Mn(15-冠-5)(NCS)_2的晶体和分子结构

在碱金属离子或碱土金属离子与过渡金属离子共存的情况下，全氧冠醚一般选择前者与之配位［1，2］，而与过渡金属离子直接配位的情况则报道较少［3，4］我们在Na+与Mn2+共存的体系中制得了标题配合物的单晶体，并用四圆衍射仪测定了其晶体结构和分子结构．本文对进一步探讨全氧冠醚与过渡金属离子的配位性能及配位特点具有重要的意义．1实验部分1．1单晶生长在10mL称量瓶中，加入0．5gMnCI。·4H。0、08gNaSCN和5mL蒸馏水，溶解后再加入0．ig15一冠一5，搅拌均匀，静置于有机玻璃恒温箱中（25士0．SC），6h后长出无色棒状单晶．经红外…     

冠醚B15C5萃取分离锂同位素的阴离子效应

本文研究了B15C5冠醚萃取锂盐时,不同阴离子对体系的同位素分离效应的影响。结果表明,阴离子在冠醚萃取过程中不仅对萃取络合物的稳定性有显著影响,而且阴离子半径及软度越大时,萃取体系的锂同位素分离系数(α_(LI))也越大。     

One-pot synthesis of N-protected α-amino aldehyde acetals from three-component reaction of fluoroalkanesulfonyl azide, vinyl ether and alcohol

A facile one-step method has been developed for the synthesis of N-protected α-amino aldehyde acetals in moderate to good yields by three-component reaction of fluoroalkanesulfonyl azides, vinyl ethers and alcohol at 0 °C within 10 min. This practical synthetic method provides a convenient and expeditious access to N-per(poly)fluoroalkanesulfonyl α-amino aldehyde acetals.     

New stage in living cationic polymerization: An array of effective Lewis acid catalysts and fast living polymerization in seconds

Our recent extensive research on Lewis acid catalysts with a weak base for the cationic polymerization of vinyl ethers led to unprecedented living reaction systems: fast living polymerization within 1–3 s; a wide choice of metal halides containing Al, Sn, Fe, Ti, Zr, Hf, Zn, Ga, In, Si, Ge, and Bi; and heterogeneously catalyzed living polymerization with Fe₂O₃. The use of added bases for the stabilization of the propagating carbocation and the appropriate selection of Lewis acid catalysts were crucial to the success of such new types of living polymerizations. In addition, the base‐stabilized living polymerization allowed the quantitative synthesis of star‐shaped polymers with a narrow molecular weight distribution via polymer‐linking reactions and the precision synthesis and self‐assembly of stimuli‐responsive block copolymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1801–1813, 2007.     

芳醚树枝形聚合物的合成及分子内光敏异构化反应研究

利用收敛法合成了一代到四代外围带有二苯酮、核心带有降冰片二烯的芳醚树枝形聚合物, 初步研究了这些化合物的分子内光敏异构化反应. 以波长大于350 nm的光选择激发外围的二苯酮官能团引起核心处降冰片二烯基团异构化为四环烷, 随着代数的增长, 光敏异构化反应的速率逐渐加快.     

Density and Speed of Sound for Binary Mixtures of a Cyclic Ether with a Butanol Isomer

Densities and speeds of sound of the binary mixtures 1,3-dioxolane + 1-butanol, 1,3-dioxolane + 2-butanol, 1,4-dioxane + 1-butanol, and 1,4-dioxane + 2-butanol have been measured at 25 and 40°C. The excess molar volumes and excess isentropic compressibility coefficients were calculated from experimental data and fitted to a Redlich–Kister polynomial function. Results were analyzed in terms of molecular interactions and compared with literature data.     

Thermochemistry of interactions of Na+ with benzo-15-crown-5 ether in acetonitrile-water mixtures at 298.15 K

Enthalpies of dissolution of benzo-15-crown-5 ether (B15C5) in mixtures of acetonitrile with water and in solutions of NaI and NaBPh₄ (I=0.05 mol dm^–3) in these mixtures were measured at 298.15 K. From the obtained results and appropriate literature data, the thermodynamic functions of B15C5/Na⁺ complex formation in acetonitrile-water mixtures were determined. The enthalpies of transfer of the complex B15C5/Na⁺ from pure acetonitrile to the examined mixtures were calculated and are discussed.     

First Synthesis of 2a-Thiol Ether Analog of Docetaxel

The chemistry of anticancer drug paclitaxel (=Taxol, 1a) has been extensively explored in recent years. A variety of its analogs with modified taxane frame work or substitutions to its core structure, as well as C-13 substituted isoserine side chains have been synthesized and biologically evaluated1. The marketing of docetaxel (=Taxotere, 1b) is one of the fruitful results from these research efforts. The beginning of clinical trial for analog 2 developed by Indena is the new example. Ba…     

Selective transport of cesium ion in polymeric CTA membrane containing calixcrown ethers

A series of calixcrown ethers for which the cavity size of the crown ring is varied from crown-6 to crown-7 to crown-8 were examined for the transport abilities toward alkali metal ions. These ligands were incorporated into supported liquid membranes (SLMs) and into polymer inclusion membranes (PIMs) composed of cellulose triacetate (CTA) as a support and 2-nitrophenyl octyl ether (NPOE) and tris(2-butoxyethyl) phosphate (TBEP) as a plasticizer. In both membrane systems, calixcrown-6 showed the best selectivity toward a cesium ion over other alkali metal ions. The polymeric CTA membrane showed more rapid transport rate as well as higher durability than did the SLMs.     

Thermocontrolling ion permeation through binary component membrane composed of crown ether liquid crystal/PVC

In view of the nature of orderness in structure and the mesomorphism in property of liquid crystal, the function of which is further exploited by integrating it with the feature of crown ether. The monoarmed crown ether liquid crystals are successfully applied to the imitation of biomembrane transport. Binary component membrane composed of crown ether liquid crystal and PVC was first developed. Such a novel model of biomimetic membrane is capable of imitating ingeniously the thermocontrolling transport of biomembrane, thus the essential function of liquid crystal in membane transport is more fully exploited. It was suggested, consequently, that the molecules of the crown ether liquid crystal could assemble themselves to form ionic channels, as they exist in mesophase.Of still more significance is that the thermocontrolling transport of ions through the membrane is found to be operative selectively and the permeation of ion is under the direct influence of the thermal turmoil of the crown ether liquid cr