Materials Literature
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The ligand orientations in the nonplanar porphyrin complexes 1a–e and 2a–e have been investigated using molecular mechanics calculations and proton NMR spectroscopy. The minimum energy structures calculated for complexes 1a–e show that the planes of the axial pyridine or imidazole ligands are orientated approximately…
Abstract The influence of water vapour on the oxidation of Ti‐50 at.% Al was studied at 900°C. Thick, well‐adherent oxide scales were formed consisting of an outer TiO 2 layer and an inner heterogeneous mixture of TiO 2 and Al 2 O 3 . The interface between these layers is marked by large pores and Al 2 O 3 particles e…
The use of a precursor-based synthetic method, namely, the freeze-drying of acetic acid solutions, allows the preparation, at temperatures as low as 600 °C, of single phase perovskites in the solid solution series La 1-x K x MnO 3+δ . This soft treatment of the precursors yields products constituted of homogeneous nan…
Description STP 1326 features the most current information from the world's leading experts on innovative methods describing the physical properties and oxidative behavior of polymers, lubricants and petrochemicals. 18 comprehensive papers, including two key-note addresses, are divided into two major categories: Oxida…
We studied the structure and the magnetic properties of the oxygen deficient perovskite ${\mathrm{PrBaCuFeO}}_{5+\mathrm{y}}$ as a function of the removable oxygen y. The average crystal structure was refined from x-ray and neutron powder diffraction data which both confirm the presence of the additional oxygen y in t…
We use dynamic light scattering to measure the dynamic structure factor of density fluctuations occurring in colloidal suspensions that have attained a quiscent state long after aggregation. We find a stretched-exponential decay to a finite plateau. Our interpretation of the arrested decay is that these systems are ge…
The fracture energies of glassalumina interfaces were measured using the bimaterial bend test. These experiments comprise one of the few studies in which the bimaterial bend test has been applied to an all‐ceramic materials system. The experiment was used to evaluate the effect of materials purity, processing and envi…
A model system was developed for the in vitro quantitative investigation of the calcification process occurring in heart valves. The process of heart valve calcification consists of the formation of calcium phosphates at the heart valve-biological fluid interface. Calcium phosphate deposits may consist of more than on…
Powders of Nb and C mixed in various mole fractions (C=10–80 mol%) have been ground in a planetary ball mill. When thus mechanically activated mixtures were transferred into a graphite crucible and exposed to air, they ignited spontaneously and self-propagating high-temperature synthesis (SHS) took place. NbC, Nb2C an…
Eight polyazomethine polymers were synthesized with different backbone structures and side groups attached. Five of these polymers, with high melting point, were subjected to DC conductivity (σ) measurements versus temperature change (300–500K). The annealed samples show consistent behaviour. The [log σ] versus [1/T]…
A family of related compounds of general formula (PPh 4 ) 2 Mn 2 [Cu(L)] 3 · n H 2 O have been synthesized, where PPh 4 + is the tetraphenylphosphonium cation and L stands for o -phenylenebis( N ‘-benzyloxamidate) (PhMe 2 opbox) ( 1 ), o -phenylenebis[ N ‘-(3-phenylpropyl)oxamidate] (PhPr 2 opbox) ( 2 ), and o -phenyl…
Nitrogen pressure and gravity conditions were found to affect the density, sample elongation and microstructure of foam boron nitride synthesized from borane hydrazine.
The methods of Bürgi and Dunitz, using crystal structures to map out an exchange pathway for the carbonyls, have been applied to [Fe 3 (CO) 12 ] and its derivatives. It has been shown that the exchange pathway follows that predicted by the concerted bridge-opening and bridge-closing mechanism. The data are inconsisten…
A series of oligomers or low molecular weight polymers of lactic and/or glycolic acid has been synthesized with different molar ratios of lactic to glycolic acid. These oligomers have been characterized with respect to oligomer composition, molecular weight, intrinsic viscosity, crystallinity, melting temperature, and…
Several anionic complexes of lanthanoid metals with the 2,6-diphenylphenolate ligand have been synthesized and their room-temperature single-crystal structures determined. In novel reactions of anhydrous LnCl 3 (Ln = Nd or Er) with NaOC 6 H 3 Ph 2 -2,6·0.5thf (thf = tetrahydrofuran) in 1,3,5-tri-tert-butylbenzene at 3…
Abstract When polymers are added to a solution containing proteins, the protein may deposit as an amorphous precipitate or as crystals. Experimental evidence indicates that from a thermodynamic viewpoint, an amorphous precipitate should be treated as a liquid phase dense in the protein and crystals as true solids. To…
2,4,6-Trinitrotoluene (TNT) can crystallise in both monoclinic and orthorhombic polymorphic forms characterised by two distinct molecular packing configurations in the solid-state associated with two conformationally unique molecules (A and B) in the asymmetric unit with four asymmetric units in the unit cell. In this…
Polyvinyl N-alkyl carbamates belong to the general class of long alkyl side chain polymers. Such polymers are commonly used as release coatings for pressure sensitive adhesive tapes. In this paper the bulk, surface, and interfacial structures of polyvinyl N-alkyl carbamates having either decyl or octadecyl side chains…
The first examples of thiophenotribenzoporphyrazines have been synthesised. The compounds obtained bear either six or eight alkyl chains and show Q-band absorptions which are red shifted relative to analogous phthalocyanine derivatives. Their formulations as spin coated films show broad band absorption extending into…
meso-Tris(4-pyridyl)[[(omega-hydroxyhexamethylene)carbamoyl]phenyl ] porphyrin was converted to its H-phosphonate derivative and conjugated using solid phase synthesis with the 5'-hydroxyl group of deoxyribonucleotides d(TCTTCCCA) and d(T)12. These conjugates were transformed into their (N-methylpyridiniumyl)porphyrin…