Et-Ph-BCTABipy的合成及其对Pd2+的萃取性能

合成了N,N′-二乙基-N,N′-二苯基-［2,2′-联吡啶］-6,6′-二硫代酰胺(Et-Ph-BCTABipy)萃取剂,并利用¹³C NMR和¹H NMR对其进行了表征;研究了相接触时间、萃取剂浓度、水相初始酸度和Pd²⁺浓度等因素对Et-Ph-BCTABipy萃取Pd²⁺性能的影响,利用摩尔比法确定了Et-Ph-BCTABipy与Pd²⁺所形成的配合物组成;同时,在Ln(Ⅲ)与Pd²⁺共存体系中研究了Et-Ph-BCTABipy对Pd²⁺的萃取选择性。结果表明：Et-Ph-BCTABipy在HNO₃体系中对Pd²⁺具有较强的萃取性能和较高的萃取选择性;萃取过程中Et-Ph-BCTABipy与Pd²⁺以1∶2的比例结合,其萃取平衡常数K_ex=3.42×10⁶。     

Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.     

A Fluorescent Cobalt Probe with a Large Ratiometric Fluorescence Response via Modulation of Energy Acceptor Molar Absorptivity on Metal Ion Binding

Probe 1 has been synthesized as the first ratiometric fluorescent cobalt probe, and it exhibits several highly favorable features, in particular a remarkable ratiometric fluorescence response at two wavelengths. Importantly, the electronic energy transfer (EET) efficiency of the probe is modulated by the energy acceptor molar absorptivity variations on cobalt binding, which then transforms to a large ratiometric fluorescence response at two wavelengths. This signaling mechanism should open a new avenue for the development of powerful ratiometric probes with large emission signal ratios at two wavelengths for exciting applications in many fields.     

Continuous‐Flow C?H Borylation of Arene Derivatives

A new continuous‐flow system for C H borylation has been developed. An insoluble catalyst prepared from chloro(1,5‐cyclooctadien)iridium(I) dimer and 2,2′‐bipyridine‐4,4′‐dicarboxylic acid in the presence of bis(pinacolato)diboron exhibited high reactivity under continuous‐flow processing without the loss of expensive iridium metal.     

甲基丙烯酸2,2,2-三氟乙酯的原子转移自由基聚合

以α-溴代丙酸乙酯(EPN-B)/CuCl/ 联二吡啶(bpy)作为引发/催化体系、环己酮为溶剂,对甲基丙烯酸2,2,2-三氟乙酯(TFEMA)进行原子转移自由基聚合(ATRP),研究了TFEMA的反应动力学,并考察了引发/催化体系、引发剂EPN-B用量、配位剂bpy用量及单体配比对聚合反应的影响.结果表明,采用EPN-B/CuCl/bpy引发/催化体系对TFEMA进行ATRP,可得到窄分子量分布的聚甲基丙烯酸2,2,2-三氟乙酯(PTFEMA),在实验范围内,聚合速率对单体浓度呈一级动力学关系,该反应过程具有活性聚合特征;随着引发剂EPN-B和配位剂bpy用量的增加,聚合速率加快,当EPN-B相对摩尔用量为0.5,1.0,2.0时,其相应的表观链增长速率常数分别为3.143×10~(-4),3.478×10~(-4),4.435×10~(-4)s~(-1);增大[TFEMA]/[EPN-B](摩尔比),聚合速率明显降低,但无论[TFEMA]/[EPN-B]高与低,聚合物的分布指数均为1.15～1.23.     

An aqueous ZnCl2/Fe(bpy)3Cl2 flow battery with mild electrolyte

The kinetics of electrode reaction was investigated by cyclic voltammetry, and cyclic voltammograms show that the reversibility of the Fe(bpy)₃²⁺/Fe(bpy)₃³⁺ electrode reaction is better than that of the Zn/Zn²⁺ electrode reaction on the graphite disc. However, the Fe(bpy)₃²⁺ ion diffusion in electrolyte is subject to greater resistance than that of the Zn²⁺ ion one. The stability of the Fe(bpy)₃Cl₂ solution was investigated by UV–vis spectroscopy, and the performance of a mild redox flow battery employing ZnCl₂ and Fe(bpy)₃Cl₂ in the NaCl aqueous solution with various membranes as the separator was also investigated. It was found that the Celgard 3501 membrane cannot effectively prevent Fe(bpy)₃²⁺ ions from leaking into anolyte, leading to the rapid failure of the flow battery. Although the Nafion 115 membrane can be polluted by Fe(bpy)₃²⁺ ions, it is not invalidated. The Nafion 115 membrane shows good selectivity, which can avoid Fe(bpy)₃²⁺ ions from leakage into anolyte. The ZnCl₂/Fe(bpy)₃Cl₂ flow battery with the Nafion 115 membrane exhibits the capacity retention of 80% after 200 cycles.     

An electrochemically assisted mechanically controllable break junction approach for single molecule junction conductance measurements

We report an electrochemically assisted mechanically controllable break junction (EC-MCBJ) approach to investigating single molecule conductance. Electrode pairs connected with a gold nanobridge were fabricated by electrochemical deposition and then mounted on a homebuilt MCBJ platform. A large number of Au- molecule-Au junctions were produced sequentially by repeated breaking and reconnecting of the gold nanobridge. In order to measure their single molecule conductance, statistical conductance histograms were generated for benzene-1,4-dithiol (BDT) and 4,4′-bipyridine (BPY). The values extracted from these histograms were found to be in the same range as values previously reported in the literature. Our method is distinct from the ones used to acquire these previously reported literature values, however, in that it is faster, simpler, more cost-effective, and changing the electrode material is more convenient.      

Deposition of α-SiΜο12Ο40-[Ru(bipyridine)(terpyridine)Cl] multilayer film on single wall carbon nanotube modified glassy carbon electrode: Improvement of the electrochemical properties and chemical stability

A simple procedure was developed for the preparation of glassy carbon electrodes modified with single wall carbon nanotubes (SWCNTs) and multilayers of SiΜο₁₂Ο₄₀⁴⁻-[Ru(bpy)(tpy)Cl]⁺(byp; bipyridine, tpy; terpyridine). Layer-by-layer deposition technique was used for the multilayer formation of SiΜο₁₂Ο₄₀⁴⁻-[Ru(bpy)(tpy)Cl]⁺ onto SWCNTs films. Based on the strong electrostatic attraction of oppositely charged species a Ru-complex/poly oxometalate hybrid film strongly and irreversibly adsorbed on the glassy carbon electrode modified with single walled carbon nanotubes. The multilayer assembly exhibited good stability and excellent electrochemical reversibility for both redox systems in the pH range1-7. It was found that up to fifteen monolayers could be deposited onto a carbon nanotube film with well defined redox behavior. The modified electrode shows excellent electrocatalytic activity towards sulfite oxidation. Due to synergistic effect between SWCNTs and oppositely charged species the repeated alternate adsorption of anions and cations by this simple dipping method leads to molecular sandwiches with interesting redox activity and remarkable stability.     

光度法测定药品和食物中的微量VC

采用一种简单、快速的方法测定VC,该方法基于在室温下,抗坏血酸能快速地将Fe3 还原成Fe2 ,Fe2 与2,2’-联吡啶反应生成红色配合物,配合物的最大吸收峰位于520 nm波长处,VC的质量浓度在0.088~7.0 mg/L范围内符合比尔定律,该方法用于食品和药片中VC含量的测定,结果的相对标准偏差小于1.5%,回收率在96.3%~105.0%之间.     

联吡啶钌配合物对末端炔烃的催化

以6,6＇-二甲基-2,2＇-联吡啶为配体合成了二水合氯化顺一二氯·二（6,6＇-二甲基-2,2＇联吡啶）合钌（Ⅲ）配合物,进一步用三氟甲基磺酸银脱氯得到三（三氟甲基）磺酸顺一二水·二（6,6＇-二甲基-2,2＇联吡啶）合钌（Ⅲ）配合物．研究了后者对1-己炔、苯乙炔和丙炔酸乙酯环三聚反应的催化作用．实验结果显示环三聚产物具有区域选择性：产物只有1,2,4一三取代苯与1,3,5-三取代苯两种同分异构体,且主要为1,2,4一三取代苯．催化机理研究表明,三（三氟甲基）磺酸顺一二水·二（6,6＇-二甲基-2,2＇联吡啶）合钌（Ⅲ）中的两个水分子配体首先被两分子炔烃取代生成π-炔基配合物,然后通过氧化偶联反应得到钌杂环戊二烯配合物;第三个炔烃分子经由插入反应或双烯加成反应生成钌杂环庚三烯或7一钌杂双环[2．2．1]-2,5-庚二烯中间体,随后发生还原消除反应得到三取代苯．