Materials Literature
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The localized-density-matrix method (Yokojima, S.; Chen, G. H. Chem. Phys. Lett . 1998, 292, 379) is employed to simulate the optical responses of very large carbon nanotubes and polyacetylene oligomers containing 10 000 carbon atoms. The Pariser−Parr−Pople Hamiltonian is used to describe the π electrons in these syst…
4,4′-(Hexafluoroisopropylidene)-bis-(phthalic anhydride) (1) was reacted with L-leucine (2) in toluene solution at refluxing temperature in the presence of triethylamine and the resulting imide-acid (4) was obtained in quantitative yield. The compound (4) was converted to the diacid chloride (5) by reaction with thion…
The relationship between the porous texture, the coordination number of Al atoms, the type of surface acidity, and the sol−gel acidic synthesis conditions at two pH values (pH ≈ 2 and pH ≈ 0), was studied in SiO 2 −Al 2 O 3 aerogels made with a molar Si to Al ratio r Si/Al = 100. The influences of chelation of the Al…
A series of single crystals of quasi-one-dimensional bromo-bridged Ni-Pd mixed-metal MX chain compounds Ni(1)(-)(x)()Pd(x)()(chxn)(2)Br(3) (chxn = 1(R),2(R)-diaminocyclohexane) have been obtained by electrochemical oxidation methods of the mixed methanol solutions of parent Ni(II) complex [Ni(chxn)(2)]Br(2) and Pd(II)…
The contributions to catalysis of the conserved catalytic aspartate (Asp149) in the phosphorylase kinase catalytic subunit (PhK; residues 1-298) have been studied by kinetic and crystallographic methods. Kinetic studies in solvents of different viscosity show that PhK, like cyclic AMP dependent protein kinase, exhibit…
Amine-functionalized thin films were prepared by plasma-induced deposition of allylamine. Radio frequency (rf) plasma polymerization was carried out under both continuous wave (CW) and pulsed conditions to control the film chemistry. The chemical and physical nature of plasma-polymerized allylamine films was investiga…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTChalcogen-Rich Lanthanide Clusters from Lanthanide Halide Starting Materials: A New Approach to the Low-Temperature Synthesis of LnSx Solids from Molecular PrecursorsJonathan H. Melman, Mark Fitzgerald, D. Freedman, T. J. Emge, and John G. BrennanView Author Informatio…
The 15 K visible (VIS) upconversion-luminescence of Cs 2 ZrBr 6:0.2% Os 4+ upon excitation in the near-infrared (NIR) is presented and analyzed. Crystals of Cs 2 ZrBr 6:0.2% Os 4+ were synthesized and grown by the Bridgman technique. At 15 K VIS luminescence around 16000 cm - 1 is induced by NIR excitation around 1140…
Room-temperature addition of 1-undecanol (UD-OH), 1-hexadecanol (HD-OH), 1-octanol (OC-OH), and 1,12-dodecanediol DD-(OH) 2 completely quenched the photoluminescence of silicon nanocrystallites, Si-nc. Heating Si-nc with UD-OH, HD-OH, and OC−OH resulted in the partial recovery of the photoluminescence and in the forma…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTTransfer of Chirality from Circularly Polarized Light to a Bulk Material Property: Propagation of Photoresolution by a Liquid Crystal TransitionKikue S. Burnham and Gary B. SchusterView Author Information Department of Chemistry and Biochemistry Georgia Institute of Te…
We report the preparation, crystallization, and solid-state characterization of a spiro-biphenalenyl radical. The crystal structure shows that the radical is monomeric in the solid state and without intermolecular contacts that fall within the van der Waals atomic separation. Magnetic susceptibility measurements show…
Common experience tells us that a knot significantly weakens the polymer strand in which it is tied, which in turn leads to more facile chain rupture under tensile loading. Using first-principles molecular dynamics calculations we describe the dynamical evolution of the radicals that form after chain rupture of a sing…
Zero-field muon spin relaxation (ZF-$μ$SR) data for dilute spin magnetic systems have been widely interpreted with what is called a Kubo-Toyabe form based on a Lorentzian distribution of local field components. We derive here the proper magnetic field \textit{magnitude} distribution using independent and uncorrelated…
We describe an experimental technique for the production of highly monodisperse emulsions (with minimum achievable polydispersities <3%). The phase to be dispersed is introduced into a coflowing, surfactant-laden continuous phase via a tapered capillary. Drops detach from the capillary when the streamwise forces excee…
To explore the relationship between local electromagnetic field enhancement and the large SERS (surface enhanced Raman scattering) enhancement that enables the observation of single molecule Raman spectra, we measure both resonant Rayleigh scattering spectra and rhodamine 6G Raman spectra from single Ag particles. Our…
MnBi/Al/MnBi thin films were prepared by using an electron-beam evaporation method then vacuum annealing. The effective magnetic anisotropy constant K eff of the MnBi/Al/MnBi thin film increases compared with MnBi thin film of similar magnetic thickness without an Al interlayer. This increase of K eff may be caused by…
Pure and chromium substituted barium ferrites BaFe 12- x Cr x O 19 (0 x 6.0) have been synthesised in air by self-propagating high-temperature synthesis (SHS): a combustion process involving a reaction of barium peroxide, iron oxide, chromium oxide and iron metal powder. Two series of SHS samples were produced: series…
Burkholderia sp. was grown on sucrose-containing mineral salts medium with phosphate limitation to induce poly(hydroxyalkanoate) (PHA) accumulation. Under these conditions the cultures accumulated 3-hydroxybutyric acid (3HB) and 3-hydroxy-4-pentenoic acid (3HPE) containing polyesters. Solvent fractionation of the puri…
A series of phosphorus(V), germanium(IV), and tin(IV) porphyrin-based, "axial-bonding"-type hybrid trimers have been readily constructed by employing a new "building-block" approach. The approach is modular in nature, and it involves simple "inorganic" reactions such as axial bond formation of main group element conta…
Two series of redox-active, iron−sulfur core dendrimers of the general structure (nBu 4 N) 2 [Fe 4 S 4 (S-Dend) 4 ] (Dend = dendrons of generations 1 through 4) were prepared. Heterogeneous electron-transfer rate constants indicated that the rigid series of dendrimers were more effective at attenuating the rate of ele…