Effects of stereoisomerism in the mass spectra of 2,4-disubstituted thiacyclohexanes

The mass spectra of cis- (Ia-c) and trans-2-methyl-4-R-thiacyclohexanes (IIa-c; a R = n-C₄H₉, b R = n-C₅H₁₁, c R = Ph) were studied. It was established that [M-CH₃]⁺ ions, which correspond to the loss of a methyl group from the 2 position, are formed more readily in the case of the less stable trans isomers IIa-c than in the case of cis isomers Ia-c. The three-dimensional structures of the substances have no effect on the degree of elimination of the R substituent. The relative ionization energies (RIE) for Ia,b and IIa,b and the relative appearance energies (RAE) of the [M-CH₃]⁺ ions were measured by the electron impact method. It was found that the RIE are almost 0.05 eV lower and that the RAE of the [M-CH₃]⁺ ions are 0.1 eV lower for trans isomers IIa,b than for cis isomers Ia,b.Communication 4 from the series Ionization and appearance energies in organic chemistry, See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 333–338, March, 1981.     

过碳酸钠-醋酸酐作用下的Baeyer-Villiger反应

在醋酸酐介质中, 过碳酸钠可以与酮进行Baeyer-Villiger反应, 将它们氧化成相应的酯。其中脂环酮的反应结果较好, 环内酯的产率约为80%。芳香酮除芳环被活化的以外, 效果欠佳。当反应施加超声辐射后可显著加快反应速度, 并对过碳酸钠的作用机理进行了讨论。     

A new anode material LiMoS2 for use in rechargeable Lithium Ion Batteries

The novel applications of molybdenum disulfide in recent research were reviewed, such as in lubricant, catalyst and photoelectrochemical solar cells. Recently, we found that LiMoS2 is a good candidate for new anode materials for lithium ion batteries with high lithium storage capacity.Here, the anode material LiMoS2 was synthesized by a hydrothermal method at 150℃ and the electrochemical characterization as an anode material for lithium ion batteries was examined.put in Teflon-lined stainless steel autoclaves of capacity 40 mL. Distilled water was used to fill the autoclaves to 70 % of the total volume. The autoclaves were maintained at 150℃ for 24 h and then cooled naturally. The resulting dark-gray powders were filled and washed with distilled water,diluted hydrochloric acid and ethanol, successively. The final products were dried at 80℃ for 24 h.The powder X-ray diffraction pattern showed the prepared LiMoS2 was amorphous structure. A test cell using LiMoS2 as the active material was discharged and charged between 3 and 0.01 V with respect to Li metal at a constant current density of C/5 (that is, one lithium per formula unit in 5 hours). During the first discharge, the potential rapidly drops to reach a large plateau at 2.2 V, then slowly drops to the other plateau at 0.8 V, and then continuously decreases down to 0.01V. There is only a plateau at 1.35 V in the subsequent discharge curves. The plateaus of charge potential appear at about 1.9 V.The irreversible loss was 41% in the first cycle. The ratio of discharge and charge is more than 99%in the subsequent cycles. Moreover, the ratio of discharge and charge almost reaches 100% after thedemonstrated that LiMoS2 has a very high capacity and a good cycle-ability as an anode material forlithium ion batteries.     

A thermochemical study of dissociative ionization of 4,4-dimethyl-1-thia-4-silacyclohexane and 2,3,3-trimethyl-1-thia-3-silacyclopentane. Decomposition pathways to produce a dimethylsilanethione ion-radical [Me2SiS]+•

The dissociative ionization of 4,4-dimethyl-1-thia-4-silacyclohexane (I) and 2,3,3-trimethyl-1-thia-3-silacyclopentane(II) has been studied by electron photoionization (PI) mass spectrometric methods. The molecular ion fragmentation is mainly related to the loss of ethylene and results in a [Me₂SiSC₂H₄]^+? (m/z 118) ion-radical (A). Further loss of ethylene from A produces a dimethylsilanethione [Me₂SiS]^+? (m/z 90) ion-radical (B). The latter is the most abundant ion in the mass spectra of I and II at 70 eV.The ionization energies (IE) of I (8.22 ± 0.07 eV) and II (8.06 ± 0.03 eV) and the appearance energies (AE) of ion-radicals A and B have been determined. Also, the following heats of formation were calculated (kJ/mol): ΔH_f⁰(I) = ?31.1; ΔH_f⁰(II) = ?65.8; ΔH_f⁰(M_I^+?) = 762.0; ΔH_f⁰(M_II^+?)= 712.1; ΔH_f⁰(A)_aver = 780.2; ΔH_f⁰(B)_aver = 847.7.     

环戊二烯基氟尿嘧啶基钛（Ⅳ）、锆（Ⅳ）配合物的合成及其抗肿瘤活性的研究

用（ＲＣｐ）２ＭＣｌ２和（ＲＣｐ）ＴｉＣｌ３（Ｒ＝Ｈ，Ｍｅ；Ｍ＝Ｔｉ，Ｚｒ）分别与具有生物活性的２－甲氧基－５－氟尿嘧啶、２－甲硫基－５－氟尿嘧啶在甲苯溶剂中１１０℃下反应，合成了２０个未见报道的（ＲＣｐ）·Ｍ（Ｏｐｍ）２Ｃｌ、（ＲＣｐ）２Ｍ（ＯＰｍ）Ｃｌ和（ＲＣｐ）Ｍ（ＯＰｍ）Ｃｌ２（ＯＰｍ＝２－甲氧基－５－氟尿嘧啶基，２－甲硫基－５－氟尿嘧啶基）型钛锆配合物，这些配合物均经元素分析、１ＨＮＭＲ、ＩＲ光谱鉴定．初步动物试验表明，配合物１、４、１１、１４对小白鼠移植性艾氏腹水场的抑制作用居首，而配合物２、３、５、６、１２、１３、１５、１６次之，其它锆配合物几乎没有抑制作用。     

Preparation of α- and γ-(α-furyl)pyridines

Mixtures of isomeric alkyl-substituted (in the pyridine ring) - and -(-furyl)-pyridines were obtained in up to 40% yields by condensation of furfural and ammonia with several aliphatic ketones and aldehydes (at 370–380 °C with a cadmium calcium phosphate catalyst). The dependence of the yields and structures of the corresponding isomers on the structure of the starting carbonyl compound was examined. Data from the PMR and mass spectra were used to prove the structures of the pyridine bases obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 383–387, March, 1981.     

微波辅助-光催化降解氯酚的QSPR研究

本文运用PM3算法计算得到氯酚(CPs)的分子结构参数,并结合光解速率进行PLS分析,建立了速率与量子化参数之间的关系模型,模型的Q2cum分别为0.8776和0.9545(>0.5),具有良好的预测能力。研究结果表明,参数Ehomo、Elumo Ehomo、Elumo、N、Mw、Elumo-Ehomo、(Elumo-Ehomo)2是决定CPs光解速率的主要因素;CPs的光解速率随Ehomo、Elumo Ehomo、Elumo、Elumo-Ehomo、(Elumo-Ehomo)2的增大而增大,随N、Mw的增大而减小。     

利用“网包法”制备高效液相色谱大环抗生素类手性固定相

万古霉素和替考拉宁都属于糖肽类的大环抗生素，具有立体的环状结构和多个手性中心，是两种常见的手性识别材料，广泛应用于对映体的色谱手性分离分析。该文以万古霉素和替考拉宁为手性选择剂，哌嗪为单体，4，4'-二苯基甲烷二异氰酸酯（MDI）、1，6-己二异氰酸酯（HDI）和2，4-甲苯二异氰酸酯（TDI）为交联剂，通过界面聚合反应形成网状层包裹硅胶载体的方法制得6种高效液相色谱手性固定相，用于分离外消旋化合物，并与MDI直接交联万古霉素和替考拉宁在硅胶表面所得固定相进行了比较。结果表明，利用"网包法"和直接交联法制备的手性柱与商品万古霉素和替考拉宁柱之间具有互补性，均对不同的外消旋体有不同程度的拆分。     

Synthesis and properties of sym-triazine derivatives. 7. Synthesis of pyridyl-substituted 2-amino- and 2,4-diamino-sym-triazines

N-Substituted 2,4-diamino-6-pyridyl-sym-triazines were synthesized by cyclocondensation of pyridinecarboxylic acid esters with biguanides. 4,6-Disubstituted 2-amino-sym-triazines containing pyridyl residues were obtained by the reaction of pyridinecarboxylic acid nitriles with guanidine or of pyridinecarboxylic acid esters with N-imidoylguanidines. Aminotriazines of this type are also formed in the condensation of N-acylguanidines with nitriles or imino esters. The general principles of the fragmentation of 2-amino-4-dialkylamino-6-pyridyl-sym-triazines under the influence of electron impact were established.See [1] for Communication 6.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 674–680, May, 1988.     

酵母核糖核酸在碳纳米管修饰电极上的电化学行为及其分析测定

研究了酵母核糖核酸（yRNA）在碳纳米管（MWNT）修饰电极上的电化学行为，优化了测定参数，在此基础上建立了一种直接测定yRNA的电分析测试方法。yRNA在碳纳米管修饰电极上于磷酸盐缓冲溶液中在0．758V处产生不可逆的氧化电流峰，峰电流与yRNA的质量浓度在1～10mg／mL之间有良好的线性关系，线性回归方程为：Iρ=0．0813ρ＋0．1807，相关系数r为0．9980，检出限为0．6mg／mL。