一种裸眼识别Cu~(2+)和Hg~(2+)传感器的合成与性质研究

设计合成了一种香豆素修饰的罗丹明类衍生物L,用作程序型Cu2+与Hg2+检测传感器。采用核磁共振谱、高分辨质谱、红外光谱对其结构进行了表征。利用紫外光谱考察L对不同金属离子的识别作用,研究发现L可以高选择性和高灵敏度识别Cu2+。向L溶液中加入不同的金属离子时(Zn2+,Hg2+,Cu2+,Fe3+,Cd2+,Co2+,Ni 2+,Mg2+,Ca2+,Al 3+,La3+,K+,Na+,Mn2+,Pb2+和Ag+),只有Cu2+的加入会使溶液由无色变为粉色,并且在534nm出现一个新的吸收峰,说明传感器L可以裸眼识别Cu2+。通过紫外滴定得到L可以识别Cu2+的最低检测限为1.9×10-8 mol·L-1。制备了基于L的Cu2+检测试纸,该试纸可以方便快捷的检测水中的Cu2+。通过Job’s曲线和高分辨质谱确定了配合物L-Cu2+之间的结合比为1∶1。另外,若向L-Cu2+的DMSO溶液中加入1equiv.EDTA,溶液瞬间由粉色变为无色,说明EDTA可以取代L并与Cu2+结合,因此传感器L识别Cu2+是可逆的。另外,向L-Cu2+的配合物中加入Hg2+,溶液会由粉色变为无色(而加入其他阳离子没有明显变化),这可顺序实现对Hg2+的裸眼识别。通过紫外滴定计算出L-Cu2+识别Hg2+的最低检测限为2.9×10-7 mol·L-1。因此该程序型传感器L可以有序的裸眼识别Cu2+和Hg2+。     

Improved simultaneous adsorption of Cu(II) and Cr(VI) of organic modified metakaolin-based geopolymer

In this paper, a metakaolin-based mesoporous geopolymer (GP-CTAB) was used as adsorbent for Cu(II) and Cr(VI) through a novel and simple synthetic route using cetyltrimethylammonium bromide (CTAB) as an organic modifier. The application of GP-CTAB for the simultaneous removal of metal anions and cations in aqueous solution was studied for the first time. The results of X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Brunauer, Emmett and Teller (BET), and Barrett, Joyner, and Halenda (BJH) methods indicate that GP-CTAB is still geopolymer even in the presence of quaternary ammonium salt cations. The material was tested to simultaneously adsorb Cu(II) and Cr(VI) from an aqueous solution. The results show that GP-CTAB can adsorb anions simultaneously without sacrificing the adsorption properties of heavy metal cations, which is superior to conventional geopolymers. The maximum theoretical adsorption capacity of GP-CTAB for Cu(II) and Cr(VI) was 108.2 mg/g and 95.3 mg/g in the binary system, respectively. It was also found that the presence of Cu(II) in the solution promoted the adsorption of Cr(VI). Given this characteristic of GP-CTAB, it has shown great application prospects in the prevention and control of heavy metal pollution.     

Separation of micro and sub-micro diamagnetic particles in dual ferrofluid streams based on negative magnetophoresis

In the present study, we numerically demonstrate an approach for separation of micro and sub-micro diamagnetic particles in dual ferrofluid streams based on negative magnetophoresis. The dual streams are constructed by an intermediate sheath flow, after which the negative magnetophoretic force induced by an array of permanent magnets dominates the separation of diamagnetic particles. A simple and efficient numerical model is developed to calculate the motions of particles under the action of magnetic field and flow field. Effects of the average flow velocity, the ratio of sheath fluid flow to sample fluid flow, the number of the magnet pair as well as the position of magnet pair are investigated. The optimal parametric condition for complete separation is obtained through the parametric analysis, and the separation principle is further elucidated by the force analysis. The separation of smaller micro and sub-micro diamagnetic particles is finally demonstrated. This study provides an insight into the negative magnetophoretic phenomenon and guides the fabrication of feasible, low-cost diagnostic devices for sub-micro particle separation.     

Highly efficient copper-catalyzed hydroacylation reaction of aldehydes with azodicarboxylates

The hydroacylation reaction of aldehydes with azodicarboxylates catalyzed by copper(II) acetate monohydrate has been reported. The reaction of various aldehydes gave the corresponding hydroacylation products in 60-98% yields under mild conditions. The method is simple, economical, and has practical advantages for the construction of the carbon-nitrogen bonds.     

Oxidative nucleophilic substitution: transformation of alkylboronic derivatives

An efficient amidation reaction is described in this paper. Potassium alkyltrifluoroborate salts can be transforming to amides from nitriles in the presence of copper acetate and boron trifluoride. An extension of this reaction allowed the formation of amines, ethers, and C-C bond.     

Application of Modified Tafel Analysis to the Identification of Corrosion Products on Archaeological Metals Using Voltammetry of Microparticles

An operational modification of Tafel analysis, applied to the intermediate region of square wave voltammetric curves, devoted to the identification of corrosion products on archaeological metal, is described. This is based on the voltammetry of microparticles methodology using conventional abrasive conditioning of the electrode, as well as ‘one‐touch’ and layer‐by‐layer techniques. The proposed methodology is applied to the identification of copper and silver corrosion products in mediaeval silver‐copper coins from the Libertad street hoard in Valencia (Spain).     

Total synthesis of PDE-I and -II by copper-mediated double aryl amination

A concise total synthesis of PDE-I and -II featuring copper-mediated double aryl amination with the combination of CuI, CsOAc, and Cs₂CO₃ is described. The highly substituted pyrroloindole skeleton was constructed by a one-pot five-step sequence including double aryl amination, β-elimination, deprotection of a Cbz group, and unexpected formation of an indole via removal of an Ns group followed by rearomatization. The undesired elimination of the protecting group (Ns group) was hampered by using the Boc group as a protecting group in the second-generation synthesis, which excluded the reduction of the indole required in the first-generation synthesis.     

Triphenylamine-substituted 2-pyridyl-1,2,3-triazole copper(I) complexes: an experimental and computational investigation

Abstract

Four new heteroleptic copper(I) complexes bearing either 2-pyridyl-1,2,3-triazole (pytri) or the related triphenylamine (TPA) substituted (TPA-tripy) ligands and the ancillary ligands 6,6′-dimesityl-2,2′-bipyridine (diMesbpy) or bis[(2-diphenylphosphino)phenyl] ether (POP) were synthesized in good yields (75-95%). All the complexes were extensively characterized using nuclear magnetic resonance (NMR) spectroscopies and electrospray ionization mass spectrometry (ESIMS) and in the case of the two pytri compounds the solid state structures were determined via X-ray crystallography. The pytri complexes showed MLCT absorption bands which shift from 433?nm for the diMesbpy complex to 347?nm for POP. TPA-pytri complexes introduce an ILCT band resulting in improved visible absorption (376?nm, 26,400 M^?1 cm^?1 for [Cu(TPA-pytri)(diMesbpy)](PF₆)). Emission from this ILCT state (470?nm, Φ?=?0.08) was red-shifted compared to the free ligand with negligible effects from ancillary ligands. Band assignments were confirmed with resonance Raman spectroscopy and TD-DFT calculations.     

A trinuclear Cu(II) precursor for solvatochromically distinguishing CH3OH from C2H5OH

Abstract

In order to develop an easy and rapid identification method for distinguishing CH₃OH from C₂H₅OH, a new carbonate-based trinuclear Cu(II) precursor, [Cu₃(bpy)₆(μ₃-CO₃)(CH₃OH)](BF₄)₄·(CH₃OH)₂·(H₂O)₂ (1), has been isolated. We report here the synthesis, crystal structure, and characterizations by various spectroscopic (IR, UV–Vis, powder XRD) techniques, as well as the solvatochromic behavior of this coordination compound. Its X-ray crystal structure reveals that the main structure of 1 consists of three [(bpy)₂Cu]²⁺ centers, which are bridged by carbonate via a μ₃-η¹,η¹,η¹ fashion. Strong O–H?O hydrogen bonding between the carbonate and solvent molecules has been observed for the first time in similar structures. Its ground powder exhibits solvatochromic behavior that selectively distinguishes CH₃OH from C₂H₅OH.     

CuI/Cu(OTf)2/DMSO system-catalyzed intramolecular oxidative cyclization of (o-alkynyl)arylketones: Efficient synthesis of 1,4-naphthoquinones

A concise and efficient method for the synthesis of 1,4-naphthoquinones has been successfully developed involving a CuI/Cu(OTf)₂/DMSO system-catalyzed intramolecular oxidative cyclization of (o-alkynyl)arylketones. The present protocol provided a novel approach to access functionalized 1,4-naphthoquinones from non-naphthoquinone precursors with good selectivity and functional group tolerance.