Physical and Chemical Properties of Four-Membered Bis(triphenylphosphane)platinum(II) Sulfenato Thiolato Complexes

The reaction of isolable dithiirane 1-oxides with (Ph 3 P) 2 Pt( m 2 -C 2 H 4 ) provided the title complexes in high yields. 31 P NMR spectroscopy of the phosphine ligands of the complexes and x-ray crystallographic analysis of a complex were reported.     

Thermal and evolved gas analyses of the oxidation of a cellulose/copper(II) oxide mixture

Cellulosic biomass is a promising alternative energy resource from the viewpoint of sustainability. The use of waste materials as cellulosic biomass could additionally contribute to a recycling society. It is thus essential to develop safer processes in order to expand utilization of cellulosic biomass as a useful resource in the future. For example, in some cases, construction wastes contain wood preservatives, including metal oxides that can act as catalysts for the oxidation of organic materials. Copper(II) oxide (CuO) is a major component in wood preservatives and is known to catalyze the oxidation of cellulose. There is, therefore, possibility for spontaneous ignition within large piles of wood chips from construction wastes. In this study, we focused on the thermal behavior of a cellulose/CuO mixture, measured using a Calvet-type heat flux calorimeter. In addition, Fourier transform infrared spectroscopy and gas chromatography were applied to analyze the oxidative decomposition gases of the cellulose/CuO mixture, and a reaction mechanism was proposed. It was revealed that CuO promotes the oxidative decomposition of cellulose and increases the quantity of the gases that evolved from cellulose with a catalytic cycle. The influence of CuO on oxidation of cellulose is greater at lower temperatures and spontaneous ignition, fires, and explosions are likely to increase when wood chips containing CuO are stored for long periods of time.     

Synthesis and Reactions of 1-Phenylbenzo[b]thiophenium Salts

1-Phenylbenzo[b]thiophenium salts are prepared and reacted under thermal and photochemical conditions. The chemical behaviors are discussed.     

Membrane-based microchannel device for continuous quantitative extraction of dissolved free sulfide from water and from oil

Underground fluids are important natural sources of drinking water, geothermal energy, and oil-based fuels. To facilitate the surveying of such underground fluids, a novel microchannel extraction device was investigated for in-line continuous analysis and flow injection analysis of sulfide levels in water and in oil. Of the four designs investigated, the honeycomb-patterned microchannel extraction (HMCE) device was found to offer the most effective liquid–liquid extraction. In the HMCE device, a thin silicone membrane was sandwiched between two polydimethylsiloxane plates in which honeycomb-patterned microchannels had been fabricated. The identical patterns on the two plates were accurately aligned. The extracted sulfide was detected by quenching monitoring of fluorescein mercuric acetate (FMA). The sulfide extraction efficiencies from water and oil samples of the HMCE device and of three other designs (two annular and one rectangular channel) were examined theoretically and experimentally. The best performance was obtained with the HMCE device because of its thin sample layer (small diffusion distance) and large interface area. Quantitative extraction from both water and oil could be obtained using the HMCE device. The estimated limit of detection for continuous monitoring was 0.05 μM, and sulfide concentrations in the range of 0.15–10 μM could be determined when the acceptor was 5 μM FMA alkaline solution. The method was applied to natural water analysis using flow injection mode, and the data agreed with those obtained using headspace gas chromatography-flame photometric detection. The analysis of hydrogen sulfide levels in prepared oil samples was also performed. The proposed device is expected to be used for real time survey of oil wells and groundwater wells.     

Abnormal Li diffusion in β-LiGa by the formation of defect complex

The diffusion coefficients of Li in the NaTl-type Li intermetallic compound of β-LiGa have been measured by using a short-lived radioactive diffusion tracer. As the tracer, the α-emitting radioisotope of ⁸Li delivered as the energetic and pulsed beam from Tokai Radioactive Ion Accelerator Complex (TRIAC) was implanted into the β-LiGa compounds with the composition in the range of about 43 to 54 at.% Li. By analyzing the time-dependent yields of the α-particles measured according to the repetition cycle of the beam, the tracer diffusion coefficients were extracted over the wide range of Li composition. Abnormal composition-dependence of Li diffusion coefficients in β-LiGa was observed; the stoichiometric β-LiGa showed the highest diffusivity of Li. By referring to the composition-dependent diffusivity of Li in the iso-structural β-LiAl and β-LiIn, we could identify the abnormal diffusion of Li in very Li-poor composition of β-LiGa. The anomaly has been discussed qualitatively in terms of the formation of defect complex and the interaction between the constitutional defects.     

Linear polybiurets: Facile synthesis and characteristic properties

Linear polybiurets have been synthesized by polyaddition of benzyloxyamine and diisocyanates, and properties of the novel polymeric materials have been elucidated. Prior to polymerization, model reactions between benzyloxyamine and phenyl isocyanate were examined in detail and proved to be controlled by the molar ratio of reagents and by catalysts to give the urea (1:1 adduct) and/or biuret (1:2 adduct). Under appropriate conditions, the biuret was synthesized in a quantitative yield. Polymerization of equimolar amounts of benzyloxyamine and diphenylmethane or hexamethylene diisocyanate proceeded smoothly to give polybiurets with inherent viscosities up to 0.52 dL/g. The benzyl group of the model biuret and polybiuret could be removed by catalytic hydrogenation. Both the N-benzyloxy-type and N-hydroxy-type polybiurets showed excellent solubility in common organic solvents. The two kinds of polybiurets as well as model biurets adsorbed metal cations efficiently. The N-hydroxybiuret structure exhibited particularly high affinity for iron(III) and was useful for selective removal of iron from metal cation mixtures. © 1996 John Wiley & Sons, Inc.     

Rearrangement of 6,7-dithiabicyclo[3.1.1]heptane 6-oxides to a 7,8-dithia-6-oxabicyclo[3.2.1]octane catalyzed by montmorillonite K 10

Treatment of 2,2,4,4-tetramethyl-1,5-diphenyl-6,7-dithiabicyclo[3.1.1]heptane 6-endo-oxide ( 2 ) with Montmorillonitc K 10 in dichloromethane gave 2,2,-4,4-tetramethyl-1,5-diphenyl-7,8-dithia-6-oxabicyclo-[3.2.1]octane ( 6 ) (11%) with recovery of 2 (87%). Under similar reaction conditions, the 6-exo-oxide 7 and the sulfenate 6 gave a mixture of 6 (21%), 2 (67%), and 7 (9%) and a mixture of 2 (89%) and 6 (9%), respectively. These results indicate the relative thermodynamic stabilities of the three compounds to be 2 > 6 > 7 . PM3 calculations on these compounds showed the heats of formation (kcal/mol) to be in the following order: 6 (44.12783), 2 (57.46721), and 7 (59.37918). The driving force of this unusual 1,2-rearrangement of 2 and 7 to 6 would be the release of the ring strain of the bicyclo[3.1.1]heptane system of 2 and 7 by ring expansion.     

Distinguishability and Disturbance in the Quantum Key Distribution Protocol Using the Mean Multi-Kings’ Problem

We introduce a quantum key distribution protocol using mean multi-kings’ problem. Using this protocol, a sender can share a bit sequence as a secret key with receivers. We consider a relation between information gain by an eavesdropper and disturbance contained in legitimate users’ information. In BB84 protocol, such relation is known as the so-called information disturbance theorem. We focus on a setting that the sender and two receivers try to share bit sequences and the eavesdropper tries to extract information by interacting legitimate users’ systems and an ancilla system. We derive trade-off inequalities between distinguishability of quantum states corresponding to the bit sequence for the eavesdropper and error probability of the bit sequence shared with the legitimate users. Our inequalities show that eavesdropper’s extracting information regarding the secret keys inevitably induces disturbing the states and increasing the error probability.