Materials Literature
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We report the first synthesis and characterization of nanocrystalline Bi 2 Te 3 with particle sizes less than 10 nm. The reaction of BiOClO 4 · x H 2 O with (Me 3 Si) 2 Te in a reverse micelle formed by sodium dioctylsulfosuccinate and water in hexane has produced good yields (71%) of a black powder that has been char…
We present a versatile method, based on the electrostatic self-assembly of oppositely charged species onto sacrificial templates, for the preparation of nanotubes. Polymer and polymer composite nanotubes were prepared by the layer-by-layer (LbL) deposition of polyelectrolytes and/or a charged inorganic molecular precu…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFluorous Catalysis without Fluorous Solvents: A Friendlier Catalyst Recovery/Recycling Protocol Based upon Thermomorphic Properties and Liquid/Solid Phase SeparationMarc Wende, Ralf Meier, and J. A. GladyszView Author Information Institut für Organische Chemie Friedric…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMolecular Recognition Inside of Multifunctionalized Mesoporous Silicas: Toward Selective Fluorescence Detection of Dopamine and GlucosamineVictor S.-Y. Lin, Cheng-Yu Lai, Jianguo Huang, Se-Ahn Song, and Shu XuView Author Information Department of Chemistry, Iowa State…
The mean-square optical anisotropy 〈Γ 2 〉 was determined from anisotropic light scattering measurements for nine samples of poly( n -hexyl isocyanate) (PHIC), a typical semiflexible polymer, in the range of weight-average molecular weight from 1.65 × 10 4 to 1.04 × 10 5 in n -hexane at 25.0 °C. It was found that the b…
The Debye equation gives the spherically averaged diffracted intensity from a group of atoms and is exact under the first Born, or kinematic, approximation. Algebraic simplifications are developed for calculating multiplicities in the double summation and are used in a new algorithm for implementing this equation. The…
Abstract Sb‐doped ZnO nanocrystallites of average grain size about 10 nm were made by using the citrate method. Raman spectra of the Sb‐doped ZnO nanocrystallites at room temperature are reported. Shifts and broadening of the Raman peak with Sb increasing content were observed and it was found that the intensity of a…
Abstract Hot‐stage optical microscopy was used to study the crystal morphology, nucleation, and spherulitic growth rates of poly( p ‐dioxanone) (PDS) homopolymer and an 89/11 PDS/glycolide segmented block copolymer. A wide range of crystallization conditions were experimentally accessible, allowing the inspection of v…
Highly aligned carbon nanotubes (NTs) have been directly grown on metallic surfaces and in the channels of anodic aluminum oxide (AAO) templates at a low temperature by bias-enhanced microwave plasma chemical vapor deposition. Microwave plasma generated nanoparticles of various sizes (10−100 nm) on metallic surfaces,…
Although a commonly neglected fact, the physical properties of chiral carbon nanotubes may differ significantly from those of the usually considered, simpler achiral tubes. We show that the phonon eigenvectors, e.g., of the high-energy eigenmodes no longer fall into axial and circumferential modes as in armchair and z…
We have determined the crystal structure of MTH938 (Fig. 1), a hypothetical protein encoded by the Methanobacterium thermoautotrophicum (Mthe) genome (DNA bases 843,263–862,747),1 at 2.2 Å resolution by Se-Met multiwavelength anomalous diffraction (MAD) techniques. Se-Met labeled MTH938 crystallized with the symmetry…
The compounds A(1+x)M'(3-2x)Bi(7+x)Se(14) and A(1-x)M'(3-x)Bi(11+x)Se(20) (A = K, Rb, Cs; M' = Sn, Pb) were discovered from reactions involving A(2)Se, Bi(2)Se(3), M', and Se at 760 degrees C. The single-crystal structures reveal that A(1+x)M'(3-2x)Bi(7+x)Se(14) are isostructural to K(2.5)Bi(8.5)Se(14) whereas A(1-x)M…
Sodium may be topotactically inserted into the perovskite layers (under thermodynamic control) or the rock-salt layers (under kinetic control) of the cation-deficient n = 2 Ruddlesden-Popper oxysulfides Ln2Ti2O5S2 with concomitant reduction of TiIV.
Abstract The Raman spectra of the isomorphous series descloizite [PbZn(VO 4 )(OH)] and mottramite [PbCu(VO 4 ) (OH)] were obtained at 298 and 77 K. The Raman band at 844 cm −1 , assigned to the ν 1 symmetric (VO 4 − ) stretching mode for descloizite, is shifted to 814 cm −1 for mottramite. The ν 3 mode of descloizite…
Abstract This work validated a SERS probe able to compare adenyl reactivity in DNA and RNA. A Creighton silver colloid including adenine (A) [or 2 ′ ‐deoxyadenosine 5 ′ ‐phosphate (pdA)] from 2 × 10 −3 to 2 × 10 −8 M is stabilized in the absence or presence of chloride. Concentration‐dependent SER spectral profiles re…
The interpretation of Opechowski-Guccione symbols for magnetic space-group types is based on coordinate triplets given in the now superceded International Tables for X-ray Crystallography [(1952), Vol. 1, edited by N. F. M. Henry & K. Lonsdale. Birmingham: Kynoch Press]. Changes to coordinate triplets in International…
Abstract We introduce the concept of low‐resolution surface enhanced Raman spectroscopy (SERS) for cyanide as a potentially highly useful, cost‐effective approach to detection and analysis for monitoring water contamination. We present high‐sensitivity, low‐resolution measurements of cyanide in water using a solid‐sta…
Abstract The Raman spectra of liquid ethylene glycol (EG) and EG confined to series of nanoporous silica glasses with pores ranging from 30.7 to 68.5 Å were recorded at 303 K. Using vibrational assignments of specific Raman bands to the trans and gauche conformers of EG allowed us to follow the effect of confinement o…
gamma-Hexachlorocyclohexane dehydrochlorinase (LinA) is a unique dehydrochlorinase that has no homologous sequence at the amino acid-sequence level and for which the evolutionary origin is unknown. We here propose that LinA is a member of a novel structural superfamily of proteins containing scytalone dehydratase, 3-o…
High-resolution X-ray photoelectron spectroscopy (XPS) has been applied to a series of free-base and Zn-porphyrin polymers in which the macrocycles are separated by oligo(phenylene vinylene) units (OPV) of different, controllable lengths. Neat films of all the Zn-porphyrin polymers unexpectedly reveal two peaks in the…