Materials Literature
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The systematic presence of a spectrum has been observed that has been termed anomalous SERS in the spectra on silver sols of a set of monocarboxylic acids, characterized by being independent of the adsorbate that is initially added and whose bands cannot be correlated with the respective Raman solution spectra. It has…
The cationic amphiphilic cobalt(II) phthalocyanines have been prepared, and are characterized by UV-absorption spectra in water and organic solvents and in their mixtures. The monomer–dimer transformation equilibrium was affected by solvent polarity and the length of the alkyl chains in the amphiphilic parts. All comp…
Polymeric two- and three-dimensional, homo- and heterometallic oxalatebridged coordination compounds offer exciting opportunities, mainly in the fields of molecular magnetism and photophysics. Given that a large variety of magnetic phenomena have been reported so far from these molecular magnets, very limited experien…
The high-brilliance beamline (BL4/ID2) at the European Synchrotron Radiation Facility (ESRF) in Grenoble has been constructed with the emphasis on time-resolved small-angle X-ray scattering and macromolecular crystallography. It has been open to users for two years. The beamline has opened up new areas in small-angle…
The complex anion bis(azido)(tetraphenylporphinato)ferrate(III) has been synthesized and characterized by variable-temperature X-ray structure determinations, powder and single-crystal EPR, IR, and Mössbauer spectroscopy, and magnetic susceptibility measurements. The synthesis utilizes 18-crown-6 to solubilize sodium…
Abstract Specific volumes are presented for 4-n-pentyl-4´-cyanobiphenyl (5CB) and trans-4-(4´-octyl-cyclo-hexyl)-benzonitrile (8PCH) for temperatures between 300 and 370 K up to 300 MPa. The p,V m ,T data were determined for the liquid crystalline and isotropic phases, and partly also for the solid phase adjacent to t…
Microporous manganese oxides with layer and tunnel structures have been synthesized by methods such as redox precipitation, thermal and hydrothermal alteration, sol-gel processing, and microwave heating. The open frameworks of these materials are composed of edge and corner shared MnO6 octahedra, with the internal por…
Infra-Red spectra of a series of substituted salicylaldehyde and 2-hydroxy-naphthaldehyde Schiff bases were used to investigate enol-keto tautomeric equilibrium. Two model compounds, namely, salicylidinaniline and naphthylidinequinolineamine Schiff bases were used to represent the enol and keto forms, respectively. Fr…
Porous silicon electroluminescent devices have been fabricated from n-type substrates using indium tin oxide, hole-transporting poly(9-vinyl carbazole) and p-type nickel oxide films as hole injecting contacts. The addition of the polymer layer, which increases the contact area by penetrating into the porous microstruc…
The oxidation of vinyl and silyl enol ethers with aqueous hydrogen peroxide was first achieved by the use of peroxotungstophosphate (PCWP) as the catalyst. For example, the oxidation of 1-ethoxy-1-octene with a stoichiometric amount of 35% H(2)O(2) in the presence of PCWP (0.5 mol %) in a mixed solvent of methanol and…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTLow-Temperature Synthesis of Aluminum Sulfide as the Solvate Al4S6(NMe3)4 in Hydrocarbon SolutionRudolf J. Wehmschulte and Philip P. PowerView Author Information Department of Chemistry University of California Davis, California 95616 Cite this: J. Am. Chem. Soc. 1997,…
A bisphthalocyanine lutetium derivative substituted with benzo-15-crown-5 subunits, [(15C5) 4 Pc] 2 Lu ( 1 ), has been shown to form sandwich complexes with cations such as potassium ion, the complexes further form pillarlike aggregates. Light scattering studies have been carried out as a function of the ratio [K + ]/…
New aliphatic polycarbonates derived from trimethylene carbonate ( 1 ) (TMC, 1,3-dioxan-2-one),have been prepared by ring opening polymerization. The synthesis is achieved by using new aluminum alkoxide initiators which allow for the incorporation of controlled functionality in the resulting polymer. The synthesis of…
Multidimensional transition-state theory was used to simulate methane jump motions in glassy atactic polypropylene at 233 K in the limit of small methane concentrations. Transition states were found with respect to both penetrant and polymer degrees of freedom, using all generalized coordinates associated with atoms i…
As a model for the splitting of pyrimidine base pair defects by DNA photolyase, the uracil dimer and its anion radical have been studied by ab initio HF and MP2 methods. A transition state and an intermediate of the uracil dimer anion radical cleavage reaction have been located. The activation barrier for breaking the…
A study was undertaken of hydrogen accumulation on grain boundaries, at inclusions, and near a kneaded notch tip; the susceptibility for blistering; and hydrogen-induced cracking (HIC) of tubular steels (API C90). Results showed the accumulation coefficients of hydrogen on the grain boundaries, various inclusions, and…
<div class="htmlview paragraph">For meeting 21st-century exhaust emission standards for HD diesel engines, new methods are necessary for reducing NOx and PM emissions without increasing fuel consumption. The stratified diesel fuel-water-diesel fuel (DWD) injection in combination with exhaust gas recirculation (E…
Diamond metal-insulator-semiconductor diodes and field-effect transistors (MISFETs) have been prepared using CaF2 gate insulator and nondoped (in some cases, boron was doped) diamond homoepitaxial films. The resultant capacitance-voltage (C-V) curves and drain current-drain voltage (ID−VD) curves strongly depended on…
In the past few years neutron-scattering experiments have shown very intriguing stripe correlations of spins and holes in hole-doped ${\mathrm{La}}_{2}{\mathrm{NiO}}_{4}$ and ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$. As yet, no x-ray-diffraction experiment has confirmed the neutron results and the topic is still controve…
The R –curve for Si 3 N 4 −40 wt% TiN composites was estimated by the indentation‐strength method and compared to that of monolithic Si3N4 with duplex microstructure. Both materials exhibited rising R ‐curve behavior. The Si3N4‐TiN composites, however, displayed better damage tolerance and higher resistance to crack g…