Oxidation of alcohols to aldehydes and ketones using selenium ionic liquid

A new type of ionic liquid supported selenium reagents were synthesized and found to be an excellent catalyst in the oxidation of alcohols to aldehydes and ketones in the presence of 30%H₂O₂.The predictable solubility of ionic liquids allows an easy separation of the oxidation products from the reaction mixture.Furthermore,the oxidation reaction can be carried out using an ionic liquid as the solvent,and the ionic liquid-supported selenium reagents can be recycled and used for four times with a little decrease in catalytic performance.     

The Hydrogen Evolution Reaction in Alkaline Solution: From Theory,Single Crystal Models,to Practical Electrocatalysts

The hydrogen evolution reaction (HER) is a fundamental process in electrocatalysis and plays an important role in energy conversion for the development of hydrogen‐based energy sources. However, the considerably slow rate of the HER in alkaline conditions has hindered advances in water splitting techniques for high‐purity hydrogen production. Differing from well documented acidic HER, the mechanistic aspects of alkaline HER are yet to be settled. A critical appraisal of alkaline HER electrocatalysis is presented, with a special emphasis on the connection between fundamental surface electrochemistry on single‐crystal models and the derived molecular design principle for real‐world electrocatalysts. By presenting some typical examples across theoretical calculations, surface characterization, and electrochemical experiments, we try to address some key ongoing debates to deliver a better understanding of alkaline HER at the atomic level.     

An “<Emphasis Type="Italic">In Vivo</Emphasis> Self-assembly” Strategy for Constructing Superstructures for Biomedical Applications

The interfacing study of biopolymer and supramolecular chemistry enables a better understanding of fundamental biochemical processes and the creating of new high-performance biomaterials. In this review, we introduced an “in vivo self-assembly” strategy which means in situ construction of functional self-assembled superstructures in specific physiological or pathological conditions in cell, tissue or animal levels that exhibit diverse biomedical effects. By using this strategy, unexpected phenomena and insights, e.g, assembly/aggregation induced retention (AIR) effect have been demonstrated where the self-assembled nanostructures showed extraordinary enhanced accumulation and retention of therapeutics in targeted sites.     

Temperature-response polymer coating for in-tube solid-phase microextraction coupled to high-performance liquid chromatography

The silica nanoparticle (SiO₂ NP)-deposited capillary fabricated by liquid phase deposition (LPD) was bonded by 3-(triethoxysilyl) propyl methacrylate and then modified with poly(N-isopropylacrylamide) (PNIPAAm) by polymerization. The resulting PNIPAAm modified SiO₂ NP-deposited capillary was applied to in-tube solid-phase microextraction coupled to high-performance liquid chromatography (in-tube SPME-HPLC). To investigate the extraction performance of the prepared capillary, diethylstilbestrol (DES) with moderate polarity was selected as the model analyte. Results demonstrate that PNIPAAm modified SiO₂ NP-deposited capillary exhibited obvious temperature responsive character. Finally, the PNIPAAm modified SiO₂ NP-deposited capillary was applied to the analysis of three synthetical estrogens from milk samples. The detection limit of the method was found to be in the range 1.2-2.2 ng/g, and recovery was 71.7-98.9% with relative standard deviations in the range of 2.8-12.6%.     

Studies toward the total synthesis of clavulactone

Synthetic studies directed toward a total synthesis of clavulactone are reported. In light of the analysis made in our previous work, cyclopentane 4a (a key intermediate in the present work) was synthesized through a radical-mediated ring closure of a rationally designed substrate 25. Using HWE reactions, the lower and upper side-chains of 4a were converted into an allyl chloride and an allyl cyanohydrin, respectively. Subsequent treatment of the allyl chloride/cyanohydrin in a highly diluted THF solution with sodium bis(trimethylsiliyl)amide led to intramolecular alkylation and thus completed a major endeavor in synthesizing the dolabellane framework, construction of the eleven-membered ring. SmI(2)-mediated lactonization as a model reaction for the formation of the alpha,beta-unsaturated delta-lactone segment of clavulactone is also described.     

含吡唑啉酮酰肼类衍生物的合成与结构

报道了PMBP-NTH(NTH为烟酰肼)与PMBP-PAH(PAH为对甲氧基苯甲酰肼)的合成、表征和晶体结构分析,PMBP-NTH晶体属三斜晶系,具有P1空间群,a=0.9024(2)nm,b=1.0953(2)nm,c=1.1635(2)nm,α67.070(10)°,β=68.220(10)°,γ=84.770(10)°,V=0.9816(3)nm^3,Z=2,Dc=1.345g/cm^3,μ=0.090mm^-1,F(000)=416,R=0.0363,ωR=0.0870.PMBP-PAH属单斜晶系,具有P21/c空间群,a=1.2715(4)nm,b=0.91710(10)nm,c=1.8979(3)nm,β=106.890(10)°,V=2.1177(8)nm^3,Z=4,Dc=1.338g/cm^3,μ=0.090mm^-1,F(000)=896,R=0.0414,ωR=0.0972.这两个化合物在分子内都形成了大的共轭体系,由于分子间氢键力的作用,又使它们在晶体中以二聚体形式存在.     

氨基功能化金属有机骨架光催化剂的制备及性能研究

氨基功能化金属有机骨架材料(Metal-organic frameworks,MOFs)是一种非常具有吸引力的功能化MOFs,其兼具MOFs的高比表面积、孔道易调控及氨基的可后处理修饰的性能。通过简单的化学反应可实现功能基团的转化,从而制得新型的功能化MOFs,在气体存储、药物载体、选择性吸附气体小分子和催化等领域具有潜在的应用价值,因此开发氨基功能化的MOFs备受人们关注。本文综述了近年来氨基功能化MOFs在催化和吸附领域的研究进展,包括氨基功能化MOFs的制备方法、影响因素以及在环境方面的应用,并对今后的发展前景进行了展望。     

On the application of ICP-MS techniques for measuring uranium and plutonium: a Nordic inter-laboratory comparison exercise

Inductively coupled plasma mass spectrometry (ICP-MS) techniques are widely used for determination of long-lived radionuclides and their isotopic ratios in the nuclear fields. Uranium (U) and Plutonium (Pu) isotopes have been determined by many researchers with ICP-MS due to its relatively high sensitivity and short measurement time. In this work, an inter-laboratory comparison exercise among the Nordic countries was performed, focusing on the measurement of U and Pu isotopes in certified reference materials by ICP-MS. The performance and characters of different ICP-MS instruments are evaluated and discussed in this paper.     

Ambient Electrosynthesis of Ammonia: Electrode Porosity and Composition Engineering

Ammonia, a key precursor for fertilizer production, convenient hydrogen carrier, and emerging clean fuel, plays a pivotal role in sustaining life on Earth. Currently, the main route for NH₃ synthesis is by the heterogeneous catalytic Haber–Bosch process (N₂+3 H₂→2 NH₃), which proceeds under extreme conditions of temperature and pressure with a very large carbon footprint. Herein we report that a pristine nitrogen‐doped nanoporous graphitic carbon membrane (NCM) can electrochemically convert N₂ into NH₃ in an acidic aqueous solution under ambient conditions. The Faradaic efficiency and rate of production of NH₃ on the NCM electrode reach 5.2 % and 0.08 g m^?2 h^?1, respectively. Functionalization of the NCM with Au nanoparticles dramatically enhances these performance metrics to 22 % and 0.36 g m^?2 h^?1, respectively. As this system offers the potential to be scaled to industrial levels it is highly likely that it might displace the century‐old Haber–Bosch process.