[B(O–C6H4–CN)4]– based Silver and Copper Coordination Polymers

A series of new coordination polymers bearing the [B(O–C₆H₄–CN)₄]^– anion was synthesized. Two new, one dimensional coordination frameworks of the type M[B(O–C₆H₄–CN)₄] (M = Ag, Cu) were obtained by salt metathesis. The reactivity towards organic Lewis‐bases was studied. The reaction with bidentate ligands yielded two dimensional networks with the general formula [M(L)][B(O–C₆H₄–CN)₄] {L = 2,2′‐bipyridine, 4,4′‐bipyridine, 1,2‐bis(pyridyl)ethane, 1,4‐diazabicyclo[2.2.2]octane}. The synthesis, properties and single crystal structure are reported.     

表面增强拉曼光谱研究自组装单分子层在化学接触和纳米隔绝下的分子振动活性变化(英文)

为确定表面增强拉曼光谱中某些有争议的弱振动模式是来自高阶的影响还是分子基团对称性变化的影响,本文以1,4-苯二硫醇作为探针分子提供了一种实验验证的框架方法.光谱实验显示,观测到的有争议的弱振动模式并不是来自高阶的影响,而是分子基团对称性变化所致.我们的实验框架方法很容易拓展开来,如用于研究其它波长激光激发的类似体系或有机分子搭接的分子结.     

Silver(I)-mediated reaction of trimethylsilylated arylacetylenes with sulfonyl chlorides:Unexpected formation of vinvl sulfones

A novel reaction of trimethylsilylated arylacetylenes with sulfonyl chlorides was performed in the presence of silver nitrate or triflate.Conjugated vinyl sulfones as dramatic products were obtained in moderate yields and with Z-selectivity.A free radical mechanism has been proposed to account for the formation of the products.     

NEUTRAL COMPLEXES OF SILVER HALIDES AND TETRAMETHYLTHIURAM MONOSULFIDES

Abstract

The preparation and characterization of 1:1 adducts of silver haelides AgX (X = Cl, Br, I) with N,N,N′,N′-tetramethylthiuram monosulfides is reported. the products are characterized by elemental analyses, magnetic measurements and IR-Raman spectroscopy. The data are interpreted in terms of a halogen-dibridged structure of D_2h symmetry.     

聚乙烯吡咯烷酮纳米银荧光增强测定番茄红素

合成了聚乙烯吡咯烷酮纳米银,研究了番茄红素对聚乙烯吡咯烷酮纳米银体系的荧光增强效应。考察了缓冲体系、纳米银用量、聚乙二醇浓度、反应时间和温度等因素的影响,建立了测定番茄红素的新方法。在最佳条件下,体系的相对荧光强度与番茄红素浓度呈良好的线性关系,其线性范围为2.0×10-6~8.0×10-5 mol/L,检出限为1.6×10-8 mol/L。方法应用于实际样品检测,回收率为98.29%~109.36%。     

Studies on Curcumin Loaded Poly(N-isopropylacrylamide) Silver Nanocomposite Hydrogels for Antibacterial and Drug Releasing Applications

Design of silver nanoparticles containing poly(N-isopropylarclamide) (PNIPAAm) hydrogels were prepared by free-radical polymerization of N-isopropylarclamide as an environmentally sensitive monomer and MBA as a crosslinker in an aqueous medium. The embedded silver nanocomposite hydrogels (AgNCH) structure were characterized by, UV-Vis, FTIR, DLS, TEM and X-ray analysis. Curcumin loading and release characteristics were performed for PNIPAAm hydrogel, silver ions loaded hydrogels as well as silver nanocomposite hydrogels. These curcumin loaded silver nanocomposite hydrogels exhibit excellent antibacterial action on Escherichia coli (E. coli). Therefore, the present study clearly provides novel antimicrobial hydrogels which are potentially useful in biomedical applications.     

Preparation of Silver Nanoparticles‐Based Sensors for the Electrochemical Detection of Thiourea in Leaching Solutions of Waste Electrical and Electronic Equipment

Waste of electrical and electronic equipment is an interesting secondary resource of base and precious metals. Particularly the use of thiourea‐leaching in acidic medium was proposed for noble metals recovery. In this work, a novel and easy‐to‐use electrochemical sensor was developed, aimed to test thiourea from leaching solutions containing significant thiourea and copper amounts. The sensor was constructed using silver nanoparticles (AgNPs) deposited on screen‐printed electrodes. Its performance was studied in a synthetic leaching solution; changes in the overall surface charge of AgNPs resulting in changes in the charge‐transfer resistance for the copper ions were evaluated by electrochemical impedance spectroscopy.     

Ionic liquid behavior and high thermal stability of silver chloride nanoparticles: Synthesis and characterization

Silver chloride was found to be stable even after calcination at 650 °C for 10 h. SEM studies revealed the morphology of silver chloride as hexagonal particles. TEM studies show the size of silver chloride particles to have an average size of 6–7 nm. Thermal studies suggest that silver chloride nanoparticles behave like ionic liquid or molten salt in the range of 455–650 °C.     

Development of a manual method for the determination of mineral oil in foods and paperboard

So far the majority of the measurements of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) were obtained from on-line high performance liquid chromatography–gas chromatography–flame ionization detection (on-line HPLC–GC–FID). Since this technique is not available in many laboratories, an alternative method with more easily available tools has been developed. Preseparation on a small conventional liquid chromatographic column was optimized to achieve robust separation between the MOSH and the MOAH, but also to keep out the wax esters from the MOAH fraction. This was achieved by mixing a small portion of silica gel with silver nitrate into highly activated silica gel and by adding toluene into the eluent for the MOAH. Toluene was also added to the MOSH fraction to facilitate reconcentration and to serve as a keeper preventing loss of volatiles during solvent evaporation. A 50 μl volume was injected on-column into GC–FID to achieve a detection limit for MOSH and MOAH below 1 mg/kg in most foods.