1,5-Diazabicyclo[3.1.0]hexanes and 1,6-diazabicyclo[4.1.0]heptanes: a new method for the synthesis,quantum-chemical calculations,and X-ray diffraction study

A new method was developed for the synthesis of 6-substituted 1,5-diazabicyclo[3.1.0]hexanes and 7-substituted 1,6-diazabicyclo[4.1.0]heptanes by condensation of N-monohalotrimethylene- and N-monohalotetramethylenediamines with carbonyl compounds in the presence of bases. X-ray diffraction studies and quantum-chemical B3LYP/6-31G* calculations demonstrated that the conformations of the resulting bicyclic systems are stabilized by stereoelectronic interactions. As a result, a boat conformation prevails in 1,5-diazabicyclo[3.1.0]hexanes, whereas the energies of chair, half-chair, and boat conformations of 1,6-diazabicyclo[4.1.0]heptanes are equalized.     

几种改进的CoMFA方法比较研究血小板活化因子拮抗剂

由于传统的比较分子场分析(CoMFA)方法本身存在一些缺陷，使得分子的叠合 规则以及叠合分子的空间取向和空间位置等因素对q~2的影响很大，因此相继提出 了几种改进的CoMFA方法。为了优化CoMFA结果，应用传统的CoMFA方法和交叉验证 的R~2引导的区域选择法(q~2-GRS)、全取向搜索法（AOS）、全空间搜索法（APS） 以及比较分子相似性指数(CoMSIA)等四种改进的CoMFA方法，对18个pinusolide类 衍生物这类新发现的血小板活化因子（PAF）拮抗剂进行了比较研究。结果表明四 种改进的CoMFA方法得到的q~2值均比传统CoMFA的高。q~2-GRS方法得到的q~2值有 所提高，但综合结果并不理想，AOS与APS得到的q~2较为理想，而在CoMSIA中， q~2几乎不受空间取向或空间位置的影响。同时我们引人基于样本的偏最小二乘法 （SAMPLS）取代原AOS／APS程序中的传统PLS进行统计分析，明显提高了其运行速 度。最后，根据q~2最高的CoMFA模型和CoMSIA模型设计了几个预测活性更高的 pinusolide类似物。     

Synthesis of Substituted 6-Amino-4-aryl-5-cyano-2H,4H-pyrano[2,3-c]pyrazoles. Crystal and Molecular Structure of 6-Amino-5-cyano-3-methyl-4-(2',4',6'-triethylphenyl)-2H,4H-pyrano[2,3-c]pyrazole

Substituted 6-aminopyrano[2,3-c]pyrazoles were synthesized by the two-component condensation of arylidenemalononitriles and substituted 5-pyrazolones or three-component condensation of aromatic aldehydes, malononitrile, and substituted 5-pyrazolones. It was established by X-ray crystallographic analysis that pyranopyrazoles exist in the 2H and not the 1H tautomeric form.     

Thermoanalytical investigation of layered titanium salts

The investigated materials have similar routes of thermal decomposition; i.e. they lose their crystal water first, then at a higher temperature their structural one. At least the result TiP₂O₇ goes through a phase change at about 1000 K. The amorphous titanium phosphate lost its crystal and structural water at higher temperature than those of crystalline forms. Both α- and γ-titanium phosphates and also their transition metal containing forms have layered structure. In case of α- and γ-forms after the loss of crystal water a phase change occurs which is followed by the decomposition of the molecule. Various transition metals containing γ-titanium phosphates lose their crystal water at the same temperature, with the exception of Ni containing ones. The process is finished in this case at temperature 90 K higher than that of the others. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparison of procedures for correction of matrix interferences in the multi-element analysis of soils by ICP-AES with a CCD detection system

Three procedures, matrix matching, plasma optimisation and single-point standard-addition, have been evaluated to ascertain the best procedure for simultaneous multi-element analysis of industrial soils by ICP-AES with CCD detection. A standard reference material, CRM143 from the Bureau Communautaire de Réference (BCR), has been analysed for Cd, Cr, Cu, Mn, Ni and Pb using the three different matrix interference correction procedures. All three procedures give comparable results which are in good agreement with the BCR values, except for Cr. The single-point standard addition procedure was chosen, on the basis of economy and ease of implementation, to correct for matrix interferences in the determination of Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sn and V in soil samples collected from an industrial site in England. Concentrations of some of the elements were found to vary greatly with sampling depth. For example, the concentration of Mn, determined using the atomic line at 279.920 nm, increased from 426 ± 3 g/g at a depth of 18–28 cm to 5996 ± 144 g/g at 60–85 cm.     

Vibrational assignment, <Emphasis Type="Italic">ab initio</Emphasis> calculation and normal coordinate analysis of 2,2′-biquinoline

The vibrational wavenumbers and the fundamental modes of 2,2′-biquinoline were obtained by density functional theory (DFT) with the B3LYP functional using the 6-31G(d,p) basis set. The calculated wavenumbers were scaled by a single factor of 0.965 to correct them for vibrational anharmonicity, but the force constants were overestimated. Normal coordinate analysis of the molecule was also carried out by using the force field of the quinoline molecule and the force field parameters of quinoline are shown to be transferable to 2,2′-biquinoline. The potential energy distribution associated with the normal modes is also given. The theoretical wavenumbers are found to be in good agreement with the experimental data.     

As(Ⅲ)-Cu(Ⅱ)协同抑制鲁米诺-MnO_4~-化学发光反应的研究及其应用

本文报道了As(Ⅲ)-Cu(Ⅲ)两种离子对鲁米诺-MnO_4~-化学发光反应的协同抑制作用,据此拟定了测定微量As(Ⅲ)的化学发光新方法。该法灵敏度较高,检测限为6.8×10~(-9)g/ml As(Ⅲ),选择性也较好,同时线性范围宽(7.0×10~(-9)～3.0×10~(-6)g/ml),测定手续简便。应用本法测定工业废水中的As(Ⅲ),结果满意。     

Solid-state interactions and drug release of teicoplanin in binary combinations with peracetylated α-, β-, and γ-cyclodextrins

Triacetyl α-cyclodextrin, triacetyl β-cyclodextrin and triacetyl γ-cyclodextrin were tested as possible hydrophobic carriers to prolong the release of hydrophilic teicoplanin (TCP). Physical–chemical characterization of individual components, drug-carrier physical mixtures at 0.5, 0.67 and 0.75 mass fraction of carrier, and the respective interaction products by kneading or evaporative crystallization under microwave irradiation was carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In vitro drug release in pH 7.4 phosphate buffer at 37 °C was determined by intrinsic dissolution rate (IDR) measurements on non disintegrating compressed discs. Solid-state interactions of TCP with triacetyl α-cyclodextrin by evaporative crystallization and kneading and with triacetyl β-cyclodextrin by evaporative crystallization (probably resulting in carrier amorphization) were demonstrated. The role of carrier hydrophobicity, carrier mass fraction and preparation method of solid drug-carrier combinations on solid-state drug-carrier interactions and slowing down of TCP release was assessed. Modulation of drug release can be achieved using TCP-triacetyl γ-cyclodextrin combinations at 0.5 mass fraction of carrier.     

1-烃基-1-硅杂环丁烷的合成及其Si—H键伸缩振动频率与结构关系的研究

硅杂环丁烷在有机硅化学中是一类非常重要的小分子环系化合物。由于硅杂环丁烷和环丁烷的环张力相似,因而显示出较高的反应活性。例如能与某些试剂作用,生成开环产物;在光解或热解条件下,产生具有Si=C结构的高活性中间体,可用以合成多种有机硅化合物。     

四川省德阳地区泥炭资源的表征及质量评估

本文报导了对四川省德阳地区八种不同来源的泥炭进行全面分析的结果,并与黑龙江省腐值土及山西褐煤进行比较。结果表明,四川省德阳地区泥炭的腐植酸含量大都在20—30%之间,属于中腐酸泥炭,有机质含量在40—50%之间,属于中有机质炭。对从上述八种泥炭中提取的腐植酸进行表征,平均分子量为327.78,其结构是由C、N、H、O、S等元素组成,含有-COOH、-NH、-OH基的结构比较复杂的芳香有机化合物。