Modulating the iron (hydr)oxides/sulfides by HO for a high-performance sulfidated zero-valent iron.

Sulfidation of zero-valent iron (SZVI) can enhance the reactivity of ZVI to contaminants removal. The composition and structure of ZVI surface have a significant impact on the sulfidation efficiency. Pre-corrosion of ZVI with oxidizing substances has emerged as a promising means to modulate the ZVI surface composition.

Interfacial slow-release reduction modulates iron cycling on the ZVI surface: Accelerated electron transfer and generation of Fe(II).

Slow iron cycling is an important factor limiting the reactivity of zero-valent iron (ZVI). Developing novel strategies to facilitate iron cycling is vital for the ZVI practical application. This study reports a novel interfacial slow-release reduction strategy for synthesizing L-ZVI with excellent performance by adding L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate (AAPS).

Predictions of Ac and Ra production cross sections from p, α and heavy ion irradiated thorium and uranium targets.

-This work studies effective methods for producing Ac and Ra by bombarding Th and natural uranium targets with different incident particles. Direct production of Ac via high-energy proton bombardment of Th inevitably contains Ac impurities, complicating the separation and purification processes. In contrast, obtaining Ac through the generated Ra can avoid Ac contamination.

In-situ observation of heavy ion beam-induced luminescence of AlO (Cr) in a 0 - 10 T magnetic field background.

High energy density physics driven by intense heavy ion beams will be an important new project for the high intensity heavy-ion accelerator facility and the Dongjiang Laboratory. This paper presents an experimental investigation of ion beam-induced luminescence in a strong magnetic field background at HIRFL. The experiment utilizes a 430 MeV/u Kr ion beam with a pulse duration of 300 ns to bombard an AlO (Cr) solid target.

Trade-off between sulfidated zero-valent iron reactivity and air stability: Regulation of iron sulfides by ammonium dihydrogen phosphate.

The reactivity and stability of zero-valent iron (ZVI) and sulfidated zero-valent iron (S-ZVI) are inherently contradictory. Iron sulfides (FeS) on the S-ZVI surface play multiple roles, including electrostatic adsorption and catalyzing reduction. We proposed to balance the reactivity and air stability of S-ZVI by regulating FeS.

Remediation of Cr(VI)-contaminated soil by sulfidated zero-valent iron: The effect of citric acid as eluant and modifying agent.

Leaching and chemical reduction are two commonly used methods for Cr(VI)-contaminated soil remediation. Leaching focuses more on leaching Cr(VI) out of the soil. Chemical reduction has the disadvantages of poor fluidity of reductant.

Mn(CeZr)O chelation-induced synthesis and its hydrothermal aging characteristics for catalytic abatement of toluene.

In this work, Mn(CeZr)O was synthesized by using chelation-induced synergistic self-assembly strategy for the combustion of toluene. The physicochemical properties of the synthesized catalysts were characterized by XRD, ICP-MS, SEM, TEM, XPS and N sorption. The Mn(CeZr)O catalyst with T = 225 °C exhibited improved catalytic performance than the original MnO catalyst (T = 260 °C) and had significant low-temperature activity.

Facile synthesis of Pt-CeZrO-Y catalysts and the application in catalytic oxidation of toluene.

In this work, a series of Pt-CeZrO-Y catalysts were prepared by unique simple mechanical mixing method. The catalytic activity of these catalysts for toluene oxidation was investigated. The physicochemical properties of the catalysts were characterized by XRD, ICP-MS, SEM, TEM, XPS and N sorption.

Viability and distribution of bacteria immobilized on Sawdust@silica: The removal mechanism of phenanthrene in soil.

Immobilized cells (ICs) have been widely used to enhance the remediation of organic-contaminated soil (e.g., polycyclic aromatic hydrocarbons, PAHs).

Preliminary research on flow rate and free surface of the accelerator driven subcritical system gravity-driven dense granular-flow target.

A spallation target is one of the three core parts of the accelerator driven subcritical system (ADS), which has already been investigated for decades. Recently, a gravity-driven Dense Granular-flow Target (DGT) is proposed, which consists of a cylindrical hopper and an internal coaxial cylindrical beam pipe. The research on the flow rate and free surface are important for the design of the target whether in Heavy Liquid Metal (HLM) targets or the DGT.

Synthesis of highly substituted benzene ring systems through three-component coupling of enyne imines, Fischer carbene complexes, and electron-deficient alkynes.

Three-component coupling of Fischer carbene complexes, enyne aldehyde hydrazones, and electron-deficient alkynes leads to simple benzoate derivatives in a process involving the formation of an N-aminopyrrole derivative, Diels-Alder reaction, and nitrene extrusion. The products are readily converted into isoquinolones through reaction with primary amines. The reaction proceeds best with highly substituted and electron-rich pyrroles even though these are the sterically least favorable substrates, and this reactivity trend is supported by a computational study.

N-allyl-N-sulfonyl ynamides as synthetic precursors to amidines and vinylogous amidines. An unexpected N-to-C 1,3-sulfonyl shift in nitrile synthesis.

A detailed study of amidine synthesis from N-allyl-N-sulfonyl ynamides is described here. Mechanistically, this is a fascinating reaction consisting of diverging pathways that could lead to deallylation or allyl transfer depending upon the oxidation state of palladium catalysts, the nucleophilicity of amines, and the nature of the ligands. It essentially constitutes a Pd(0)-catalyzed aza-Claisen rearrangement of N-allyl ynamides, which can also be accomplished thermally.

Synthesis of amidines using N-allyl ynamides. A palladium-catalyzed allyl transfer through an ynamido-pi-allyl complex.

A de novo transformation of N-allyl-N-sulfonyl ynamides to amidines is described featuring a palladium-catalyzed N-to-C allyl transfer via ynamido-palladium-pi-allyl complexes.

Copper(II)-catalyzed amidations of alkynyl bromides as a general synthesis of ynamides and Z-enamides. An intramolecular amidation for the synthesis of macrocyclic ynamides.

A general and efficient method for the coupling of a wide range of amides with alkynyl bromides is described here. This novel amidation reaction involves a catalytic protocol using copper(II) sulfate-pentahydrate and 1,10-phenanthroline to direct the sp-C-N bond formation, leading to a structurally diverse array of ynamides including macrocyclic ynamides via an intramolecular amidation. Given the surging interest in ynamide chemistry, this atom economical synthesis of ynamides should invoke further attention from the synthetic organic community.

A ring-closing yne-carbonyl metathesis of ynamides.

[reaction: see text] An acid-catalyzed ring-closing ynamide-carbonyl metathesis is described here. This hetero RCM methodology is applicable to the construction of carbocycles as well as heterocycles such as chromenes, quinolizidines, indolizidines, and pyrrolizidines.

Copper-catalyzed stereospecific N-allenylations of amides. Syntheses of optically enriched chiral allenamides.

[reaction: see text] Syntheses of chiral allenamides via a stereospecific amidation of optically enriched allenyl iodides using catalytic copper(I) salt and N,N'-dimethylethylene-diamine are described here.

Brønsted acid-catalyzed highly stereoselective arene-ynamide cyclizations. A novel keteniminium Pictet-Spengler cyclization in total syntheses of (+/-)-desbromoarborescidines A and C.

[reaction: see text] A Brønsted acid-catalyzed highly stereoselective arene-ynamide cyclization is described. These reactions constitute a keteniminium variant of Pictet-Spengler cyclizations, leading to efficient synthesis of nitrogen heterocycles and related alkaloids. Total syntheses of desbromoarborescidines A and C are illustrated here as first applications of this methodology.

Sonogashira cross-couplings of ynamides. Syntheses of urethane- and sulfonamide-terminated conjugated phenylacetylenic systems.

[reaction: see text] The first successful Sonogashira coupling of ynamides with aryl and vinyl iodides is described here. This study resolves the problem of the competing pathway involving homocoupling of ynamides and provides a practical entry to novel urethane- or sulfonamide-terminated conjugated acetylenic systems. An interesting tandem hydrohalogenation and Sonogashira coupling was also observed to give an en-ynamide.

Copper sulfate-pentahydrate-1,10-phenanthroline catalyzed amidations of alkynyl bromides. Synthesis of heteroaromatic amine substituted ynamides.

A practical cross-coupling of amides with alkynyl bromides using catalytic CuSO(4).5H(2)O and 1,10-phenanthroline is described here. This catalytic protocol is more environmentally friendly than the use of CuCN or copper halides and provides a general entry for syntheses of ynamides including various new sulfonyl and heteroaromatic amine substituted ynamides.

Synthesis of pyrroles through coupling of enyne-hydrazones with Fischer carbene complexes.

[reaction: see text] The coupling of enyne-imines with Fischer carbene complexes leads to the formation of alkenylpyrrole derivatives. Maximum yields of pyrrole adducts were obtained using N,N-dimethylhydrazones. A mechanism involving alkyne insertion followed by nucleophilic attack of the imine nitrogen at the intermediate alkenylcarbene complex was proposed.

Synthesis of furano[2,3-c]pyran-3-one and thieno[2,3-c]pyran-3-one derivatives through the coupling of 3-alkynyl-2-heteroaromatic carboxaldehydes with Fischer carbene complexes: total synthesis of a Baccharis-derived cadinene derivative.

The coupling of Fischer carbene complexes with 3-alkynyl-2-heteroaromatic carboxaldehyde derivatives has been examined. The reaction affords pyrones fused to furans or thiophenes in a single step. The compounds are stable enough for isolation.