Materials Literature
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Readily available N-acylbenzotriazoles 2a-q efficiently acylate aqueous ammonia and primary and secondary amines to give primary, secondary, and tertiary amides in good to excellent yields. The wide applicability of the procedure is illustrated by the preparation of (i) alpha-hydroxyamides from alpha-hydroxy acids and…
We report the magnetotransport properties up to 7 T in the organic highly conducting Langmuir-Blodgett(LB) films formed by a molecular association of the electroactive donor molecule bis(ethylendioxy)tetrathiafulvalene (BEDO-TTF) and stearic acid CH$_3$(CH$_2$)$_{16}$COOH. We show the logarithmic decrease of dc conduc…
The structural interface properties of layered Pt/Ti/SiO2/Si electrodes have been investigated using high-resolution specular and diffuse x-ray reflectivity under grazing angles. Currently this multilayer system represents a technological standard as bottom electrodes for ferroelectric thin film applications. For the…
Well-crystallized layered double hydroxides (LDH) containing Mg 2+ or Ni 2+ as divalent cations and Al 3+ as trivalent cations were obtained either by coprecipitation (cp) or with the sol−gel (sg) method. After calcination, mixed oxide structures were achieved, as shown by XRD. Their acid−base properties were investig…
The structure of nylon 46 lamellar crystals was investigated by molecular dynamics simulations taking into account the occurrence of chain folding. Fold arrangements compatible with adjacent chain reentry were simulated and comparatively analyzed. The C 14 fold consisting of a 14-membered loop with one amide group inc…
Green [{Cu(amox)(amoxH)}2](NO3)2 (amoxH = 4-amino-4-methylpentan-2-one oxime) has twofold symmetrical, oximato-bridged, dinuclear cations. Each copper(II) ion is bonded to the nitrogen atoms of one bidentate amox – and one bidentate amoxH (marked *) ligand {Cu–Namine 2.039(4), 2.006(4)* Å and Cu–Noxime 1.975(5), 2.192…
A synthetic strategy is developed to attach semirigid lipophilic sidearms to the 6-positions of bent aromatic tridentate 2,6-bis(benzimidazol-2-yl)pyridine cores to produce U-shaped ligands, L6,7. Differential scanning calorimetry (DSC) reveals that entropic contributions severely affect the isotropization processes o…
Potential energy and electron paramagnetic resonance (EPR) g tensor surfaces of model five- and six-coordinated porphyrins were examined. For both types of complexes, the NO ligand is preferably coordinated end-on, with a Fe-N-O bond angle of approximately 140 degrees. In the free five-coordinated structure, NO underg…
The cyano-bridged complexes [L14CoIIINCFeII(CN)5]-, [L14CoIIINCFeIII(CN)5], [L15CoIIINCFeII(CN)5]-, and [L15CoIIINCFeIII(CN)5] (L14 = 6-methyl-1,4,8,11-tetraazacyclotetradecan-6- amine, L15 = 10-methyl-1,4,8,12-tetraazacyclopentadecan-10-amine) are prepared and characterized both structurally and spectroscopically. In…
The melting points of crystals of ( S )- and ( RS )- N -benzoylalanine methyl ester derived from solutions of ethyl acetate/light petroleum are 56–57.5° and 81.5–82.5°, respectively, reflecting differences in lattice energy that are apparent from the crystal structures. A more extensive mode of association between cha…
The rate constants for decay of the Eu 3+ ( 5 D 0 ) excited state are reported for aqueous Eu(dipicolinate) n 3-2 n complexes with n = 0−3 in H 2 O and D 2 O at 295 K. These rate constants are used to estimate water coordination numbers, and the results are compared to parallel molecular dynamics calculations, showing…
In the structural design of fast breeder reactors, irradiation effects and sodium environmental effects on structural materials have to be taken into account. In this paper, firstly, an evaluation procedure for irradiation effects on the mechanical properties of 316FR (FBR Grade 316 stainless steel), which is a newly…
The foams of poly(ethylene terephthalate) (PET) and polycarbonate (PC) are prepared by rapid depressurization of CO 2 -saturated molten resin. It is found that the foamable temperature and pressure for PET and PC are nearly identical, and the attainable expansion ratio of the produced foam is generally less than 10. T…
Monometal hydrotalcite-like compounds of Co II 0.74 Co III 0.26 (OH) 2.01 (NO 3 ) 0.21 (CO 3 ) 0.02 ·0.6H 2 O and Co II 0.74 Co III 0.26 (OH) 1.99 (CO 3 ) 0.13 (NO 3 ) 0.01 ·0.7H 2 O have been prepared via precipitation and anion-exchange methods. After being heated at 150−600 °C, the two precursor compounds were oxid…
Thin films produced by plasma-enhanced chemical vapor deposition (PECVD) have potential application as conformal coatings on implantable devices with complex topologies and small dimensions. Coatings on such devices need to be biocompatible, insulating, and flexible enough to minimize static forces on the surrounding…
We investigate, via three-dimensional atomistic computer simulations, phase separation in an alloy under external load. A regular two-dimensional array of cylindrical precipitates, forming a mesoscopic precipitate lattice, evolves in the case of applied tensile stress by the movement of mesoscopic lattice defects. A s…
We report extensive self-consistent calculations of jellium surface energies, by going beyond the local-density approximation. The density-response function of a bounded free-electron gas is evaluated within the random-phase approximation, with use of self-consistent electron density profiles. The exchange-correlation…
The effect of surfactants on the thermodynamics and kinetics of semiconductor heteroepitaxy is briefly discussed. It is argued that the way the surfactants suppress the thermodynamic driving force for 3D islanding depends on the mechanism of exchange of overlayer and surfactant atoms. If the overlayer atoms occupy bul…
The atomic structures of nanocrystalline powders of ceria, CeO 2, and ceria-zirconia solid solution, (Ce,Zr)O 2, were studied by the pulsed neutron diffraction technique. Ceria is used as an oxygen storage component in automotive exhaust emission control systems, but the degradation of its oxygen storage capacity (OSC…
Introduction to glassy polymers The glass transition When a polymer is cooled down from the liquid or rubbery state, it becomes much stiffer as it goes through a certain temperature range. This stiffening is the result of one of two possible events: crystallization or glass transition. For crystallization to occur, th…