Copolymerization of carbon disulfide and N-(β-cyanoethyl)ethylenimine

It was found that carbon disulfide copolymerizes with N-(β-cyanoethyl) ethylenimine by using water as a catalyst. The copolymerization was conducted in detail by using water as a catalyst in the temperature range between 0 and 50°C with various initial concentrations of carbon disulfide and N-(β-cyanoethyl)ethylenimine in the absence of solvent. The copolymer obtained was always composed of the two monomers: 1:1 ratio, independent of the initial concentration of the monomers. The copolymer was white solid material soluble in dimethyl sulfoxide, insoluble in other usual organic solvents and decomposed at 155°C. Spectroscopic analysis of the copolymer combined with the results of elemental analysis indicates that the copolymer had the following structure:      

Selective syntheses of metalated pyridines from two different unsymmetrical acetylenes, a nitrile, and a titanium(II) alkoxide

Cyclotrimerization of two different, unsymmetrical acetylenes and p-toluenesulfonylnitrile with a divalent titanium alkoxide reagent, Ti(O-i-Pr)4/2 i-PrMgCl, yielded single pyridyltitanium compounds in a highly selective manner. These metalated pyridines were confirmed by deuteriolysis to give the corresponding deuterated pyridines and underwent iodinolysis and copper-catalyzed alkylation to demonstrate their synthetic utility. Alternatively, a different type of cyclotrimerization of an alkynamide, terminal acetylenes, and alpha-alkoxynitriles mediated by the same titanium(II) alkoxide again proceeded in a highly selective manner to give single pyridines having a titanated side chain.     

One-pot reductive amination of aldehydes and ketones with α-picoline-borane in methanol, in water, and in neat conditions

A one-pot reductive amination of aldehydes and ketones with amines using α-picoline-borane as a reducing agent is described. The reaction has been carried out in MeOH, in H₂O, and in neat conditions in the presence of small amounts of AcOH. This is a highly efficient and mild procedure that is applicable for a wide variety of substrates. In particular, this is the first successful demonstration that this type of reaction can be carried out in water and in neat conditions.     

Copolymerization of ethylene sulfide and carbon disulfide

Ethylene sulfide was found to copolymerize with carbon disulfide to give poly(ethylene trithiocarbonate) in the presence of Hg(SC₄H₉)₂, Zn(C₂H₅)₂, or Cd(C₂H₅)₂, which are well known as the effective catalysts for the coordinated anionic copolymerization of episulfides. The structure and the composition of the copolymer was determined by the infrared and NMR spectra. To establishe the mechanism of the copolymerization, the reaction of carbon disulfide and Hg(SC₄H₉)₂, and also the ring-opening polymerization of ethylene trithiocarbonate were examined. Carbon disulfide was found to insert easily into the metal-sulfur bond of Hg(SC₄H₉)₂ under the experimental conditions of the copolymerization. On the other hand, the ring-opening polymerization of ethylene trithiocarbonate did not take place with these catalysts, occurring only with the use of sulfuric acid. From these results, the mechanism of the copolymerization was discussed.     

Surface ionization detector with a supersonic free jet for gas chromatography some applications

A new design for a gas chromatographic surface ionization detector based upon hyperthermal positive surface ionization has been developed: There were two requirements: supersonic free jet nozzle and the high work function surface of Re-oxide. This detector, which is highly sensitive in response to all organic compounds, can be operated as an universal detector with an additional selectivity towards some species that have low ionization energy, but with selectivity to a much lesser degree than a conventional surface ionization detector. The minimum detectable amount of toluene is ca. 10⁻¹² g/s with a linearity greater than 10⁴. Some applications are demonstrated using three examples for the analysis of different formulations: (1), terpene mixture, (2), polycyclic aromatic hydrocarbon mixture and (3), alkyl alcohol mixture.     

[2.2](2,6)Biphenylenophane and [2](2,6)Biphenyleno[2](2,6)naphthalenophane

Two cyclophanes, [2.2](2,6)biphenylenophane and [2](2,6)biphenyleno[2](2,6)naphthalenophane, were prepared.     

Mechanism of 7Be scavenging from the atmosphere through precipitation in relation to seasonal variations in Rokkasho Village, Aomori Prefecture, Japan

⁷Be deposition fluxes and atmospheric concentrations were measured at Rokkasho Village, Aomori Prefecture, Japan, from 2000 to 2005. It was confirmed that the ⁷Be deposition fluxes were minimum in summer, and the fallout maximizes in winter. The atmospheric concentration of ⁷Be was especially low in summer, and high in the other three seasons. A positive correlation was observed between the amount of precipitation and ⁷Be deposition. Clear seasonal differences were evident among the ratios of ⁷Be deposition flux to precipitation amounts in the four seasons. The ratios were especially high in winter, higher than those in the other three seasons. ⁷Be deposition flux was estimated by a simple simulation model using atmospheric ⁷Be concentrations and local meteorological data. As a result, the estimated deposition value was relatively lower than the measured value in winter.     

Interpenetrating Coordination Polymers from CuI or AgI and Flexible Ligands: 2D Polyrotaxanes and Interpenetrating Grids

The reaction of [Cu(CH₃CN)₄]NO₃ or AgNO₃ with flexible ligands 1,4‐bis(4‐pyridylmethyl)‐2,3,5,6‐tetrafluorobenzene (bpf) or 4,4′‐bis(4‐pyridylmethyl)‐2,2′,3,3′,5,5′,6,6′‐octafluorobiphenyl (bpfb) afforded two types of interpenetrating coordination polymers. The structures of [Cu₂(bpf)₃(NO₃)₂]_n and [Ag₂(bpf)₃‐(NO₃)₂]_n are 2D polyrotaxane networks in which 1D polymeric chains are aligned in a grid. The structure of {[Cu(bpfb)₂]NO₃}_n is a 2D grid polymer with two‐fold parallel interpenetration.     

Syntheses of polythia[n]ruthenocenophanes

Thiacrown ethers containing ruthenocene as a subunit were synthesized by the reaction of 1,1′-bis(3-chloropropyl-1-thia)ruthenocene with disodium dithiolates in THF/EtOH. In these reactions, some unexpected products were obtained.