Materials Literature
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Oxotitanium(IV) phthalocyanine (OTiPc) has been reported to be a near-IR-active photoconductor, where crystal modifications termed phases I, II, and Y exist. In this paper, solid-state electronic absorption spectra of OTiPc have been theoretically calculated by considering three origins (i.e., exciton, charge transfer…
Abstract A series of intercalated poly(trimethylene terephthalate) (PTT)/clay nanocomposites were prepared in a twin‐screw extruder by the melt mixing of PTT with either quaternary or ternary ammonium salt‐modified clays. The morphology and structure, along with the crystallization and melting behavior, and the dynami…
Hin und her, das ist nicht schwer: Ein vollständig reversibler Ligandenaustausch unter Bindung und Dissoziation von gasförmigem Wasser und Pyrimidin induziert die wiederholte allosterische Umwandlung dreier ineinander verwobener Netzwerke zu einem einzigen, dreidimensionalen Netz. Die Umwandlung betrifft nicht die Kri…
Crystallization of pharmaceutically active compounds from saturated solutions by means of solvent evaporation typically involves a nucleation and growth process. At slow solvent evaporation rates, nuclei of the stable forms (polymorphs) will grow at the expense of any metastable forms present in the crystallizing mixt…
Fehlordnung, Ordnung und wieder Fehlordnung: Im Widerspruch zu allen früheren Untersuchungen befindet sich zwischen den zwei bekannten, fehlgeordneten Phasen (LS und HS) von [Fe(2-pic)3]Cl2⋅EtOH eine geordnete Phase (ZP) mit zwei kristallographisch verschiedenen Eisenlagen. Im Bild sind die Eisen-x-Koordinaten für all…
Abstract The compatibility of low‐density polyethylene and poly(ethylene‐ co ‐vinyl acetate) containing 18 wt % vinyl acetate units (EVA‐18) was studied. For this purpose, a series of different blends containing 25, 50, or 75 wt % EVA‐18 were prepared by melt mixing with a single‐screw extruder. For each composition,…
A new purpose: Microreactors are commonly used in molecular high-throughput synthesis. Their use for the formation of catalysts through the precipitation of inorganic components is new. The product shows a high degree of nanostructuring (see electron microscopy image), which is at least partly retained in the subseque…
Mesoporous materials get wired: Micelles of the thienyl-substituted ammonium ion 1 in aqueous ammonia solution are applied as matrices for the formation of mesoporous silicate particles from tetraethylorthosilicate. After oxidation with FeCl3 and treatment with HF, polymeric wires with a bimolecular diameter of 3 nm a…
There is much debate about the photoluminescence (PL) mechanisms of the nanoscale Si/Si oxide systems containing oxidized porous silicon and a nanoscale-Si-particle (NSP)---embedded Si oxide deposited by chemical vapor deposition, sputtering, or Si-ion implanting into Si oxide. In this paper, we suggest that two compe…
We present calculations of the optical absorption spectra of clusters ${\mathrm{SiH}}_{4},$ ${\mathrm{Si}}_{10}{\mathrm{H}}_{16},$ ${\mathrm{Si}}_{17}{\mathrm{H}}_{36},$ ${\mathrm{Si}}_{29}{\mathrm{H}}_{24},$ and ${\mathrm{Si}}_{35}{\mathrm{H}}_{36},$ as determined from two different methods: the Bethe-Salpeter equati…
We describe fluorescence visualization of highly stable worm micelle superpolymers. The worm micelles are self-assembled in water from nonionic, block copolymer amphiphiles. By blending and polymerizing inert and cross-linkable copolymers, we form micelles up to tens of microns long with persistence lengths that conti…
Democratic behavior: A strong bias for the amplification of assemblies, the composition of which reflects the overall composition of the library, can be observed in selection processes with dynamic combinatorial libraries. As a consequence, it is not necessarily the assembly with the highest affinity to a given target…
Solvothermal techniques allow the crystallization of high nuclearity products that are otherwise inaccessible by conventional techniques, directly from the reaction mixture. By this method, the reaction of the triangular species [Fe3O(OAc)6(H2O)3]Cl with benzotriazole (BtaH) produces an [Fe14] cluster (depicted) with…
Crypt analysis: The reaction of manganese(II) chloride with sodium hydroxide, di-(2-pyridyl)-ketonoxime, and sodium azide yields a metallacryptate consisting of 26 manganese centers, namely, four MnII (see picture; gold spheres) and 22 MnIII ions (green, aqua, and blue spheres). Results obtained from ac SQUID magnetic…
Composite ab initio CBS-Q and G3 methods were used to calculate the bond dissociation energies (BDEs) of over 200 compounds listed in CRC Handbook of Chemistry and Physics (2002 ed.). It was found that these two methods agree with each other excellently in the calculation of BDEs, and they can predict BDEs within 10 k…
[Tetrakis ( N -methylpyridyl) porphyrinato] cobalt (CoTMPyP) and 1:12 silicotungstic acid (SiW 12 ) were alternately deposited on a 4-aminobenzoic acid (4-ABA) -modified glassy carbon electrode through a layer-by-layer method. The resulting organic−inorganic hybrid films were characterized by cyclic voltammetry (CV) a…
We have grown high-quality single crystals of the colossal-magnetoresistance (CMR) material La0.7Ca0.3MnO3 by using the laser heated pedestal growth (LHPG) method. Samples were grown as fibers of different diameters, and with lengths of the order of centimeters. Their composition and structure were verified through X-…
Novel photochromic single crystals composed of three different kinds of diarylethenes, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1a), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2a), and 1,2-bis(2-methyl-5-p-methoxyphenyl-3-thienyl)perfluorocyclopentene (3a), have been prepared. The three-compone…
A new dual-function hybrid molecular material has been obtained from the organic donor bis(ethylenedithio)tetraselenafulvalene and the honeycomb oxalate-based bimetallic network [MnCr(ox)3]-. This multilayer material consists of layers of the inorganic anionic 2D network, responsible for the appearance of ferromagneti…
We show that in YVO3 new hard phonons gradually become zone center active below ~210 K verifying that a lattice phase transition takes place at about that temperature. The Debye-Waller factor found from EXAFS measurements show an additional disorder below 150K seen as a departure from the thermal behavior. We bring up…