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。
We present a study of the optical properties of Tb 3+ -doped NaPO 3 –GdPO 4 -based glasses by means of optical absorption measurements performed at room temperature both before and after x-ray irradiation. A numerical decomposition of the absorption spectra is performed, and the possible nature of the defects responsi…
Ein atmendes Molekularsieb für kleine Alkohole: Durch Komplexierung des Keggin-artigen Polyoxometallats [α-SiW12O40]4− (rot) mit dem Makrokation [Cr3O(OOCH)6(H2O)3]+ (grün und weiß) wird der atmende Ionenkristall 1 synthetisiert. Die Gastmolekül-freie Phase 2 wird einfach durch Evakuierung der Wassermoleküle hergestel…
Riesenringe und Nanoscheren: Während sich Nanoobjekte auf Mo-O-Basis mit einer Vielzahl von Modifikationen einer Grundstruktur durch Selbstaggregation bei variablen Randbedingungen generieren lassen, können drastische Veränderungen – quasi durch die Wirkungsweise einer molekularen Schere – zu (großen) verknüpfbaren Ob…
The structural characterization of organotin compounds that are grafted onto insoluble cross-linked polymers has necessarily been limited to elemental analysis, infrared spectroscopy, and in a few instances, solid-state NMR spectroscopy. This important bottleneck in the development of such grafted systems has been add…
This paper provides the results on experimentally measured and numerically predicted surface tensions of undercooled liquid cobalt. The experiments were performed by using the oscillation drop technique combined with electromagnetic levitation. The simulations are carried out with the Monte Carlo (MC) method, where th…
Aza-crown ethers 2 and 3 with anthracene-containing pendant arms have been synthesised and characterised. Both compounds bind Group 1 metal cations in solution, forming complexes of 1:1 stoichiometry. The properties of compound 2 and its complexes have been studied by a range of techniques, including NMR, UV and fluor…
The temperature dependence of the ac susceptibility under pressure has been used to track the N\'eel temperature ${T}_{\mathrm{N}}$ of the Mott insulators ${\mathrm{L}\mathrm{a}\mathrm{M}\mathrm{n}\mathrm{O}}_{3}$, ${\mathrm{C}\mathrm{a}\mathrm{M}\mathrm{n}\mathrm{O}}_{3}$, and ${\mathrm{Y}\mathrm{C}\mathrm{r}\mathrm{…
Box clever: A very stable box-shaped cyclic tetramer (see picture) was formed from meso-pyridyl substituted meso–meso-linked zinc(II) diporphyrin, in which the porphyrin subunits are held in a rigorous perpendicular orientation.
Transgenic goats to spin webs! The silk of spider nets (see picture) possesses unique mechanical properties. By using suitable microbiological methods, a structurally similar fiber protein has recently been prepared that, after spinning, exhibits comparable strength and elasticity to natural spider silk. The American…
The ground state and the light-induced metastable states of ${\mathrm{Na}}_{2}[\mathrm{Fe}(\mathrm{CN}{)}_{5}\mathrm{NO}]\ensuremath{\cdot}2{\mathrm{H}}_{2}\mathrm{O}$ were investigated by polarized optical absorption spectroscopy on single crystals. An orbital level scheme is proposed for the ground state and the two…
A [3×3] Ag+9 metallogrid self-assembles by a highly complex mechanism involving several intermediates, which may be generated at different metal/ligand stoichiometries. Extensive NMR spectroscopic studies have allowed the unraveling of the structure of these species and have revealed that the final grid entity present…
Polyaspartic acid (PASP) is an environmentally benign agent for the dissolution of calcium salt deposits. In this study, the chelating power of PASP with calcium is investigated by performing the potentiometric titration against PASP solutions. It was found that PASP is fully deprotonated at pH 7. The titration curves…
Porphyrin (P), porphycene (Pc), corrphycene (Cn), and hemiporphycene (Hpc) represent a series of well defined "4-N in" constitutional porphyrin isomers. These isomers, in the form of their octaethyl derivatives, represent a congruent set of porphyrinoids whose properties can be compared. In this study we report how va…
An analysis on the conductance of multiwall carbon nanotubes (MWNT's) is presented. Recent experiment indicated that MWNT's are good quantum conductors. Our theory shows that tunneling current between states on different walls of a defect-free, infinitely long MWNT is vanishingly small in general, which leads to the q…
The tripodal ligand tris[4-(2-hydroxy-3-methoxyphenyl)-3-aza-3-buten]amine (LH(3)) is capable of coordinating to two different lanthanide ions to give complexes formulated as [LLnLn'(NO(3))(3)].x H(2)O. The stepwise synthetic procedure consists of introducing first a Ln(III) ion in the inner N(4)O(3) coordination site…
We report the two-photon-induced photoisomerization of 3-[1-(1,2-dimethyl-1H-indol-3-yl)-ethylidene]-4-isopropylidene-dihydrofuran-2,5-dione ( 1 ), a photochromic compound with λ max = 385 nm, using 775-nm femtosecond pulsed laser irradiation. The resulting photoisomer had λ max = 582 nm. The kinetic rate constant for…
Upon treating elemental sulfur with [AgSbF(6)], [AgAl(hfip)(4)], [AgAl(pftb)(4)] (hfip=OCH(CF(3))(2), pftb =OC(CF(3))(3)) the compounds [Ag(S(8))(2)][SbF(6)] (1), [AgS(8)][Al(hfip)(4)] (2), and [Ag(S(8))(2)](+)[[Al(pftb)(4)](-) (3) formed in SO(2) (1), CS(2) (2), or CH(2)Cl(2) (3). Compounds 1-3 were characterized by…
Chains change: Novel valence-ordering structures of the ground states of MMX chain compounds, [Pt2(RCS2)4I]∞ (1: R=nBu, 2: R=Et), are determined by low-temperature crystal-structure analyses to be -Pt2+-Pt3+-I−-Pt3+-Pt2+-I−-. Magnetic susceptibility measurements of 1 (see graph) revealed an abrupt drop in magnitude fr…
Molecular sieving to take your breath away: The breathing ionic crystal 1 is synthesized by the complexation of Keggin-type [α-SiW12O40]4− (red) polyoxometalate with a macro cation [Cr3O(OOCH)6(H2O)3]+ (green and white). The water of crystallization is easily removed from 1 by evacuation to form a guest-free phase 2.…
The distinctive features of well-defined, three-dimensional macromolecules with topologies designed to enhance solubility and amplify end-group functionality facilitated nanophase morphologies in mixtures with organosilicates and ultimately nanoporous organosilicate networks. Novel macromolecular architectures includi…