基于桔子皮废弃物从含铼废水中高效、高选择地提取钼

以生物质废弃物桔子皮为原料, 直接氨化后得到OW-NH₂生物吸附剂, OW-NH₂对Mo(Ⅵ)的吸附具有很高的选择性, 对其他共存离子Re(Ⅶ)、Pb(Ⅱ)、Fe(Ⅲ)、Zn(Ⅱ)、Mn(Ⅶ)、Ca(Ⅱ)和Cu(Ⅱ)基本不吸附, 尤其是对Mo(Ⅵ)、Re(Ⅶ)的分离具有高选择性。红外光谱分析表明阴离子形式的H₃Mo₇O₂₄^3-、H₂Mo₇O₂₄^4-、HMo₇O₂₄^5-、Mo₈O₂₆^4-、Mo₇O₂₄^6- 和MoO₄^2-与引入在纤维素上的RNH₃⁺发生离子缔合反应。OW-NH₂吸附Mo(Ⅵ)的过程符合Langmiur吸附模型, 最大吸附量为1.71 mol·kg^-1。另外, OW-NH₂对工业实际料液的动态模拟实验的结果表明Mo(Ⅵ)回收率可达99%以上。     

Cu/MoS2的熔盐电解法制备及其在碱性条件下析氢反应性能的提高

通过熔盐电解法并掺杂过渡金属Cu制备2种不同纳米结构的Cu/MoS_2。采用涂敷法制备工作电极,通过X射线衍射(XRD)、透射电子显微镜(TEM)、能量散射X射线谱(EDS)、扫描电子显微镜(SEM)、选区电子衍射(SAED)以及各种电化学手段验证了其结构和性能。结果表明,纳米片状Cu/MoS_2在碱性溶液(1 mol·L~(-1)KOH)中表现出优异的析氢催化性能:在电流密度为10 mA·cm~(-2)时过电位为199.6 mV,Tafel斜率为59 mV·dec~(-1),双电层电容为26.1 mF·cm~(-2),等效电荷转移电阻为12.4Ω,具有较为良好的电化学耐久性和稳定性。     

Contradictory effect of gold nanoparticle-decorated molybdenum sulfide nanocomposites on amyloid-β-40 aggregation

The effect of gold nanoparticle-decorated molybdenum sulfide (AuNP-MoS₂) nanocomposites on amyloid-β-40 (Aβ₄₀) aggregation was investigated. The interesting discovery was that the effect of AuNP-MoS₂ nanocomposites on Aβ₄₀ aggregation was contradictory. Low concentration of AuNP-MoS₂ nanocomposites could enhance the nucleus formation of Aβ₄₀ peptides and accelerate Aβ₄₀ fibrils aggregation. However, although high concentration of AuNP-MoS₂ nanocomposites could enhance the nucleus formation of Aβ₄₀ peptides, it eventually inhibited Aβ₄₀ aggregation process. It might be attributed to the interaction between AuNP-MoS₂ nanocomposites and Aβ₄₀ peptides. For low concentration of AuNP-MoS₂ nanocomposites, it was acted as nuclei, resulting in the acceleration of the nucleation process. However, the structural flexibility of Aβ₄₀ peptides was limited as the concentration of AuNP-MoS₂ nanocomposites was increased, resulting in the inhibition of Aβ₄₀ aggregation. These findings suggested that AuNP-MoS₂ nanocomposites might have a great potential to design new multifunctional material for future treatment of amyloid-related diseases.     

Single‐Layered Ultrasmall Nanoplates of MoS2 Embedded in Carbon Nanofibers with Excellent Electrochemical Performance for Lithium and Sodium Storage

The preparation and electrochemical storage behavior of MoS₂ nanodots—more precisely single‐layered ultrasmall nanoplates—embedded in carbon nanowires has been studied. The preparation is achieved by an electrospinning process that can be easily scaled up. The rate performance and cycling stability of both lithium and sodium storage were found to be outstanding. The storage behavior is, moreover, highly exciting from a fundamental point of view, as the differences between the usual storage modes—insertion, conversion, interfacial storage—are beneficially blurred. The restriction to ultrasmall reaction domains allows for an almost diffusion‐less and nucleation‐free “conversion”, thereby resulting in a high capacity and a remarkable cycling performance.     

Aliphatic Organoimido Derivatives of Polyoxometalates Containing a Bioactive Ligand

A series of aliphatic organoimido derivatives of hexamolybdate based on amantadine, namely (nBu₄N)₂[Mo₆O₁₈(?NC₁₀H₁₅)] ( 1 ), (nBu₄N)₂ {cis‐[Mo₆O₁₇(?NC₁₀H₁₅)₂]} ( 2 ), (nBu₄N)₂{trans‐[Mo₆O₁₇(?NC₁₀H₁₅)₂]} ( 3 ), and (nBu₄N)₂[Mo₆O₁₆(?NC₁₀H₁₅)₃] ( 4 ), was synthesized in reasonable yield by dehydration with N,N′‐dicyclohexylcarbodiimide (DCC). They were characterized by IR and UV/Vis spectroscopy, elemental analysis, ESI mass spectrometry, and single‐crystal X‐ray structure analysis. The spectral and structural similarities and differences between monosubstituted, cis‐disubstituted, and trans‐disubstituted organoimido derivatives were elucidated and may provide guidance for related work on organoimido‐functionalized Lindqvist‐type polyoxometalates. In addition, trans‐disubstituted and polysubstituted derivatives containing aliphatic organoimido ligands have not yet been reported, and the crystal structure of the trans isomer may lead us to a deeper understanding of disubstituted derivatives. Furthermore, proliferation and morphology of MCF‐7 cells were studied with compound 1 . The present results show that the DCC‐dehydrating protocol could be an efficient approach to covalently graft bioactive ligands such as amantadine onto POMs and enhance their application in clinical cancer treatment.     

Experimental and Theoretical Studies on Arene‐Bridged Metal–Metal‐Bonded Dimolybdenum Complexes

The bis(hydride) dimolybdenum complex, [Mo₂(H)₂{HC(N‐2,6‐iPr₂C₆H₃)₂}₂(thf)₂], 2 , which possesses a quadruply bonded Mo₂^II core, undergoes light‐induced (365 nm) reductive elimination of H₂ and arene coordination in benzene and toluene solutions, with formation of the Mo^I₂ complexes [Mo₂{HC(N‐2,6‐iPr₂C₆H₃)₂}₂(arene)], 3?C₆H₆ and 3?C₆H₅Me , respectively. The analogous C₆H₅OMe, p‐C₆H₄Me₂, C₆H₅F, and p‐C₆H₄F₂ derivatives have also been prepared by thermal or photochemical methods, which nevertheless employ different Mo₂ complex precursors. X‐ray crystallography and solution NMR studies demonstrate that the molecule of the arene bridges the molybdenum atoms of the Mo^I₂ core, coordinating to each in an η² fashion. In solution, the arene rotates fast on the NMR timescale around the Mo₂‐arene axis. For the substituted aromatic hydrocarbons, the NMR data are consistent with the existence of a major rotamer in which the metal atoms are coordinated to the more electron‐rich C?C bonds.     

Formal Total Synthesis of Kendomycin by Way of Alkyne Metathesis/Gold Catalysis

In an attempt to study the ability of the latest generation of alkyne metathesis catalysts to process sterically hindered substrates, two different routes to the bacterial metabolite kendomycin ( 1 ) were explored. Whereas the cyclization of the overcrowded arylalkyne 39 and related substrates turned out to be impractical or even impossible, ring closure of the slightly relaxed diyne 45 was achieved in excellent yield under notably mild conditions with the aid of the molybdenum alkylidyne 2 endowed with triphenylsilanolate ligands. The resulting cycloalkyne 46 was engaged into a gold‐catalyzed hydroalkoxylation, which led to benzofuran 47 that had already previously served as a late‐stage intermediate en route to 1 .     

N‐Heterocyclic Carbene,High Oxidation State Molybdenum Alkylidene Complexes: Functional‐Group‐Tolerant Cationic Metathesis Catalysts

We synthesized the first N‐heterocyclic carbene (NHC) complexes of Schrock’s molybdenum imido alkylidene bis(triflate) complexes. Unlike existing bis(triflate) complexes, the novel 16‐electron complexes represent metathesis active, functional‐group‐tolerant catalysts. Single‐crystal X‐ray structures of two representatives of this novel class of Schrock catalysts are presented and reactivity is discussed in view of their structural peculiarities. In the presence of monomer (substrate), these catalysts form cationic species and can be employed in ring‐closing metathesis (RCM), ring‐opening metathesis polymerization (ROMP), as well as in the cyclopolymerization of α,ω‐diynes. Monomers containing functional groups, which are not tolerated by the existing variations of Schrock’s catalyst, e.g., sec‐amine, hydroxy, and carboxylic acid moieties, can be used. These catalysts therefore hold great promise in both organic and polymer chemistry, where they allow for the use of protic monomers.     

Catalytic Ethanolysis of Kraft Lignin into High‐Value Small‐Molecular Chemicals over a Nanostructured α‐Molybdenum Carbide Catalyst

We report the complete ethanolysis of Kraft lignin over an α‐MoC_1?x/AC catalyst in pure ethanol at 280 °C to give high‐value chemicals of low molecular weight with a maximum overall yield of the 25 most abundant liquid products (LP25) of 1.64 g per gram of lignin. The LP25 products consisted of C₆–C₁₀ esters, alcohols, arenes, phenols, and benzyl alcohols with an overall heating value of 36.5 MJ kg^?1. C₆ alcohols and C₈ esters predominated and accounted for 82 wt % of the LP25 products. No oligomers or char were formed in the process. With our catalyst, ethanol is the only effective solvent for the reaction. Supercritical ethanol on its own degrades Kraft lignin into a mixture of small molecules and molecular fragments of intermediate size with molecular weights in the range 700–1400, differing in steps of 58 units, which is the weight of the branched‐chain linkage C₃H₆O in lignin. Hydrogen was found to have a negative effect on the formation of the low‐molecular‐weight products.