四环素类抗生素-钨酸钠-乙基紫体系的共振瑞利散射光谱及其分析应用

在pH为9.0的Clark-Lubs缓冲溶液中, 强力霉素、土霉素、四环素和金霉素等四环素类抗生素与钨酸钠反应形成1∶1的阴离子螯合物, 它仅能引起吸收光谱的变化, 不能引起共振瑞利散射(RRS)的增强, 但是当该螯合物进一步与乙基紫反应形成三元离子缔合物时, RRS显著增强并产生新的RRS光谱, 它们具有相似的光谱特征, 最大RRS波长均位于328 nm处. 4种抗生素的线性范围和检出限分别为0.047～4.8 μg•mL^－1和14.1 ng•mL^－1(强力霉素); 0.078～5.0 μg•mL^－1和23.5 ng•mL^－1(土霉素); 0.081～5.7 μg•mL^－1和24.4 ng•mL^－1(四环素); 0.122～7.7 μg•mL^－1和36.6 ng•mL^－1(金霉素). 考察了三元离子缔合配合物的组成, 讨论了配合物的结构和反应机理, 并发展了一种高灵敏、简便快速测定四环素类抗生素的新方法.     

血清白蛋白与巴比妥钠相互作用的光谱研究

采用荧光光谱、紫外-可见光谱研究了药物巴比妥钠(BBTS)和牛血清白蛋白(BSA)的相互作用机理,运用热力学方法确定了巴比妥钠和牛血清白蛋白相互作用力的类型主要是疏水力,该过程是一个熵增加、Gibbs自由能降低的自发超分子作用过程,根据Stern-Volmer方程和Lineweaver-Burk双倒数曲线方程求出了其结合常数在高温时比在低温时小,用F ster非辐射能量转移理论计算了二者结合时给体和受体之间的距离r=2.76 nm,能量转移效率E=0.332,证实了巴比妥钠和牛血清白蛋白之间的作用是生成复合物的静态猝灭过程,说明了猝灭机制是通过能量转移产生的。     

SB粉水热分解铝酸钠溶液制取大孔容高比表面拟薄水铝石

 以德国Condea公司用有机醇铝法生产的拟薄水铝石SB粉为晶种,采用水热分解铝酸钠溶液结合乙醇分散洗涤种分产物的方法制得了大孔容高比表面拟薄水铝石. 研究了铝酸钠溶液组成(Al2O3浓度和苛化系数)以及晶种循环使用次数等条件对溶液分解率、 Na2O析出率和种分产物孔体积、孔径分布、比表面积以及钠含量等物化性质的影响. 研究表明, 在晶种比为1.0, 温度为125 ℃的条件下用SB粉分解铝酸钠溶液(Al2O3含量为100～140 g/L, 苛化系数为1.30～1.45), 3 h后溶液分解率可达30%左右,而SB粉连续循环使用3次所得产物的孔容和比表面积分别达到0.84 cm3/g和213.6 m2/g, Na2O含量在0.3%以下,部分性质甚至超过了SB粉的技术指标. 该方法为从廉价的铝酸钠溶液制备高附加值的拟薄水铝石提供了一条新的可供选择的路径.     

Synthesis and Crystal Structure of a Sodium Monosulfuron-ester (N-[2'-(4-Methyl)pyrimidinyl]-2-carbomethoxy Benzyl Sulfonylurea Sodium)

Monosulfuron-ester is a novel sulfonylurea herbicide with ultra-low dosage. Herein sodium monosulfuron-ester was synthesized and its crystal structure was determined by X-ray diffraction method. The title compound belongs to monoclinic, space group P21/c with a = 9.335(5), b = 20.632(12), c = 13.853(8) (A), β = 107.193(9)°, Mr = 487.46, Z = 4, Dc = 1.270 g/cm3, μ = 0.293 mm-1, F(000) = 1015, R = 0.0859 and wR = 0.2633. In the title compound, Na coordinates with N(1), O(1) and O(3) from one monosulfuron-ester molecule, N(4A) and O(5A) from the other monosulfuron-ester molecule and one oxygen atom from DMSO to give six coordination bonds.     

Investigation on Molecular Non-covalent Interaction in the Sodium Dodecyl Benzene Sulfonate-polychrome Blue B-protein Replacement Reaction

Introduction Supramolecular assembly is always an importantresearch direction for chemists and biochemists.1-5 It isvery helpful for us to accurately analyze the physico-chemical action and process occurring inside biologicalcell, for example, function of a drug, damage of a toxi-cant, detection of oncogene and so on. Understandingthe chemical, physical, biological and pharmacologicalactivity of a complex system requires knowledge of thestate of molecular aggregation of the system compo-ne…     

Metal-insulator transition in Ni-doped Na0.75CoO2: Insights from infrared studies

Nickel substitution at the cobalt site in Na_0.75CoO₂ induces an upturn in the resistivity on lowering the temperature, with the metal-to-insulator transition temperature (T _MIT) increasing with the Ni content. Low temperature far infrared measurements on polycrystalline samples of Na_0.75CoO₂ and Na_0.75Co_0.95Ni_0.05O₂, the latter having T _MIT ∼ 175 K, have been carried out. Dramatic changes in the Na mode frequencies, and relative intensities of the out-of-plane modes corresponding to the two Na sites are observed, coincident with the MIT in Na_0.75Co_0.95Ni_0.05O₂. It is argued that these changes are associated with a charge ordering of the CoO₂ layer, associated with the metal-insulator transition.     

KIO4-鲁米诺化学发光体系测定青霉素钠

在碱性介质中,KIO4氧化鲁米诺产生化学发光,青霉素钠对该体系有增强作用.在最佳的实验条件下,青霉素钠浓度与增强的发光强度成正比,线性范围为0.01～20μg/mL,检出限(3σ)为3.0 ng/mL,对1.0μg/nL青霉素钠进行11次平行测定,其相对标准偏差为1.2%.方法已用于粉针剂、合成样品及尿样中青霉素钠的测定.     

Synthesis,structure characterization and catalytic activity of lanthanide complexes containing an ansa carbonous‐bridged cyclopentadienyl—thienyl ligand

A kind of new lanthanocene complex with an ansa carbonous‐bridged cyclopentadienyl/aromatic heterocycle ligand was prepared and characterized. Based on the data of elemental analyses, MS and IR, they were presumed to be solvent‐free complexes (cyclo‐C₄H₃SCMe₂C₅H₄)₂LnCl [Ln = Er (1), Dd ( 2 ), Y ( 3 ), Sm ( 4 )]. These complexes were effective for the polymerization of methyl methacrylate in the presence of co‐catalyst. When AlEt₃ and NaH (nanometric) were used as different co‐catalysts, the lanthanocene complexes 1–4 showed different catalytic behavior. These differences resulted from the formation of different active species. The catalyst system (cyclo‐C₄H₃SCMe₂C₅H₄)₂LnCl/NaH (nanometric) showed high catalytic activity (yield ≥ 95% and Mη > 10⁵) in a short time at the ambient temperature. Copyright © 2008 John Wiley & Sons, Ltd.     

用正电子研究NaCl在NaY沸石上的固溶过程

用正电子湮没谱学研究NaCl与NaY沸石机械混合后, NaCl在NaY中的固溶扩散过程.分别测量不同质量比的NaCl/NaY［(1—20)%］经500℃烘烤1h，NaCl/NaY(15%)经不同温度烘烤1h,以及NaCl/NaY(15%)经500℃烘烤不同时间后的正电子寿命谱.所有寿命谱都出现了5个寿命分量, 其中第3，4，5寿命分别与β笼、超笼及沸石微粒界面空洞的大小和数量相关.实验表明正电子湮没谱学能敏感地表征NaCl在NaY中的固溶扩散过程. 关键词： 正电子湮没谱学 氯化钠 沸石