Synthesis,Crystal Structures,and Magnetic Properties of Two Copper(II) Radical Heterospin Complexes

Two heterospin complexes [Cu(NIT3Py)(cda)H₂O] · H₂O ( 1 ) and [Cu(NIT2Py)(cda)H₂O] · H₂O · CH₃OH ( 2 ) with Cu^II ions and pyridyl‐substituted nitronyl nitroxide radicals (NITxPy = 2‐(x′‐pyridyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide, x = 3, 2; H₂cda = 4‐hydroxy‐pyridine‐2,6‐dicarboxylic acid) were synthesized and characterized structurally and magnetically. The single crystal structures show that the two complexes are both two‐spin complexes, in which the different radicals make the two complexes have different hydrogen bonding interactions to form 2D and 1D supramolecular network for complexes 1 and 2 , respectively. The magnetic measurements indicate that complexes 1 and 2 both exhibit antiferromagnetic interactions between Cu^II and radicals.     

Dinuclear Macrocyclic Quinoline Bridged Mercury and Silver Bis(N‐heterocyclic Carbene) Complexes: Synthesis,Structure, and Spectroscopic Studies

Quinoline bridged imidazolium precursors 5,8‐bis(N‐R‐imidazolylidenylmethylene)quinoline PF₆^– salts [H₂L](PF₆)₂ [R = Me ( 1a ), R = naphthylmethyl ( 1b )] were prepared by quaternization of N‐methylimidazole and N‐naphthylmethylimidazole with 5,8‐bis(bromomethyl)quinoline, respectively. Reaction of the imidazolium ligands 1a and 1b with Hg(OAc)₂ and Ag₂O in acetonitrile gave the macrocyclic transition metal carbene complexes [Hg₂L₂](PF₆)₄ ( 2a and 2b ) and [Ag₂L₂](PF₆)₂ ( 3a and 3b ), respectively. All the N‐heterocyclic carbene complexes were characterized in detail by NMR, ESI‐MS, and elemental analysis. Structures of complexes 2a and 3a were determined by X‐ray diffraction studies. Structural studies revealed that the coordination arrangement of the central mercury atom in complex 2a displays a tricoordinate mode and the molecular conformation results in a“closed” form with the bridging quinoline functionality in the macrocycle, whereas the silver complex 3a does not show an coordiantion between the bridging quinoline and the Ag^I ion, which results in an “open” conformation of the macrocycle. The Hg^II and Ag^I NHC complexes showed similar UV absorption and luminescence in acetonitrile solutions.     

Synthesis,Structures, and Luminescent Properties of two 3, 5‐Dimethyl‐1‐H‐1, 2,4‐triazole‐Based Zinc Metal‐Organic Frameworks with Aromatic Carboxylate as Coligand

Two metal‐organic frameworks, [Zn(dmtrz)(btrc)_1/3]_n ( 1 ) and [Zn₂(dmtrz)₂(btec)(H₂O)₂]_n ( 2 ) (dmtrz = 3, 5‐dimethyl‐1‐H‐1, 2,4‐triazole, btrc = 1, 3,5‐benzenetricarboxylate, btec = 1, 2,4, 5‐benzenetetracarboxylate), were synthesized by hydrothermal reaction. The crystal structure analysis reveals that compound 1 is a dense 3D framework with Schläfli symbols of {4³}₂{4⁶ · 6⁶ · 8³}₃, which is a loh1 structure. Compound 2 is a 2D network. In addition, the photoluminescence of two compounds were studied in solid state at room temperature, together with their thermal analysis.     

Preparation and application of trimethylamine amination polychloromethyl styrene nanolatex coated capillary column for the determination of bromate by field‐amplified sample stacking open‐tubular capillary electrochromatography

A new trimethylamine amination polychloromethyl styrene nanolatex (TMAPL) and TMAPL coated capillary column (ccc‐TMAPL) were successfully prepared. The TMAPL coating was characterized with reversed steady EOF values of ca. ?16.8 × 10^?5 cm² V^?1 s^?1. It was applied to establish open‐tubular (OT) CEC and field‐amplified sample stacking (FASS) OT‐CEC methods for the determination of bromate in tap water. Compared to OT‐CEC, the LOD with FASS‐OT‐CEC was improved from 80 to 8 ng/mL. The developed FASS‐OT‐CEC method was practically used for the analysis of bromate in tap water samples with recoveries ranging from 93.6 to 103.5%.     

Multiscale geometric modeling of macromolecules II: Lagrangian representation

Geometric modeling of biomolecules plays an essential role in the conceptualization of biolmolecular structure, function, dynamics, and transport. Qualitatively, geometric modeling offers a basis for molecular visualization, which is crucial for the understanding of molecular structure and interactions. Quantitatively, geometric modeling bridges the gap between molecular information, such as that from X‐ray, NMR, and cryo‐electron microscopy, and theoretical/mathematical models, such as molecular dynamics, the Poisson–Boltzmann equation, and the Nernst–Planck equation. In this work, we present a family of variational multiscale geometric models for macromolecular systems. Our models are able to combine multiresolution geometric modeling with multiscale electrostatic modeling in a unified variational framework. We discuss a suite of techniques for molecular surface generation, molecular surface meshing, molecular volumetric meshing, and the estimation of Hadwiger's functionals. Emphasis is given to the multiresolution representations of biomolecules and the associated multiscale electrostatic analyses as well as multiresolution curvature characterizations. The resulting fine resolution representations of a biomolecular system enable the detailed analysis of solvent–solute interaction, and ion channel dynamics, whereas our coarse resolution representations highlight the compatibility of protein‐ligand bindings and possibility of protein–protein interactions. © 2013 Wiley Periodicals, Inc.     

Microwave-Assisted Chemical Demulsification of Water-in-Crude-Oil Emulsions

Two case studies are presented that shows the effects of chemical demulsifiers used under conventional heating and in combination with microwave radiation on efficiency of demulsification and light transmittance of the water separated from the emulsions. The data shows that the chemical demulsifiers coupling with microwave radiation does a better job at demulsifying the water-in-crude-oil emulsions than when the chemical demulsifiers are used under conventional heating. The demulsification efficiency of AE-121 could reach 100% under microwave irradiation (300 W) for 50 seconds.     

Studies of Interfacial Activities of Four Kinds of Surfactants at Oil/Water Interface

This article aims to compare the interfacial activities of different kinds of surfactants in the same oil/water system. The anionic surfactants of alkylbenzene sulfonates, the polyoxyethylenated nonionic surfactants, the cationic surfactants of alkyl trimethyl ammonium chlorides, and the zwitterionic surfactants of alkyl hydroxyl sulfobetaines were used, and the interfacial tensions of the surfactant solutions against kerosene at different NaCl concentrations were measured. It is found that the interfacial activities of the alkylbenzene sulfonates are high and ultralow interfacial tensions (<0.01 mN/m) can be obtained at proper salinities. While, the nonionic surfactants have relatively low interfacial activities and the minimum tensions are around 0.01 mN/ms. The salinity scanning curves of the alkylbenzene sulfonates and nonionic surfactants decrease first, then increase, showing their interfacial activities can be changed by the salinity effectively. The cationic and zwitterionic surfactants have very low interfacial activities, of which all the tensions are higher than 0.1 mN/ms and are hard to be changed by the salinity. The experimental results may have important reference values for enhanced oil recovery.     

pH-Sensitive Dye-Polyether Derivatives as Dispersants for Its Parent Dye. Part 1: Synthesis and Hydrolysis Behavior

A series of dye-polyether derivatives, supposedly to be used as dispersants for parent dye, were synthesized by grafting poly(oxyalkylene)-amines based on differing both molecular weights and degrees of hydrophilicity/hydrophobicity, onto C.I. disperse red 60 via a stable urea linkage. The structures of the dye-polyether derivatives were characterized by FTIR, ¹H NMR, and SEC. The influence of pH on the hydrolysis behaviors of the dye-polyether derivatives were studied in buffered aqueous solutions within the pH range of 4 to 10. The hydrolysis of dye-polyether derivatives was pH dependent and relatively faster in mild alkaline buffer solution than in acidic one. The influence of poly(oxyalkylene)-amine structure on the hydrolysis behavior was also investigated; it was found that the hydrolysis rate is affected little by the molecular weight and increases with the increasing hydrophilicity of the poly(oxyalkylene)-amine.     

纳米金标记抗体增强SPR检测大肠杆菌O157∶H7

将金纳米粒子(AuNPs)标记的大肠杆菌O157∶H7(E.coli O157∶H7)的多克隆抗体(PAb)作为二抗,采用氨基偶联法将PAb固定在传感器表面作为一抗,通过三明治方法用双通道表面等离子体子共振(SPR)传感器对E.coli O157∶H7进行检测,并与SPR直接法检测进行了比较.结果表明,直接法的检出限为103cfu/mL,线性范围为103～109cfu/mL;AuNPs增强三明治法的检出限为10 cfu/mL,线性范围为10～1010cfu/mL,灵敏度比直接法提高了100倍,且具有更宽的检测范围.本方法不仅检测时间短,而且具有良好的选择性和重现性.     

Effect of Inorganic Ions on the Oxidation of Methyl Violet with Gliding Arc Plasma Discharge

Gliding arc discharge process was used for the treatment of methyl violet wastewater. First, the intermediate products were studied by gas chromatography coupled with mass spectrometry and Fourier transform infrared spectrometry, and ultraviolet–visible spectrometer. Second, the effects of inorganic anions including chloride (Cl^?), carbonate (CO₃ ^2?), sulfate (SO₄ ^2?), phosphate (PO₄ ^3?), nitrate (NO₃ ^?) on the degradation efficiency of methyl violet were examined. The research results indicated that hydroxyl radicals attacked carbon atom that situated in the center of dye molecule, and the conjugating structure of methyl violet was destroyed, and dye was degraded and decolored, so a possible degradation pathway was proposed by the analysis of intermediate products detected. The methyl violet degradation rate decreased with increasing anions concentrations, and their order of sequence according to the inhibition reaction was CO₃ ^2? > Cl^? > SO₄ ^2? > NO₃ ^?.