反相高效液相色谱法半制备分离[T(4-MOP)PS4]卟啉的研究

本文研究了新水溶性５，１０，１５，２０－四（４－甲氧基－３－磺酸苯基）卟啉［Ｔ（４－ＭＯＰ）ＰＳ４］的反相高效液相色谱（ＨＰＬＣ）分离条件。采用ＳｈｉｍｐａｃｋＰＲＥＰ－ＯＤＳ半制备色谱柱，用含有１０ｍｍｏｌ／Ｌ四乙基碘化铵的乙腈－水（体积比２５：７５）为流动相，流速１８ｍＬ／ｍｉｎ，于４１８ｎｍ波长下检测。［Ｔ（４－ＭＯＰ）ＰＳ４］与合成中生成的杂质组分完全分离。经此制备的卟啉纯度高，已成功地应用于自来水样中微量钴、锌、铜离子的ＨＰＬＣ测定中。     

Novel optically active 1,3-aminoalcohols derived from D-glucal

A series of ethyl(phenyl) 6-amino-2,3,6-trideoxy--D-glucopyranosides (amino=piperidino (Pip), pyrrolidino (Pyr), azetidino (Az), Bu₂N) have been prepared from tri-O-acetyl-D-glucal to obtain catalysts for asymmetric synthesis and the starting compounds for the syntheses of other bidentate ligands.Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 45–52, January, 2000.     

磷钨钼钒杂多蓝光度法测定钼的探索

本文研究了磷钨钼钒四元杂多酸及其还原产物杂多蓝的形成条件、光度性质、组成和在测定高速钢中高钼的应用。试验表明,磷钨钼钒杂多蓝光度法测定钼具有新颖性、高选择性、较高准确性和简便性,适于高速钢中>1％Mo的测定。     

Investigation of gas chromatographic interaction mechanism on permethylated cyclodextrins by molecular modelling

Summary The capillary gas chromatographic retention behavior of -pinene and tricyclene has been investigated on stationary phases of different polarities. On all but one of the columns employed, tricyclene eluted before -pinene; only permethylated -cyclodextrins dissolved in moderately polar polisiloxanes gave a reversed elution order. The intermolecular interactions which caused the unexpected retention behavior were investigated in detail, applying methods of computer simulation. To achieve this, we have developed a calculation algorithm on the basis of molecular mechanical optimizations and programmed it in a macro. This makes it possible to systematically investigate a given configuration space in which all the possible interactions can take place. It was shown that permethylated -cyclodextrin as host molecule for both guest molecules offers an optimum cavity size. As a result the number of energetically favorable contacts between host and guest molecules as well as the strength of the interactions in this stationary phase were larger. As a consequence the elution order, normally only influenced by the vapor pressure of the compounds at a given temperature, was changed. Nonspecific interactions played an especially important role for these kinds of substances.     

MNDO study of reaction paths: Diboration of acetylene

The reaction of B₂H₄ with acetylene has been studied by the MNDO method. It is shown that the reaction is exothermic and proceeds in two steps. The first step is the formation of a three-center -complex and this is the rate-determining step of the reaction. The second step is the rearrangement of the -complex to the product and this step requires a very small amount of activation energy. The activation barrier for the diboration reaction is 12.8 kcal/mol.The proposed mechanism is significantly different from those proposed earlier and explains all experimental data relating to this reaction.     

Synthesis of some phosphonocarbonyl compounds via Horner-Emmons reaction of methylenbisphosphonate

Summary The -carbonyl substituted vinylphosphonates6–9 were synthesized from the -dicarbonyl compounds2–5 and the methylenbisphosphonate1 by a Horner-Emmons reaction in different yields.

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Synthese von Phosphonocarbonylverbindungen durch Horner-Emmons-Reaktion von Methylenbisphosphonsäuretetraethylester

Zusammenfassung Es wurden die -carbonylsubstituierten Vinylphosphonate6–9 mittels Horner-Emmons-Reaktion aus den -Dicarbonylverbindungen2–5 und Methylenbisphosphonat1 in verschiedenen Ausbeuten hergestellt.

     

Synthesis and structure of novel derivatives of thieno[2,3-b]thiocine. An unusual product of intramolecular cycloaddition of 2-homomethallylthio-5-methyl-3-thiophenecarbonitrile oxide

9-Methyl-3,3a,4,5-tetrahydro-6H-thieno[2,3-b]thiocino[4,5-c]isoxazole and 9-hydroxyimino-2-methyl-7-methylene-6, 7,8,9-tetrahydro-5H-thieno[2,3-b]thiocine have been prepared for the first time by the oxidation of 2--alkenylthio-3-thiophenecarbaldoximes with NaOCl. X-ray structural investigations of thieno[2,3-b]thiocine and 2-homomethallylthio-5-methyl-3-thiophenecarbaldoxime have been carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1262–1266, July, 1993.     

Hydride generation atomic fluorescence spectrometric determination of ultratraces of selenium and tellurium in cow milk

A sensitive procedure has been developed for selenium and tellurium determination in milk by hydride generation atomic fluorescence spectrometry (HG-AFS) after microwave-assisted sample digestion. The method provides sensitivity values of 1591 and 997 fluorescence units ng⁻¹ ml⁻¹ with detection limits of 0.005 and 0.015 ng ml⁻¹ for Se and Te, respectively. The application of the developed methodology to the analysis of cow milk samples of the Spanish market evidenced the presence of concentration ranges from 11.1 to 26.0 ng ml⁻¹ for Se, and from 1.04 to 9.7 ng ml⁻¹ for Te having found a good comparability with data obtained after dry-ashing of samples.     

The search for a new model structure of β-Factor XIIa

We present the search for a new model of -factor XIIa, a blood coagulation enzyme, with an unknown experimental 3D-structure. We decided to build not one but three different models using different homologous proteins as well as different techniques and different modellers. Additional studies, including extensive molecular dynamics simulations on the solvated state, allowed us to draw several conclusions concerning homology modelling, in general, and -factor XIIa, in particular.