Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The cisright harpoon over left harpoon trans photoisomerization of the azobenzene building block 4-(4-aminophenylazo)benzoic acid incorporated in a cyclic peptide (see scheme) facilitated a two-state transition of the peptide chain from a rigid constrained conformation in the trans isomer into the largely free conform…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPorphyrin Core Star Polymers: Synthesis, Modification, and Implication for Site IsolationStefan Hecht, Henrik Ihre, and Jean M. J. FréchetView Author Information Department of Chemistry, University of California, Berkeley, California 94720-1460 Cite this: J. Am. Chem.…
Potentiodynamic generation of polypyrrole films at an extremely low reaction rate causes the resulting material to show an additional oxidation wave that is more negative and sharper than the one normally observed. The additional peaklike oxidation wave belongs to an unknown structural entity PPy(II). The treatment of…
Eighty isolated channels are present in the array microreactor system that was coupled to a quadrupole mass spectrometer for high-throughput testing of heterogeneous catalyst libraries. The system was used to monitor the activities, selectivities, and reaction kinetics of 66 ternary Pt/Pd/In catalysts for the dehydrog…
Robust hexagonal cavities (dimensions: 17x20x15 Å), encompassed by the pyridyl groups of cyclic metalloporphyrin hexamers (see picture), are the characteristic structural motifs of the nanoporous materials [{M(tpyp)}(6)] small middle dotn G (M=Co, Mn; tpyp=tetrakis(4-pyridyl)porphyrinato; G=guest molecule), which were…
Eine Blaupause für das Design von Oxidmaterialien kann uns die Natur liefern, da sie bei Biomineralisationsprozessen und bei der Hydrothermalsynthese komplexer Mineralien anorganische Mikrostrukturen beeinflussen kann. Eine Anleihe bei dieser Fähigkeit führt zu einer ganz neuen Klasse von Materialien, bei denen organi…
The Onsager reaction-field (ORF) theory is extended so that it applies to any three-dimensional Bravais lattice with a basis. The ORF calculation is used to predict the critical temperature for classical Ising, XY, and Heisenberg magnetic models, in particular, on diamond and hexagonal close packed lattices. Results a…
The protonic conductivity in the hydrogen bonded chains is investigated theoretically in the framework of the two-stage transport model. The strong interactions with optical phonon stretching mode are considered. We obtain the transition from the insulator to the metal-type state from the temperature dependencies of t…
In a recent Letter, Gurovitch and Sens studied the adsorption of a weakly charged polyelectrolyte chain onto an oppositely charged colloidal particle. By using a variational technique they found that the colloidal particle can adsorb a polymer of higher charge than its own, and thus be ``overcharged.'' I argue that th…
A stabilization of the liquid-crystalline mesophase and thus an enlarged temperature range of the mesogenic phase is achieved by adding perfluorotriphenylene to a chiral liquid-crystalline triphenylene. This mesophase is based on 1:1 perfluoroarene-arene interactions (see picture). In a polymer with triphenylenes as m…
Hansen solubility parameters (HSPs) are used to predict molecular affinities, solubility, and solubility-related phenomena. Revised and updated throughout, Hansen Solubility Parameters: A User's Handbook, Second Edition features the three Hansen solubility parameters for over 1200 chemicals and correlations for over 4…
A blueprint for the design of oxide materials is provided by nature. By borrowing from nature's ability to influence inorganic microstructures in biomineralization processes and in the hydrothermal synthesis of complex minerals, a new class of materials in which organic components exert a role in controlling inorganic…
Polyaniline (PANi) was synthesized by using lignosulfonic acid as a template/dopant and ammonium persulfate as the oxidizing agent. The product was water-borne and showed a conductivity of 10 -1 S/cm lignosulfonic add-poiyaniHne (Ligno-PANi) was characterized by UV-Vis spectroscopy which showed peaks for both benzenoi…
A single Er 3+ centre in CaGdAlO 4 :Er 3+ has been identified to have C 4v symmetry from polarized laser selective excitation. This is consistent with isovalent substitution of the Er 3+ ions for host crystal Gd 3+ ions. Using both optical and infrared absorption and polarized laser excited fluorescence, 59 crystal-fi…
We investigate absorption, emission and excitation properties of an SrB 2 O 4 :Eu crystal grown from the melt using the Czochralski method. Eu 2+ absorption and Eu 3+ emission spectra are obtained. The five broad absorption bands peaking at 344, 288, 259, 235 and 212 nm correspond to the transitions from the 4f 7 ( 8…
Electron momentum spectroscopy (EMS) has been used to measure the valence band electronic structure of thin magnesium and magnesium oxide films. The band structures have also been calculated within the linear muffin-tin orbital (LMTO) approximation. The free-electron-like parabola characteristic of metallic solids was…
The reaction mechanism of poly(benzo[1,2- d:5,4- d ‘]bisoxazole-2,6-diyl-1,4-phenylene) (PBO) at elevated temperatures was studied by means of model compounds and a 13 C-labeled PBO polymer. Products from model compound thermal degradation suggest that the dominating reactions are homolytic scission of a single bond a…
We report on the photoluminescence properties of CuCl thin films with the thicknesses of 20 and 100 nm under intense-excitation conditions produced with a pulsed nitrogen laser. We have clearly observed two photoluminescence bands with a superlinear (almost quadratic) excitation-power dependence. The high-energy band…
The novel sulfidic mesophase [C14H29N(CH3)3]2MnGe4S10 forms via the surfactant-templated assembly of adamantane Ge4S104- clusters and Mn2+ ions in water. The material possesses a continuous, fully bonded framework of MnGe4S10 which is perforated with large parallel tunnels arranged with hexagonal order. The materials…
Experimental solubilities are reported for 2-hydroxybenzoic acid dissolved in 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 1-octanol, dibutyl ether, 1,4-dioxane, tetrahydrofuran, ethyl acetate, butyl acetate, 2-propanone, 2-butanone, and cyclohexanone at 298.15 K.…