O2/n2-separation by polymer-bound cobalt complexes

Facilitated or complexation-mediated transport of oxygen in the solid membrane containing a fixed carrier was described, by using the polymer-bound cobalt Schiff's base chelate (CoS) and cobaltporphyrin (CoP). α³ β-Substituted cobaltporphyrin derivatives were synthesized: The oxygen-binding reaction to cobalt was affected by the cavity structure on porphyrin, i.e., unbulky amido-substituted groups such as acetylamido- and acrylamido-substituents enhanced oxygen-binding and -dissociation rate constant or provided an oxygen-binding pathway. Oxygen transport through the membranes of these polymer-bound CoP derivatives was selectively augmented due to the rapid and reversible oxygen-binding. Diffusion constants via the fixed CoPs correlated to the characteristics of oxygen-binding reaction.     

New synthesis of polyaromatics through oxidative polymerization by using metal complexes with air

The oxidative polymerization provides a new synthetic route to polyaromatics. Poly(p-phenylene sulfide) (PPS) is produced by oxidative polymerization of thiophenol with a vanadyl complex catalyst. The metal complexes act as an efficient catalyst of oxygen oxidative polymerization. The polymerization to yield PPS is discussed especially focusing on the catalytic mechanism of the complexes.     

Uptake and Reduction of Arsenate by Dunaliella sp.

Uptake and reduction of arsenate [AS(V)] by Dunaliella sp. cells were determined to investigate the metabolic processes of arsenic in the alga. Cellular uptake of arsenic by Dunaliella sp. cells was markedly affected by the form of arsenic in the medium. The content of arsenic taken up by Dunaliella sp. cells increased rapidly with time on addition of As(V) to the medium. However, in the case of addition of arsenite [As(III)], the gradient of arsenic uptake by Dunaliella sp. cells was low, and arsenic content was small. In the water-soluble fraction of arsenic taken up by Dunaliella sp. cells with exposure to As(V), arsenic was in the forms of organic arsenic, As(V) and As(III). The content of As(V) in the water-soluble fraction increased with exposure time. The content of As(III) also increased with time, but remained constant after 5 h of exposure. On the other hand, organic arsenic content was small and did not increase with time. It was found that Dunaliella sp. takes up As(V) and readily reduces it to As(III)     

Fiber-optic distributed measurement of polarization beat length using slope-assisted Brillouin optical correlation-domain reflectometry

Optical Review - We demonstrate distributed measurement of the polarization beat length along single-mode optical fibers (SMFs) using slope-assisted Brillouin optical correlation-domain...     

XAFS spectra from X-ray fluorescence Kβ line using conventional energy-discriminating detector

X-ray fluorescence spectra of copper (Cu) metal, copper monoxide (CuO), and potassium chromate (K₂CrO₄) were recorded as a function of incident X-ray energy near the Cu K-edge and chromium (Cr) K-edge, respectively, using a conventional silicon drift detector. The spectra contained components due to elastic, inelastic, and multiple scattering, in addition to the Kα and Kβ lines. Cu and Cr K-edge X-ray absorption fine structure (XAFS) spectra of Cu, CuO, and K₂CrO₄ were obtained by an intensity analysis of the Kα and Kβ lines. The intensity of the Kβ line for the different incident photon energies was obtained by numerically removing the additional scattering components using the MUSCAT program. These spectra exhibited a jump near the K absorption edges, which reproduced the spectral features obtained in transmission mode for both Cu, CuO, and K₂CrO₄. A chemical shift was also clearly identified in the X-ray absorption near edges structure using the X-ray fluorescence Kβ line. In addition, the Cr K-edge extended XAFS spectrum of K₂CrO₄ was clearly observed using the Cr Kβ fluorescent line. The XAFS measurements on the Kα and Kβ lines are possible, and they carry equally valuable information.     

Proton Conduction at High Temperature in High-Symmetry Hydrogen-Bonded Molecular Crystals of RuIII Complexes with Six Imidazole-Imidazolate Ligands

A new H-bonded crystal [Ru^III(Him)₃(Im)₃] with three imidazole (Him) and three imidazolate (Im⁻) groups was prepared to obtain a higher-temperature proton conductor than a Nafion membrane with water driving. The crystal is constructed by complementary N−H⋅⋅⋅N H-bonds between the Ru^III complexes and has a rare Icy-c* cubic network topology with a twofold interpenetration without crystal anisotropy. The crystals show a proton conductivity of 3.08×10⁻⁵ S cm⁻¹ at 450 K and a faster conductivity than those formed by only HIms. The high proton conductivity is attributed to not only molecular rotations and hopping motions of HIm frameworks that are activated at ∼113 K, but also isotropic whole-molecule rotation of [Ru^III(Him)₃(Im)₃] at temperatures greater than 420 K. The latter rotation was confirmed by solid-state ²H NMR spectroscopy; probable proton conduction routes were predicted and theoretically considered.