A Ru/Zn synergism in extraction of ruthenium by calixarene phosphine oxides

Diesters on the basis of 16-hydroxyisosteviol and dicarboxylic acids, exhibiting anti-tubercular activity, transport Fe(III) through liquid chloroform membrane which models a cell membrane. It is revealed that fluxes and anti-tubercular activity increase, as the length of the chain (spacer) between two ent-beyran skeletons of diesters increases. Computations on the level DFT/PBE explain the dependence of complexes stability on a structure of diterpenoid ligands. The structures of three diesters were established by single crystal X-ray analysis.     

Matching and price competition: would personalized prices help?

We analyze the generalized deferred-acceptance algorithm when preferences are known with an error. This algorithm incorporates personalized salaries and is considered as a replacement for the current algorithm for National Resident Matching Program (NRMP). Maintaining Bulow and Levin’s (in Am Econ Rev 96(3):652–668, 2006) assumption on preferences, we show that an error in preferences of a worker propagates through the algorithm, leading to a change in the salary of every more productive worker. Thus, relatively small individual errors accumulate toward the top and may lead to highly distorted salaries for top workers the same way as mild compression translates into highly compressed salaries on the top in the Bulow and Levin study of the current NRMP algorithm.     

Novel structurally characterized o-semiquinonato PCP-pincer nickel complexes

Structural study of dialkyl (PCP)-pincer o-semiquinonato nickel complexes indicated sloped relative positions of bi- and tri-dentate ligands. It became bright confirmation of propositions made on the base of their EPR spectra followed by molecular modelling.     

Visualization of supramolecular framework of perfluorinated-oligomer colloid particles by supercritical drying

Aerogels of the tetrafluoroethylene radical polymerization products H(C₂F₄)_nR, where R is the radical formed by the abstraction of a hydrogen atom from a solvent molecule, have been obtained by replacing the solvent with supercritical CO₂ and its subsequent rapid evaporation. According to the data of scanning electron and atomic force microscopy, the aerogel consists of loosely bound particles of 1–3 μm in diameter, which is two to three times that of colloid particles in the initial solution, where the particles consist of an oligomer framework filled with solvent molecules. The internal structure of the framework is manifested in the surface topography with a roughness coefficient of 1.6–1.8. High roughness leads to the formation of ultrahydrophobic coatings with contact angles of >160°. A model of supercritical drying in which the solvent is removed from the colloidal particles without alteration of the supramolecular structure is discussed.     

New morpholine- and piperazine-functionalized triphenylantimony(V) catecholates: The spectroscopic and electrochemical studies

Novel functionalized triphenylantimony(V) catecholates - Ph₃Sb[4-O(CH₂CH₂)₂N-3,6-DBCat] (1), Ph₃Sb[4-PhN(CH₂CH₂)₂N-3,6-DBCat] (2), Ph₃Sb[4-Ph₂CHN(CH₂CH₂)₂N-3,6-DBCat] (3), Ph₃Sb[4,5-Piperaz-3,6-DBCat] (4) and binuclear bis-catecholate Ph₃Sb[3,6-DBCat-4-N(CH₂CH₂)₂N-4-3,6-DBCat]SbPh₃ (5) were synthesized by the oxidative addition reaction of corresponding o-quinones with triphenylantimony. The [4-O(CH₂CH₂)₂N-3,6-DBCat]²⁻, [4-PhN(CH₂CH₂)₂N-3,6-DBCat]²⁻, [4-Ph₂CHN(CH₂CH₂)₂N-3,6-DBCat]²⁻ and [4,5-Piperaz-3,6-DBCat]²⁻ are 4-(morpholin-1-yl)-, 4-(4-phenyl-piperazin-1-yl)-, 4-(4-dephenylmethyl-piperazin-1-yl)-, and 4,5-(piperazin-1,4-diyl)-3,6-di-tert-butyl-catecholate dianionic ligands, correspondingly. Complexes 1-5 were characterized in details by IR-, ¹H and ¹³C NMR spectroscopy and cyclic voltammometry. Molecular structure of 4·CH₃OH was determined by X-ray crystallography to be a distorted tetragonal-pyramidal. The NMR spectroscopic and electrochemical investigations of complexes in the presence of air reveal the reactions of complexes with dioxygen leading to the formation of spiroendoperoxides of 1,2,4,3-trioxastibolane type in a NMR yield of 25-37%.     

Crystal and molecular structure of [RuNO(NO2)4OHCuPy n ] heterometallic complexes

Heterometallic complexes [RuNO(NO₂)₄OHCuPy₂(H₂O)] (I) and [RuNO(NO₂)₄OHCuPy₃] (II) are described structurally for the first time. In complex I, the ruthenium anion is coordinated to the copper atom by the bridging OH group and two bridging nitro groups; in complex II, by the bridging OH group and one bridging nitro group. Dimers are formed in the crystal lattice of complex II due to the interaction of the copper atom and the nitro group of the ruthenium anion in trans position to the bridging NO₂ group.     

Status of the EBIT in the ReA3 reaccelerator at NSCL

At the NSCL a reaccelerator with design end energy of 3 MeV/u for ²³⁸U, called ReA3, is approaching the end of construction. ReA3 will be coupled to a gas stopper at the NSCL fragmentation facility to provide rare-isotope beams of nuclides not available at ISOL facilities in this energy range. An Electron Beam Ion Trap (EBIT) will be used to provide highly charged ions at an energy of about 12 keV/u. The charge breeder is followed by a room-temperature radiofrequency quadrupole (RFQ) and a series of superconducting linear accelerator structures. Initial commissioning results from the EBIT and its charge-over-mass separator are presented.     

Direct bonding of silicon wafers with the concurrent formation of diffusion layers

An original technique for Si-Si direct bonding combined with impurity diffusion in a single process is suggested. A dopant (aluminum) source is located at the interface. The high-temperature treatment of the polished wafers in an oxidizing atmosphere results in the diffusion of Al atoms and the formation of a p-n junction in n-silicon. The presence of aluminum is shown to improve the continuity of the interface. Results obtained are explained within a model whereby the initial contact between the hydrophilic silicon surfaces in a water solution of aluminum nitrate Al(NO₃)₃ serves to increase the bonding area of the wafers at room temperature due to the interaction of Al-OH groups with water molecules adsorbed on the surfaces of the wafers.     

Structure of the O-Specific Polysaccharide of Hafnia Alvei 23 Having an Oligosaccharide-Phosphate Repeating Unit

ABSTRACT

Lipopolysaccharide (LPS) of Hafnia alvei 23 has an acid-labile O-specific polysaccharide (OPS) with a pentasaccharide-phosphate repeating unit containing D-Glc1P, D-GlcNAc, L-Fuc, 6-deoxy-D-talose (D-6dTal), 4-acetamido-4,6-dideoxy-D-glucose (D-Qui4NAc), and an O-acetyl group. A partially degraded OPS was obtained by hydrolysis of LPS with 0.25 M sodium acetate in aqueous 0.5% acetic acid. Fractionation of LPS on Sephadex G-200 in DOC buffer allowed isolation of long-chain LPS species which, together with OPS, were studied by methylation analysis, chemical degradations (O-deacetylation, dephosphorylation with 48% hydrofluoric acid, Smith degradation), and ¹H and ¹³C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, and H-detected ¹H,¹³C heteronuclear single-quantum coherence (HSQC) experiments. The following structure of the repeating unit of OPS was established: