Organometallic derivatives of N-phenylmaleimidetriazoles and quinonetriazoles

The syntheses, properties, and structures of Mn, Cr, Re, and W organometallic derivatives of N-phenyl-1,2,3-triazoles and quinone-1,2,3-triazoles are described. The X-ray structures of eleven compounds are described. 9, a = 11.588(2), b = 11.904(2), 14.179(2) Å, α = 69.407(3)°, β = 70.879(3)°, γ = 78.627(3)°, P-1, R = 0.0739. 10, a = 7.643(1), 9.375(1), 13.077(2) Å, α = 74.292(2)°, β = 74.763(2)°, γ = 71.694(2)°. P-1, R = 0.0415. 11, a = 14.325(4) Å, b = 17.508(5) Å, c = 15.465(5), β = 99.282(5)°, P2/n, R = 0.0610. 17, a = 7.679(2) Å, b = 9.273(2) Å, c = 13.084(3) Å, α = 75.166(3)°, β = 74.651(3)°, γ = 71.613(3)°, P-1, R = 0.0428. 18, a = 5.757(1), 13.470(3), 23.056(4) Å, P2₁2₁2₁, R = 0.0697. 19, a = 8.118(1) Å, b = 10.471(2), 15.027(2) Å, α = 72.848(2)°, β = 82.237(2)°, γ = 71.829(2)°, P-1, R = 0.0597. 23, a = 7.993(1), 9.302(1) Å. C = 13.318(2) Å, α = 94.471(2)°, β = 105.269(2)°, γ = 109.523(2)°, P-1, R = 0.0271. 24, a = 7.583(4), 9.595(5), 13.030(6) Å, α = 76.389(7)°, β = 74.883(7)°, γ = 71.102(7)°, P-1, R = 0.0502. 26, a = 32.757(5) Å, b = 6.7083(9) Å, c = 26.033(4) Å, β = 128.895(5)°, C2/c, R = 0.0489. 31, a = 8.302(2), 8.347(2), 13.794(4) Å, α = 85.749(4)°, β = 81.176(4)°, γ = 74.849(4)°, P-1, R = 0.0400. 32, a = 11.321(2) Å, b = 12.110(2), 18.179(3) Å, β = 103.951(3)°, P2₁/c, R = 0.0318.     

Comparison of standard addition and conventional isotope dilution mass spectrometry for the quantification of endogenous progesterone in milk

In this study, a standard addition–isotope dilution mass spectrometry (SA-IDMS) method for quantification of endogenous progesterone in milk has been described. The method validation results, linearity, limits of detection and quantification, recovery and uncertainty were fit for the purpose of assigning reference mass fractions to proficiency testing schemes. The developed technique was compared to the isotope dilution mass spectrometry (IDMS) method already existing in the laboratory. Analytical results of two milk samples were (1.377 ± 0.048) μg/kg and (4.457 ± 0.155) μg/kg by SA-ID-LC/MS method, while the results were (1.355 ± 0.019) μg/kg and (4.359 ± 0.059) μg/kg by ID-LC/MS, respectively. Since SA-IDMS was an effective quantitative method that overcame matrix effect, similar quantitative results from IDMS and SA-IDMS indicated that the quantification of progesterone in milk was barely influenced by matrix. Both IDMS and SA-IDMS could be used to assign reference mass fractions to progesterone in milk inter-laboratory proficiency testing schemes.     

Synergistic extraction of uranium(VI) with 1-phenyl-3-methyl-4-(2′-chlorobenzoyl)-pyrazolone-5 and acidic organophosphorus reagents

A study of the synergistic extraction of uranium(VI) from sulphuric acid solution with 1-phenyl-3-methyl-4-(2-chlorobenzoyl)-pyrazolone-5 (PMCBP) together with di-(2-ethylhexyl)-phosphoric acid (HDEHP) and also mono-(2-ethylhexyl)-2-ethylhexyl-phosphate (HEHEHP) is described. The results suggest that the compositions of the extracted species is UO₂XHA₂ and UO₂X₂H₂A₂ respectively. Models for the extraction mechanism is also discussed.     

化学位移估算研究ATP构象随溶液pH值的变化

利用Johnson和Bovey的理论和方法计算了不同扭曲角χ(O4′－C1′－N9－C4)的ATP(5′-三磷酸腺苷)分子中糖环质子H1′和H2′由于环流效应引起的化学位移.H1′的化学位移与扭曲角χ有较强的依赖关系,反映了ATP在溶液中细微的构象变化.将计算结果与实验结果比较,证明在本文讨论的pH值范围(1～10)内,Mg2＋加入后,ATP的扭曲角χ在230～360°范围内变化.随溶液的pH值减小,ATP分子的构象由trans 构象通过-gauche构象转变为cis构象. 从而证明在酸性条件下, ATP倾向于以cis构象存在,而在碱性条件下trans构象更为稳定,从另一方面支持了在酸性条件下N1参与配位而在碱性条件下N7参与配位的结论.在讨论中也考虑了由pH变化所引起的环流强度的变化.     

氨基酸及味精的分离鉴定——纸层析法

高中化学教材介绍有关“氨基酸”的知识时,只介绍了氨基酸的名称和结构式、物理性质及氨基酸具有两性电离性质以及它是构成蛋白质的“基石”,通过实验说明氨基酸是构成蛋白质的“基石”已有一些文章介绍。通过纸上层析实验进行氨基酸混合物的分离鉴定也已经有一些文章介绍,但是配合中学化学教材内容的学生实验尚未见介绍,为此我们设计了“氨基酸及味精的分离鉴定—纸层析法”实验。     

INFLUENCE OF COMPOSITIONAL HETEROGENEITY ON MORPHOLOGY AND PROPERTIES OF SEGMENTED COPOLYMERS

Polyethylene terephthalate(PET)/polycaprolactone(PCL) segmented copolymers with different hard segment contents and a blend of two of them were studied by using DSC, WAXS, TEM and IR techniques and dynamic mechanical, stress-strain and isothermal crystallization measurements. Emphasis was laid on the studies of influence of compositional heterogeneity on the morphology and properties of these segmented copolymers. It was found that the solution cast specimens of the more heterogeneous sample exhibit better segregation of segments, high crystallinity and melting temperature. They have higher thermal stability of mechanical properties at small deformations. However, they are less stable against large deformations and may become softer than the more homogeneous ones.     

三价铀的制备和稳定性研究

在盐酸和硫酸介质中,研究了汞阴极电解还原和液态Zn-Hg齐还原制备U(Ⅲ)的实验方法,比较了不同介质、酸度、铀浓度和电解时间对U(Ⅲ)还原率的影响,获得了用电解法定量还原制备U(Ⅲ)的最佳条件。经对U(Ⅲ)在空气和氮气中稳定性的测定,得出U(Ⅲ)在空气中的氧化速率呈一级反应。