Materials Literature
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Solid-state NMR is especially useful when the structures of peptides and proteins should be analyzed by taking into account the structural distribution, that is, the distribution of the torsion angle of the individual residue. In this study, two-dimensional spin-diffusion solid-state NMR spectra of 13C-double-labeled…
The equilibrium geometries of four asymmetric spirosilabifluorene derivatives are optimized by means of the DFT/B3LYP method with the 6-31G* basis sets in this paper. On the basis of the optimized structures, the electronic structure and second-order nonlinear optical properties are calculated by using time-dependent…
Abstract Polycrystalline hexagonal alkaline earth aluminates M 3 Al 16 O 27 doped by divalent europium were prepared by solid state reaction. The crystal structure and optical properties at room temperature were investigated. The structure parameters were refined using Rietveld refinement procedures. The space group o…
Abstract Chitosan is functionalized with poly(ethylene glycol) methyl ether (mPEG) at the amino and hydroxyl groups via a single step reaction in a homogeneous aqueous system. A chitosan aqueous solution obtained from the mixture of chitosan and hydroxybenzotriazole (HOBt) in water is a key factor in providing mild co…
Abstract Carbohydrate‐modified cyclosiloxanes were synthesized by hydrosilylation reactions of protected allyl‐monosaccharides and subsequent deprotection with a gel‐type ion exchanger. They were characterized by 1 H and 13 C‐NMR, FT‐IR, GPC and surface tension measurements. These compounds, as well as other water sol…
The illicit use of explosives has become a growing international concern. Those investigating the scenes of these bombings must do so expeditiously and effectively in order to locate any and all evidence among the rubble that can identify the culprits and bring them to justice. Written by an explosives expert with ove…
Members of the mechanistically diverse enolase superfamily catalyze reactions that are initiated by abstraction of the alpha-proton of a carboxylate anion to generate an enolate anion intermediate that is stabilized by coordination to a Mg2+ ion. The catalytic groups, ligands for an essential Mg2+ and acid/base cataly…
Olefin epoxidations are a class of reactions appropriate for the investigation of oxygenation processes in general. Here, we report the catalytic epoxidation of various olefins with a novel, cross-bridged cyclam manganese complex, Mn(Me2EBC)Cl2 (Me2EBC is 4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane), using…
A systematic study of the valence states of Mn and Co in the perovskite series ${\mathrm{LaMn}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x}{\mathrm{O}}_{3}\phantom{\rule{0.3em}{0ex}}(x=0\phantom{\rule{0.3em}{0ex}}\mathrm{to}\phantom{\rule{0.3em}{0ex}}1)$ by means of x-ray absorption near edge spectroscopy (XANES) at the K-edg…
Self-assembling building blocks that are readily functionalizable and capable of achieving programmed hierarchical organization have enabled us to create various functional nanomaterials. We have previously demonstrated that N,N'-disubstituted 4,6-diaminopyrimidin-2(1 H)-one (DAP), a guanine-cytosine hybridized molecu…
A new approach to control molecular aggregation of pi-conjugated chromophores in the solid state has been investigated. Our strategy was to use a modifiable bulky fragment which should induce a J-aggregation and offer the possibility to reach an H-aggregation upon its chemical modification by lateral slip of pi-conjug…
During the antisolvent crystallization of l -histidine from aqueous solution with the antisolvent ethanol, the polymorphic fraction of the metastable polymorph B increased with increasing supersaturation ratio. For supersaturation ratio S A ≤ 2.0, a mixture of the stable polymorph A and the metastable polymorph B was…
A simple solution synthesis of germanium (Ge0) nanowires under mild conditions (<400 degrees C and 1 atm) was demonstrated using germanium 2,6-dibutylphenoxide, Ge(DBP)2 (1), as the precursor where DBP = 2,6-OC6H3(C(CH3)3)2. Compound 1, synthesized from Ge(NR2)2 where R = SiMe3 and 2 equiv of DBP-H, was characterized…
Ordered mesoporous silicas such as micelle-templated silicas (MTS) feature unique textural properties in addition to their high surface area (approximately 1000 m2/g): narrow mesopore size distributions and controlled pore connectivity. These characteristics are highly relevant to chromatographic applications for resi…
In this paper a new model has been proposed to describe the oxidation of Si–Al–O–N materials in both isothermal and non‐isothermal conditions in the form of powders and pellets. All these formulae are analytic with a form of explicit function; therefore, they are not only easy to use but also enable the easy performan…
Abstract Rare‐earth fluorides are a class of materials with considerable potential in optical applications. Fluoride lattices typically permit high coordination numbers for the hosted rare‐earth ions, and the high ionicity of the rare‐earth‐to‐fluorine bond leads to a wide bandgap and very low vibrational energies. Th…
High‐temperature piezoceramics based on W 6+ ‐doped Bi 3 TiNbO 9 (BTNO) were prepared by solid‐state reaction sintering. A study of the donor doping effects on the structure, microstructure, and electrical properties was conducted. The Curie point ( T c ) decreased in the range of 860°–910°C with increasing amount of…
Nitrogen-enriched activated carbons were prepared from a Polish brown coal. Nitrogen was introduced from urea at 350 °C in an oxidizing atmosphere both to carbonizates obtained at 500−700 °C and to activated carbons prepared from them. The activation was performed at 800 °C with KOH in argon. It has been observed that…
The structure of glucose dehydrogenase from the extreme halophile Haloferax mediterranei has been solved at 1.6-A resolution under crystallization conditions which closely mimic the "in vivo" intracellular environment. The decoration of the enzyme's surface with acidic residues is only partially neutralized by bound p…
A photo- and thermoresponsive physical gel has been developed based on crosslinked supramolecular polymer networks. The gel shows reversible sol–gel phase transitions induced by heat or light irradiation. The photoinduced sol–gel phase transition shown in the figure results from the cis–trans photoisomerization of an…