Influence of the Size of Aromatic Chelate Ligands on the Structures of Cadmium(II) Tetracarboxylates Polymers: From 2D Layered Network to 3D Metal‐Organic Framework

To determine the influence of the size of the aromatic chelate ligands on the frameworks of metal tretracarboxylate polymers, two new coordination polymers [Cd(btc)_0.5 (2,2′‐bpy)] ( 1 ) and [Cd(btc)_0.5(phen)]·H₂O ( 2 ) (H₄btc = biphenyl‐3,3′,4,4′‐tetracarboxylic acid, 2,2′‐bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline) have been synthesized under similar hydrothermal conditions. In complex 1 , the dimeric Cd₂ units are linked by bridging btc^4? ligand to form a 2D layered network, whereas complex 2 possesses a 3D metal‐organic framework consisting of the dimeric Cd₂ units. The differences of two metal‐organic frameworks demonstrate that the size of the rigid aromatic chelate ligands have an important effect on the structures of their complexes. Additionally, the two complexes show strong fluorescence in the solid state at room temperature.     

Tuning the arrangement of mono-crown ether-substituted phthalocyanines in Langmuir-Blodgett films by the length of alkyl chains and the cation in subphase

Amphiphilic phthalocyanines with one crown ether and three alkyl chain substitutions can form stable monolayers on a water surface. This monolayer can be transferred to a substrate by a vertical dipping method. The arrangement of phthalocyanine molecules in LB films was affected by the length of alkyl chains and the coordination of alkali ions in crown ether. Davydov splitting was observed in the absorption spectra of the LB films of phthalocyanine with the shortest alkyl chain substitutions, and this splitting was affected by the alkali ions in the subphase.     

Synthesis and optical properties of unsymmetrical conjugated dendrimers focally anchored with perylenes in different geometries

Two sets of light-harvesting monodendrons with unsymmetrical conjugated phenylacetylene branches and perylene cores, one with pi-conjugation from the branches to the core and one without, were synthesized and their photophysical properties were studied by steady-state and time-resolved spectroscopic methods. These monodendrons show comparably high fluorescence quantum yields and efficient energy-transfer properties.     

Synthesis and antimicrobial activity of a perfluoroalkyl-containing quaternary ammonium salt

A novel perfluoroalkyl-containing quaternary ammonium salt 5 was designed and synthesized. Consequently, the antimicrobial activities of compound 5 were measured with Escherichia coli 8099 as a Gram-negative strain and Staphylococcus aureus ATCC 6538 as a Gram-positive strain. Both the minimum inhibitory concentration (MIC, the lowest concentration of compound 5 that inhibits microbial growth) values of quaternary ammonium salt 5 against Escherichia coli 8099 and Staphylococcus aureus ATCC 6538 were 7.8 μg/ml.     

配位化学的创始与现代化

本文扼要介绍了韦尔纳配位理论的第一篇文章的内容，讨论了配位化学的发展和现代化。配合物稳定性决定于多种作用力与组分间的互补性和拓扑约束性。     

Triboelectric pulsed direct current for self-powered sterilization of cellulose fiber

A variety of liquid energy exists in papermaking engineering and has not yet been developed and utilized. In addition, for the papermaking industry, the presence of slime can seriously affect the quality of the finished paper and can lead to paper breaking. The current slime control strategies cannot completely solve the problem and also have some low toxicity. In this study, a method of self-powered sterilization of cellulose fibers by using triboelectric pulsed direct current is reported. A liquid–solid triboelectric nanogenerator (L–S TENG) was used to convert the liquid energy of nanocellulose suspension into electrical energy and convert this electrical energy into pulsed direct current for self-powered sterilization of cellulose fiber. A hydrophobic coating material is used as solid triboelectric material and electrode for sterilization. Driven by L–S TENG, the electrodes exhibited an excellent sterilization rate against four microorganisms including Escherichia coli, Aspergillus niger, Candida albicans, and Klebsiella pneumoniae, which from slime in the papermaking industry. This study could provide a basic research theory for liquid energy harvesting in the papermaking industry, and also provide a new strategy for pulp sterilization.

Graphical abstract

     

Grape tissue-based electrochemical sensor for the determination of hydrogen peroxide

The use of grape tissue as a source of catalase for the determination of hydrogen peroxide is reported. A slice of grape tissue attached to the membrane of a Clark-type oxgen sensor was used to monitor the oxidation of hydrogen peroxide by catalase. At the steady state, the sensor responds linearly to hydrogen peroxide in the concentration range 1 × 10^?5–5 × 10^?4 M. The response time (T₉₀) was of the order of 1 min for this sensor. No interference was observed from ethanol, amino acids, glucose and lactic acid. The long-term stability of the grape tissue sensor was much better than previously reported immobilized enzyme and liver tissue-based hydrogen peroxide sensors.     

Preparation and study on the novel solid inclusion complex of ciprofloxacin with HP-beta-cyclodextrin

The interaction of ciprofloxacin with HP-beta-cyclodextrin (HP-beta-CD) has been studied by several analytical techniques, including 1H nuclear magnetic resonance (NMR), 13C NMR, fluorescence spectra, infrared spectroscopy, thermal analyzer and scanning electron microscope. In this paper, solid inclusion complex of ciprofloxacin with HP-beta-CD was synthesized by the coprecipitation method. In addition, the characterization of the inclusion complex has been proved by fluorimetry, infrared, differential scanning calorimetry and one-dimensional (1D), 2D NMR. The experimental results confirmed the existence of 1:1 inclusion complex of ciprofloxacin with HP-beta-CD. The formation constant of complex was determined by fluorescence method and 1H NMR. Spacial configuration of complex has been proposed on two-dimensional NMR technique.     

The Color Reaction of Mercury(II) with the New Reagent 2-Methylthiophenyldiazoaminoazobenzene and Its Application

A new and very sensitive and selective chromogenic reagent, 2-methylthiophenyldiazoaminoa-zobenzene (MTDAA), was synthesized and studied in detail for the determination of trace mercury(II) in water samples. The method is based on the color reaction between MTDAA and mercury(II). It was found that mercury(II) reacts with MTDAA in Na₂B₄O₇-NaOH buffer solution (pH = 10.0) to form 1 : 2 red complexes; these show maximum absorption at 520 nm. Beer’s law is obeyed in 0–15 µg of mercury(II) in 25 mL of solution. The apparent molar absorptivity of the complex is 1.33 × 10⁵ L/(mol cm); its limit of quantification, limit of detection, and relative standard deviation are 0.75 ng/mL, 0.27 ng/mL, and 1.0%, respectively, giving better sensitivity. The influence of the reaction variables and the effect of interfering ions are reported; most of the metal ions in water samples can be tolerated in considerable amounts. Only a few ions can interfere with the determination of trace mercury(II), but these can be eliminated by prior extraction. The proposed method is sensitive, simple, and rapid. It has been applied to the determination of trace mercury(II) in water samples with satisfactory results.__________From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 7, 2005, pp. 703–706.Original English Text Copyright © 2005 by Guo, Din, Tian, Liu, Chang, Meng.The text was submitted by the authors in English.