Pd‐Cu alloy nanoparticle supported on amine‐terminated ionic liquid functional 3D graphene and its application on Suzuki cross‐coupling reaction

Well distributed Pd‐Cu bimetallic alloy nanoparticles supported on amine‐terminated ionic liquid functional three‐dimensional graphene (3D IL‐rGO/Pd‐Cu) as an efficient catalyst for Suzuki cross‐coupling reaction has been prepared via a facile synthetic method. The introduction of IL‐NH₂ cations on the surface of graphene sheets can effectively avoid the re‐deposition of graphene sheets, allowing the catalyst to be reused up to 10 cycles. The addition of Cu not only saves cost but also ensures high catalytic efficiency. It is worthy to note that the catalyst 3D IL‐rGO/Pd_2.5Cu_2.5 can efficiently catalyze the Suzuki cross‐coupling reaction with the yield up to 100% in 0.25 h, almost one‐fold higher than that by the pristine IL‐rGO/Pd_2.5 catalyst (52%). The Powder X‐Ray Diffraction (XRD), combining energy dispersive X‐ray spectroscopy (EDS) mapping results confirm the existence and distribution of Pd and Cu in the bimetallic nanoparticles. The transmission electron microscopy (TEM) reveals the nanoparticle size with an average diameter of 3.0 ± 0.5 nm. X‐ray photoelectron spectroscopy (XPS) analysis proved the presence of electron transfer from Cu to Pd upon alloying. Such alloying‐induced electronic modification of Pd‐Cu alloy and 3D ionic liquid functional graphene with large specific surface area both accounted for the catalytic enhancement.     

A General Strategy Towards Encapsulation of Nanoparticles in Sandwiched Graphene Sheets and the Synergic Effect on Energy Storage

A novel and universal approach towards the unique encapsulation of nanoparticles in the sandwiched graphene sheets is presented here. In the method, a low‐cost, sustainable and environmentally friendly carbon source, glucose, is firstly applied to yield the high‐quality, uniform and coupled graphene sheets in a large scale, and the pre‐fabricated hydrated nanosheets act as the sacrificial templates to generate the enveloped metallic nanoparticles. After controllable oxidation or removal of the encapsulated nanoparticles, sandwiched nanocomposite with oxidizes nanoparticles encapsulated in graphene sheets or pure phase of sandwich‐like and coupled graphene sheets would be achieved. Moreover, the synergic effect on energy storage via Li‐ion batteries is solidly verified in the Co₃O₄@graphene nanocomposite. More importantly, the unique structure of the nanoparticles‐encapsulated sandwiched graphene sheets will definitely result in additional applications, such as biosensors, supercapacitors and specific catalyses. These results have enriched the family of graphene‐based materials and recognized some new graphene derivatives, which will be considerably meaningful in chemistry and materials sciences.     

Nickel‐substituted cobalt ferrite nanoparticles supported on arginine‐modified graphene oxide nanosheets: Synthesis and catalytic activity

The amino acid arginine was used to modify the surface of graphene oxide nanosheets and then nickel‐substituted cobalt ferrite nanoparticles were supported on those arginine‐grafted graphene oxide nanosheets (Ni_0.5Co_0.5Fe₂O₄@Arg–GO). The prepared Ni_0.5Co_0.5Fe₂O₄@Arg–GO was characterized using flame atomic absorption spectroscopy, inductively coupled plasma optical emission spectrometry, energy‐dispersive spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The application of Ni_0.5Co_0.5Fe₂O₄@Arg–GO as a catalyst was examined in a one‐pot tandem oxidative cyclization of primary alcohols with o ‐phenylenediamine to benzimidazoles under aerobic oxidation conditions. The results showed that 2‐phenylbenzimidazole derivatives were successfully achieved using Ni_0.5Co_0.5Fe₂O₄@Arg–GO nanocomposite catalyst via the one‐pot tandem oxidative cyclization strategy.     

Microwave‐Induced In Situ Synthesis of Zn2GeO4/N‐Doped Graphene Nanocomposites and Their Lithium‐Storage Properties

Zn₂GeO₄/N‐doped graphene nanocomposites have been synthesized through a fast microwave‐assisted route on a large scale. The resulting nanohybrids are comprised of Zn₂GeO₄ nanorods that are well‐embedded in N‐doped graphene sheets by in situ reducing and doping. Importantly, the N‐doped graphene sheets serve as elastic networks to disperse and electrically wire together the Zn₂GeO₄ nanorods, thereby effectively relieving the volume‐expansion/contraction and aggregation of the nanoparticles during charge and discharge processes. We demonstrate that an electrode that is made of the as‐formed Zn₂GeO₄/N‐doped graphene nanocomposite exhibits high capacity (1463 mAh g^?1 at a current density of 100 mA g^?1), good cyclability, and excellent rate capability (531 mAh g^?1 at a current density of 3200 mA g^?1). Its superior lithium‐storage performance could be related to a synergistic effect of the unique nanostructured hybrid, in which the Zn₂GeO₄ nanorods are well‐stabilized by the high electronic conduction and flexibility of N‐doped graphene sheets. This work offers an effective strategy for the fabrication of functionalized ternary‐oxide‐based composites as high‐performance electrode materials that involve structural conversion and transformation.     

Self‐Construction from 2D to 3D: One‐Pot Layer‐by‐Layer Assembly of Graphene Oxide Sheets Held Together by Coordination Polymers

Deposition of Ni‐based cyanide bridged coordination polymer (NiCNNi) flakes onto the surfaces of graphene oxide (GO) sheets, which allows precise control of the resulting lamellar nanoarchitecture by in situ crystallization, is reported. GO sheets are utilized as nucleation sites that promote the optimized crystal growth of NiCNNi flakes. The NiCNNi‐coated GO sheets then self‐assemble and are stabilized as ordered lamellar nanomaterials. Regulated thermal treatment under nitrogen results in a Ni₃C–GO composite with a similar morphology to the starting material, and the Ni₃C–GO composite exhibits outstanding electrocatalytic activity and excellent durability for the oxygen reduction reaction.     

Functional Graphene by Thiol‐ene Click Chemistry

Thiol‐ene click reaction was successfully employed for chemical modification of graphene oxide (GO) by one‐step synthesis. Herein, 2,2‐azobis(2‐methylpropionitrile) (AIBN) was used as thermal catalyst and cysteamine hydrochloride (HS?(CH₂)₂?NH₂HCl) was used as thiol‐containing compound, which is incorporated to GO surface upon reaction with the C=C bonds. The hydrochloride acts as protecting group for the amine, which is finally eliminated by adding sodium hydroxide. The modified GO contains both S‐ and N‐containing groups (NS‐GO). We found that NS‐GO sheets form good dispersion in water, ethanol, and ethylene glycol. These graphene dispersions can be processed into functionalized graphene film. Besides, it was demonstrated that NS‐GO was proved to be an excellent host matrix for platinum nanoparticles. The developed method paves a new way for graphene modification and its functional nanocomposites.     

Functionalization of graphene oxide towards thermo‐sensitive nanocomposites via moderate in situ SET‐LRP

A mild and efficient strategy is presented for growing thermo‐sensitive polymers directly from the surface of exfoliated graphene oxide (GO). This method involves the covalent attachment of Br‐containing initiating groups onto the surface of GO sheets followed by in situ growing poly[poly(ethylene glycol) ethyl ether methacrylate] (PPEGEEMA) via single‐electron‐transfer living radical polymerization (SET‐LRP). Considering the lack of reactive functional groups on the surface of GO, exfoliated GO sheets were subjected to an epoxide ring opening reaction with tris(hydroxymethyl) aminomethane (TRIS) at room temperature. The initiating groups were grafted onto TRIS‐GO sheets by treating hydroxyls with 2‐bromo‐2‐methylpropionyl bromide at room temperature. PPEGEEMA chains were synthesized by in situ SET‐LRP using CuBr/Me₆TREN as catalytic system at 40 °C in H₂O/THF. The resulting materials were characterized using a range of testing techniques and it was proved that polymer chains were successfully introduced to the surface of GO sheets. After grafting with PPEGEEMA, the modified GO sheets still maintained the separated single layers and the dispersibility was significantly improved. This TRIS‐GO‐PPEGEEMA hybrid material shows reversible self‐assembly and deassembly in water by switching temperature at about 34 °C. Such smart graphene‐based materials promise important potential applications in thermally responsive nanodevices and microfluidic switches. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Carboxymethylated polyethylenimine modified magnetic nanoparticles specifically for purification of His‐tagged protein

Employing immobilized metal‐ion affinity chromatography and magnetic separation could ideally provide a useful analytical strategy for purifying His‐tagged protein. In the current study, a facile route was designed to prepare CMPEI‐Ni²⁺@SiO₂@Fe₃O₄ (CMPEI=carboxymethylated polyethyleneimine) magnetic nanoparticles composed of a strong magnetic core of Fe₃O₄ and a Ni²⁺‐immobilized carboxymethylated polyethyleneimine coated outside shell, which was formed by electrostatic interactions between polyanionic electrolyte of carboxymethylated polyethyleneimine and positively charged surface of 3‐(trimethoxysilyl)propylamin modified SiO₂@Fe₃O₄. The resulting CMPEI‐Ni²⁺@SiO₂@Fe₃O₄ composite nanoparticles displayed well‐uniform structure and high magnetic responsiveness. Hexa His‐tagged peptides and purified His‐tagged recombinant retinoid X receptor alpha were chosen as the model samples to evaluate the adsorption, capacity, and reusability of the composite nanoparticles. The results demonstrated the CMPEI‐Ni²⁺@SiO₂@Fe₃O₄ nanoparticles possessed rapid adsorption, large capacity, and good recyclability. The obtained nanoparticles were further used to purify His‐tagged protein in practical environment. It was found that the nanoparticles could selectively capture His‐tagged recombinant retinoid X receptor protein from complex cell lysate. Owing to its easy synthesis, large binding capacity, and good reusability, the prepared CMPEI‐Ni²⁺@SiO₂@Fe₃O₄ magnetic nanoparticles have great potential for application in biotechnological fields.     

Graphene-wrapped Ni2P materials: a 3D porous architecture with improved electrochemical performance

Ni₂P/graphene hybrid with a 3D architecture has been successfully accomplished through a series of controlled chemical processes. In contrast to random mixture of Ni₂P nanoparticles and graphene nanosheets, the architecture hybrid exhibits superior electrochemical stability because the Ni₂P nanoparticles are firmly riveted on the graphene sheets. The 3D graphene network enhances the electrical conductivity over the 2D nanostructure. As anode materials for lithium-ion batteries, the graphene-wrapped Ni₂P nanoparticles can deliver a reversible capacity of ~400 mAh g^?1 after 30 cycles with nearly no fading and also exhibit a good rate performance. The graphene network can serve as a conducting network for fast electron transfer from all directions between the active materials and charge collector, and better buffer spaces to accommodate the volume expansion/contraction during discharge/charge process, which can be considered to contribute to the remarkable cyclic stability, thereby pointing to a new synthetic route to hybridizing graphene with active materials for advanced lithium ion batteries.

Rose‐like Nanocomposite of Fe‐Ni Phosphides/Iron Oxide as Efficient Catalyst for Oxygen Evolution Reaction

In order to accelerate the reaction rate of water splitting, it is of immense importance to develop low‐cost, stable and efficient catalysts. In this study, the facile synthesis of a novel rose‐like nanocomposite catalyst (Ni₂P/Fe₂P/Fe₃O₄) is reported. The synthesis process includes a solvothermal step and a phosphatization step to combine iron oxides and iron‐nickel phosphides. Ni₂P/Fe₂P/Fe₃O₄ performs well in catalyzing oxygen evolution reaction, with a very low overpotential of 365 mV to reach 10 mA cm^?2 current density. The Tafel slope is as low as 59 mV dec^?1. Ni₂P/Fe₂P/Fe₃O₄ has a large double‐layer capacitance that contributes to a high electrochemically active area. Moreover, this catalyst is very stable for long‐term use. Therefore, the Ni₂P/Fe₂P/Fe₃O₄ catalyst has a high potential for use in oxygen evolution reactions.     

In situ green synthesis of Cu‐Ni bimetallic nanoparticles supported on reduced graphene oxide as an effective and recyclable catalyst for the synthesis of N‐benzyl‐N‐aryl‐5‐amino‐1H‐tetrazoles

In the present work, for the first time we have designed a novel approach for the synthesis of N‐benzyl‐N‐aryl‐5‐amino‐1H‐tetrazoles using reduced graphene oxide (rGO) decorated with Cu‐Ni bimetallic nanoparticles (NPs). In situ synthesis of Cu/Ni/rGO nanocomposite was performed by a cost efficient, surfactant‐free and environmentally benign method using Crataegus azarolus var. aronia L. leaf extract as a stabilizing and reducing agent. Phytochemicals present in the extract can be used to reduce Cu²⁺ and Ni²⁺ ions and GO to Cu NPs, Ni NPs and rGO, respectively. Analyses by means of FT‐IR, UV–Vis, EDS, TEM, FESEM, XRD and elemental mapping confirmed the Cu/Ni/rGO formation and also FT‐IR, NMR, and mass spectroscopy as well as elemental analysis were used to characterize the tetrazoles. The Cu/Ni/rGO nanocomposite showed the superior catalytic activity for the synthesis of N‐benzyl‐N‐aryl‐5‐amino‐1H‐tetrazoles within a short reaction time and high yields. Furthermore, this protocol eliminates the need to handle HN₃.     

TiO2–B Nanosheets/Anatase Nanocrystals Co‐Anchored on Nanoporous Graphene: In Situ Reduction–Hydrolysis Synthesis and Their Superior Rate Performance as an Anode Material

A unique hybrid, TiO₂–B nanosheets/anatase nanocrystals co‐anchored on nanoporous graphene sheets, can be synthesized by a facile microwave‐induced in situ reduction–hydrolysis route. The as‐formed nanohybrid has a hierarchically porous structure, involving both mesopores of approximately 4 nm and meso‐/macropores of 30–60 nm in the graphene sheets, and a large surface area. Importantly, electrodes composed of the nanohybrid exhibit superior rate capability (160 mA h g^?1 at ca. 36 C; 154 mA h g^?1 at ca. 72 C) and excellent cyclability. The synergistic effects of conductive graphene with numerous nanopores and the pseudocapacitive effect of ultrafine TiO₂–B nanosheets and anatase nanocrystals endow the hybrid a superior rate capability.     

Nickel(II) cluster‐based mixed‐cation coordination polymer synthesized from 2‐mercaptobenzoic acid and its application

High‐nuclearity metal clusters have received considerable attention not only because of their diverse architectures and topologies, but also because of their potential applications as functional materials in many fields. To explore new types of clusters and their potential applications, a new nickel(II) cluster‐based mixed‐cation coordination polymer, namely poly[hexakis[μ₄‐(2‐carboxylatophenyl)sulfanido]di‐μ₃‐chlorido‐tri‐μ₂‐hydroxido‐octanickel(II)sodium(I)], [Ni₈NaCl₂(OH)₃(C₇H₄O₂S)₆]_n, 1 , was synthesized using nickel chloride hexahydrate and mercaptobenzoic acid (H₂mba) as starting reactants under hydrothermal conditions. The material was characterized by single‐crystal X‐ray diffraction (SCXRD), Fourier transform IR spectroscopy, thermogravimetric analysis, powder X‐ray diffraction and X‐ray photoelectron spectroscopy analysis. SCXRD shows that 1 consists of a hexanuclear nickel(II) [Ni₆] cluster, dinuclear Ni^II nodes and a mononuclear Na^I node, resulting in the formation of a complex covalent three‐dimensional network. In addition, a tightly packed NiO/C&S nanocomposite is fabricated by sintering the coordination precursor at 400 °C. The uniform nanocomposite consists of NiO nanoparticles, incompletely carbonized carbon and incompletely vulcanized sulfur. When used as a supercapacitor electrode, the synthesized composite shows an extra‐long cycling stability (>5000 cycles) during the charge/discharge process.     

Synergistic Ternary Composite (Carbon/Fe3O4@Graphene) with Hollow Microspherical and Robust Structure for Li‐Ion Storage

The electrode materials with hollow structure and/or graphene coating are expected to exhibit outstanding electrochemical performances in energy‐storage systems. 2D graphene‐wrapped hollow C/Fe₃O₄ microspheres are rationally designed and fabricated by a novel facile and scalable strategy. The core@double‐shell structure SPS@FeOOH@GO (SPS: sulfonated polystyrene, GO: graphene oxide) microspheres are first prepared through a simple one‐pot approach and then transformed into C/Fe₃O₄@G (G: graphene) after calcination at 500 °C in Ar. During calcination, the Kirkendall effect resulting from the diffusion/reaction of SPS‐derived carbon and FeOOH leads to the formation of hollow structure carbon with Fe₃O₄ nanoparticles embedded in it. In the rationally constructed architecture of C/Fe₃O₄@G, the strongly coupled C/Fe₃O₄ hollow microspheres are further anchored onto 2D graphene networks, achieving a strong synergetic effect between carbon, Fe₃O₄, and graphene. As an anode material of Li‐ion batteries (LIBs), C/Fe₃O₄@G manifests a high reversible capacity, excellent rate behavior, and outstanding long‐term cycling performance (1208 mAh g^?1 after 200 cycles at 100 mA g^?1).     

Caesium carbonate supported on hydroxyapatite‐encapsulated Ni0.5Zn0.5Fe2O4 nanocrystallites as a novel magnetically basic catalyst for the one‐pot synthesis of pyrazolo[1,2‐b]phthalazine‐5,10‐diones

A novel nanomagnetic basic catalyst of caesium carbonate supported on hydroxyapatite‐coated Ni_0.5Zn_0.5Fe₂O₄ magnetic nanoparticles (Ni_0.5Zn_0.5Fe₂O₄@HAP‐Cs₂CO₃) was prepared. This new catalyst was fully characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopy, X‐ray diffraction and vibrating sample magnetometry techniques, and then the catalytic activity of this catalyst was investigated in the synthesis of 1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives. Also, Ni_0.5Zn_0.5Fe₂O₄@HAP‐Cs₂CO₃ could be reused at least five times without significant loss of activity and could be recovered easily by applying an external magnet. Thus, the developed nanomagnetic catalyst is potentially useful for the green and economic production of organic compounds. Copyright © 2015 John Wiley & Sons, Ltd.     

Core–Shell LiFePO4/Carbon‐Coated Reduced Graphene Oxide Hybrids for High‐Power Lithium‐Ion Battery Cathodes

Core‐shell carbon‐coated LiFePO₄ nanoparticles were hybridized with reduced graphene (rGO) for high‐power lithium‐ion battery cathodes. Spontaneous aggregation of hydrophobic graphene in aqueous solutions during the formation of composite materials was precluded by employing hydrophilic graphene oxide (GO) as starting templates. The fabrication of true nanoscale carbon‐coated LiFePO₄‐rGO (LFP/C‐rGO) hybrids were ascribed to three factors: 1) In‐situ polymerization of polypyrrole for constrained nanoparticle synthesis of LiFePO₄, 2) enhanced dispersion of conducting 2D networks endowed by colloidal stability of GO, and 3) intimate contact between active materials and rGO. The importance of conducting template dispersion was demonstrated by contrasting LFP/C‐rGO hybrids with LFP/C‐rGO composites in which agglomerated rGO solution was used as the starting templates. The fabricated hybrid cathodes showed superior rate capability and cyclability with rates from 0.1 to 60 C. This study demonstrated the synergistic combination of nanosizing with efficient conducting templates to afford facile Li⁺ ion and electron transport for high power applications.     

SO3H‐functionalized nano‐MGO‐D‐NH2: Synthesis,characterization and application for one‐pot synthesis of pyrano[2,3‐d]pyrimidinone and tetrahydrobenzo[b]pyran derivatives in aqueous media

An SO₃H‐functionalized nano‐MGO‐D‐NH₂ catalyst has been prepared by multi‐functionalization of a magnetic graphene oxide (GO) nanohybrid and evaluated in the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3‐d]pyrimidinone derivatives. The GO/Fe₃O₄ (MGO) hybrid was prepared via an improved Hummers method followed by the covalent attachment of 1,4‐butanesultone with the amino group of the as‐prepared polyamidoamine‐functionalized MGO (MGO‐D‐NH₂) to give double‐functionalized magnetic nanoparticles as the catalyst. The prepared nanoparticles were characterized to confirm their synthesis and to precisely determine their physicochemical properties. In summary, the prepared catalyst showed marked recyclability and catalytic performance in terms of reaction time and yield of products. The results of this study are hoped to aid the development of a new class of heterogeneous catalysts to show high performance and as excellent candidates for industrial applications.     

A new one‐dimensional nickel metal–organic framework: catena‐poly[[[diaquabis(4‐{[(1‐phenyl‐1H‐tetrazol‐5‐yl)sulfanyl]methyl}benzoato‐κO)nickel(II)]‐μ‐4,4′‐bipyridine‐κ2N:N′] monohydrate]

The title complex, {[Ni(C₁₅H₁₁N₄O₂S)₂(C₁₀H₈N₂)(H₂O)₂]·H₂O}_n, was synthesized by the reaction of nickel chloride, 4‐{[(1‐phenyl‐1H‐tetrazol‐5‐yl)sulfanyl]methyl}benzoic acid (HL) and 4,4′‐bipyridine (bpy) under hydrothermal conditions. The asymmetric unit contains two half Ni^II ions, each located on an inversion centre, two L⁻ ligands, one bpy ligand, two coordinated water molecules and one unligated water molecule. Each Ni^II centre is six‐coordinated by two monodentate carboxylate O atoms from two different L⁻ ligands, two pyridine N atoms from two different bpy ligands and two terminal water molecules, displaying a nearly ideal octahedral geometry. The Ni^II ions are bridged by 4,4′‐bipyridine ligands to afford a linear array, with an Ni...Ni separation of 11.361 (1) Å, which is further decorated by two monodentate L⁻ ligands trans to each other, resulting in a one‐dimensional fishbone‐like chain structure. These one‐dimensional fishbone‐like chains are further linked by O—H...O, O—H...N and C—H...O hydrogen bonds and π–π stacking interactions to form a three‐dimensional supramolecular architecture. The thermal stability of the title complex was investigated via thermogravimetric analysis.     

Synthesis,characterization and catalytic performance of core‐shell structure magnetic Fe3O4/P(GMA‐EGDMA)‐NH2/HPG‐COOH‐Pd catalyst

A strategy has been developed for the synthesis, characterization and catalysis of magnetic Fe₃O₄/P(GMA‐EGDMA)‐NH₂/HPG‐COOH‐Pd core‐shell structure supported catalyst. The P(GMA‐EGDMA) polymer layer was coated on the surface of hollow magnetic Fe₃O₄ microspheres through the effect of KH570. The core‐shell magnetic Fe₃O₄/P(GMA‐EGDMA) modified by ‐NH₂ could be grafted with HPG. Then, the hyperbranched glycidyl (HPG) with terminal ‐OH were modified by ‐COOH and adsorbed Pd nanoparticles. The hyperbranched polymer layer not only protected the Fe₃O₄ magnetic core from acid–base substrate corrosion, but also provided a number of functional groups as binding sites for Pd nanoparticles. The prepared catalyst was characterized by UV–vis, TEM, SEM, FTIR, TGA, ICP‐OES, BET, XRD, DLS and VSM. The catalytic tests showed that the magnetic Fe₃O₄/P(GMA‐EGDMA)‐NH₂/HPG‐COOH‐Pd catalyst had excellent catalytic performance and retained 86% catalytic efficiency after 8 consecutive cycles.     

Tailored Synthesis of Various Nanomaterials by Using a Graphene‐Oxide‐Based Gel as a Nanoreactor and Nanohybrid‐Catalyzed CC Bond Formation

New graphene oxide (GO)‐based hydrogels that contain vitamin B₂/B₁₂ and vitamin C (ascorbic acid) have been synthesized in water (at neutral pH value). These gel‐based soft materials have been used to synthesize various metal nanoparticles, including Au, Ag, and Pd nanoparticles, as well as nanoparticle‐containing reduced graphene oxide (RGO)‐based nanohybrid systems. This result indicates that GO‐based gels can be used as versatile reactors for the synthesis of different nanomaterials and hybrid systems on the nanoscale. Moreover, the RGO‐based nanohybrid hydrogel with Pd nanoparticles was used as an efficient catalyst for C? C bond‐formation reactions with good yields and showed high recyclability in Suzuki–Miyaura coupling reactions.