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。
Magnetic resonance angiography (MRA) has put forth an impetus for the development of macromolecular GdIII complexes that have a prolonged lifetime in the vascular system. Herein, we report the synthesis and GdIII complexation of a new sugar conjugate based on inulin and the DO3A ligand (DO3A = 1,4,7,10-tetraazacyclodo…
We report a new clathrate phase composed of europium atoms occupying cage voids in a gallium/germanium tetrahedral cage network. Eu 4 Ga 8 Ge 16 crystallizes in orthorhombic space group Cmcm with a = 4.1349(6), b = 11.2842(15), and c = 13.2408(18). The compound is believed to satisfy the Zintl−Klemm concept of bonding…
The polymerization-filling technique has been used to coat glass beads by a polyolefinic layer. This precoating allows for improving the mechanical properties of polyethylene composites prepared by melt-blending HDPE with the surface-modified filler. As a typical example, a 10-fold increase of the impact resistance ha…
The synthesis, characterization, and metal-binding studies of chelate-functionalized dendrimers is reported. Salicylate, catecholate, and hydroxypyridinonate bidentate chelators have been coupled to the surface of both poly(propyleneimine) (Astramol) and poly(amidoamine) (Starburst, PAMAM) dendrimers up to the fifth g…
Solid-state 31 P/ 27 Al and 31 P/ 23 Na TRAPDOR NMR experiments have been used to investigate the spatial distribution of aluminum and sodium cations with respect to the phosphate backbone for a series of sodium aluminophosphate glasses, x Al 2 O 3 ·50Na 2 O· (50− x )P 2 O 5 (0 ≤ x ≤ 17.5). From the 31 P/ 27 Al and 31…
Lanthanide complexes of the Schiff base ligand 4-dodecyloxy-N-hexadecyl-2-hydroxybenzaldimine and with perfluorinated alkyl sulfate counterions were synthesised. All of the metal complexes show a smectic A mesophase. The viscosity of this mesophase is much lower than that of analogous compounds with nitrate or alkyl s…
Two derivatives of 1,4,7,10-tetraazacyclododecane with trans-acetate and trans-amide side-chain ligating groups have been prepared and their complexes with lanthanide cations examined by multinuclear NMR spectroscopy. These lanthanide complexes exist in aqueous solution as a mixture of slowly interconverting coordinat…
We apply first-principles calculations to study the structure and the relative stability of several stoichiometric and nonstoichiometric boron nitride fullerenes of sizes ranging from 28 to 128 atoms. Among the structures considered, we observe an overall tendency for the formation of octahedrally faceted shapes as th…
Novel proton-conducting gels have been prepared by entrapping heteropolyacids solutions in polar aprotic solvents within the polymer matrix. The influence of the type of solvent, polymer matrix, and acid concentration on the conductivity, mechanical properties, and thermal stability has been examined. Poly(methyl meth…
Electrogenerated polymers based on the nickel(II) complex 2,3-dimethyl-N,N'-bis(salicylidene)butane-2,3-diaminatonickel(II), poly[Ni(saltMe)], were characterised by in situ FTIR and UV/Vis spectroscopy and ex-situ EPR spectroscopy in order to gain insights into film structure, electronic states and charge conduction.…
The synthesis of the layered double hydroxide (LDH) [Zn−Cr−Cl], well-known for its ability to be synthesized only with the ratio Zn:Cr = 2:1, has been followed by UV−visible and extended X-ray absorption fine structure (EXAFS) spectroscopy in order to understand the mechanisms of its formation. The UV−visible spectrum…
Three new one-dimensional nickel(II) complexes with the formulas trans-[Ni(N-Eten)2(mu1.3-N3)]n(ClO4)n (1), trans-[Ni(N-Eten)2(mu1.3-N3)]n(PF6)n (2), and cis-[Ni(N-Eten)(mu1.1-N3)2]n (3) (N-Eten = N-Ethylethylenediamine) were synthesized and characterized. Complex 1 has the P2(1)/c space group and consists of a struct…
Based on a previously discovered method for amine oxidations using flavins as catalysts and hydrogen peroxide as oxidant, a comparative kinetic study using NMR spectroscopy was undertaken with a series of flavins for amine and thioether oxidations. Included in this series is the newly prepared 7,8-difluoro-1,3-dimethy…
The homoleptic rare-earth pyrazolate complexes [Sc(tBu2pz)3], [Ln2(tBu2pz)6] (Ln = La, Nd, Sm, Lu), [Eu4(tBu2pz)8] and the mixed oxidation state species [Yb2(tBu2pz)5] (tBu2pz = 3,5-di-tert-butylpyrazolate) have been prepared by a simple reaction between the corresponding rare-earth metal and 3,5-di-tert-butylpyrazole…
BaTiO 3 and anatase with platelike particle morphology were prepared by using a hydrothermal soft chemical process. A layered titanate of K 0.8 Ti 1.73 Li 0.27 O 4 with a lepidocrocite-like layered structure, which has a platelike particle morphology, was used as a precursor. In the first step, the layered titanate wa…
Unser gestiegenes Verständnis der Struktur-Eigenschafts-Beziehungen einiger ausgewählter Biomakromoleküle hat – zusammen mit unseren verbesserten Fertigkeiten, Makromoleküle mit einer strukturellen Genauigkeit, die der der Proteine nahekommt, herzustellen – den Horizont zu einem neuen Forschungsbereich geöffnet, der d…
We analytically study the photorefractive Gunn effect in n-GaAs subjected to two external laser beams which form a moving interference pattern (MIP) in the semiconductor. When the intensity of the spatially independent part of the MIP, denoted by $I_0$, is small, the system has a periodic domain train (PDT), consisten…
Numerical studies of amorphous silicon in harmonic approximation show that the highest 3.5% of vibrational normal modes are localized. As vibrational frequency increases through the boundary separating localized from delocalized modes, near omega_c=70meV, (the "mobility edge") there is a localization-delocalization (L…
The complex Ni[S2C2(CF3)2]2 reacts with light olefins, including ethylene and propylene, selectively and reversibly. The reaction is not poisoned by hydrogen gas, carbon monoxide, acetylene, or hydrogen sulfide, which are commonly present in olefin streams, presumably because olefin binding occurs through the sulfur l…
Intramolecular junctions in single-walled carbon nanotubes are potentially ideal structures for building robust, molecular-scale electronics but have only been studied theoretically at the atomic level. Scanning tunneling microscopy was used to determine the atomic structure and electronic properties of such junctions…