Enantioselective addition of Et_2Zn to aldehydes catalyzed by chi-ral aliphatic β-amino alcohols

This paper describes the preparation of two new optically active aliphatic β-amino alcohols (R)-5,5-dimethyl-2-(dimethy-lamino)-1,1-diphenyl-1-hexanol (1a) and (S)-8,8-dimethyl-2-(dimethylamino)-1, 1-diphenyl-1-nonanol (1b). They were synthesized by methylation of the corresponding β-amino alcohols 2a and 2b. Compounds la and 1b catalyze the addition of diethylzinc to various aldehydes enantioselectively. The catalyst structure-enantioselectivity relationships were discussed.     

Synthesis of Dispiro[indeno[1,2-b]quinoxaline-11,1′-pyrrolo-[2,1-a]isoquinoline-3′,3′′-indolin]-2′′-one Derivatives via Cycloaddition Reactions

Russian Journal of General Chemistry - The 1,3-dipolar cycloaddition reaction of (Z)-1-aryl-2-(11H-indeno[1,2-b]quinoxalin-11-ylidene)ethan-1-one with generated in situ azomethine ylide leads to...     

Highly selective ratiometric fluorescent sensing for Hg(2+) and Au(3+), respectively, in aqueous media

A nonsulfur probe based on a 1,8-naphthalimide and alkyne conjugate for the ratiometric fluorescent sensing for Hg(2+) and Au(3+) through the tuning of pH in different aqueous solutions is described. This work provides a novel reaction-based approach for selective recognition of these two ions with significant change of fluorescence color and constitutes the first ratiometric case for Au(3+).     

A simply and highly selective “turn-on” type fluorescent chemosensor for Hg based on chiral BINOL-Schiff’s base ligand

A chiral BINOL derivative bearing Schiff’s base group has been synthesized for the selective fluorescent recognition of Hg²⁺. Highly selective “turn-on” type fluorescence changes were observed upon the addition of Hg²⁺. The fluorescence intensity enhancement was ascribed to the complex formation between (R)-1 and Hg²⁺ which blocked the photo-induced electron transfer process.     

基于静态呼吸图技术的图案化方法

对呼吸图技术制备二维有序多孔结构的研究进展进行了综合评述, 并重点介绍了本课题组发展的静态呼吸图技术. 利用静态呼吸图法, 可制备高度有序的聚合物、聚合物/无机物微孔膜. 这些有序的结构可以直接应用于光掩膜. 进一步, 多孔聚合物膜可以被紫外光交联和改性. 表面改性的多孔聚合物膜可以用于细胞支架. 而交联的聚合物/无机物前驱体微孔膜可以用来制备无机纳米材料阵列. 结果表明, 静态呼吸图技术是一种简单、高效的对聚合物、聚合物/无机物薄膜进行图案化的通用方法,并展示了图案化薄膜广阔的功能化前景.     

合金化程度对炭载Pt-Ru催化剂性能的影响

在含四氢呋喃(THF)的水溶液中, 室温下用NaBH₄还原H₂PtCl₆和RuCl₃制得Pt-Ru/C催化剂. 其Pt-Ru 粒子的合金化程度较高, 平均粒径较小, 相对结晶度较低. 因此对甲醇氧化的电催化活性远高于Pt-Ru 粒子的平均粒径和相对结晶度相似的, 而且Pt-Ru合金化程度低的商业化的E-TEK的Pt-Ru/C催化剂, 表明Pt-Ru的合金化程度对Pt-Ru/C催化甲醇氧化的电催化活性有很大的影响.     

Determination of dichloroacetic acid and trichloroacetic acid by liquid-liquid extraction and ion chromatography

An extraction technique using MTBE (methyl tert. butyl ether) and reagent water in combination with ion chromatography and conductivity determination was developed to quantify dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) concentrations in raw water after chlorination. The detection limit of the method was 0.45 and 1.50 μg/L for DCAA and TCAA, respectively. Mean values of recovery ranged from 90 to 96% for DCAA and 95 to 108% for TCAA. The evaluation of recovery and precision of the method indicates that the performance characteristics are comparable with gas chromatographic (GC) methods reported in literature. In addition, the procedure is simple, fast, and does not need any derivatization step. Application of the analytical method to the determination of DCAA and TCAA in real samples is shown.     

Characterization and DNA Interaction of Lanthanide Complexes Based on Thiourea Ligand

Three isostructural lanthanide complexes,namely[Ln(L)₃·CH₃ OH](Ln=Tb(1),Dy(2),Ho(3),HL=N-(pyridin-2-ylcarbamothioyl)benzamide),were successfully synthesized and characterized by IR,UV,elemental analysis,single-crystal X-ray diffraction and DNA-biding analysis.X-ray single-crystal diffractions show that the family of lanthanide complexes crystallizes in monoclinic C2/c space group.Each lanthanide atom is coordinated with three carbonyl-O atoms,three pyridyl-N atoms and three imine-N atoms from three distinct L^-1 ligands,forming a distorted tricapped trigonal prism.The binding properties of complexes with ct-DNA were studied by simulating the physiological environment of human body.The results suggest that compounds could bind with ct-DNA through interaction under a spontaneous process.     

4(R)-(2,4,6-三甲基苄氧基)-(S)-脯氨酸促进的直接不对称羟醛反应

方便地合成了一种新的不对称羟醛反应的手性催化剂4(R)-(2,4,6-三甲基苄氧基)-(S)-脯氨酸. 以过量的丙酮作溶剂, 使用5 mol%该催化剂, 有效地催化了多种取代苯甲醛与丙酮间的不对称羟醛反应, 产率最高达91.0%, ee最高达84.3%.     

Ir/CNTs催化剂的制备及对氨的电催化氧化

分别以碳纳米管(CNTs)和XC-72活性碳为载体制备了Ir/CNTs和Ir/C催化剂. X射线衍射(XRD)结果显示, CNTs拥有更高的石墨化程度. 电化学研究结果表明, 与Ir/C催化剂相比, Ir/CNTs对氨氧化具有更高的电流密度、更低的起始氧化电位和更好的稳定性. 同时, Ir/CNTs催化剂对氨检测的线性范围更宽, 灵敏度更高, 检出限更低.