Synthesis and Crystal Structure of Ethyl 2-Methylthio-7-phenylpyrazolo[1,5-a]pyrimidine-3-carboxylate

The crystal structure of ethyl 2-methylthio-7-phenylpyrazolo[l,5-a]pyrimidine-3- carboxylate (C16H15N3O2S, Mr = 313.37) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/n with a = 19.361(7), b = 7.595(3), c = 20.910(8) (A), β = 94.925(6)°, V= 3064(2) (A)3, Z = 8, Dc= 1.359 g/cm3,μ = 0.222 mm-1, F(000) = 1312, R = 0.0546 and wR = 0.1082 for 5374 unique reflections with 3419 observed ones (I ＞ 2σ(I)). The results show that all ring atoms in the pyrazolopyrimidine moiety are coplanar with strong tensile force. The structure analysis indicates that the single crystal contains strong nonclassical hydrogen bonds.     

Isolation and Structure of 1-Deoxybaccatin VI from the Root of Taxus chinensis, Rehd. var. mairei

Deoxybaccatin Ⅵ (4α,7β,9α,10β,13α-penta-acetoxy-2α-benzoyloxy-5β,20-epoxytax-11-ene) was isolated from the roots of Taxus chinensis, Rehd. var. mairei. The structural assignments of the compound were based on their spectral data, including 2D NMR experiments and chemical correlation. The X-ray crystallographic analysis of 1-deoxybaccatin Ⅵ provided unambiguous characterization for the structures. In the structure, the six-membered A ring exhibits boat conformation, the eight-membered B ring adopts boat-chair conformation, and the six-membered C ring exhibits a sofa conformation.     

离子缔合物二级散射光谱的分析应用 Ⅲ.汞(Ⅱ)-硫氰酸盐-罗丹明染料体系

本文研究[Hg（SCN）4]2-络阴离子与罗丹明B和罗丹明6G离子缔合络合物的二级散射（DS）和“反二级散射”（ADS）光谱，考察了光谱特征、影响因素及适宜的反应条件；确定了DS和ADS强度与溶液中汞（Ⅱ）浓度的关系；提出了用ADS法测定痕量汞的新的高灵敏度分析方法，并对有关机理作了初步的探讨。     

泼尼松的示波极谱测定及其电化学行为

基于泼尼松产生的极谱还原波 ,提出了测定泼尼松的单扫描示波极谱法。在0 .1 2 mol/ L HAc-0 .0 8mol/ L Na Ac ( p H 4.6)的缓冲溶液中 ,泼尼松于 -1 .1 3 V处产生一极谱还原波。二阶导数峰电流与其浓度在 2 .4× 1 0 - 6～ 1 .6× 1 0 - 5mol/ L范围内有良好的线性关系 ( r=0 .9991 ,n=8) ,检出限为 8.0× 1 0 - 7mol/ L。测定了片剂中泼尼松的含量。讨论了泼尼松的电化学行为     

铝酸钠熔体Monte Carlo法计算机模拟研究

用计算机Monte Carlo 法研究铝酸钠熔体结构.计算了径向分布函数和局部结构.表明NaAlO_2熔体是由畸变的共隅AlO_4四面体离子集团、Na~+离子和xNa~+·yO~(2-)离子集团所组成.     

Quantum Chemical Study on Reaction of Acetaldehyde with Hydroxyl Radical

The reaction of acetaldehyde with hydroxyl radical was studied by means of quantum chemical methods. The geometries for all the stationary points on the potential energy surfaces were optimized fully, respectively, at the G3MP2, G3, and MP2/6-311 G(d,p) levels. Single-point energies of all the species were calculated at the QCISD/6-311 G(d,p) level. The mechanism of the reaction studied was confirmed. The predicted product is acetyl radical that is in agreement with the experiment.     

电位控制ZnO/表面活性剂复合多层膜在固/液界面上的自组装

通过控制固/液界面电极电位的方式, 控制表面活性剂和金属离子在电极表面的自组装, 制备出了高度取向的ZnO/表面活性剂复合多层膜. 对无机层形态和结构进行了分析, 并采用X射线反射率和X射线漫散射研究了电极电位控制下ZnO/表面活性剂复合多层膜在固/液界面的自组装生长. 结果表明, 在一定电位下, 只有当表面活性剂浓度低于其饱和吸附浓度时, 采用阶跃电位沉积方式才能明显改变复合薄膜的周期厚度; 恒电位沉积方式控制电极电位时, 随着沉积电位的提高, 多层膜层状结构由一组层状相变为多组层状相, 同时层状结构的取向变差. 实验研究结果验证了电化学自组装过程是由金属离子的还原速度和表面活性剂的吸附速度二者共同控制完成的.     

格隆溴铵脱氢杂质的合成

以扁桃酸为起始原料，经环化、缩合、脱水、开环、酯化和甲基化反应合成了格隆溴铵的脱氢杂质--3-[2-(环戊-1-烯-1-基)-2-羟基-2-苯基乙酰氧基]-1,1-二甲基吡咯烷-1-溴化物，总收率50.8%，纯度97.5%，其结构经¹H NMR， ¹³C NMR， IR和元素分析确证。     

2-氨基-5-取代-1,3,4-噻二唑与2-氯代-1-(2,4-二氯苯基)乙酮的反应研究

2-氨基-5-烷基/芳基1,3,4-噻二唑与2-氯代-1-(2′,4′-二氯苯基)乙酮在热乙醇中反应生成一系列2-烷基/芳基-6-(4,4-二氯)苯基咪唑并[2-1-b]-1,3,4-噻二唑.产物通过元素分析, IR, 1H NMR, 13C NMR及MS分析,化合物5g的X衍射晶体结构分析表明,产物的芳基是在咪唑并[2-2-b]-1,3,4-噻二唑的6-位而不在5-位.     

2-甲硫基-7(5)-取代-3-吡唑并[1,5-a]嘧啶甲酸乙酯的区域选择性合成与2D NMR 研究

利用3-甲硫基-4-乙氧羰基-5-氨基-1H-吡唑分别与甲基/芳基烯胺酮反应, 合成了8种新的化合物2-甲硫基-7-取代-3-吡唑并[1,5-a]嘧啶甲酸乙酯(3a～3g)和2-甲硫基-5-甲基-3-吡唑并[1,5-a]嘧啶甲酸乙酯(4a). 化合物的结构均经元素分析, IR, ¹H NMR, MS所证实, 异构体3a和4a的结构进一步由¹³C NMR, HMQC和HMBC确认. 同时, 探讨了区域选择性合成吡唑并[1,5-a]嘧啶类化合物可能的反应机理, 并对部分化合物杀菌活性进行了测试.