溶液中芳香单酮的聚集态

本文对九种芳香单酮(苯乙酮、对氯苯乙酮、对甲氧基苯乙酮、对氨基苯乙酮、对硝基苯乙酮、间硝基苯乙酮、2.4-二甲基苯乙酮、1-萘乙酮和1-萘基苯基甲酮)在丙酮溶液中的吸收光谱进行了比较。发现芳香单酮在溶液中的分散是不均匀的, 随浓度增加, 有芳香单酮的聚集体生成。且芳香单酮分子的共轭体系越发达或苯环上电子云密度越犬, 分子就越易聚集。同时提出芳香单酮聚粲时的分子排列是苯环对苯环“面对面”取向的推断。     

Solid state synthesis and structure of two novel polyoxometalates [(n-Bu)4N]4[M6O19][Ag2I4](M?Mo,W)†

The reaction of [NH₄]₂[MO₂S₂], AgI and (n-Bu)₄NBr in solid state produced the polyoxometalates [(n-Bu)₄N]₄[M₆O₁₉][Ag₂I₄] (1, M? Mo; 2, M? W) which were structurally determined. The crystals of 1 and 2 are isomorphous, monoclinic, space group P2₁/c. 1, a = l.6624(2), b=1.6699(3), c=l.7217(2) nm, β=98.29(1)°, V=4.729(1) nm³, Z=2, R=0.040, R_w“0.037; 2, a = 1.6636(3), b = 1.6733(3), c = 1.7190(3) nm, β=98.25(1)°, V=4.736(l) nm³, Z = 2, R = 0.038, R_w = 0.047. The results of the structure determination showed that the two compounds had the same structures whose skeletons are composed of [Ag₂I₄]². and [M₆O₁₉]^2-. The difference of them and heteropolymetalate compounds synthesized in solution is that the title compounds contain cluster. ion, heteropolymetalate and organic cations, while the latter is only composed of heteropolymetalate and organic cations.     

Synthesis and biological activity of novel 2-(3-trifluoromethylphenoxy)-4-trifluoromethylthiazole-5-carboxamide derivatives

Novel 2-(3-trifluoromethylphenoxy)-4-trifluoromethylthiazole-5-carboxamides were designed and synthesized utilizing ethyl 3-amino-4,4,4-trifluoro-2-butenoate as a starting material via six steps. Subsequently, their biological activities were evaluated in the greenhouse. Results indicated that several compounds have some insecticidal or fungicidal activity at 600 g ai/ha and 300 g ai/ha, respectively.     

尼龙1010／尼龙6共聚物的表观相图研究

采用显微熔点法和ＤＳＣ测定了尼龙１０１０／尼龙６共聚物的表观相图；分析了投料比与链节结构单元含量的关系。最低熔点时尼龙１０１０／尼龙６的理论重量投料比为６０／４０，摩尔比为３３．３／６６．７，实验结果与此相近。     

Unicyclic Graphs with Minimal Energy

If G is a graph and ₁,₂,..., _n are its eigenvalues, then the energy of G is defined as E(G)=|₁|+|₂|++| _n |. Let S _n ³ be the graph obtained from the star graph with n vertices by adding an edge. In this paper we prove that S _n ³ is the unique minimal energy graph among all unicyclic graphs with n vertices (n6).     

Study of Manganese Promoter on a Precipitated Iron-Based Catalyst for Fischer-Tropsch Synthesis

The effects of Manganese(Mn)incorporation on a precipitated iron-based Fischer-Tropsch synthesis(FTS)catalyst were investigated using N_2 physical adsorption,air differential thermal analysis (DTA),H_2 temperature-programmed reduction(TPR),and M(?)ssbauer spectroscopy.The FTS perfor- mances of the catalysts were tested in a slurry phase reactor.The characterization results indicated that Mn increased the surface area of the catalyst,and improved the dispersion ofα-Fe_2O_3 and reduced its crystallite size as a result of the high dispersion effect of Mn and the Fe-Mn interaction.The Fe-Mn inter- action also suppressed the reduction ofα-Fe_2O_3 to Fe_3O_4,stabilized the FeO phase,and(or)decreased the carburization degree of the catalysts in the H_2 and syngas reduction processes.In addition,incorporated Mn decreased the initial catalyst activity,but improved the catalyst stability because Mn restrained the reoxidation of iron carbides to Fe_3O_4,and improved further carburization of the catalysts.Manganese suppressed the formation of CH_4 and increased the selectivity to light olefins(C_(2-4)~=),but it had little effect on the selectivities to heavy(C_(5 )) hydrocarbons.All these results indicated that the strong Fe-Mn interaction suppressed the chemisorptive effect of the Mn as an electronic promoter,to some extent,in the precipitated iron-manganese catalyst system.     

Theoretical study of the local structure and Raman spectra of CaO-SiO2 binary melts

A procedure for the Raman spectra calculation of vitreous and molten silicates was presented in this paper. It includes molecular dynamics MD simulation for the generation of equilibrium configurations, Wilson's GF matrix method for the calculations of eigenfrequencies and corresponding vectors, electro-optical parameters method (EOPM) for the Raman intensity calculations, and the bond polarizability model (BPM) for the determination of polarizability and polarizability derivative. One of the most important characteristics of this procedure is the achievement of the partial Raman spectra of five tetrahedral units, as well as the total spectral envelope. In this paper, the calculation was carried out for the vitreous and molten calcium silicates with different compositions and at various temperatures. It is worthwhile to note that the calculation is based on statistical configurations distribution in the space and so it is not needed to artificially adjust the full width at half maximum (FWHM) of spectra. It was also tested through the good agreement of the calculated spectra with the experimental, including some regularity of spectral properties. According to the calculation, the symmetrical stretching of whole tetrahedral units, to which the stretching of Si-O(nb) bond gives the main contribution to intensity, is proven to be the dominance in the high-frequency range (800-1200 cm(-1)) and the symmetrical bending of Si-O(b)-Si, to which the stretching of Si-O(b) bond exhibits the main contribution, is the dominance in the medium-frequency range (400-700 cm(-1)). As the first theoretical results, the Raman scattering coefficient of each Q(i) was found little change along with the variation of composition and temperature.     

Unexpected differences in the alpha-halogenation and related reactivity of sulfones with perhaloalkanes in KOH-t-BuOH

Most alkyl phenyl sulfones are readily alpha-chlorinated with CCl(4) and alpha-brominated with CBrCl3 in KOH-t-BuOH via radical-anion radical pair (RARP) reactions. While isopropyl mesityl sulfone (4) is easily alpha-chlorinated with CCl(4), it was completely recovered when treated with the more reactive CBrCl3. Subsequent investigations showed the latter result to be due to the poor acidity of 4 together with the rapid depletion of CBrCl3 and KOH by their reaction with each other, and led to a variety of other important results. 4-Hydroxyphenyl isopropyl sulfone (6) is unreactive with either CCl4 or CBrCl3 in KOH-t-BuOH, its phenoxide anion strongly reducing the electronegativity of the sulfonyl group, thereby inhibiting alpha-anion formation. This effect is reversed by the electron-withdrawing influence of two alpha-phenyls, so that benzhydryl 4-hydroxyphenyl sulfone (8) is readily alpha-halogenated in KOH-t-BuOH with CCl4 or CBrCl3. On further contact with KOH-t-BuOH the alpha-halogenated sulfones from 8 are decomposed into benzophenone and phenol. While the alpha-halogenated derivatives of 4-methoxyphenyl benzhydryl sulfone (9) are stable to base, they are decomposed even under mildly acidic conditions into 4-methoxyphenyl 4-methoxybenzenethiolsulfonate (9c), phenol, and benzophenone. Mono-alpha-halogenation of benzyl phenyl sulfone (10) enhances the rate of the subsequent halogenation, so that alpha,alpha-dihalogenation is attained while much substrate is still present and the mono-alpha-halogenated product is not detected. The ease of reductive debromination of alpha-bromo sulfones with Cl3C- was correlated with the stability of the formed alpha-anions, explaining the success with alpha-bromobenzylic sulfones but failure with alpha-bromoalkyl sulfones. In the presence of air and the absence of competing halogenation, formation of the alpha-anions of alkyl aryl sulfones is quickly accompanied by oxidative cleavage by atmospheric O2, leading to the formation of arenesulfonyl alcohols, arenesulfonyl halides, and haloarenes.