Materials Literature
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Double K-shell photoionization of Ne at 5000 eV was observed by recording the KK-KLL Auger-electron hypersatellite spectrum. The measured Auger spectrum is compared with the results of multiconfiguration Dirac-Fock calculations. Shake calculations are used to identify likely multivacancy states produced by photoexcita…
Isothermal dielectric relaxation measurements were carried out on xylitol and threitol. These, together with existing data on sorbitol and glycerol, enabled us to identify the general features in the frequency dispersion and the changes when increasing the number of carbon atoms in the molecule in these polyalcohols.…
Abstract Metal‐driven self‐assembly has emerged as a viable alternative to covalent synthesis in the construction of large and sophisticated multi‐porphyrin architectures, whose complexity and function begin to approach the properties of naturally occurring systems. The design and preparation of robust and shape‐persi…
Figures of eight correlate with corrolates: The surprising formation of the spirodicorrole dinickel complex 1, the first spirodiporphyrin as a metal complex, is the result of the varied chemistry of the “figure-eight” cyclooctapyrrole octaphyrin-(1.1.1.0.1.1.1.0). The conversion of the cyclooctapyrrole into 1 is broug…
Abstract Oxygen‐excessive LaMnO 3+ y samples with 0.02 ⩽ y ⩽ 0.26 have been prepared by thermal decomposition in air at 450 °C of a precursor obtained from an aqueous solution of lanthanum nitrate and manganese acetate (atomic ratio La/Mn = 1). The obtained solid is annealed at different temperatures from 700 to 1000…
Abstract Polylactide (PLA)‐grafted dextran was synthesized with a trimethylsilyl protection method to produce novel biodegradable, biomedical materials. PLA‐grafted dextrans with various lengths and numbers of graft chains were synthesized. The properties of solution‐cast films prepared from PLA‐grafted dextrans were…
This paper discusses the synthesis of linear polyolefin elastomers containing divinylbenzene (DVB) units, including poly(ethylene- ter -propylene- ter -divinylbenzene) (EP-DVB) and poly(ethylene- ter -1-octene- ter -divinylbenzene) (EO-VDB). Several metallocene catalysts were evaluated to identify a system that can ca…
[reaction: see text] Polymer-supported bisBINOL ligands were successfully utilized for the immobilization of multicomponent asymmetric catalysts. The polymer-supported Al-Li-bis(binaphthoxide) (ALB) catalyst was more effective than the dendrimer-supported ALB in the Michael reaction of 2-cyclohexen-1-one with dibenzyl…
Abstract An ion‐pair complex [FBzPyNH 2 ][Ni(mnt) 2 ] {[FBzPyNH 2 ] + = [1‐(4′‐fluorobenzyl)‐4‐amino]pyridinium and mnt 2− = maleonitriledithiolate} has been obtained by I 2 oxidation of the corresponding dianion complex. It forms a wellsegregated stacking column structure in the solid state, and exhibits antiferromag…
Pyridoxine 5'-phosphate oxidase catalyzes the terminal step in the synthesis of pyridoxal 5'-phosphate. The cDNA for the human enzyme has been cloned and expressed in Escherichia coli. The purified human enzyme is a homodimer that exhibits a low catalytic rate constant of approximately 0.2 sec(-1) and K(m) values in t…
First principles density functional theory is used to study the compositional dependence of the structural, elastic, electronic, and bonding properties of newly prepared Sn x Ge 1 - x alloys and compounds. The calculated variation of lattice constant a ( x ) with composition for tin content (% Sn, x < 0.20) exhibits a…
Making 13 from 55: Au55 nanoclusters that interact with the major groove of B-DNA (see energy-minimized structure), are broken down into Au13 clusters by the transformation of B-DNA into A-DNA, during which the major groove shrinks dramatically. This transformation, which results in the formation of Au13 wires, is ini…
Breaking the law: Whereas antiferromagnetic interactions in crystalline carboxylates of lanthanides are often observed, ferromagnetism is unknown. The first example of a ferromagnetic interaction is observed for a crystalline sample of the gadolinium compound [{Gd(OAc)3(H2O)2}2]⋅4 H2O (see picture Gd: gray, O: red).
A self-inducing template-growth approach to the production of nanofibers of 1,3-diphenyl-2-pyrazoline (DP) in the presence of cetyltrimethylammonium bromide (CTAB) in an aqueous phase is discussed (see picture). Not only the surfactant CTAB molecules assume the role of surface-active colloidal stabilizers; but also th…
This paper reports the synthesis, optical, and thin-film-forming properties of a new water-soluble poly(phenylene ethynylene) that features phosphonate solubilizing groups. The new polymer, PPE-PO 3 -, is prepared by a synthetic route that involves initial preparation of a neutral analogue polymer in which the phospho…
Uniform crystalline Cu 2 O cubes were synthesized in high yield by reducing the copper−citrate complex solution with glucose. A series of shape evolutions of Cu 2 O particles from the transient species such as multi-pod and star-shaped particles to cubic crystals have been arrested based on TEM and SEM observation. Th…
Undoped CoS$_2$ is an isotropic itinerant ferromagnet with a continuous or nearly continuous phase transition at $T_{\rm C} = 122$ K. In the doped CoS$_{1.9}$Se$_{0.1}$ system, the Curie temperature is lowered to $T_{\rm C} = 90$ K, and the transition becomes clearly first order in nature. In particular we find a disc…
Following the hypothesis of the electrochemically stimulated conformational relaxation model (ESCRM), electrochemically generated films of poly(1-methylpyrrole), polythiophene, poly(3-methylthiophene), polyaniline, and polymethylaniline were studied by potential steps in lithium perchlorate/acetonitrile solutions. All…
It is shown analytically that there exists a natural basis in terms of which the nonperturbative time evolution of an important class of driven four-level systems in the strong-coupling regime decouples and essentially reduces to the corresponding time evolution in the weak-field regime, exhibiting simple Rabi oscilla…
The members of the mechanistically diverse, (beta/alpha)(8)-barrel fold-containing enolase superfamily evolved from a common progenitor but catalyze different reactions using a conserved partial reaction. The molecular pathway for natural divergent evolution of function in the superfamily is unknown. We have identifie…