Materials Literature
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Self-assembly and non-covalent interactions are employed for the preparation of a new family of cationic artificial supramolecular multiporphyrin aggregates incorporating Pd II and Pt II bisphosphane complexes as auxiliaries.
It has recently been demonstrated that hexagonal mesoporous silica films can be grown at mica/water interfaces. In this report it is established that the films can also be synthesized on cleaved pyrolytic graphite. Diffraction and microscopy studies of the growth, structure and form of the films indicate that the chan…
The application of combinatorial methods to the synthesis and characterization of novel materials is described for the case of solution‐phase synthesis of phosphors based on rare‐earth‐activated refractory metal oxides. A scanning multiinkjet system is shown to be suitable for the fabrication of a liberry such as (La…
The ionic and n‐type conductivities of ceria‐based electrolytes doped with gadolinium (10 and 20 cation %) or gadolinium and praseodymium (2% Pr and 18% Gd) were studied by impedance spectroscopy in air, between 573 and 1273 K, and by constant frequency (10 kHz) conductivity measurements as a function of the oxygen pa…
Active catalysts for the epoxidation of alkenes by tert-butyl hydroperoxide are provided by silasesquioxane titanium(IV) derivatives; a non-leaching catalyst, not prone to irreversible protic cleavage of its siloxy functions by the oxidizing agent, contains a terdentate silasesquioxane ligand.
By synthesising and structurally characterising new soluble titanosilsesquioxanes, and by following the dynamics of epoxidation of cyclohexene in their presence, the tripodally anchored TiIV active sites in Ti–SiO2 heterogeneous catalysts are modelled structurally and catalytically.
Ordered ultrafine platinum particles are expected to have properties differing from those of isolated particles, however, few measurements have been made because of the difficulty of producing monodispersed Pt particles. A method is reported for controlling the size and size distribution of polymer‐protected ultrafine…
The optical properties of rare-earth organic complexes have been studied because of their possible application to polymer optical fibers and waveguides. Er3+, Nd3+, and Sm3+ ions are encapsulated in tetrakis(benzoyltrifluoroacetonate) and tetrakis(dibenzoylmethide) chelates, and their radiative properties are evaluate…
The solid-state shape, size, and intermolecular packing of a fifth-generation dendritic macromolecule were determined by a combination of site-specific stable-isotope-labeling, rotational-echo double-resonance (REDOR) NMR and distance-constrained molecular dynamics simulations. REDOR experiments measured dipolar coupl…
Highly crystalline MCM-41 with a very narrow pore-size distribution (FWHM=1.5 Å), high surface area (1185 m2 g -1 ), large grain size and thick channel walls (ca. 17 Å) was prepared in alkali-free media. The properties of the product depend on the source and concentration of the reactants, the gel aging time, the temp…
Molecular or polymeric π-electron donors based on the association of tetrathiafulvalene (TTF) with linear π-conjugated systems are reviewed. Two main classes of materials are considered, namely electrogenerated polymers, either conjugated or not, and linearly extended TTF analogues built by insertion of different π-co…
Silanation of the internal pore surface of the mesoporous molecular sieve MCM-41 (40 Å) has yielded ethylenediamine (ED), diethylenetriamine (DET), and ethylenediaminetriacetic acid salt (EDT) functionalized sites. These grafted ligands were used for the preparation of cobalt(II) complexes covalently bound to the MCM-…
Superlattices of self‐assembled Ag nanocrystals have been prepared and the structure analyzed using a combination of techniques. It is shown that the supercrystals are hexagonally close‐packed, attributed to a high proportion of icosahedral and decahedral particles. The Figure (a TEM image of the Ag supercrystals) ill…
Testosterone (17β-hydroxy-4-androsten-3-one) was studied by the semiempirical AM1 and PM3 and ab initio STO-3G*, 3–21G*, and 6–31G* methods. The goals were to compare those methods and to know the electronic structure of the hormone. Full geometry optimization was performed, and two crystal conformers (T1 and T2), and…
Abstract Polyamide, polyester and polyoxymethylene having presently a worldwide sales volume of 2,4 million tons a year are important engineering thermoplastics. Based on their special property profiles they are mainly used in the automotive and electronic industry for high performance functional parts. This contribut…
原子炉の解体に伴い、大量の非放射性コンクリートが発生する。環境への配慮から、このコンクリートを処理して重量比で80 %を占める骨材を回収し、新設の工事等に使用することが期待されている。そこで、コンクリート塊に加熱処理とすりもみ処理を施して骨材を回収することを検討した。 加熱処理が分離した骨材の性能に与える効果は温度が高いほど大きいが、高温になるにしたがって骨材そのものも劣化する。骨材の品質へ与える影響を考慮した効果的な加熱温度は200～500 ℃であった。加熱保持時間の影響は相対的に小さかった。また、300 ℃の加熱を施し、すりもみ効果の卓越したロッドミルおよび攪拌ミルによりそれぞれ30～120分処理したとき、建築工事標準仕様書・…
The radula teeth of the littoral gastropod, Nerita atramentosa, have been analysed using energy dispersive spectrometry. The matrix of the mature major lateral teeth contains sulfur, chlorine, potassium, calcium and magnesium. The teeth are tanned, and additionally hardened by the possession of biomineralised granules…
The Raman spectra of the C=O stretching mode of formamide, N-methylformamide and N,N-dimethylformamide mixed with various solvents were systematically studied as a function of concentration. It was found that the hydrogen bond effect plays an important role in reducing the carbonyl stretching wavenumbers for both isot…
This study investigated the chemical stability of pure gallium in water and saline solutions in order to obtain fundamental knowledge about the corrosion mechanism of gallium-based alloys. A pure gallium plate (99.999%) was suspended in 50 mL of deionized water, 0.01%, 0.1% or 1% NaCl solution at 24 +/- 2 degrees C fo…
Hardness of a molecule has been formulated as an average of a set of terms representing various types of reactivity. Hardness parameters for molecules and bonded atoms have been calculated by the ab initio Hartree-Fock self-consistent field (HF SCF) method. An analysis has been presented of the correlation between the…