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A methyl group on an arene, despite its small size, can have a profound influence on biologically active molecules. Typical methods to form a methylarene involve strong nucleophiles or strong and often toxic electrophiles. We report a strategy for a new, highly efficient, copper and iodide co-catalyzed methylation of aryl- and heteroarylboronic esters with the mild, nontoxic reagent trimethylphosphate, which has not been used previously in coupling reactions. We show that it reacts in all cases tested in yields that are higher than those of analogous copper-catalyzed reactions of MeOTs or MeI. The combination of C-H borylation and this methylation with trimethylphosphate provides a new approach to the functionalization of inert C-H bonds and is illustrated by late-stage methylation of four medicinally active compounds. In addition, reaction on a 200 mmol scale demonstrates reliability of this method. Mechanistic studies show that the reaction occurs by a slow release of methyl iodide by reaction of PO(OMe)3 with iodide catalyst, rather than the typical direct oxidative addition to a metal center. The low concentration of the reactive electrophile enables selective reaction with an arylcopper intermediate, rather than nucleophilic groups on the arylboronate, and binding of tert-butoxide to the boronate inhibits reaction of the electrophile with the tert-butoxide activator to form methyl ether.

A methyl group on an arene, despite its small size, can have a profound influence on biologically active molecules. Typical methods to form a methylarene involve strong nucleophiles or strong and often toxic electrophiles. We report a strategy for a new, highly efficient, copper and iodide co-catalyzed methylation of aryl- and heteroarylboronic esters with the mild, nontoxic reagent trimethylphosphate, which has not been used previously in coupling reactions. We show that it reacts in all cases tested in yields that are higher than those of analogous copper-catalyzed reactions of MeOTs or MeI. The combination of C-H borylation and this methylation with trimethylphosphate provides a new approach to the functionalization of inert C-H bonds and is illustrated by late-stage methylation of four medicinally active compounds. In addition, reaction on a 200 mmol scale demonstrates reliability of this method. Mechanistic studies show that the reaction occurs by a slow release of methyl iodide by reaction of PO(OMe)3 with iodide catalyst, rather than the typical direct oxidative addition to a metal center. The low concentration of the reactive electrophile enables selective reaction with an arylcopper intermediate, rather than nucleophilic groups on the arylboronate, and binding of tert-butoxide to the boronate inhibits reaction of the electrophile with the tert-butoxide activator to form methyl ether.

The predominant method for pest control has been the use of pesticides, which have been shown to have detrimental effects on soil, freshwater, and crop quality. Therefore, the development of novel and sustainable crop protection strategies has become increasingly imperative. In this study, a novel orange–red emitting Ba2SrWO6: Sm3+ phosphor was synthesized using the high‐temperature solid‐state reaction. Under ultraviolet excitation, the phosphors showed obvious emission peaks at 575, 614, and 662 nm. The Ba2SrWO6: Sm3+ was used to fabricate a fluorescence film with polydimethylsiloxane (PDMS), and attracted twice as many insects as the blank control group under 365 nm ultraviolet light. This material holds great potential as a fluorescent agent for insect trapping in the pest control fields of tea, cotton, eggplant, rice, potato, grape, and other agricultural industries. Our findings provide an eco‐friendly approach to pest management for the increment of food production. [ABSTRACT FROM AUTHOR]

A novel nano‐ternary spinel oxides of Zn−Ni‐Co−O are synthesized via the coprecipitation method and used for detection towards Cu(II). The Zn doping effect on morphologies and microstructures of ZnxNi1‐xCo2O4 (x=0, 0.2, 0.4, 0.6, 0.8, 1.0) is systematically characterized and investigated. At the x of 0.4, the prepared Zn0.4Ni0.6Co2O4 modified electrode nanomaterials can realize electrochemical ultratrace detection of Cu(II), which shows the lowest detection limit of 1.96 nM with a linear range of 0.1 μM∼1.0 μM and the highest sensitivity of 15.2 μA/μM. Meanwhile, Zn0.4Ni0.6Co2O4 modified electrodes exhibit excellent repeatability (relative standard deviation (RSD) of 0.34 %), reproducibility (RSD of 0.3 %), stability (RSD of 3.0 %) as well as anti‐interference analysis, which has been successfully applied in the actual water environment. These results indicate that ZnxNi1‐xCo2O4 nanoparticles as a promising modified electrode materials for the electrochemical detection Cu(II). [ABSTRACT FROM AUTHOR]

It is of vital importance to design efficient and low-cost bifunctional catalysts for the electrochemical water splitting under alkaline and neutral pH conditions. In this work, we report an efficient and stable NiCo2S4/N, S co-doped reduced graphene oxide (NCS/NS-rGO) electrocatalyst for water splitting, in which NCS microspheres are composed of one-dimentional (1D) nanorods grown homogeneously on the surface of NS-rGOs). The synergetic effect, abundant active sites, and hybridization of NCS/NS-rGO endow their outstanding electrocatalytic performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in both alkaline and neutral conditions. Furthermore, NCS/NS-rGO employed as both anode and cathode in a two-electrode alkaline and neutral system electrolyzers deliver 10 mA/cm2 with the low cell voltage of 1.58 V in alkaline and 1.91 V in neutral condition. These results illustrate the rational design of carbon-supported nickel-cobalt based bifunctional materials for practical water splitting over a wide pH range. [ABSTRACT FROM AUTHOR]

ZnFe2O4 (ZFO) spinel magnetic nanoparticles with a small particle size (11.2 nm) and large specific surface area (54.1 m2/g) are synthesized by a one-step hydrothermal method without the calcination process. ZFO-modified electrodes are first utilized for the simultaneous electrochemical trace detection of Hg-(II), Pb-(II), and Cu-(II), which show an outstanding linear response for Hg-(II), Pb-(II), and Cu-(II), and the limit of detection (LOD) is 1.61, 7.38, and 12.03 nM, respectively. Meanwhile, ZFO-modified electrodes exhibit excellent repeatability [relative standard deviation (RSD) of 0.785%], reproducibility (RSD of 0.896%), stability (RSD of 3.240%), and anti-interference analysis, which is successfully applied to the real water environment. Moreover, the ZFO-modified electrode also exhibits a high sensitivity of 1160 μA mM–1 cm–2 and LOD of 0.8 μM for glucose. These results indicate that ZFO nanoparticles as a promising modified electrode material will be potentially applied in the field of electrochemical sensors for heavy metal ions and nonenzymatic glucose. [ABSTRACT FROM AUTHOR]

Designing low-cost and high-performance bifunctional electrocatalysts towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is vitally important for water splitting. Herein, we synthesize Co2−xNixO2 (0 < x < 1.0) hexagonal nanosheets with different Co/Ni molar ratios via a facile coprecipitation process followed by calcination under an Ar atmosphere. Changing the Co/Ni molar ratios of the Co2−xNixO2 products is found to have a momentous influence on the microstructures, specific surface areas and electrocatalytic performances. At a Co/Ni molar ratio of 0.6, the Co1.4Ni0.6O2 nanosheet exhibits the largest specific surface area of 60.63 m2 g−1, the best OER with an onset overpotential of 278.5 mV, and HER of 72.8 mV as a bifunctional electrocatalyst. Meanwhile, the minimum Tafel slope is 113.6 mV dec−1 for OER and 77.4 mV dec−1 for HER. The Co1.4Ni0.6O2 nanosheet has excellent OER and HER activity at 0.1 mg cm−2 trace loading. Moreover, we construct an overall water splitting cell using the Co1.4Ni0.6O2 bifunctional electrocatalyst in a two-electrode system to further demonstrate the practical application, which needs a cell voltage of 1.75 V at a current density of 10 mA cm−2 and exhibits great long-term stability. These results provide an efficient strategy for the rational design of Co-based oxides towards bifunctional overall water electrocatalysts. [ABSTRACT FROM AUTHOR]

Mesoporous CoNiO2 (CNO) hexagonal nanoparticles are prepared via a hydrothermal microwave carbon bath process. The nanostructure and morphology of CNO NPs prepared at different hydrothermal temperatures are systematically studied and characterized. At the hydrothermal temperature of 140 °C, CNO hexagonal nanoparticles have a porous structure and a specific surface area of 53.56 m2 g−1. In addition, the as-prepared CNO electrode material exhibits a large capacitance of 801.00 F g−1 at a current density of 0.5 A g−1. The assembled CNO asymmetric supercapacitor shows a high energy density of 10.34 W h kg−1 at the power density of 300 W kg−1, which shows great potential as a novel electrode material in energy storage applications. [ABSTRACT FROM AUTHOR]