Materials Literature
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The generation of photoelectrical effects through the spectral sensitization of wide band gap (SnO 2 ) nanostructured semiconductor electrode by the excitation of a novel porphyrin−fullerene ( P − C 60 ) dyad is reported. P − C 60 was synthesized from 5-(4-amidophenyl)-10,15,20-tris(4-methoxylphenyl) porphyrin ( P ) l…
The reaction of the bis-chelating ligand 1,2-bis(2,2'-bipyridine-6-yl)ethane (L) with the trinuclear species of formula [Mn(3)O(O(2)CR)(6)(py)(3)](ClO(4)) (R = Me (1); R = Et (2); R = Ph (3)) has afforded the new tetranuclear mixed-valent complexes [Mn(4)O(2)(O(2)CR)(4)L(2)](ClO(4))(2) (R = Me (4); R = Et (5); R = Ph…
The crystal structures of phase-change materials, GeTe–Sb 2 Te 3 and Ag–In–Sb–Te compounds, crystallized by laser irradiation, have been investigated for several years. These investigations revealed that these two compounds crystallize into a single phase with a cubic or a pseudo-cubic structure as the structural unit…
Mixtures of a properly chosen oil (poly(dimethylsiloxane) (PDMS) or hydrocarbon) and hydrophobic particles (e.g., hydrophobized silica) have a strong deteriorating effect on foam stability, even when introduced in a very low concentration. These mixtures are widely used for foam control and are commonly termed antifoa…
The combustion kinetics of a laminate with intumescent behavior were determined by thermogravimetry for heating rates between 5 and 20 K/min and a final temperature of 873 K. The devolatilization stage consists of three consecutive first-order reactions that can be associated with the release of (1) water vapor (from…
The synthesis, electrochemistry, and optical spectroscopy of an extensive series of cofacial bis[(porphinato)zinc(II)] compounds are reported. These species were synthesized using sequential palladium-catalyzed cross-coupling and cobalt-mediated [2+2+2] cycloaddition reactions. This modular methodology enables facile…
Polyelectrolyte microcapsules (PEMCs) have been prepared by coating red blood cells with the polyelectrolytes poly(styrenesulfonate), poly(allylamine hydrochloride), and dextran sulfate applying the layer-by-layer technique with subsequent dissolution of the core. The capsule permeability for human serum albumin (HSA)…
Mössbauer and Raman spectroscopies, calorimetric measurements, the LIESST effect (light induced excited spin state trapping) and dynamics of the high-spin (HS) to low-spin (LS) relaxation have been investigated in order to thoroughly study the spin-crossover compounds of formula {Fe(L)[H 2 B(pz) 2 ] 2 }, where L = 2,2…
Organized monolayer films of a manganese tetraphenylporphyrin have been prepared and used as supported oxidation catalysts. Manganese 5,10,15,20-tetrakis(tetrafluorophenyl-4'-octadecyloxyphosphonic acid) porphyrin (1) has been immobilized as a monolayer film by a combination of Langmuir-Blodgett (LB) and self-assemble…
On the basis of the possibility that there might exist a mixed composition of the Y(As,Nb,P,V)O 4 system of better luminescent performance than the single-compound phosphors at the VUV excitation, a solution combinatorial chemistry synthesis and characterization was employed in the present investigation. Quaternary an…
An anomalous thermalization effect induced by optical excitation of Er 3+ ions in nanocrystals of Y 2 O 2 S is investigated. Due to the absence of low-energy phonon modes in the 20−40 nm crystals we studied, phonon relaxation is restricted, and as a result, the intensity of hot bands that originate from the upper crys…
The reaction of superoxide with nitrogen monoxide has been reinvestigated. Photolysis of alkaline peroxynitrite solutions results in the formation of superoxide and nitrogen monoxide, which subsequently react at a rate of (1.5 ± 0.1) × 10 10 M -1 s -1 . When hydrogen peroxide is photolyzed in the presence of nitrogen…
We report the results of magnetic measurements for the solid solution Ce$_2$Au$_{1-x}$Co$_x$Si$_3$. The results reveal that this solid solution is characterized by a magnetic phase diagram (plot of magnetic transition temperature versus $x$) unusual for Kondo lattices. In particular, the spin-glass freezing induced by…
We present a new process for the synthesis of colloidal europium-doped yttrium vanadate with a particle diameter of about 10 nm. Nanocrystals are produced by precipitation of citrate complexes of rare-earth salts with sodium orthovanadate. NMR and IR studies show that the interaction between citrate ligands and lantha…
Four metakaolins were prepared by calcination of a natural Spanish kaolin (Navalacruz deposit, Zamora province) at 600, 700, 800, and 900 °C. These four metakaolins, more reactive than the parent kaolin, were submitted to acid and alkaline activations. Acid activation was carried out with 6 M HCl at room temperature a…
Gold nanoparticles (NPs) were prepared by reduction with salicylic acid in aqueous solution. The resulting dispersions were found to contain a mixture of flat triangular/hexagonal and smaller close-to-spherical NPs. As expected from theoretical considerations, such nanocolloids display two clearly differentiated surfa…
The electrochemistry of horse heart cytochrome c was studied by cyclic voltammetry at a glassy carbon electrode modified with single-wall carbon nanotubes (SWNTs). A pair of well-defined redox waves was obtained in cytochrome c aqueous solution at an activated SWNT film-modified electrode. The optimal conditions for a…
This paper describes a general approach that generates nanoscale hollow structures of metals by reacting solutions of appropriate salt solutions with solid templates of a more reactive metal. Typical examples include Au 3+, Pt 2+, and Pd 2+ salts and nanoparticles or nanowires of silver. The morphology, void space, an…
The title compound, trimercury(II) bis[selenite(IV)] selenate(VI), contains three crystallographically inequivalent HgII cations with coordination numbers of eight (denoted Hg1 and Hg2) and five (denoted Hg3). The corresponding coordination polyhedra around the metal atoms might be described as intermediates between a…
First-principles pseudopotential calculations using plane-wave basis functions have been made to quantitatively evaluate the formation energy of Cr/Al vacancies in ${\mathrm{MgCr}}_{2}{\mathrm{O}}_{4}$ and ${\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}.$ Relaxation of atoms within the second nearest neighbor shell of the vacanc…