2020 Roadmap on two-dimensional nanomaterials for environmental catalysis

This roadmap demonstrates a series of two-dimensional nanomaterials, such as graphene, black phosphorus, oxides, layered double hydroxides, chalcogenides, bismuth-based layered compounds, MXenes, metal organic frameworks, covalent organic frameworks, and others, for environmental catalysis.     

兔肝金属硫蛋白稀水溶液的脉冲辐解

金属硫蛋白(Metallothioneins,简称MTs)是一类富含巯基和金属的低分子量蛋白质,广泛存在于哺乳动物中.MTs 通常含61个氨基酸,其中20个为半胱氨酸,不含芳香族氯基酸和组氨酸,因此在280nm 附近没有吸收峰.MTs 通常结合7个Cd 或zn,20个巯基全部去质子化并参与配位,从而形成牢固的结构域.有证据表明MTs 可能有储存Zn 和Cu 的作用,同时能减轻重金属对动物细胞的毒性,但其生理功能一直不很清楚.近几年的研究表明,MTs 能增强机体对电离辐射的耐受力、修复DNA 损伤,这可能与MTs 中含有丰富的巯基有关.体外实验测得k_(MT/OH)=10~(12)dm~3·mol~(-1)·s~(-1),k_(MT/O(?))=5×10~5dm~3·mol~(-1)·s~(-1),但其辐解机理尚不清楚.本工作利用脉冲辐解技术研究了免肝MT-I 稀水溶液辐解时的中间过程,并作了初步的解释.     

Electrogenerated Chemiluminescence (ECL) Determination of Ephedrine with a Self-Assembly Multilayer Ni(II)-Polyluminol Modified Electrode

By combining the layer-by-layer (LBL) self-assembly technique with the electrochemical polymerization method, multilayer Ni(II)-polyluminol films were modified on the surface of a vaseline-impregnated graphite electrode. It was found that, compared with an electrode modified by direct electrochemical polymerization, this modified electrode offered a suitable ECL reaction micro-environment created by the special multilayer films, which was beneficial to the ephedrine hydrochloride enhancing effect for luminol ECL intensity. The ECL enhancing effect of ephedrine hydrochloride on the electro-oxidation luminol was improved on this modified electrode. Based on this finding, a new sensitive ECL method was developed for ephedrine hydrochloride determination under the optimal conditions. At the same time, a new idea is proposed for improving the analytical performance of the luminol ECL system by modifying the ECL reaction micro-environment with the layer-by-layer self- assembly method. Under the optimum experimental conditions, the ephedrine hydrochloride concentration in the range of 2.0 × 10⁻⁸–7.0 × 10⁻⁶ mol L⁻¹ was proportional to the enhanced ECL signal, and it offered an 8.0 × 10⁻⁹ mol L⁻¹ detection limit for ephedrine hydrochloride.     

meta-Nitration of Arenes Bearing ortho/para Directing Group(s) Using C−H Borylation

Herein, we report the meta-nitration of arenes bearing ortho/para directing group(s) using the iridium-catalyzed C−H borylation reaction followed by a newly developed copper(II)-catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one-pot fashion. This protocol allows the synthesis of meta-nitrated arenes that are tedious to prepare or require multistep synthesis using the existing methods. The reaction tolerates a wide array of ortho/para-directing groups, such as −F, −Cl, −Br, −CH₃, −Et, −iPr −OCH₃, and −OCF₃. It also provides regioselective access to the nitro derivatives of π-electron-deficient heterocycles, such as pyridine and quinoline derivatives. The application of this method is demonstrated in the late-stage modification of complex molecules and also in the gram-scale preparation of an intermediate en route to the FDA-approved drug Nilotinib. Finally, we have shown that the nitro product obtained by this strategy can also be directly converted to the aniline or hindered amine through Baran's amination protocol.     

CdS/石墨烯纳米复合物的可见光催化效率和抗光腐蚀行为

制备了一系列CdS纳米晶/石墨烯(CdS/GR)复合物,并在可见光照条件下评价了其光催化降解亚甲基蓝的光催化效率和抗光腐蚀行为. 研究表明,石墨烯的引入加速了CdS纳米晶(NCs)光生电子的迁移速率,抑制了其光生电子-空穴的复合,有效改善了其光催化降解有机污染物的性能. CdS/GR复合物中的石墨烯含量显著影响其光催化效率,其中石墨烯含量为4.6%的光催化剂效率最高,其光电流是CdS NCs的2.3倍. 利用光电化学和X射线衍射技术进一步证实,石墨烯的引入抑制了CdS NCs光腐蚀的发生,提高了CdS/GR复合物的光催化稳定性.     

Simultaneous extraction and determination of fluoroquinolones,tetracyclines and sulfonamides antibiotics in soils using optimised solid phase extraction chromatography-tandem mass spectrometry

An analytical method was developed for the simultaneous extraction and determination of 18 fluoroquinolones (FQs), tetracyclines (TCs) and sulfonamides (SAs) antibiotics from soils using solid phase extraction and liquid chromatography-tandem mass spectrometry. The soils were extracted by different solvents with the help of mechanical shaking and ultrasonic treatment at 59?kHz, followed by a strong anion exchange (SAX) cartridge to clean up soil samples and a hydrophilic lipophilic balance (HLB) cartridge as enrichment. The method was evaluated by testing the following variables: extraction solvents, the type of SPE cartridges, solvent volumes, initial spiking levels and soil types (silty clay loam and clay loam soils). The soil extraction method was validated using these two types of soils, representing two typical agricultural soils in northern China. For 2?g soil, the extraction steps with the mixture of potassium phosphate buffer and acetonitrile (ACN) (1/1, v/v, pH 3.2) provided satisfactory recoveries. In the clay loam soil, the recoveries of all the compounds were from 56% to 89% at the spiking level of 50?µg?kg^?1 soil, and from 69% to 97% at the spiking level of 200?µg?kg^?1 soil, respectively. Recoveries in silty clay loam soil were similar to that in clay loam. The method was successfully employed using soil samples collected from a farmland and afforestion area irrigated with sewage in northern China. The result indicates that trace antibiotics in sewage may accumulate in soil irrigated by river water containing sewage.     

有机碱催化的H-亚磷酸酯与靛红及其衍生物的phospho-Aldol-Brook重排串联反应

在温和的反应条件下,以1,1,3,3-四甲基胍(TMG)或1,8-二氮杂二环[5.4.0]十一碳-7-烯(DBU)有机碱作为催化剂,催化H-亚磷酸酯与靛红的phospho-Aldol-Brook重排串联反应,高效、高产率合成了两个系列α-羟吲哚基-磷酸酯类化合物.     

共价有机框架催化材料:二氧化碳转化与利用

多相催化二氧化碳(CO₂)高效转化为高附加值的精细有机化学品和化工燃料,具有非常重要的研究价值和工业应用潜力。共价有机框架材料(Covalent Organic Frameworks, COFs)由于其高比表面积、有序的孔道结构、高化学和热稳定性、可控的催化位点等特性,在CO₂吸附和转化方面都展现出突出的优势。通过合理的策略从分子水平对其孔道或表面进行改性引入功能性物种或催化活性位点,能够有效实现其对特定反应的选择性调控并提供物质传输的有利微环境,因此COFs材料近年来在CO₂催化转化领域中得到了迅速的发展,也具有良好的应用前景。本文针对近几年COFs材料在CO₂转化为重要化学品的研究领域进行了简要的综述,总结当前存在的问题,并对COFs催化材料今后在CO₂转化领域的发展进行了展望。