,S*)-beta-Me-TFMHPOBC analogue shown. This CF(3)-containing liquid crystalline compound exhibits an electrooptic response in a homogeneous cell, although no macroscopic dipole is expected to exist. Moreover, the homeotropic…
We have measured depth-resolved microphotoluminescence (PL) and micro-Raman spectra on the cross section of porous silicon multilayers to sample different layer depths. The PL emission band gets stronger, blueshifts, and narrows at the high porosity layers. On the contrary, the Raman band weakens and broadens. This ba…
Boron nitride (BN) nanotubes were prepared by a high-temperature plasma jet method. While the BN nanotubes were found in quantity on the surface of a BN sintered disk, amorphous BN webs were found dominant in the water-cooled collector. These structures were studied on the basis of transmission electron microscopy obs…