Two types of templates, an active metal salt and silica nanoparticles, are used concurrently to achieve the facile synthesis of hierarchical meso/microporous FeCo‐Nx‐carbon nanosheets ...(meso/micro‐FeCo‐Nx‐CN) with highly dispersed metal sites. The resulting meso/micro‐FeCo‐Nx‐CN shows high and reversible oxygen electrocatalytic performances for both ORR and OER, thus having potential for applications in rechargeable Zn–air battery. Our approach creates a new pathway to fabricate 2D meso/microporous structured carbon architectures for bifunctional oxygen electrodes in rechargeable Zn–air battery as well as opens avenues to the scale‐up production of rationally designed heteroatom‐doped catalytic materials for a broad range of applications.
Meso/microporous Fe/Co‐Nx‐doped carbon nanosheets prepared by an active salt/silica nanoparticle templating approach achieve high performance as bifunctional oxygen electrodes. The FeCo‐Nx‐carbon has a well‐defined 2D morphology and homogenous metal‐atom doping, yielding enriched active sites for ORR‐OER. These features lead to excellent reversible oxygen electrocatalytic performance for Zn–air batteries.
Subcutaneous delivery of biotherapeutics has become a valuable alternative to intravenous administration across many disease areas. Although the pharmacokinetic profiles of subcutaneous and ...intravenous formulations differ, subcutaneous administration has proven effective, safe, well-tolerated, generally preferred by patients and healthcare providers and to result in reduced drug delivery-related healthcare costs and resource use. The aim of this article is to discuss the differences between subcutaneous and intravenous dosing from both health-economic and scientific perspectives. The article covers different indications, treatment settings, administration volumes, and injection devices. We focus on biotherapeutics in rheumatoid arthritis (RA), immunoglobulin-replacement therapy in primary immunodeficiency (PI), beta interferons in multiple sclerosis (MS), and monoclonal antibodies (mAbs) in oncology. While most subcutaneous biotherapeutics in RA, PI, and MS are self-administered at home, mAbs for oncology are still only approved for administration in a healthcare setting. Beside concerns around the safety of biotherapeutics in oncology, a key challenge for self-administration in this area is that doses and dosing volumes can be comparatively large; however, this difficulty has recently been overcome to some extent by the development of high-concentration solutions, the use of infusion pumps, and the coadministration of the dispersion enhancer hyaluronidase. Furthermore, given the increasing number of biotherapeutics being considered for combination therapy and the high dosing complexity associated with these, especially when administered intravenously, subcutaneous delivery of fixed-dose combinations might be an alternative that will diminish these burdens on healthcare systems.
Pyrolysis of a bimetallic metal–organic framework (MIL‐88‐Fe/Ni)‐dicyandiamide composite yield a Fe and Ni containing carbonaceous material, which is an efficient bifunctional electrocatalyst for ...overall water splitting. FeNi3 and NiFe2O4 are found as metallic and metal oxide compounds closely embedded in an N‐doped carbon–carbon nanotube matrix. This hybrid catalyst (Fe‐Ni@NC‐CNTs) significantly promotes the charge transfer efficiency and restrains the corrosion of the metallic catalysts, which is shown in a high OER and HER activity with an overpotential of 274 and 202 mV, respectively at 10 mA cm−2 in alkaline solution. When this bifunctional catalyst was further used for H2 and O2 production in an electrochemical water‐splitting unit, it can operate in ambient conditions with a competitive gas production rate of 1.15 and 0.57 μL s−1 for hydrogen and oxygen, respectively, showing its potential for practical applications.
I've got to split: An efficient bifunctional electrocatalyst for overall water splitting was synthesized by pyrolyzing a bimetallic metal–organic framework (MOF; MIL‐88‐Fe/Ni)–dicyandiamide composite. The resulting N‐doped carbon material with embedded FeNi3 and NiFe2O4 nanoparticles show high activity and stability for both H2 and O2 production from water.
A comprehensive study of a diastereoselective Rh‐catalyzed cyclization of terminal and internal allenols is reported. The methodology allows the atom economic and highly syn‐selective access to ...synthetically important 2,4‐disubstituted and 2,4,6‐trisubstituted tetrahydropyrans (THP). Furthermore, its utility and versatility are demonstrated by a great functional‐group compatibility and the enantioselective total synthesis of (−)‐centrolobine.
A comprehensive study of a diastereoselective Rh‐catalyzed cyclization of terminal and internal allenols is reported. The methodology allows the atom economic and highly syn‐selective access to synthetically important 2,4‐disubstituted, and 2,4,6‐trisubstituted tetrahydropyrans. Furthermore, its utility and versatility are demonstrated by a great functional‐group compatibility and the enantioselective total synthesis of (−)‐centrolobine.
Abstract
The fabrication of macroscopic objects from covalent organic frameworks (COFs) is challenging but of great significance to fully exploit their chemical functionality and porosity. Herein, ...COF/reduced graphene oxide (rGO) aerogels synthesized by a hydrothermal approach are presented. The COFs grow in situ along the surface of the 2D graphene sheets, which are stacked in a 3D fashion, forming an ultralight aerogel with a hierarchical porous structure after freeze-drying, which can be compressed and expanded several times without breaking. The COF/rGO aerogels show excellent absorption capacity (uptake of >200 g organic solvent/g aerogel), which can be used for removal of various organic liquids from water. Moreover, as active material of supercapacitor devices, the aerogel delivers a high capacitance of 269 F g
−1
at 0.5 A g
−1
and cycling stability over 5000 cycles.
Organic zeolite: A microporous, covalent organic network with high surface area was synthesized by polymerization of B(C6F4Br)4−. The countercations, located within the pore channels, are highly ...accessible and can be easily exchanged, comparable to the extra‐framework cations in zeolites. In this way a MnII(bpy)2+ complex can be synthesized and immobilized in the network.
Covalent organic frameworks (COFs) are structurally tuneable, porous and crystalline polymers constructed through the covalent attachment of small organic building blocks as elementary units. Using ...the myriad of such building blocks, a broad spectrum of functionalities has been applied for COF syntheses for broad applications, including heterogeneous catalysis. Herein, we report the synthesis of a new family of porous and crystalline COFs using a novel acridine linker and benzene‐1,3,5‐tricarbaldehyde derivatives bearing a variable number of hydroxy groups. With the broad absorption in the visible light region, the COFs were applied as photocatalysts in metallaphotocatalytic C−N cross‐coupling. The fully β‐ketoenamine linked COF showed the highest activity, due to the increased charge separation upon irradiation. The COF showed good to excellent yields for several aryl bromides, good recyclability and even catalyzed the organic transformation in presence of green light as energy source.
A new family of porous crystalline COFs bearing acridine moieties was synthesized and applied as photocatalysts in metallaphotocatalytic C−N cross‐coupling. Among these materials the fully β‐ketoenamine‐linked COF showed the highest catalytic activity and was shown to be recyclable and even catalyzed the cross‐coupling efficiently under green light irradiation.
The Yamamoto polymerization has been used for the synthesis of conjugated, microporous polymer networks. The polymerization is advantageous as only a single, halogen-functionalized monomer can be ...used to form polymer networks. Polymer networks are presented based on spirobifluorene and benzene units, which reveal high surface areas of up to 1275 m2/g. Furthermore, copolymerization can be carried out using additionally linear linkers during the polymerization. The nearly regular incorporation of such units into the networks enables to tailor the luminescence properties of the materials.
A collection of different polymeric ionic liquids (PILs) were explored as cathode binders in lithium–sulfur batteries. The PIL molecular structure, polymer backbone, and polymer architecture were ...found to influence the cell capacity, the cyclability, and the morphology of the cathode itself. PILs with styrene backbones performed better than the vinyl-based polymer, while cross-linked PILs imparted further improved capacities, cyclability, and reduced overpotentials. Unlike polyvinylidene fluoride, PIL binders mixed with the sulfide species, resulting in more uniformly distributed sulfides in the cathode and better sulfide transport. These features helped to mitigate volume change-induced degradation that typically plagues Li–S batteries. The uptake of polysulfides by PILs also constrains the polysulfide shuttle during battery cycling, leading to better cycling stability. While traditionally binders are viewed only as a “glue” to hold the active material together, PIL binders have additional functions and play an active role during Li–S battery working operation.
A regiodivergent and stereoselective transition‐metal‐catalyzed addition of 4‐pyridones to allenes furnishing N‐allylated pyridones is reported. Employing a commercially available chiral rhodium ...catalyst enabled enantioselective branched‐selective allylation. Conversely, an achiral palladium catalyst led to linear‐selective N‐allylation in high E‐selectivities. A wide range of functional groups was tolerated and assorted synthetic transformations of the N‐allylated pyridones demonstrated their utility for the syntheses of medicinally relevant heterocyclic scaffolds.
Branched or linear: The regiodivergent and stereoselective transition‐metal‐catalyzed addition of 4‐pyridones to allenes permits the selective syntheses of both valuable branched and linear allylic pyridone derivatives, the scaffolds of which can be found in a variety of bioactive compounds. The reaction tolerates a wide range of functional groups and multi‐gram scale catalysis.
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