Synthesis and structure of bis(dibenzoylmethane)copper(II)

Bis(dibenzoylmethane)copper Cu(dbm)₂ has been synthesized and its structure determined by x-ray diffraction. It crystallizes in the monoclinic system, space group C2/c, with a = 25.936(3), b = 5.9806(8), c = 16.4908(16) Å, = 114.998(8)°, Z = 4, and V = 2318.3(4) ų. The Cu atom is located at a symmetry center and surrounded by four O atoms from two dbm molecules to form a plane square coordination environment. On the a–c plane the molecules are orderly arranged to result in a layered structure, and parallel to crystallographic b-axis they form a molecular column due to the effect of aromatic stacking.     

Atomically Thin Defect‐Rich Fe–Mn–O Hybrid Nanosheets as High Efficient Electrocatalyst for Water Oxidation

Engineering non‐noble metal–based electrocatalysts with superior water oxidation performance is highly desirable for the production of renewable chemical fuels. Here, an atomically thin low‐crystallinity Fe–Mn–O hybrid nanosheet grown on carbon cloth (Fe–Mn–O NS/CC) is successfully synthetized as an efficient oxygen evolution reaction (OER) catalyst. The synthesis strategy involves a facile reflux reaction and subsequent low‐temperature calcination process, and the morphology and composition of hybrid nanosheets can be tailored conveniently. The defect‐rich Fe–Mn–O ultrathin nanosheet with uniform element distribution enables exposure of more catalytic active sites; moreover, the atomic‐scale synergistic action of Mn and Fe oxide contributes to an enhanced intrinsic catalytic activity. Therefore, the optimized Fe–Mn–O hybrid nanosheets, with lateral sizes of about 100–600 nm and ≈1.4 nm in thickness, enable a low onset potential of 1.46 V, low overpotential of 273 mV for current density of 10 mA cm^?2, a small Tafel slope of 63.9 mV dec^?1, and superior durability, which are superior to that of individual MnO₂ and FeOOH electrode, and even outperforming most reported MnO₂‐based electrocatalysts.     

CO<Subscript>2</Subscript>-responsive Polymeric Fluorescent Sensor with Ultrafast Response

Abstract Response speed is one of the most important evaluation criteria for CO₂ sensors. In this work, we report an ultrafast CO₂ fluorescent sensor based on poly[oligo(ethylene glycol) methyl ether methacrylate]-b-poly[N,N-diethylaminoethyl methacrylate-r-4-(2-methylacryloyloxyethylamino)-7-nitro-2,1,3-benzoxadiazole] [POEGMA-b-P(DEAEMA-r-NBDMA)], in which DEAEMA units act as the CO₂-responsive segment and 4-nitrobenzo-2-oxa-1,3-diazole (NBD) is the chromophore. The micelles composed of this copolymer could disassemble in 2 s upon CO₂ bubbling, accompanying with enhanced fluorescence emission with bathochromic shift. Furthermore, the quantum yield of the NBD chromophore increases with both the CO₂ aeration time and the NBD content. Thus we attribute the fluorescent enhancement to the inhibition of the photo-induced electron transfer between unprotonated tertiary amine groups and NBD fluorophores. The sensor is durable although it is based on “soft” materials. These micellar sensors could be facilely recycled by alternative CO₂/Ar purging for at least 5 times, indicating good reversibility.     

TEMPO/CuI synergetic catalyzed oxidative cross-coupling of indoles with benzylamines: Synthesis of bis(indolyl)phenylmethanes

TEMPO/CuI was found to be an effective catalyst for the cross-coupling of indoles with benzylic amines affording the corresponding bis(indolyl)phenylmethanes under air atmosphere at room temperature in good to excellent yields. The efficiency, easy workup, simplicity, and chemoselectivity of this protocol provide a green and low-cost procedure for the synthesis of these compounds.     

Design,synthesis and evaluation of a novel fluorescent probe to accurately detect H2S in lysosomes

A novel H₂S-responsive fluorescent probe Rh-Lyso-H₂S has been designed and synthesized. The Rh-Lyso-H₂S shows high sensitivity and selectivity toward H₂S, with a limit of detection of 3.36?×?10^?7?M. The reason is that Rh-Lyso-H₂S changed from a stable non-conjugated closed-ring lactone conformation with weak fluorescence to a conjugated open-ring conformation with strong fluorescence in the presence of H₂S. The Rh-Lyso-H₂S has a good lysosome-targeting capacity and is used to detect lysosomal H₂S in living cells, which is driven via the protonation of its basic morpholine moiety by acidic lysosomes. Rh-Lyso-H₂S is triggered by H₂S via removing the thiophenecarboxylate group, and the corresponding activated mechanism of Rh-Lyso-H₂S toward H₂S is proposed.     

Novel graphene oxide/bentonite composite for uranium(VI) adsorption from aqueous solution

A novel graphene oxide/bentonite composite (GO/bentonite) was synthesized and then characterized through powder X-ray diffraction, fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and energy dispersive spectroscopy. Adsorption achieved equilibrium within 10 min. Moreover, U(VI) adsorption on GO/bentonite was highly dependent on solution pH and independent of ionic strength. These characteristics suggested that inner-sphere surface complexes of U(VI) formed on GO/bentonite. The adsorption of U(VI) from aqueous solution on GO/bentonite was fitted to the pseudo-second-order and Freundlich isotherm models. The maximum sorption capacity of GO/bentonite was 234.19 mg g^?1 under neutral pH at 303 K. GO/bentonite is a potentially powerful adsorbent for the efficient removal of U(VI) from aqueous solutions.     

HTLC: A Viable Approach to Fast LC of Biogenic Amines in Food with Legacy Equipment

Nowadays, there is a demand for fast liquid chromatography (LC) of biogenic amines in food with the equipment available in the average laboratory. To this end, high-temperature liquid chromatography (HTLC) is presented in this study as a viable option, working on a conventional LC platform at moderately high temperatures up to 80 °C. The LC platform was adapted by including an appropriate length of stainless-steel microbore tubing as a preheater. Biogenic amines as benzoyl derivatives showed good thermostability on a thermally rugged column (150?×?4.6 mm, 5 µm). As a model application the HTLC conditions were developed for wine separation. The separation selectivity changed considerably with temperature in the range 36–84 °C, and baseline resolution was obtained only at temperatures well above ambient. At 73 °C oven temperature, the system allowed a flow rate as high as 3 mL min^?1 with the backpressure not exceeding 195 bar (2800 psi). The separation took less than 5 min, comparably fast to documented fast LC separations, and typically at least three to five times faster than a conventional separation.     

Experimental Evidence for a Triboluminescent Antiperovskite Ferroelectric: Tris(trimethylammonium) catena‐Tri‐μ‐chloro‐manganate(II) Tetrachloromanganate(II)

The perovskite structure is rich in ferroelectricity. In contrast, ferroelectric antiperovskites have been scarcely confirmed experimentally since the discovery of M₃AB‐type antiperovskites in the 1930s. Ferroelectricity is now revealed in an organic–inorganic hybrid X₃AB antiperovskite structure, which exhibits a clear ferroelectric phase transition 6/mmmF6mm with a high Curie point of 480 K. The physical properties across the phase transition are obviously changed along with the symmetry requirements, providing solid experimental evidence for the ferroelectric phase transition. More interestingly, the discovered antiperovskite shows intense photoluminescence and triboluminescence properties. The confirmation of the triboluminescent ferroelectric antiperovskite will open new avenues to explore excellent optoelectronic properties in the antiperovskite family.