双质谱测定地卟啉取代基组成的解析方法及其应用

根据卟啉标样的双质谱特征，建立一种计算卟啉环上取代基组成的方法。卟啉的平均分子结构简式衡量其取代基的组成，尤其对地质体中相同碳数的卟啉“混合物”大环外取代基的构成十分有效。     

Chemistry of polyfunctional molecules-123. Reactions of BiBr3, SbI3 and AsI3 with LiN(PPh2)2; X-ray structure of a cyclophosphazene salt containing arsenic(I)

BiBr₃ or SbI₃ react at 20°C with LiN(PPh₂)₂ (1) to give elementary Bi or Sb and the P---P coupled phosphazene ligand Ph₂P---N=PPh₂---PPh₂=N---PPh₂ (2). The reaction of AsI₃ with 1 at room temperature formed yellow needles of the eight-membered heterocycle (3), whereas AsI₃ interacted at 80°C with 1 in the molar ratio of 1:3 to give elementary arsenic and 2. Treatment of AsI₃ and 1 at 20°C in a 1:2 stoichiometry yielded the seven-membered, cyclic arsenium(I) salt

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I·4THF (5·4THF), which was characterized by elemental analysis, conductivity, mass, IR and NMR spectroscopy and single-crystal X-ray structural analysis.     

Interaction of aminoazoles with Meldrum’s acid and dialkyl ketones or cyclohexanone

Interaction of 3-amino-5-methylpyrazole, 3-amino-5-methylthio-, and 3,5-diamino-1,2,4-triazole with Meldrum’s acid, acetone, ethyl methyl ketone, and cyclohexanone leads to alkyl-substituted pyrazolo[3,4-b]pyridin-6-ones and 1,2,4-triazolo[1,5-a]pyrimidin-7-ones respectively. The structure of 5,5-dimethyl-2-methylthio-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]pyrimidin-7-one was demonstrated by an X-ray structural investigation. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 595–601, April, 2007.     

Reaction of 3,3-dichloropentane-2,4-dione with aromatic aldehydes under the conditions of Darzens reaction

3,3-Dichloropentane-2,4-dione reacts with aromatic aldehydes under the conditions of Darzens reaction to give 4-acetoxy-4-aryl-3,3-dichlorobutan-2-ones, the products of insertion into the -C-C bond. The reaction of ethyl dichloroacetylacetate with benzaldehyde yields a derivative of tricyclo[5.1.0.0^3,5]octane, rather than 2,6-bis(1-chlorobenzylidene)cyclohexane-1,4-dione, as the by-product.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1294–1298, July, 1995.     

Carbocyclic and nitrogen-containing fused CH-acids with an annelated indenyl fragment. Thermogravimetric and X-ray structural analysis of 6H-indeno[1,2-b]quinoline

Based on thermogravimetric characteristics first obtained for the model 6H-indeno [1,2-b]quinoline, the scheme of thermal conversions of this compound in the temperature range 20–700 °C has been proposed, and the limit of its thermal stability (300 °C) has been determined. This temperature is recommended as the optimum for synthesizing fused benzoaza(diaza)fluorenes. Based on the results of X-ray structural analysis, the molecules of the studied indenoquinoline form centrosymmetric pairs, which are arranged in (110) layers. The molecules are orientationally disordered. The observed self-association of these molecules is similar to the - association of fused heterocyclic systems with-excessive and ****- deficient fragments. It has been suggested that interferon-inducing and antitumor compounds with an annelated indenyl fragment have a common mechanism of action according to the intercalation model of stacking structures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 703–709, April, 1995.     

Lines of curvature near umbilical points on surfaces immersed in R4

LetM be a compact orientable surface,I:M R⁴ an immersion of classC ^r and a normal unitary smooth vector field. We prove that in the space of pairs (I, ) the family of pairs all whose umbilical points are Darbouxian is generic.     

Structures of boron chelates of mono- and diacylketene aminals

The molecular and crystal structures of diphenylboron chelates of acetylketeneN-benzoylaminal and 2-(N-benzoyl)diaminomethylene-4-dimethylaminomethylenecyclohexane-1,3-dione and the structure of the difluoroboron complex of diacetylketeneN-benzoylaminal were established. It was found that the aminovinylcarbonyl fragment of the ligand is involved in the formation of a boron-containing ring. A delocalized -electron system over the NCCCO fragment of the chelate ring is characteristic of the molecules studied both in crystals and solutions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2541–2546, October, 1996.     

Structure–retardation factor relationship of natural amino acids in two different mobile phases of RP-TLC

Abstract

Separation of amino acids (AAs) and their simple and inexpensive determination/identification is an interesting topic in biological and protein science, different food industries, and drug factories. Also, the presentation of the chromatographic behavior of compounds in a predictive model can be effective to estimate the structural/chemical properties of analyte and mobile phases. In this work for the first time, retardation factor (R_F) of 42 AAs in reversed-phase thin layer chromatography (RP-TLC) was modeled. Acetonitrile-sodium azide solution and 1,2 dioxane-sodium azide solution were two mobile phases which have been studied in this work. Results showed that the values of R_F are correlated with the structural properties of AAs and these properties had some similarities and differences in two noted mobile phases. For the TLC data in two mobile phases, five parametric linear models were suggested (R²_train = 0.93 and 0.97; R²_test = 0.93 and 0.99). The models were also evaluated with different statistical approaches. It was shown that increasing the sum of geometrical distances between N and O in AAs causes decreasing their R_F in RP-TLC using both mobile phases. Other structural effects of AAs on their separation in the desired RP-TLC system were also discussed.     

Conductance of potassium halides near the temperature of maximum density of water

The conductances of dilute aqueous solutions of KCl, KBr, and KI have been measured over the temperature range 2 to 8°C and have been analyzed by the Fuoss-Hsia equation. The ionic Walden products at infinite dilution have been discussed in terms of local viscosity. The temperature dependence of these products suggest that near the temperature of maximum density of water, the structure-breaking ability of these ions changes in a regular way.     

4-Hydroxy-2-quinolones 113. Synthesis and antitubercular activity of N-R-amides of 4-hydroxy-6-methyl-2-oxo-1-propyl-1,2,5,6,7,8-hexahydroquinoline-3-carboxylic acid

A preparative method has been developed and the synthesis has been effected of anilides and heterylamides of 4-hydroxy-6-methyl-2-oxo-1-propyl-1,2,5,6,7,8-hexahydroquinoline-3-carboxylic acid. A comparative analysis has been carried out of the structure and antitubercular properties of the synthesized compounds and their analogs unsubstituted in the quinoline nucleus. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 405–414, March, 2007.