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991.
Summary The reaction of substituted 1,4-naphthoquinones with 2-aminothiophenol ando-aminoheterocyclic thiones in acidic condition afforded benzophenothiazin-5-one and azabenzophenothiazin-5-one derivatives, respectively.
Die Synthese von Benzophenothiazin-Derivaten
Zusammenfassung Die Reaktion von substituierten 1,4-Naphthochinonen mit 2-Aminophenol bzw.o-aminoheterocyclischen Thionen führte unter sauren Bedingungen zu Benzophenothiazin-5-onen bzw. Azabenzophenothiazin-5-onen.
  相似文献   
992.
Potentiometric properties of manganese oxides doped with alkali metal ions (Na+, K+, Rb+ and Cs+), which were prepared by heating mixed solutions (starting solution) of each alkali metal and Mn2+ ions, were examined. Electrodes based on mixed phases of Nao44MnO2/Mn2O3 and hollandite KMn8O16/M2O3 found by X-ray powder diffraction (XRD) exhibited Na+- and K+-selective responses with a near-Nernstian slope, respectively, when the molar ratio of alkali metal ion to Mn2+ ion in the starting solution was 0.1. When no alkali metal ions were added in the manganese oxide films, no significant potentiometric response was observed to any alkali metal ions. The selectivity coefficients of these electrodes were = 6.7 × 10–2, = 7.1 × 10–3, < 9 × 10–4 and < 9x 10–4 for the Na0.44MnO2/Mn2O3, and <4 × 10–4 <4x 10–4, =60 × 10–2 ×10–4, < 4 × 10–4, for the KMn8O16/Mn2O3, respectively. Electrodes based on manganese oxides made from mixed solutions of Rb+/Mn2+ and Cs+/Mn2+ also responded to the respective primary ions, that is, Rb+ and Cs+ ions, although XRD patterns for the manganese oxides thus made did not show any peaks except for Mn2O3 (bixbyite); it was concluded in these cases that some amorphous type manganese oxides were formed in the Rb+/Mn2+ and Cs+/Mn2+ systems and they responded to the respective ions. Conditioning of these electrodes in an aerated indifferent electrolyte solution, 0.1M tetramethylammonium nitrate (TMA-NO3), for relatively long time, typically more than 2 hours, was found to be a prerequisite for near-Nernstian response to the respective alkali metal ions. During this electrode conditioning, vacant sites (template) suitable in size for selective uptake of primary ions seemed to be formed by releasing the doped alkali metal ions from the solid phase into the adjacent electrolyte solution accompanying oxidation of the manganese oxide film.  相似文献   
993.
Soluble polyimide having an inherent viscosity up to 1.4 dL/g was synthesized by the high-temperature solution polycondensation of 2,5-bis(4-isocyanatophenyl)-3,4-diphenylthiophene with 3,3′,4,4′-benzophenonetetracarboxylic dianhydride. The polycondensation of the tetraphenylthiophene diisocyanate with trimellitic anhydride afforded polyamide-imide with an inherent viscosity up to 0.9 dL/g. These polymers showed limited solubility in organic solvents and had glass transition temperatures around 320°C.  相似文献   
994.
The mechanism of two-dimensional polymerization of octadecyl acrylate in lamellar crystal was investigated in two-step postpolymerizations by temperature increase and stepwiseγ-ray irradiation in lieu of the usual one-step reaction. Two-step postpolymerizations by these procedures are interpreted satisfactorily by the cone model, which assumes that the polymerization probability of the monomer molecules in a single layer is distributed conically around the initiation point. It was found that the propagating radicals were living, even in the saturated stage, and the effect of the polymer chains already formed on the propagating and terminating reactions was evident. Furthermore, molecular weight distributions of the resultant poly(octadecyl acrylate) measured by gel permeation chromatography (GPC) were broad. The values of Mw /M n for the two-step post polymerizations were 4.71–7.03, whereas those for one-step reactions were 3.26–5.54.  相似文献   
995.
Racemic and optically active 3-pyrrolidinecarboxylic acids (β-proline) were synthesized, and their polymers, poly[(RS)-β-proline] and poly[(R)-β-proline], were prepared by the polycondensation reaction of the p-nitrophenyl esters. Model compounds, N-cyclopentylcarboxylic acid pyrrolidide and N-cyclopentylcarbonyl-(R)-3-pyrrolidinecarboxylic acid pyrrolidide, were synthesized to elucidate the conformation of the polymer. The solution properties of poly[(R)-β-proline] and the model compounds were investigated by means of circular dichroism (CD) and NMR spectroscopy. The spectral patterns of the polymer and model compounds were similar in various solvents. Poly[(R)-β-proline] and poly[(RS)-β-proline] showed identical NMR spectra. These results suggest that poly[(R)-β-proline] may exist in a random conformation consisting of mixtures of cis and trans amide bonds. The conformational study of cyclopentanecarboxylic acid pyrrolidide by NMR spectroscopy with a shift reagent, Eu(fod)3, in CDCl3 implied that the plane containing the amide group bisects the cyclopentane ring. This suggests that each amide plane in the polymer in chloroform may also bisect the pyrrolidine ring.  相似文献   
996.
In 1956, Tong established an asymptotic formula for the mean square of the error term of the summatory function of the Piltz divisor function d3(n). The aim of this paper is to generalize Tong's method to a class of Dirichlet series L(s) which satisfies a functional equation. Let a(n) be an arithmetical function related to a Dirichlet series L(s), and let E(x) be the error term of ′n xa(n). In this paper, after introducing a class of Diriclet series with a general functional equation(which contains the well-known Selberg class), we establish a Tong-type identity and a Tong-type truncated formula for the error term of the Riesz mean of the coefficients of this Dirichlet series L(s). This kind of Tong-type truncated formula could be used to study the mean square of E(x) under a certain assumption. In other words, we reduce the mean square of E(x) to the problem of finding a suitable constant σ*which is related to the mean square estimate of L(s). We shall represent some results of functions in the Selberg class of degrees 2–4.  相似文献   
997.
A novel method for preparation of biomacromolecular imprinted nanoparticles is described. Combinations of functional monomers were polymerized in the presence of the imprinting peptide melittin in aqueous solution at room temperature to produce a small library of polymer nanoparticles. The template peptide and unreacted monomers are subsequently removed by dialysis. Nanoparticles (NPs) from the library were evaluated for their binding to melittin by 27 MHz QCM analysis. NPs prepared with optimized functional monomer combinations bind strongly to the target molecule. Nanoparticles that were polymerized in the absence of template peptide were found to have little affinity to the peptide. Binding affinity and the size of imprinted particles are comparable to those of natural antibodies. They interact specifically with the target peptide and show little affinity for other proteins. These NPs are of interest as inert and stable substitutes for antibodies. Extension of this approach to other targets of biological importance and the applications of these materials are currently being evaluated.  相似文献   
998.
We report the enantioselective total syntheses of preussomerins EG1, EG2, and EG3. The key transformation is a stereospecific photochemical reaction involving 1,6-hydrogen atom transfer to achieve retentive replacement of a C−H with a C−O bond, enabling otherwise-difficult control of the spiroacetal stereogenic center.  相似文献   
999.
Spontaneously resolvable conglomerate crystals are obtained by combining racemic (rac)-1,1'-binaphthyl-2,2'-dicarboxylic acid and rac-1,2-diphenylethylenediamine, and this spontaneous resolution system is induced by water which is present in the crystallization solvent.  相似文献   
1000.
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