改性环糊精气相色谱手性固定相拆分对映体的选择性及拆分机理的讨论

改性环糊精气相色谱手性固定相拆分对映体的选择性及拆分机理的讨论周昕，万宏，欧庆瑜（中国科学院兰州化学物理研究所兰州７３００００）１前言自１９８８年Ｋｏｎｉｇ￣［１］等人成功地将改性环糊精用于毛细管气相色谱固定相拆分对映体以来，环糊精衍生物以其高选择性...     

(1R,2S)或(1S,2R)-1,2-二苯基-2-氨基乙醇衍生物手性配体的合成及其用于不对称催化反应

重点报道了以（１Ｒ，２Ｓ）或（１Ｓ，２Ｒ）－１，２－二苯基－２－氨基乙醇衍生物手性配体的合成及其用于不对称催化反应的研究，如去氢氨基酸的氢化、醛的乙基锌加成、酮的还原、活泼亚甲基化合物的烷基化、醛的硅腈化和瑞福马斯基反应等．研究了手性配体的结构、底物和反应条件等对上述反应的对映选择性和催化活性的影响．     

Inhibitory effects of 1,3-selenazol-4-one derivatives on mushroom tyrosinase

This study reports depigmenting potency of 1,3-selenazol-4-one derivatives, which would be based upon the finding of direct inhibition to mushroom tyrosinase. 1,3-Selenazol-4-one derivatives exhibited inhibitory effect on dopa oxidase activity of mushroom tyrosinase. In this study, inhibitory effects of six kinds of 1,3-selenazol-4-one derivatives (A, B, C, D, E and F) on mushroom tyrosinase were investigated. Compounds at a concentration of 500 microM exhibited 33.4-62.1% of inhibition on dopa oxidase activity of mushroom tyrosinase. Their inhibitory effects were higher than that of kojic acid (31.7%), a well known tyrosinase inhibitor. 2-(4-Methylphenyl)-1,3-selenazol-4-one (A) exhibited the strongest inhibitory effect among them dose-dependently and in competitive inhibition manner.     

Alkyl and aryl substituted corroles. 1. Synthesis and characterization of free base and cobalt containing derivatives. x-ray structure of (Me(4)Ph(5)Cor)Co(py)(2)

The synthesis, spectroscopic properties, and electrochemistry of six different alkyl- and aryl-substituted Co(III) corroles are presented. The investigated compounds contain methyl, ethyl, phenyl, or substituted phenyl groups at the eight beta-positions of the corrole macrocycle and four derivatives also contain a phenyl group at the 10-meso position of the macrocycle. Each cobalt corrole undergoes four reversible oxidations in CH(2)Cl(2) containing 0.1 M tetra-n-butylammonium perchlorate and exists as a dimer in its singly and doubly oxidized forms. The difference in potential between the first two oxidations is associated with the degree of interaction between the two corrole units of the dimer and ranges from an upper value of 0.62 V, in the case of (Me(6)Et(2)Cor)Co, to a lower value of about 0.17 V, in the case of four compounds which have a phenyl group located at the 10-meso position of the macrocycle. These Co(III) corroles strongly coordinate two pyridine molecules or one carbon monoxide molecule in CH(2)Cl(2) media, and ligand binding constants were evaluated using spectroscopic and electrochemical methods. The structure of (Me(4)Ph(5)Cor)Co(py)(2) was also determined by X-ray diffraction. Crystal data: (Me(4)Ph(5)Cor)Co(py)(2).3CH(2)Cl(2).H(2)O, orthorhombic, a = 19.5690(4) A, b = 17.1070(6) A, c = 15.9160(6) A, V = 5328.2(5) A(3), space group Pna2(1), Z = 2, 35 460 observations, R(F) = 0.069.     

氨基酸柱前衍生化的3种新荧光试剂的光谱特性及高效液相色谱研究

合成了３种新的荧光标记试剂：吖啶－Ｎ－乙酰氯，咔唑－９－乙酰氯和咔唑－９－丙酰氯。它们的最大发射降激发波长分别为４３０ｎｍ，３６８ｎｍ，和３６５ｎｍ。３种衍生化试剂与氨基酸形成的衍生物在ｐＨ６．５的条件下结合梯度洗脱程序在Ｃ１８反相柱上对色谱条件进行了优化。     

Highly Regioselective Sequential 1,1‐Dihydrosilylation of Terminal Aliphatic Alkynes with Primary Silanes

A regioselective double 1,1‐hydrosilylation of terminal aliphatic alkynes with primary silanes catalyzed by one cobalt catalyst has been developed. gem‐Bis(dihydrosilyl)alkanes containing four silicon‐hydrogen bonds are efficiently constructed in an atom‐economical manner. Tolerated substrates include simplest alkyne‐ethyne, a complicated drug derivative and various functionalized terminal aliphatic alkynes. Asymmetric approach using two catalysts is achieved with excellent enantioselectivities to access corresponding chiral products. The transformations of Si—H bonds into Si—C, Si—O, and Si—F bonds and the synthesis of enantioriched α‐hydroxysilane show synthetic utility.     

连接基团链长度对季铵盐二聚表面活性剂C12-s-C12·2Br在水溶液中胶团化行为的影响

用电导法、稳态荧光法和粘度法研究了二聚表面活性剂C12-s-C12*2Br分子中的连接基团链长度(s=2, 3, 4, 6)对其在水溶液中聚集行为的影响. 实验发现, C12-s-C12*2Br的胶团生成能力远比其单体C12TABr强得多, 前者cmc值较后者降低一个数量级. 胶团聚集数N随表面活性剂浓度c的增大而增大, 其中当s=2时的N值在c=7.7 mmol/L后开始急剧增大. 计算结果表明, 此时胶团形状发生了明显变化, 形成了椭球形的胶团. 粘度测定结果也证实了这一点.     

Two-photon Dissociation Study of Carbon Disulfide in Acetonitrile at 266 nm

Using laser flash photolysis/transient absorption technique for the study of two photon photodissociation of carbon disulfide in acetonitrile solution at 266 nm, the transient UV-Vis absorption spectrum of Rydberg state CS2 （6sσg） within 240-370 nm and subsequent dissociation product CS （α^3П） with the maximum absorption at 260 nm were directly observed. The lifetime of CS （α^3П） in the nitrogen and oxygen saturated solution is also studied in our experiment.     

C12-s-C12•2Br和C12En混合水溶液的胶团化行为

季铵盐二聚表面活性剂C12 s C12•2Br（s=2、3、4、6）和非离子表面活性剂C12E10或C12E23在水溶液中生成混合胶团.其临界胶团总浓度cmcT值介于二元复配体系中各组分的临界胶团浓度和之间.当添加少量非离子型表面活性剂（在水溶液中的摩尔分数α2=0.1）时,混合胶团中C12E10或C12E23的摩尔分数均已超过0.35;随着溶液中非离子型表面活性剂含量的增大,混合胶团中逐渐以C12E10或C12E23成分为主.     

含IIIA或VA族杂原子的碳原子簇负离子的研究

在自制的仪器上，以脉冲激光束在高真空中溅射适当的样品，产生了一系列合有1个VA族原子（N、P、As）或ⅢA族原子（B、Al）及13个以下碳原子的原子簇负离子。在实验记录的飞行时间质谱中，这些簇离子的信号强度均因其碳原子数的奇偶而发生交替变化．对实验结果的分析研究显示：这些簇离子均为直链构型．VA或ⅢA族原子位于链的一端，所有成簇原子的价键均得到满足．