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211.
In the present study, biosynthesis of CuO nanoparticles using a rapid, eco‐friendly, cost‐effective and efficient method has been reported employing aqueous Euphorbia maculata extract as mild, renewable and non‐toxic reducing and capping agents without adding any surfactants. The biogenic and green method has some benefits compared to conventional physical and chemical methods. It is simple, cheap and environmentally friendly. The biosynthesized CuO NP displayed a color change pattern (from sky blue to black) on preparation and presented its respective broad peak at 365 nm, which was analyzed by UV–Vis spectroscopy. Using the FT‐IR analysis, biomolecules in E. maculata extract which are responsible for bioreduction activity and synthesize of CuO NP, were identified. The XRD, EDX and FESEM results confirmed the successful synthesis of CuO nanoparticles of 18 nm sizes, with spherical and sponge crystal structure. The catalytic activity of biosynthesized CuO NPs was studied in C‐S cross‐coupling reaction. This method has the advantages of high yields, easy work‐up, and simple reusability. The recovered CuO NP can be reused four times without any considerable loss of its catalytic activity. 相似文献
212.
Gold nanoparticles have unique and excellent medical and nonmedical properties and application compared with other metallic nanoparticles. Recently, they have been used for the prevention, control, and treatment of bacterial and fungal diseases. In the recent study, fresh and clean leaves of Allium noeanum Reut. ex Regel leaves have been used for the synthesis of gold nanoparticles. Also, we evaluated the cytotoxicity, antioxidant, and antibacterial properties of HAuCl4, A. noeanum, and the synthesized nanoparticles (Au NPs). These nanoparticles were analyzed by FT‐IR, UV, XRD, EDS, FE‐SEM, and TEM tests. FTIR results offered antioxidant compounds in the plant were the sources of reducing power, reducing gold ions to Au NPs. In TEM images revealed an average diameter of 10‐30 nm. At the beginning of biological experiments, DPPH free radical scavenging test was carried out to examine the antioxidant property. Also, in the bacterial part of this study, the concentration of HAuCl4, A. noeanum, and AuNPs with minimum dilution and no turbidity was considered MIC. To determine MBC, 60 μL of MIC and three preceding chambers were cultured on Muller Hinton Agar. The minimum concentration with no bacterial growth was considered MBC. Au NPs revealed excellent antioxidant potential against DPPH, non‐toxicity property against human umbilical vein endothelial cells, and antibacterial activities against Streptococcus pneumonia, Bacillus subtilis, Staphylococcus aureus, Staphylococcus saprophyticus, Salmonella typhimurium, Pseudomonas aeruginosa, Shigella flexneri, and Escherichia coli O157:H7. These findings show that the inclusion of A. noeanum extract improves the solubility of Au NPs, which led to a notable enhancement in the antioxidant and antibacterial effects. 相似文献
213.
2,3-Disubstituted Fluorene Scaffold for Efficient Green Phosphorescent Organic Light-Emitting Diodes
Jia-Jia Wei Yong-Jian Yang Dr. Xiang-Yang Liu Dr. Runlai Li Prof. Dr. Shu-an Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(39):e202200756
Fluorene is a classic three-membered polycyclic aromatic hydrocarbon, and it has been widely used in optoelectronic devices. Here we explore a simple and efficient strategy for the derivatization at the 2- and 3- positions in fluorene unit. By introducing different types of substituents, we design two pairs of 2,3-disubstituted fluorene isomers and use them as host materials for phosphorescent organic light-emitting diodes (PHOLEDs). The green PHOLEDs hosted by these fluorene derivatives realize high external quantum efficiencies (EQE) over 20 % with low efficiency roll-off. Particularly, the devices hosted by 2TRz3TPA and 2TPA3TRz achieve nearly 24 % EQE and 104 lm W−1 power efficiency. These results clearly demonstrate that the 2,3-disubstituted fluorene platforms are potentially useful for constructing host materials. 相似文献
214.
Mahdieh Yahyazadehfar Enayatollah Sheikhhosseini Sayed Ali Ahmadi Dadkhoda Ghazanfari 《应用有机金属化学》2019,33(9)
In this study, Co3O4 nanocatalysts were constructed in environmentally appropriate conditions using controlled, effective, and facile microwave method. The final nanostructures were characterized by SEM, XRD, and TEM analyses. The products had a small size distribution, homogeneous morphology, and crystallographic structures associated with the formation of Co3O4 nanostructures. Moreover, EDS mapping analysis confirmed the existence of Co and O elements in the final structure, and the magnetic properties of the samples were investigated by VSM. The application of this nanostructure in a catalytic process was further examined, and the results suggested that it could be used as a novel candidate for the synthesis of arylidene barbituric and Meldrum,s acid through Knoevenagel condensation of aldehydes by barbituric and Meldrum,s acid in aqueous media. The high yield of these nanocatalysts would be justified by the nature of the nanostructure as well as the experimental procedure developed in this study, which affected the physicochemical features of the products. 相似文献
215.
Ambarish Mondal Rajat K. Tripathy Parul Dutta Manas Kumar Santra Anvarhusein A. Isab Christopher W. Bielawski Hemanta K. Kisan Swapan K. Chandra Joydev Dinda 《应用有机金属化学》2019,33(1)
The syntheses, structures, and chemotherapeutic activities of Ag(I)‐, Au(I)‐, and Ru(II)‐complexes ligated to a novel N‐heterocyclic carbene ligand, 2‐(4‐nitrophenyl)imidazo[1,5‐a]pyridin‐2‐ylidene ( 1 ), are described. The corresponding complexes, [Ag( 1 )2][PF6], [Au( 1 )2][PF6] ( 3 ), and [Ru( 1 )(p‐cymene)Cl][PF6] ( 4 ), were prepared using convenient transmetallation chemistry and characterized using a range of spectroscopic and analytical techniques. X‐ray crystallography revealed that complexes 2 and 3 adopted linear structures whereas 4 exhibited a prototypical “piano‐stool”‐like geometry; the structural assignments were further supported by DFT calculations. A series of in vitro studies revealed that while the aforementioned Ag(I), Au(I) and Ru(II) complexes exhibited significant cytotoxicities against the human colon adenocarcinoma (HCT 116), lung cancer (A549), and breast cancer (MCF7) cell lines, the Ru derivative was most prominent. 相似文献
216.
In this study, nanocrystalline cellulose (NCC) prepared from microcrystalline cellulose using high‐intensity ultrasonication as mechanical method without any chemical treatment. The obtained NCC with around 30–50 nm diameters, utilized as support, reducing and stabilizing agent for in‐situ green and eco‐friendly synthesis of silver nanoparticles (Ag NPs). The catalytic activity of composite was examined for degradation of environmental pollutants. The structure of as‐synthesized composite (Ag@NCC) was characterized by ultraviolet–visible spectroscopy (UV–vis), field emission scanning electron microscopy (FE‐SEM); Transmission electron microscopy (TEM); Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD) and thermogravimetric analysis (TGA). The results of the catalytic reaction experiments showed that spherically shaped silver nanoparticles of around 20 nm distributed on the surface of nanocellulose demonstrated high catalytic efficiency towards the removal of methyl orange (MO) and 4‐nitrophenol (4‐NP). 相似文献
217.
CoO–xCo(OH)2 supported silver nanoparticles: electrosynthesis in acetonitrile and catalytic activity
《Mendeleev Communications》2020,30(4):456-458
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218.
Nagaraju Kerru Lalitha Gummidi Surya Narayana Maddila Sandeep V.H.S. Bhaskaruni Sreekantha B. Jonnalagadda 《应用有机金属化学》2020,34(5):e5590
The bismuth loaded on fluorapatite (Bi2O3/FAp) proved to be an excellent catalyst for the synthesis of novel dihydro-[1,2,4]triazolo[1,5-a]pyrimidine derivatives via a three-component reaction involving the mixture of 1H-1,2,4-triazol-5-amine, ethyl cyanoacetate or ethyl acetoacetate, and different benzaldehydes in ethanol at room temperature. The catalyst material was characterized by X-ray diffraction, Brunauer–Emmett–Teller surface area analysis, Fourier-transform infrared, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy techniques. The efficacy of Bi2O3/FAp as a heterogeneous catalyst was evaluated with the loading of different wt% of bismuth on FAp. The 2.5% bismuth on FAp performed extremely well as a catalyst with a high yield of products (92%–96%) in a short reaction time (25–35 min). The catalyst was recovered by simple filtration. It showed undiminished activity up to five runs. Simple work-up, room temperature reaction, short reaction time, high yields, no column chromatography, and good reusability of catalyst are the merits of the proposed protocol. In addition, this process offers 100% carbon efficiency and 98% atom economy with noteworthy fiscal and environmental benefits. 相似文献
219.
Somayeh Rahaiee Mojtaba Ranjbar Hossein Azizi Mostafa Govahi Mahboobeh Zare 《应用有机金属化学》2020,34(8):e5705
To increase the profitability and sustainability of agricultural waste, a facile green approach was established to synthesize zinc oxide nanoparticles (ZnO NPs) using saffron leaf extract as a reducing and stabilizing agent. Structural characteristics of NPs were investigated by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), field emission scanning electron microscopy (FESEM), and UV–Visible (UV–Vis) spectroscopy. Characterization results revealed that ZnO NPs is highly crystalline with a hexagonal wurtzite structure and spherical particles with diameter less than 50 nm, as confirmed by XRD and FESEM techniques. UV–Vis absorption spectra depicted an absorption peak at 370 nm, which confirms the formation of ZnO NPs. FTIR spectral analysis confirmed the presence of functional groups and metal oxygen groups. The biological activities of ZnO NPs were also investigated. The antibacterial effect of ZnO NPs was investigated against selected food pathogens (Salmonella Typhimurium, Listeria monocytogenes, and Enterococcus faecalis). The study results prove that the green synthesized ZnO NPs show enhanced antibacterial activity against S. Typhimurium when compared with other strains. A dose-dependent free radical scavenging activity was observed for ZnO NPs in both 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and fluorescence recovery after photobleaching (FRAP) assays. The ZnO NPs were evaluated for their photocatalytic activity during the degradation of methylene blue (MB) dye in aqueous solutions. The maximum removal of MB achieved was 64% with an initial ZnO NP concentration of 12 mg/mL under UV light. The present study revealed that the agricultural waste (saffron leaf) provides a simple and eco-friendly option to sustainably synthesize ZnO NPs for use as a photocatalyst. In addition, this is the first report on saffron leaf-mediated synthesis of ZnO NPs. 相似文献
220.
通过熔融退火的方法以及热处理技术制备得到含有Er2WO6,La2WO6晶体的TeO2-WO3-La2O3-Er2O3-Yb2O3微晶玻璃,该玻璃具有优异的上转换发光性能。结果表明,在含银纳米晶的碲酸盐微晶玻璃中,银纳米晶和微晶的析出情况与银纳米晶的引入方式和热处理温度有关。经过390℃下15 min的热处理后,AgCl和AgNO3共掺的碲酸盐微晶玻璃比单掺AgCl或AgNO3的碲酸盐微晶玻璃具有更高的发光强度。银纳米晶与微晶的引入可协同提高碲酸盐玻璃的上转换发光性。 相似文献