Synthesis,Characterization, DNA Binding Properties,and Antioxidant Activity of Novel Copper(II) and Zinc(II) Complexes with Bis(pyrrol‐2‐yl‐methylamine) Ligands

Three novel ligands H₄Lⁿ (n = 1–3) and their copper(II) and zinc(II) complexes were prepared and characterized on the basis of elemental analyses, molar conductivity, ¹H NMR, UV/Vis, and IR spectroscopy as well as mass spectrometry. DNA binding properties of the ligands and their complexes were investigated by absorption spectroscopy, ethidium bromide displacement experiments, and viscosity measurements. The experimental results indicate that the new ligands and their complexes can bind to DNA and the binding affinities of the complexes are higher than those of the ligands. In addition, the antioxidant activity of the ligands and complexes was determined by superoxide and hydroxyl radical scavenging methods in vitro, indicating that the complexes exhibit more effective antioxidant activity than the ligands alone.     

羧基化单壁碳纳米管涂层同时测定纯净水中的烷基酚和双酚A

用溶胶-凝胶方法制备了羧基化碳纳米管溶胶凝胶固相微萃取涂层,采用顶空固相微萃取-气相色谱法测定纯净水中的烷基酚和双酚A.优化了萃取涂层的萃取时间、萃取温度、盐浓度以及解析时间等实验参数.结果表明,在萃取温度为90℃和盐浓度为0.36 g/mL的条件下萃取30 min,250℃下解析3 min,涂层的萃取效果最好.与商用...     

Synthesis and drug release properties of novel pH- and temperature-sensitive copolymers based on a hyperbranched polyether core

Multi-arm star amphiphilic hyperbranched copolymers with poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) shell and hyperbranched poly(3-ethyl-3-(hydroxymethyl)oxetane) (HBPO) core were synthesized by reversible addition?Cfragmentation chain transfer method. The hyperbranched copolymers were further modified by succinic anhydride (SUC) to obtain the novel pH- and thermosensitive hyperbranched copolymer HBPO-star-PDMAEMAs-SUC. The composition and morphology of synthesized copolymers were investigated by ¹H NMR, dynamic light scattering, and transmission electron microscopy. These copolymers exhibited phase transitions in response to pH and temperature. The pH-dependent release properties of the drug-loaded micelles were also investigated using indomethacin (IND) as a model drug. The IND-loaded micelles displayed a rapid drug release at an alkaline pH.     

Self-assembly and enhanced photocatalytic properties of BiOI hollow microspheres via a reactable ionic liquid

BiOI uniform flowerlike hollow microspheres with a hole in its surface structures have been successfully synthesized through an EG-assisted solvothermal process in the presence of ionic liquid 1-butyl-3-methylimidazolium iodine ([Bmim]I). The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), nitrogen sorption, and diffuse reflectance spectroscopy (DRS). A possible formation mechanism for the growth of hollow microspheres was discussed. During the reactive process, ionic liquid not only acted as solvents and templates but also as an I source for the fabrication of BiOI hollow microspheres and was vital for the structure of hollow microspheres. Additionally, we evaluated the photocatalytic activities of BiOI on the degradation of methyl orange (MO) under visible light irradiation and found that as-prepared BiOI hollow microspheres exhibited higher photocatalytic activity than BiOI nanoplates and TiO(2) (Degussa, P25) did. On the basis of such analysis, it can be assumed that the enhanced photocatalytic activities of BiOI hollow microspheres could be ascribed to its energy band structure, high BET surface area, high surface-to-volume ratios, and light absorbance.     

Determination of the interaction enthalpy between microemulsion droplets by isothermal titration microcalorimetry

A new experimental design for the measurement of the real heat of dilution of the microemulsion droplets by isothermal titration microcalorimetry (ITC) has been reported and used to study the interaction enthalpies of the droplets for the system of water/sodium bis(2-ethylhexyl)-sulfosuccinate (AOT)/toluene. The results are in good agreement with those determined from light-scattering experiments.     

Mechanics of nanoindentation on a monolayer of colloidal hollow nanoparticles

We explore the collective mechanical behavior of monolayer assemblies composed of close-packed arrays of hollow silica nanoparticles using a spherical nanoindentor. Seven types of well-defined hollow nanoparticles are studied with their radii ranging from 100 to 300 nm and shell thickness ranging from 14 to 44 nm. Micromechanical models reveal the underlying deformation mechanisms during indentation, where the consecutive contacting of the indentor with an increasing number of nanoparticles results in a nonlinear increase in the indentation force with penetration depth. Each contacted hollow nanoparticle successively locally bends, flattens, and then locally buckles. The effective indentation modulus of the monolayer film, which is obtained by a Hertzian fit to the experimental data, is found to be proportional to the elastic modulus of the nanoparticle shell material and scales exponentially with the ratio of particle shell thickness t to radius R to the power of 2.3. Furthermore, we find that for a constant film density with the same (t)/(R) of the constituent nanoparticles, smaller particles with a thinner shell can provide a higher effective indentation modulus, compared to their larger diameter and thicker shell counterparts. This study provides useful insights and guidance for constructing high-performance lightweight nanoparticle films and coatings with potential applications in tailoring stiffness and mechanical energy absorption.     

1,3-二(1-二茂铁磺酰基-2-苯并咪唑)丙烷的合成、单晶结构和量子化学研究

合成了新型的1,3-二(1-二茂铁磺酰基-2-苯并咪唑)丙烷(BFBP).用红外光谱、核磁、质谱和X射线单晶衍射对其结构进行了表征.该晶体结构属正交晶系,空间群为Pnma,晶胞参数为:a=1.30079(13)nm,b=2.9627(3)nm,c=1.01257(10)nm,y=3.9023(7)nm3,Dc=1.49...     

Soft template synthesis of ZnO nanorods and their optical properties

A simple solution route was developed to fabricate monodisperse wurtzite ZnO nanorods. The as-prepared samples were 5 ??m in length and 70?C100 nm in diameter. The crystallinity, morphology, and structure of the rod-like ZnO microcrystals were examined. The crystal phases and the microstructure of the nanorods were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Room- and low-temperature photoluminescence (PL) and Raman spectra were employed to investigate the surface states of the samples. The deep-level emission band was barely observable at both room and cryogenic temperatures.     

Mild solution synthesis of plate-like and rod-like ZnO crystals

Micro-disks and micro-rods of ZnO were successfully synthesized by a mild solution process using zinc chloride as starting material. The morphology of the ZnO crystals changed substantially, depending on the concentrations of the Zn²⁺ ion and organic additives in the solution. A plate-like Zn₅(OH)₈Cl₂·H₂O precursor with a layered structure could be produced in solutions with high concentrations of chloride ions. The thermal stability, including phase composition and morphology, of the as-prepared Zn₅(OH)₈Cl₂·H₂O in air and water was investigated.     

Molecular self-modification: homolog of a manganese laundry bleach catalyst oxidatively transforms its tetradentate ligand into a novel hexadentate derivative

On the basis of mass spectral studies alone, the relatively new manganese complex, Mn(Et₂EBC)Cl₂ (Et₂EBC = 4,11-diethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane), a homolog of the well proven, peroxide-based laundry bleach, Mn(Me₂EBC)Cl₂, has been reported to undergo a sequence of 2-electron oxidation steps, ultimately converting its ethyl groups into chelated ethoxo and methylene carboxylato groups, [Mn^IV{(^?OCH₂CH₂)(^?O₂CCH₂)}EBC)](PF₆)₂. We report here the isolation and characterization of that unusual product, and provide insight into the remarkable catalytic pathway to its formation. At temperatures above 0 °C, oxidation by aqueous H₂O₂ reliably transforms Mn(Et₂EBC)Cl₂ into [Mn^IV{(^?OCH₂CH₂)(^?O₂CCH₂)}EBC)]²⁺. The experimental data for this intramolecular ethyl group transformation is consistent with oxygen insertion into a methyl C?CH moiety of the ethyl group, ?CNCH₂C(?CH)H₂, by the Mn^IV?COOH functional group.