Materials Literature
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Abstract β‐CD‐2‐CTS was synthesized by β‐cyclodextrin reacting with p ‐toluenesulfonyl chloride, then grafting with chitosan. The infrared spectra analysis and 13 C NMR confirmed that β‐cyclodextrin reacted with p ‐toluenesulfonyl chloride at the 2‐position carbon atom in the substituted glucose unit of β‐cyclodextrin…
Dielectric enhancement was observed in polycrystalline BaTiO 3 /Ba 0.6 Sr 0.4 TiO 3 multilayered thin films deposited layer-by-layer on Pt/Ti/SiO 2 /Si substrates via pulsed laser deposition. The dielectric constant of the films was enhanced more than four times with the decrease of the individual layer thickness down…
Arborescent graft polystyrenes were prepared by the “graft on graft” technique, involving the iterative grafting of end-functional polymer chains onto reactive polymer backbones. The grafts and the reactive backbone building blocks were synthesized individually by living polymerization techniques. The first-generation…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAn Efficient, Single-Source Molecular Precursor to SilicoaluminophosphatesKyle L. Fujdala and T. Don TilleyView Author Information Department of Chemistry University of California, Berkeley Berkeley, California 94720-1460 Chemical Sciences Division Lawrence Berkeley La…
In this paper, we report polarized optical microscopy and electrical transport studies of manganese oxides that reveal that the charge ordering transition in these compounds exhibits typical signatures of a martensitic transformation. We demonstrate that specific electronic properties of charge-ordered manganites stem…
An extended Hamiltonian approach to conduct isothermal-isobaric molecular dynamics simulations with full cell flexibility is presented. The components of the metric tensor are used as the fictitious degrees of freedom for the cell, thus avoiding the problem of spurious cell rotations and artificial symmetry breaking e…
An introduction is given to the many-body coherent potential approximation (CPA) for the double-exchange (DE) model and the Holstein-DE model, the latter including coupling of the electrons to local phonons as well as to local spins. It is shown how the method can treat the local spins and phonons quantum-mechanically…
Within the framework of the exact muffin-tin orbitals (EMTO) theory we have developed a new method to calculate the total energy for random substitutional alloys. The problem of disorder is treated within the coherent potential approximation (CPA), and the total energy is obtained using the full charge density (FCD) t…
We have studied the ground-state properties of boron-related dia- and paramagnetic point defects in B-doped silica. Hartree-Fock and density functional theory calculations have been performed to determine the structure, charge, and spin distribution of the boron oxygen hole center (BOHC). The currently accepted model…
Reaction of the molecular loop [Rh(2)(cis-DAniF)(2)(CH(3)CN)](2)(malonato)(2), DAniF = N,N'-di-p-anisylformamidinate, with 2 equiv of 2,2',3,3',5,5',6,6'-octafluoro-4,4'-biphenyldinitrile gives a linear tubular structure with Rh-Rh distances of 2.435(1) A. A comparison of the structures obtained with this molecular lo…
This paper describes for the first time the synthesis of surface-grafted AB-block copolypeptides, consisting of poly( γ -benzyl l -glutamate) (PBLG) as the A-block and poly( γ -methyl l -glutamate) (PMLG) as the B-block. Immobilized primary amine groups of ( γ -aminopropyl)triethoxysilane (APS) on silicon wafers initi…
Copper(II), zinc(II), and nickel(II) complexes with tridentate imino nitroxyl diradicals, [CuCl(bisimpy)(MeOH)](PF(6)) (1), [ZnCl(2)(bisimpy)] (2), and [NiCl(bisimpy)(H(2)O)(2)]Cl x 2H(2)O (3) (bisimpy = 2,6-bis(1'-oxyl-4',4',5',5'-tetramethyl-4',5'-dihydro-1'H-imidazol-2'-yl)pyridine), were prepared, and their magnet…
Glutamate 47 is conserved in 1-aminocyclopropane-1-carboxylate (ACC) synthases and is positioned near the sulfonium pole of (S,S)-S-adenosyl-L-methionine (SAM) in the modeled pyridoxal phosphate quinonoid complex with SAM. E47Q and E47D constructs of ACC synthase were made to investigate a putative ionic interaction b…
Optical properties of a series of finite sized hydrogenated carbon nanotubes with the smallest diameter of 4 A are studied systematically. Their absorption spectra are calculated with the localized-density-matrix method. The semiempirical MNDO parametric method 3 (PM3) Hamiltonian is employed. The finite optical gaps…
The ring-opening polymerization of N -carboxyanhydrides (NCA) of γ -benzyl l -glutamate and γ-methyl l -glutamate from ( γ -aminopropyl)triethoxysilane (APS) pretreated substrates such as silicon wafers and quartz slides was investigated. FT-IR transmission spectroscopy, circular dichroism measurements, and UV/vis spe…
Two binuclear metal-radical complexes, formed by the reaction of M(hfac)(2) x 2H(2)O (M = Mn or Ni; hfac = hexafluoroacetylacetonate) with the 1,5-dimethyl-3-(4,6-dimethylpyrimidin-2-yl)-6-oxoverdazyl radical (3), were synthesized. The binuclear Mn complex 5 (i.e., 3[Mn(hfac)(2)](2)) crystallizes in the monoclinic spa…
The organic−inorganic hybrid materials obtained by the sol−gel route constitute a new class of solids prepared directly from a molecular precursor in mild conditions. These materials are better described as kinetically controlled solids instead of thermodynamically unstable materials. The reproducibility is observed o…
We report on transport properties of polycrystalline ${\mathrm{Na}}_{8}{\mathrm{Si}}_{46}$ in the temperature range 10 to 300 K. The compound is a type I clathrate with Na incorporated into polyhedra formed by framework Si atoms. Seebeck coefficient and resistivity measurements indicate metallic behavior. The thermal…
BACKGROUND: Early graft failure after the use of less satisfactory autologous grafts (30% of all vein grafts) is caused primarily by the following problems: (1) suitable autologous transplants are limited; (2) biotechnology has not yet been able to produce reliable graft substitutes that are legally and ethically appr…
A convenient synthesis of aliphatic polyesters by the distannoxane-catalyzed polycondensation of aliphatic dicarboxylic acids and aliphatic diols in solvents under azeotropic conditions was developed. To determine the optimum conditions for polycondensation of succinic acid with 1,4-butandiol, the effect of various ty…