Materials Literature
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Condensation of 2,4-bis(phenylhydroxymethyl)furan with pyrrole and p-toluylaldehyde formed, instead of the expected 5,20-diphenyl-10,15-di(p-tolyl)-2-oxa-21-carbaporphyrin, a pyrrole addition product [(H,pyr)OCPH]H(2); this product can formally be considered as an effect of hydrogenation of 3-(2'-pyrrolyl)-5,20-diphen…
The synthesis of a new oxaaza macrocyclic ligand, L, derived from O(1),O(7)-bis(2-formylphenyl)-1,4,7-trioxaheptane and tren containing an amine terminal pendant arm, and its metal complexation with alkaline earth (M = Ca(2+), Sr(2+), Ba(2+)), transition (M = Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+)), post-transition (M…
The temperature behaviour of the optical absorption edge in the range of phase transitions for CuCrP 2 S 6 crystals is studied. The absorption edge is shown to be described by the Urbach rule with different convergence point coordinates in antiferroelectric and paraelectric phases. In the intermediate phase there is n…
Abstract The effect of surface hydrophilicity was induced from the amide units in the polyesteramide. The surface energies and compositions of the polyesteramides were studied by employing contact angle and interfacial tension measurements and ESCA analysis. Biodegradability was evaluated form various methods includin…
In our recent study Xu et al (2002 Chem. Phys. Lett. 364 57–63), a phase transformation from the hexagonal to the tetragonal structure in the annealed ZnO films on silicon was studied by atomic force microscopy. Cathodoluminescence (CL) and glancing-angle x-ray diffraction analysis of the ZnO films indicated that such…
Abstract The swelling of membranes of the polyelectrolyte complex (PEC) between chitosan and alginate shows a similar pattern to that of other PECs. However, if the swelled membranes are dried, a second swelling process is seen which exhibits Fickian behavior. The apparent activation energy was estimated to be 32.8 kJ…
The synthesis, structure, and spectroscopic characterization of a series of phenylacetylenylene rodlike molecules containing dipyrromethene (dipyrrin) ligands are described. The combination of the phenylacetylenylene groups with the porphyrinogenic dipyrrin moieties results in a rich absorption spectroscopy for these…
We report the use of three enantiomerically pure and electronically tuned ruthenium carbonyl porphyrin catalysts for the asymmetric cyclopropanation and epoxidation of a variety of olefinic substrates. The D(4)-symmetric ligands carry a methoxy, a methyl or a trifluoromethyl group at the 10-position of each of the 9-[…
A new strategy to effect photoinduced control over molecular self-assembly is reported. This strategy uses the reversible trans-cis photoisomerization of a novel azobenzene system, where the trans- and cis-forms self-assemble into dramatically different higher-order structures. The trans-azobenzene form of this molecu…
The time evolution of the flow-induced changes in structure of two-dimensional suspensions have been studied by means of video microscopy. The interparticle forces were tailored to produce a two-dimensional (2D) particulate network that could be reversibly broken down by means of a shear flow. Two types of suspensions…
Hexagonally arranged surface oxygen atoms, oxygen point defects, and multiple oxygen defects at oxygen-terminated CeO 2 (111) surfaces in different oxidation states were visualized by noncontact atomic force microscopy (NC-AFM). The multiple defects such as line defects and triangular defects were stabilized by a loca…
Single-walled carbon nanotubes (SWNT) were reported to have record high hydrogen storage capacities at room temperature, indicating an interaction between hydrogen and carbon matrix that is stronger than known before. Here we present a study of the interaction of hydrogen with activated charcoal, carbon nanofibers, an…
Abstract Wood‐plastic composites are being increasingly examined for nonstructural or semistructural building applications. As outdoor applications become more widespread, durability becomes an issue. Ultraviolet exposure can lead to photodegradation, which results in a change in appearance and/or mechanical propertie…
The partition function of an oscillator disturbed by a set of electron particle paths has been computed by a path integral method which permits to evaluate at any temperature the relevant cumulant terms in the series expansion. The time dependent source current peculiar of the semiclassical Su-Schrieffer-Heeger model…
Rapid and precise doping of mesoporous silica beads has been achieved with luminescent quantum dots, leading to 1−2 orders of magnitude improvements over the results previously achieved with polystyrene latex beads. A surprising finding is that multivalent hydrophobic interactions provide a strong driving force for ef…
By carrying out density functional theory (DFT) analysis within the Keldysh non-equilibrium Green's function (NEGF) framework, we investigate the quantum transport properties of Au-C60-Au molecular junctions from the first principles. We briefly review the NEGF-DFT formalism and present some of our data. We found that…
This paper offers a method of obtaining constitutive equations for rheological medium. The method has been developed using the symbolic diagram illustrating the behavior of incompressible material. The studied medium operates under finite deformations. Elastic and viscous interrelations between the diagram points are…
Based on first-principles density-functional theory calculations we investigate the electronic structure of hexanuclear "ferric wheels" M Fe_6[N(CH_2 CH_2 O)_3]_6 Cl (M = Li, Na) in their antiferromagnetic ground state. The electronic structure is presented in form of spin- and site-resolved local densities of states.…
Antiferromagnetism in stacked nanographite is investigated with using the Hubbard-type model. We find that the open shell electronic structure can be an origin of the decreasing magnetic moment with the decrease of the inter-graphene distance, as experiments on adsorption of molecules suggest. Next, possible charge-se…
Supported Au nanoclusters synthesized from diblock copolymer micelles can be reliably prepared with well-controlled sizes and dispersions. For particles with diameters between approximately 1 and 6 nm, the particle size and the support were found to strongly influence the oxygen reactivity, the formation and stabiliza…