Materials Literature
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A three-component array consisting of a free-base arylporphyrin and a gold(III) arylporphyrin, assembled together with a central bis(terpyridine)ruthenium(II) complex (right), has been synthesized, and the photophysical properties determined. The observed room-temperature prevalence of photoinduced energy transfer wit…
A spiro attack on a peroxo group is calculated to be the preferred reaction pathway for olefin epoxidation with the catalytic system CH3ReO3/H2O2 (see picture). This finding is supported by density functional calculations on more than ten transition states for the most probable mechanisms. Hydration has significant ef…
Wedgelike dendrimer fragments, "dendrons", attached to linear polymers as side groups, can be used to create anisotropic "nanocylinders", leading to uncoiling and extension of the polymer chains. Synthetic macromolecules of this type can be visualized directly on surfaces and their contour length determined from scann…
A nucleophilic aromatic substitution reaction between a sterically hindered phenol and 4-nitrophthalonitrile, 3-nitrophthalonitrile or 6-fluoro-2,3-napthalonitrile has been used to prepare precursors for the synthesis of a number of phthalocyanines, such as 1, and naphthalocyanines bearing bulky substituents.
Exact control of the film thickness of polyelectrolyte shells (a transmission electron microscopy image is shown) is achieved by colloid-templated consecutive adsorption of polyanions and polycations followed by decomposition of the templating core. Possible areas of application for these shells range from the pharmac…
SrCO3 crystals display patterns of templating when grown on tailored self-assembled monolayers (right). As SrCO3 is isostructural with aragonite, comparison of the crystallisation of SrCO3 in the aragonite/strontianite modification with the crystallisation of CaCO3 in all three modifications might yield some insights…
The kinetics and mechanism of the sonolytic degradation of methyl tert -butyl ether (MTBE) have been investigated at an ultrasonic frequency of 205 kHz and power of 200 W L - 1 . The observed first-order degradation rate constant for the loss of MTBE increased from 4.1 × 10 - 4 s - 1 to 8.5 × 10 - 4 s - 1 as the conce…
The magnetic interaction in a series of isomorphous Cu2+–Ln3+ complexes (1) is antiferromagnetic for LnCe, Nd, Sm, Tm, Yb and ferromagnetic for Ln=Gd, Tb, Dy, Ho, Er, while no interaction is operative for Ln=La, Pr, Eu, Lu.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Role of Bridging Ligands in Controlling Electronic and Magnetic Properties in Polynuclear ComplexesJon A. McCleverty and Michael D. WardView Author Information School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, U.K. Cite this: Acc. Chem. Res. 19…
Exact control of the film thickness of polyelectrolyte shells (a transmission electron microscopy image is shown) is achieved by colloid-templated consecutive adsorption of polyanions and polycations followed by decomposition of the templating core. Possible areas of application for these shells range from the pharmac…
The main part of the VOCs (volatile organic compounds) contained in diesel exhaust (≈80%) is oxidized to CO and CO 2 over an SCR (selective catalytic reduction) catalyst. CO is the major product of this oxidation, representing about 50−70% of the formed products (CO + CO 2 ). This preferential formation of CO leads to…
The presence of carbonaceous contamination on common surface-enhanced Raman scattering (SERS) surfaces has been a primary limitation to the analytical utility of SERS; background contamination significantly affects reproducibility and often determines the limit of detection. Due to the strong interaction between thiol…
The synthesis of 16,20-dipropyl-2,3,6,7,10,11,15,21-octamethyl-[22]pentaphyrin-(1.1.1.0.0) (8), a stable isomer of smaragdyrin ([22]pentaphyrin(1.1.0.1.0)), and 9, a furan-containing analogue of 8, are reported. These two new expanded porphyrins were characterized in solution using UV-vis and (1)H and (13)C NMR spectr…
Surface-enhanced Raman scattering is used to determine the potential-dependent orientation of 1- and 2-methylimidazole on Ag electrodes. Frequency shifts resulting from adsorption and potential changes suggest adsorption of these molecules through the pyridine nitrogen at positively charged surfaces. Unique ν(CH 3 ) f…
The resistance against rolling of a rigid cylinder on a flat viscous surface is investigated. We found that the rolling-friction coefficient reveals strongly non-linear dependence on the cylinder's velocity. For low velocity the rolling-friction coefficient rises with velocity due to increasing deformation rate of the…
Starting from the conventional electron-hole Hamiltonian ${\cal H}_{eh}$, we derive an effective Hamiltonian $\tilde{\cal H}_{1s}$ for $1s$ excitons with spin degrees of freedom. The Hamiltonian describes optical processes close to the exciton resonance for the case of weak excitation. We show that straightforward bos…
The anomalous plasmon linewidth dispersion (PLD) measured in K by vom Felde, Sprosser-Prou, and Fink (Phys. Rev. B 40, 10181 (1989)), has been attributed to strong dynamical electron-electron correlations. On the basis of ab initio response calculations, and detailed comparison with experiment, we show that the PLD of…
The experimental observation of a three-dimensional diffraction phenomenon at a 90° Bragg reflection is reported and discussed. A refined experimental technique for the direct observation and accurate measurement of scattered intensity profiles in the vicinity of a 90° Bragg reflection was proposed and implemented. Th…
Since the invention of polyester fibre, the demand presented. for this versatile fibre is enonnously increasing. . Polyester fibre has very good strength and resilience 2 MaterIals and Methods .. properties. However, because of some limitations in For the laboratory blend preparation, unfinIshed the wearing comforts a…
The design of condensers used to reflux boiling chloride solutions for stress corrosion tests on stainless alloys was shown to have a significant effect on time to cracking. This effect resulted from the different steady-state concentrations of oxygen produced by various types of condensers. The condenser that provide…