Microwave Irradiation for Accelerating Synthesis of 5,6-Diphenylimidazo[1,2-a]pyrimidines Based on Isoflavones

Microwave irradiation was used to accelerate the cyclocondensation of isoflavones with 2-aminoimidazole to synthesize 5,6-diphenylimidazo[1,2-a]pyrimidines. A series of 17 new compounds were characterized by Fourier transform infrared, NMR, and elemental analysis. 5-(2-Hydroxyl-4-isopropoxyphenyl)-6-phenylimidazo-[1,2-a]pyrimidine was determined by x-ray diffraction. A variety of substrates can participate in the process with good yields and purities, making this methodology suitable for library synthesis in drug discovery.      

A silver(I)–rhodium(I) cooperative catalysis in the reaction of N′-(2-alkynylbenzylidene)hydrazide with 2-vinyloxirane

A novel and efficient route to H-pyrazolo[5,1-a]isoquinoline-1-carbaldehydes via a tandem reaction of N′-(2-alkynylbenzylidene)hydrazide with 2-vinyloxirane is described. The reaction proceeds through a silver(I)–rhodium(I) cooperative catalysis.     

Fusion Dynamics of Aqueous Glutamic Acid/Aminodecane/Ibuprofen Vesicles

Vesicles have been prepared at a constant molar ratio of L-glutamic acid/1-aminodecane/ibuprofen/H₂O. The fusion dynamics of the vesicles have been directly observed and followed by using optical microscopy and freeze fracture replication-electron microscopy technologies. With time increasing up to 25 minutes, the vesicles slowly fuse to form large stable vesicles. A membrane phase transition temperature is detected at 97°C.     

羟基磷灰石及其复合材料对重金属的吸附研究进展

羟基磷灰石具有特殊的晶体结构,对二价的重金属离子有很强的结合力,是一种可用于环境污染治理的新型功能性材料。它可有效地吸附去除水中的Pb2+,Cd2+,Cu2+,Zn2+,Co2+,Ni2+等重金属离子,但其粉体的结构却限制了它在水环境中的实际应用。随着纳米技术、复合材料技术的发展,在羟基磷灰石的基础上开发出的具有高效吸附性能或分离特性的新型材料在重金属吸附研究中显示了潜在的优势。本文综述了羟基磷灰石及其复合材料对水中重金属去除方面的研究进展,探讨了它对重金属吸附机理,并对羟基磷灰石进一步的研究提出了展望。     

Preparation and characterization of ZrCO/C composite aerogels

Zr-containing organic aerogels were synthesized by ligand substitution reaction of polyzirconoxone and 2, 4-dihydroxybenzoic acid, followed by polymerization with formaldehyde, and then supercritical drying using CO₂. After carbonization and carbothermal reduction under an argon atmosphere, ZrCO/C composite aerogels with controllable zirconium content (47.8–78.6 wt%) were obtained. The carbothermal reduction was substantially completed at 1,500 °C, and the obtained ZrCO/C composite aerogels exhibit low oxygen contents (9.4–6.7 wt%) and high surface areas (589–147 m²/g). Pore morphologies of the ZrCO/C composite aerogels were investigated in detail by nitrogen sorption measurements, scanning electron microscopy and its associated energy-dispersive X-ray microanalysis measurements. The results show that the aerogels are composed of carbon framework and Zr-conglomerations, and the surface area of aerogel is severely affected by its zirconium content. The presence of reductive ZrC crystals can greatly enhance the oxidation resistance ability of amorphous carbon framework and prevent collapse.     

Self‐Assembled Poly(N‐methylaniline)–Lignosulfonate Spheres: From Silver‐Ion Adsorbent to Antimicrobial Material

Self‐assembled poly(N‐methylaniline)–lignosulfonate (PNMA–LS) composite spheres with reactive silver‐ion adsorbability were prepared from N‐methylaniline by using lignosulfonate (LS) as a dispersant. The results show that the PNMA–LS composite consisted of spheres with good size distribution and an average diameter of 1.03–1.27 μm, and the spheres were assembled by their final nanofibers with an average diameter of 19–34 nm. The PNMA–LS composite spheres exhibit excellent silver‐ion adsorption; the maximum adsorption capacity of silver ions is up to 2.16 g g^?1 at an adsorption temperature of 308 K. TEM and wide‐angle X‐ray results of the PNMA–LS composite spheres after absorption of silver ions show that silver ions are reduced to silver nanoparticles with a mean diameter of about 11.2 nm through a redox reaction between the PNMA–LS composite and the silver ions. The main adsorption mechanism between the PNMA–LS composite and the silver ions is chelation and redox adsorption. In particular, a ternary PNMA–LS–Ag composite achieved by using the reducing reaction between PNMA–LS composite spheres and silver ions can be used as an antibacterial material with high bactericidal rate of 99.95 and 99.99 % for Escherichia coli and Staphylococcus aureus cells, respectively.     

Dynamic Electrosorption Analysis as an Effective Means to Characterise the Structure of Bulk Graphene Assemblies

Restacking of graphene sheets to a graphite‐like structure is a prevailing problem that is known to compromise the performance of individual graphene sheets in an assembled bulk form. To address this common problem efficiently and monitor the structure and quality of graphene products comprehensively, it is highly desirable to develop reliable metrology techniques for characterising graphene‐based materials on a bulk assembly level and in a quantitative manner. Here, by revisiting the physicochemical principle of electrosorption, we propose a simple electrochemical approach, namely dynamic electrosorption analysis (DEA), as an easily accessible and effective technique for evaluation of the self‐stacking behaviour of graphene. Taking multilayered chemically converted graphene films as a model, we demonstrate that the DEA technique can effectively reveal very subtle variation in accessible surface area and pore size of graphene assemblies in the liquid phase and thus can provide useful insights to the experimental design relating to restacking control. This work also reveals the huge effect some routine processing conditions, such as heat treatment and drying, can have on the structure and performance of graphene‐based bulk materials, providing useful guidance for future manufacturing of this class of materials.     

A Low‐dimensional Viologen/Iodoargentate Hybrid [(BV)2­(Ag5I9)]n: Structure,Properties, and Theoretical Study

A new low‐dimensional benzyl viologen/iodoargentate hybrid, [(BV)₂(Ag₅I₉)]_n ( 1 ) (BV²⁺ = benzyl viologen) was prepared. In 1 , (Ag₆I₉)_n^2– chain exhibits a new type of one‐dimensional chain constructed from vertex‐sharing of Ag₅I₁₀ units, and its two‐dimensional layer structure was constructed from C–H ··· I hydrogen bonds. Strong luminescence at 404 nm can be detected in 1 . DFT calculation suggests that 1 displays a reduced bandgap, which is led by a more dispersed LUMO band of BV²⁺ compared with MV²⁺ in [MV(Ag₂I₄)]_n.     

The effect of tourmaline on cell membrane of nitrosomonas europaea and biodegradation of micropollutant

As a kind of ammonia‐oxidizing bacteria, Nitrosomonas europaea (N. europaea) was chosen as a research model to study the alteration of cell membrane in the presence of tourmaline and biodegradation of acetochlor. atomic force microscopy images reveal that the presence of tourmaline substantially changes the structure of the outer membrane of the cell responsible for the cell permeability. SEM images show that the introduction of tourmaline makes the cell lose its ability to resist lysozyme owing to the damages. The fluorescence polarization has shown a significant decrease in membrane fluidity and the increase of permeability of cell membrane. Ca²⁺ and Mg²⁺ was measured using inductively coupled plasma mass spectrometry and was found in the supernatant from the cells treated by tourmaline. Tourmaline can improve the efficiency of biodegradation of acetochlor for N. europaea. It is proposed that the cell permeability is slightly increased, and the absorbability of nutrition from the medium becomes easier. As a result, N. europaea grows faster in the presence of tourmaline than the native cells. Copyright © 2014 John Wiley & Sons, Ltd.