查看更多>>摘要：Abstract An dual electronic and architectural engineering strategy is a good way to rationally design earth‐abundant and highly efficient electrocatalysts of the oxygen evolution reaction (OER) for sustainable hydrogen‐based energy devices. Here, a Ce‐doped Co9S8 core–shell nanoneedle array (Ce?Co9S8@CC) supported on a carbon cloth has been designed and developed to accelerate the sluggish kinetics of the OER. Profiting from valance alternative Ce doping, a fine core–shell structure and vertically aligned nanoneedle arrayed architecture, Ce?Co9S8@CC integrates modulated electronic structure, highly exposed active sites, and multidimensional mass diffusion channels; together, these afford a favorable catalyzed OER. Ce?Co9S8@CC exhibits remarkable performance in the OER in an alkaline medium, where the overpotential requires only 242?mV to deliver a current density of 10?mA?cm?2 for the OER; this is 70?mV superior to that of Ce‐free Co9S8 catalyst and other counterparts. Good stability and impressive selectivity (nearly 100?% Faradic efficiency) are also demonstrated. When integrated into a two‐electrode OER//HER electrolyzer, the as‐prepared Ce?Co9S8@CC displays a low operation potential of 1.54?V at 10?mA?cm?2 and long‐term stability, thus demonstrating great potential for economical water electrolysis.
查看更多>>摘要：Abstract Two‐photon polymerization (2PP) represents a powerful technique for the fabrication of precise three‐dimensional structures on a micro‐ and nanometer scale for various applications. While many review articles are focusing on the used polymeric materials and their application in 2PP, in this review the class of two‐photon photo initiators (2PI) used for radical polymerization is discussed in detail. Because the demand for highly efficient 2PI has increased in the last decades, different approaches in designing new efficient 2PIs occurred. This review summarizes the 2PIs known in literature and discusses their absorption behavior under one‐ and two‐photon absorption (2PA) conditions, their two‐photon cross sections (σTPA) as well as their efficiency under 2PP conditions. Here, the photo initiators are grouped depending on their chromophore system (D‐π‐A‐π‐D, D‐π‐D, etc.). Their polymerization efficiencies are evaluated by fabrication windows (FW) depending on different laser intensities and writing speeds.
查看更多>>摘要：Abstract In recent years all‐solid‐state sodium‐ion batteries (SS‐SIBs) have drawn significant attention due to their potential to be safer and lower cost than lithium‐ion batteries. However, the lack of sodium solid‐state electrolytes with high ionic conductivity has become one of the major challenges. Here, with first‐principles computation we took NaCuZrS3, consisting of earth‐abundant and environmentally benign elements only, as an example to study Na‐ion transport in the post‐perovskite‐like structure and used computation‐guided design to improve its potential as a solid‐state electrolyte. With ab initio molecular dynamics simulation and nudged elastic band calculation, we studied possible diffusion mechanisms in this material and found that Na ion interstitials have a favorable migration barrier of 0.22?eV, which is among the smallest in the literature reported values. Considering the large formation energy of Frenkel defects, we proposed doping strategy to introduce extra Na interstitials in the material. Our study suggests that the post‐perovskite‐like sulfides are worth of exploration for applications in SS‐SIBs.
查看更多>>摘要：Abstract An uncommon example of stable mixed‐ligand zinc phosphite with genuine pores has been synthesized by using zinc metal, inorganic phosphite acid, thio‐functionalized O‐donor (2,5‐thiophenedicarboxylate, TPDC), and tetradentate N‐donor [1,2,4,5‐tetrakis(imidazol‐1‐ylmethyl)benzene, TIMB] units assembled into one crystalline structure according to a hydro(solvo)thermal method. This is a very rare case of a metal phosphite incorporating both N‐ and O‐donor ligands. The tetradentate TIMB linker bound to zinc atoms of the isolated zincophosphite hexamers to form a 3D open‐framework structure by crosslinking structural components of 1D chains and 2D layers. Here, the TPDC ligand acts as a monodentate binding model to functionalize its porous structure with the uncoordinated S atom and COO? group. Interestingly, this compound demonstrates the highest H2 storage capacity among organic–inorganic hybrid metal phosphates (and phosphites), and a good CO2 capture at 298?K compared with the majority of crystalline materials. The possible adsorption sites and selectivity for CO2 over H2, N2, and CO at 298?K were calculated by using density functional theory (DFT), the ideal adsorption solution theory (IAST), and fitting experimental pure‐component adsorption data.
查看更多>>摘要：Abstract The increasing emergence of resistances against established antibiotics is a substantial threat to human health. The discovery of new compounds with potent antibiotic activity is thus of utmost importance. Within this work, we identify strong antibiotic activity of the natural product myxocoumarin B from Stigmatella aurantiaca MYX‐030 against a range of clinically relevant bacterial pathogens, including clinical isolates of MRSA. A focused library of structural analogs was synthesized to explore initial structure‐activity relationships and to identify equipotent myxocoumarin derivatives devoid of the natural nitro substituent to significantly streamline synthetic access. The cytotoxicity of the myxocoumarins as well as their potential to cure bacterial infections in vivo was established using a zebrafish model system. Our results reveal the exceptional antibiotic activity of the myxocoumarin scaffold and hence its potential for the development of novel antibiotics.
Nicolas CasarettoAudrey AuffrantCorinne GosminiPauline Schiltz...
8页
查看更多>>摘要：Abstract P,N phosphinoquinoline based ligands differing by the nature of the phosphorus substituent (iPr, Ph) were employed to synthesize a series of cobalt(II) complexes ([LCoBr2], [L2CoBr](PF6) and [L’2CoBr](PF6)). The latter were obtained in high yield and characterized among others by X‐ray analysis and elemental analysis. Complex [L2CoBr](PF6) showed a very good catalytic activity for the hydrosilylation of various ketones. The catalysis proceeds at a low catalytic loading (1?mol?%) with only 1 equivalent of Ph2SiH2 in mild conditions and was efficient with aliphatic or aromatic ketones giving moderate to excellent yields of the corresponding silylated ether.
查看更多>>摘要：Abstract Optically active cyclopropanes have been widely investigated especially from the views of pharmaceutical and agrochemical industries, and substituting one of the methylenes with the difluoromethylene unit should be promising for developing novel biologically relevant compounds and functional materials. In this paper, the copper‐catalyzed enantioselective hydrosilylation of gem‐difluorocyclopropenes to provide the corresponding chiral gem‐difluorocyclopropanes is presented. The use of copper(I) chloride, chiral ligands including bidentate BINAPs and monodentate phosphoramidites, and silylborane Me2PhSi‐Bpin accompanying sodium tert‐butoxide in methanol was appropriate for the enantioselective hydrosilylation of the strained C=C double bond, and the resultant chiral difluorinated three‐membered ring was unambiguously characterized. Subsequent activation of the silyl groups in enantio‐enriched gem‐difluorocyclopropanes showed substantial reduction of the enantiopurity, indicating cleavage of the distal C?C bond leading to the transient acyclic intermediates.
Anna GarbagnatiMichael SeidlGábor BalázsManfred Scheer...
9页
查看更多>>摘要：Abstract The oxidation of [(Cp*Mo)2(μ,η6:η6‐P6)] (1) with halogens or halogen sources was investigated. The iodination afforded the ionic complexes [(Cp*Mo)2(μ,η3:η3‐P3)(μ,η1:η1:η1:η1‐P3I3)][X] (X=I3?, I?) (2) and [(Cp*Mo)2(μ,η4:η4‐P4)(μ‐PI2)][I3] (3), while the reaction with PBr5 led to the complexes [(Cp*Mo)2(μ,η3:η3‐P3)(μ‐Br)2][Cp*MoBr4] (4) [(Cp*MoBr)2(μ,η3:η3‐P3)(μ,η1‐P2Br3)] (5) and [(Cp*Mo)2(μ‐PBr2)(μ‐PHBr)(μ‐Br)2] (6). The reaction of 1 with the far stronger oxidizing agent PCl5 was followed via time‐ and temperature‐dependent 31P{1H} NMR spectroscopy. One of the first intermediates detected at 193?K was [(Cp*Mo)2(μ,η3:η3‐P3)(μ‐PCl2)2][PCl6] (8) which rearranges upon warming to [(Cp*Mo)2(μ‐PCl2)2(μ‐Cl)2] (9), [(Cp*MoCl)2(μ,η3:η3‐P3)(μ‐PCl2)] (10) and [(Cp*Mo)2(μ,η4:η4‐P4)(μ‐PCl2)][Cp*MoCl4] (11), which could be isolated at room temperature. All complexes were characterized by single‐crystal X‐ray diffraction, NMR spectroscopy and their electronic structures were elucidated by DFT calculations.
查看更多>>摘要：Abstract Surface plasmon of coinage metal nanostructures has been employed as a powerful route in boosting the performances in heterogenous catalysis. Development of efficient plasmonic nanocatalysts with high catalytic performance and efficient light harvesting properties is of vital importance. Herein, we rationally designed and synthesized a plasmonic nanocatalyst composed of Au‐framed Pd nanocubes by an Ag(I)‐assisted seed‐mediated growth method. In the synthesis, the incorporation of Ag(I) suppresses the reduction of Au on the {100} surface of cubic Pd seeds and leads to the formation of Au nanoframes on the Pd nanocubes. The unique Au‐framed Pd nanocubes can integrate the superior electrocatalytic of Pd and the outstanding plasmonic properties of Au. Thus, these nanostructures were employed as plasmonic nanocatalysts for plasmon‐enhanced electrocatalytic oxidation of ethanol with improved stability.
NSTL
Wiley