Research on the synthesis of nanomaterials using metal-organic frameworks (MOFs), which are characterized by multi-functionality and porosity, as precursors have been accomplished through various synthetic approaches. In this study, copper and copper oxide nanoparticles were fabricated within 30 min by a simple and rapid method involving the reduction of a copper(II)-containing MOF with sodium borohydride solution at room temperature. The obtained nanoparticles consist of a copper core and a copper oxide shell exhibited catalytic activity in the oxygen reduction reaction. The as-synthesized Cu@Cu2O core-shell nanocatalyst exhibited an enhanced limit current density as well as onset potential in the electrocatalytic oxygen reduction reaction (ORR). Moreover, the nanoparticles exhibited good catalytic activity in the Huisgen cycloaddition of various substituted azides and alkynes under mild reaction conditions.

A highly porous copper metal-organic framework, [Cu 3 (BTC) 2 ] (BTC = benzene-1,3,5-tricarboxylate) was synthesized and used as a precursor for the synthesis of copper nanoparticles (NPs) and characterized by several techniques, including XRD, SEM, TEM, EDX and BET measurements. The as-synthesized copper nanoparticles were immobilized onto activated charcoal (AC) by means of ultrasonication at room temperature without any pretreatment. The Cu NPs/AC was employed as a heterogeneous catalyst for the cross-coupling of diphenyl diselenide and boronic acids to form diphenyl selenides through SeÀSe bond activation under ligand-, base-, and additive-free conditions. The copper NPs/AC, which combines the architecture of MOFs and the high surface area of charcoal, could be an efficient heterogeneous catalytic system that is compatible with a variety of substituents on diphenyl selenides. Its promising catalytic activity relative to that of other homogeneous systems and low catalyst loading for the synthesis of unsymmetrical diaryl selenides is an important application in the area of nanocatalysis. The Cu NPs/AC catalyst, which exhibits excellent catalytic activity and remarkable tolerance to a wide variety of substituents, led to Se sp 3 -, sp 2 -, and sp-carbon bond formation by using DMSO as a solvent and atmospheric air as oxidant. This approach can also be extended to the preparation of unsymmetrical organotelluride derivatives.Copper catalysts for cross-coupling reactions are an intense field of research because they are cost-effective and hold promise for the replacement of expensive metal sources for industrial purposes. Over the past decade, the construction of carbonÀselenium bonds has been an intriguing topic for researchers and the number of related publications has increased exponentially to date, mainly owing to the important therapeutic characteristics of these bonds, such as their antimicrobial, antiviral, antitumor, and antioxidant properties. In addition, chalcogens are important constituents of functional groups in biomolecules (i.e., those associated with redox chemistry) in eukaryotic biochemistry.[1] Moreover, seleniumbased ionic liquids have proven to be efficient catalysts in reactions such as the carbonylation of aniline, oxidation of thiols, syntheses of octahydroacridines and thioacetals, and the Baylis-Hillman reaction of aldehydes and electron-deficient alkenes. [2][3][4][5][6][7] Over the past decade, extensive work has been devoted to developing new methodologies for the creation of bonds between sp 3 -, sp 2 -, sp-carbon atoms and organochalcogens, especially selenium-and tellurium-based compounds. To synthesize these moieties, a number of synthetic methods have been reported so far. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Of these, two methods are generally used. These methods involve the use of diphenyl diselenide (telluride) as starting precursor owing to its stability in air, environmental friendliness, and commercial availability. Diphenyl diselenide can be reacted w...

Multipodal manganese oxide nanocrystals, synthesized through the thermal decomposition of a Mn-oleate complex, exhibited catalytic activity for the synthesis of a quinoxaline derivative from a α-hydroxy ketone with a 1,2-diamine. The have been developed, such as the condensation of 1,2-dicarbonyl compounds and 1,2-diamines, [8] the oxidative coupling of epoxides and ene-1,2-diamines, [9] the double condensation of o-phenylenediamine with 1,2-diketones, [10] solid-phase synthesis, [11] and microwave-assisted protocols. [12,13] In recent years, many of the synthetic methods to give quinoxalines were performed in the presence of various catalysts, including iodine, [14] copper, [15] palladium, [16] bismuth powder, [9] cerium ammonium nitrate, [17] zeolites, [9,18] ironexchanged molybdophosphoric acid, [19] and graphite. [20] Furthermore, manganese oxides have been applied as catalysts for the preparation of quinoxalines. [13,[21][22][23] The synthesis of quinoxalines catalyzed by manganese octahedral molecular sieves and manganese dioxide has been reported. [24] Manganese oxide nanocrystals have attracted attention as MRI contrast agents, [25] catalysts, [21] electrode materials, [26] and biomedical materials owing to their unique chemical, physical, and magnetic properties. [27][28][29] Several [a] 1279 MnO nanocrystals are single crystalline and uniform multipodal, with an average estimated distance of (47 Ϯ 2) nm between the tips of two pods.

High frequency (HF) welding of linear low density polyethylene (LLDPE) melt blends with polyamide 6 (PA6) was done at 27.12 MHz using maleic anhydride grafted polyethylene (PE-g-MAH) as compatibilizer. HF welding was not possible for the blends at room temperature, but possible at higher temperatures (50, 808C) although the maximum relaxation frequency was lower than the operating frequency. Greater dielectric constant, dissipation factor, and welding performance were obtained when PA 6 was premixed with PE-g-MAH rather than the one-shot process where all the components were mixed simultaneously. This was interpreted in terms of lowered viscosity of PA 6 phase, which encapsulates the flow effectively and provides great skin effect. Also, the peeling force of resin-resin was greater than resin-nylon mesh due to the higher melting temperature and vacancy of nylon mesh.

HKUST-1, a copper-based metal organic framework (MOF), has been investigated as a catalyst in various reactions. However, the HKUST-1 shows low catalytic activity in the oxidation of catechol. Therefore, we synthesized Fe 3 O 4 @HKUST-1 by layer-by layer assembly strategy and Cu@Cu 2 O by reduction of HKUST-1 for enhancement of catalytic activity. Cu@Cu 2 O nanoparticles exhibited highly effective catalytic activity in oxidation of 3,5-di-tert-butylcatechol. Through this method, MOF can maintain the original core-shell structure and be used in various other reactions with enhanced catalytic activity.