Separation and determination of some stereoisomers by capillary gel electrophoresis with cyclodextrin incorporated in polyacrylamide gel

Capillary gel electrophoresis (CGE) was successfully applied to the separation of optically active isomers and position isomers by incorporating a suitable cyclodextrin chiral selector in polyacrylamide gel. A commercially available ß-cyclodextrin (ß-CD) was used for enantioselectivity towards o-, m- and p-nitrobenzoic acid, o-, m- and p-hydroxybenzoic acid, o-, m- and p-toluic acid and the optical isomers of dansyl-D,L-leucine and R,S-1,1-binaphthyl-2,2-dihydrogenphosphate. Especially the effect of organic solvents, such as acetonitrile, methanol, dimethylsulphoxide and others were examined in detail. The resolution varied to some extent with the addition of the organic solvent to the polyacrylamide gel and the running buffer solution. The possible mechanism has also been discussed. In addition, quantitative aspects of the separation of stereoisomers using CGE have been studied, showing that both the resolution and accuracy of the determinations were affected by the ratio of the enantiomers.     

氟化镁锶中铕和铽的电荷迁移及其平衡解析

在氩气氛中，合成子ＳｒＭｇＦ４：ｘＥｕ，ｙＴｂ复合氟化物磷光体，该体系中Ｅｕ＾３＋和Ｅｕ＾２＋共存，随共掺入Ｔｂ浓度的增加，Ｅｕ＾３＋的荧光发射强度降低，Ｅｕ＾３＋的发光增强，并且Ｅｕ＾２＋的ＥＳＲ信号增强，认为Ｅｕ＾３＋和Ｔｂ３＋之间存在的电荷迁移，即Ｅｕ＾３＋Ｔｂ＾３＋→Ｅｕ＾２＋＋Ｔｂ＾４＋，通过半量手段研究了这一电荷迁移反应的平衡常数。     

激光拉曼光谱在高分子中的应用

论述了激光拉曼光谱对高分子结构、结晶形态和表征,反应动力学过程和取向的研究,还介绍了纵向声学模、共振、高温高压、光波导和付里叶拉曼光谱在高分子研究中的最新进展。     

痕量Au Bi和Cd的萃取浮选及原子吸收光谱法测定

浮选法分离痕量金属离子,由于灵敏度高、选择性强已得到广泛应用。本文利用浮选法使Au~(3 )、Bi~(3 )和Cd~(2 )同KBr反应生成的络合阴离子与碱性染料罗丹明B(RB)生成既疏水又疏有机溶剂的三元离子缔合物,后者经甲苯浮选分出,用二甲基甲酰胺(DMF)溶解后,可用原子吸收法测定Au、Bi和Cd的含量。本方法用于海水,锌片和矿样中上述三种元素的微量测定,可提高检测灵敏度,而且K、Na、Ca、Mg等共存离子不生干扰。具体实验方法如下:     

π-二苯铬(O)催化聚合全氟丁炔-2

本文报道π-二苯铬(O)催化聚合全氟丁炔-2,得到白色粉末状的聚全氟丁炔-2。它不溶于任何溶剂,对浓硝酸、浓硫酸和浓碱十分稳定。热重分析、差热分析和差动扫描量热法分析的结果表明它在空气中非常稳定,470℃时尚不发生氧化分解。在空气中聚全氟丁炔-2的热裂解活化能为56.5千卡/克分子。当聚合反应在甲苯溶液中进行时,用气液色谱检测到从π-二苯铬(O)分子失掉的苯分子。我们初步推测了聚合反应的机理。     

Theoretical study on intermolecular interactions in BrF/HnX adducts

Equilibrium geometries, interaction energies, and charge transfer for the intermolecular interactions between BrF and H_nX (HF, H₂O, and NH₃) were studied at the MP2/6-311++G(3d,3p) level. The halogen-bonded geometry and hydrogen-bonded geometry are observed in these interactions. The calculated interaction energies show that the halogen-bonded structures are more stable than the corresponding hydrogen-bonded structures. To study the nature of the intermolecular interactions, symmetry-adapted perturbation theory (SAPT) calculations were carried out and the results indicate that the halogen bonding interactions are dominantly inductive energy in nature, while electrostatic energy governs the hydrogen bonding interactions.     

Volumetric Properties of Ternary-Pseudobinary Mixtures Containing Benzene and Cyclohexane

Densities have been measured as a function of composition for ternary-pseudobinary mixtures of [(benzene + toluene or methylcyclohexane) + (cyclohexane + toluene or methylcyclohexane)] by means of a vibrating-tube densimeter at atmospheric pressure and the temperature 298.15 K. The excess molar volumes, V_m^E, were calculated from the densities and correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show the third component, toluene and methylcyclohexane, influences the interaction between benzene and cyclohexane.     

咪喹莫特的波谱学数据与结构表征

对咪喹莫特的红外(IR)、紫外(UV)、质谱(MS)、氢-氢相关谱(^1H--^1H COSY)、碳氢相关谱(HMQC)、碳氢远程相关谱(HMBC)予以解析并进行了报道。对所有的^1H NMR、^13C NMR谱的信号进行了归属；讨论了质谱的主要碎片离子的可能的裂解方式和红外特征吸收峰所对应的官能团的振动形式。     

Studies on fluorescent species of spiro-indolinonaphthooxazines and their fluorescence spectra

Photophysical behavior of spiro[1,3,3-trimethylindolino-2,3′-naphtho[2,1-b]-1,4-oxazine] (SP1) and spiro[1,3,3,2′-tetramethylindolino-2,3′-naphtho[2,1-b]-1,4-oxazine] (SP2) were studied. The fluorescent species and their spectra of SP1 and SP2 in polar solvents (acetonitrile and methanol) and non-polar solvent (cyclohexane) were investigated. The fluorescence decay in polar solvents was studied by picosecond time-correlated single photon counting. In most cases, fluorescence decay obeyed triexponential decay kinetics. The major fluorescent species is an excited intermediate which has similar conformation as its precursor (¹ SP ^*) formed after the bond cleavage between spirocarbon and oxygen in oxazine ring. The effects of molecular structure and solvent polarity on fluorescence spectra and fluorescence decay lifetime were studied.     

四核钴羰基簇合物Co4(CO)8(μ-CO)2(μ4-PSR)2的合成和晶体结构

The title compounds Co4(CO)8(μ-CO)2 (μ4-PSR) [R=-CH3, -C2H5, -C(CH3)3,-(CHa)4CH3] were synthesized by the reaction of Co2(CO)8 with RSPCl2. They were characterized by IR, 1HNMR, elemental analysis. The crystal and molecular structure of Co4(Co)8(μ-CO)2 (μ4-PSC2H5) has been determined by single crystal diffraction method. Crystal data: monoclinic, space group P21 /c, with a=8-445(3), 6=8.562(3), c= 17.125(6)Å, β=104.26 (3)' 9 V=1200.1Å3, Z=2, Dc=1.937gcm-3. Its molecular structure contains an octahedral Co4P2 skeleton which consists of a rectangular four cobalt atoms core and the Co4 core is capped above and below by two quadruply bridging PSR ligands.