Materials Literature
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We have linked two porphyrazinedithiolates of the type Ni[pz((S-)2:R6)] (R = 4-tert-butylphenyl) by mutual chelation of a nickel ion. The trinuclear metal-linked porphyrazine dimer 9 is a monoanion, and it exhibits the classical EPR signal of Ni(III) bis(dithiolene) complexes. The absorption spectrum of the Ni(III)-li…
Barium titanate (BaTiO 3 ) thin films that were derived from methoxypropoxide precursors were deposited onto (100) Si, Pt/Ti/SiO 2 /(100) Si, and molecular‐beam‐epitaxy‐grown (MBE‐grown) (100) BaTiO 3 on (100) Si substrates by spin coating. The crystallization behavior of the amorphous‐gel films was characterized usin…
We present measurements and theory of a fluid-solid phase transition at a hard, flat wall in a two-sized hard-sphere mixture. With particle concentrations well below the level for bulk phase separation, a fluid monolayer (enriched in the larger spheres) forms at the wall. At slightly higher concentrations, the wall-fl…
The synthesis of water-soluble, unsymmetrical, trisulfonated zinc phthalocyanines (ZnPcS3) as single products of the ring expansion of boron tri(4-sulfo)subphthalocyanine (SubPc) is reported. The novel, water-soluble trisulfo-SubPcB(OH) was prepared via hydrolysis of the tris(4-chlorosulfonyl)SubPcB(Br) which in turn…
Treatment of [Cu 2 (O 2 CCH 3 ) 4 (H 2 O) 2 ] with 2 equiv of di-2-pyridyl ketone (dpk) in methanol followed by addition of 1 equiv of NaClO 4 yields [Cu 4 (dpk·CH 3 O) 4 (CH 3 O) 2 ] (ClO 4 ) 2 ( 1 ) in ∼75% yield (dpk·CH 3 O - = the monoanion of the monomethylated diol of dpk). The same complex has also been isolate…
Oxygen nonstoichiometry of Ce 0.8 Gd 0.2 O 1.9 − x was gravimetrically measured at temperatures from 700 to 1000°C and oxygen partial pressures between 10 −24 and 1 atm. Based on the experimental data, the relationship between log x and log p O 2 , (where x is the oxygen deficiency and p O 2 the oxygen partial pressur…
It was demonstrated that porous aggregates of (NH 4 ) 3 PW 12 O 40 nanocrystallites were formed by epitaxial self-assembly, when dodecatungstophosphoric acid was precipitated by ammonium hydrogen carbonate in an aqueous solution. Scanning electron microscopy combined with nitrogen and argon adsorption measurements sho…
Laser-ablated Mn atoms react with O 2 to give MnO, OMnO, (MnO) 2, and MnO 2 - as major products, which are identified from oxygen isotopic substitution on their matrix infrared spectra. Annealing allows further association to form the cyclic Mn(O 2 ) complex, (O 2 )MnO and (O 2 )MnO 2 oxide complexes, and higher oxide…
We study the response of the magnetization to a time-dependent applied magnetic field $H(t)$ in a model for a uniaxial magnet. It is shown that a staircase structure in the magnetization curve results from Landau-Zener tunneling between different pairs of nearly-degenerate energy levels. This mechanism might be releva…
A series of comblike semiflexible polymers, in which the alkyl side chains were located nonsymmetrically on the ring, were synthesized by reacting hydroxypropylcellulose (HPC) with hexyl, octyl, dodecyl, and octadecyl isocyanates. Side-chain melting was observed in DSC experiments for polymers with 12 and 18 carbons i…
The structure, conformational behavior, and magnetic coupling constant of a prototypical organic molecular magnet (the bis(imino)nitroxide) have been investigated in vacuo and in solution, combining a recent density functional theory/Hartree−Fock model with a refined continuum description of the solvent. Comparison wi…
An innovative nanocalorimeter has been developed for measuring specific heats of thin films, multilayers (typical thickness: 1000 Å) and single crystals (mass: 1 μg) in the temperature range of 1.5–20 K. The addenda of the device are as small as 3 nJ/K at 4 K (0.5 nJ/K at 1.5 K), thus samples with a heat capacity of t…
Flash pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) was used to assess the quality and mechanism of protein preservation in the tissue of Iron Age bog bodies from Lindow, UK, and south-eastern Drenthe, The Netherlands. Abundant pyrolysis products of the fresh skin tissue, including 2,5-diketopiperazines of…
At high (> 3.5 kbar) pressures and low (< -10 degrees C) temperatures, hen egg-white lysozyme denatures readily and reversibly. Amide hydrogen exchange methods were used to investigate the structure of the pressure-assisted cold-denatured state of lysozyme. Protection factors were obtained for 52 backbone amide proton…
We have fabricated a new ferroelectric liquid crystal (FLC) display that exhibits monostable electrooptical characteristics with high contrast ratio (160:1) owing to freedom from defects, grayscale capability without threshold, and fast response (70 µs). A FLC(ZLI-4654-100, Merck) is subjected to polymer stabilization…
We investigate the statistical geometry of inherent structures (mechanically stable arrangements of particles generated by a steepest-descent mapping of equilibrium configurations to local potential minima) of liquid configurations of the shifted-force Lennard-Jones system, as an approach to elucidating mechanisms for…
Abstract Crosslinked gelatin films with entrapped poly‐L‐aspartate were used to induce the crystallization of calcite and aragonite polymorphs. Calcite with high degrees of isomorphous substitution (up to 12mol% magnesium) has been obtained. The morphology and layered organization of magnesium calcite crystals grown i…
Colloidal silica coatings were produced from suspensions of silica modified with (glycidoxypropyl)trimethoxysilane (GPS). Coating dispersions were prepared by adding GPS to a silica colloid (12 nm) suspension. Adsorption of hydrolyzed GPS species on silica surfaces was monitored by attenuated total reflection Fourier…
We present a theory of microphase separation of a diblock copolymer A fN B (1 - f ) N and homopolymer hB blend in the strong segregation limit (χ N ≫ 10), where χ is the Flory−Huggins interaction parameter. Homopolymer chains are assumed to be much longer than block copolymers: N h ≫ N . In this case, homopolymers and…
Abstract Ferricenium cations showed excellent DNA cleaving activity and cytotoxic activity. Such activities depend on the acyl group introduced into the cyclopentadienyl ring.