新药炎琥宁的碳氢NMR信号全归属

炎琥宁为中药提取物穿心莲内酯经结构改造后获得的一个抗菌、抗病毒新药,本文应用1D NMR和脉冲梯度场2D NMR实验技术（gCOSY,gHSQC,gHSQC-TOCOSY,gHMBC）对其结构进行了研究,并首次对其¹H NMR、¹³C NMR谱信号进行了全归属.     

液相色谱-串联质谱法同时测定水产品中三苯甲烷类与噻嗪类染料及其代谢产物

采用液相色谱-串联质谱法对鱼肉和虾肉中三苯甲烷类与噻嗪类染料及其代谢物进行测定。样品经对甲苯磺酸-乙酸铵-乙腈溶液提取,正己烷脱脂,二氯甲烷萃取,MCAX固相萃取净化后,以Waters BEH C18色谱柱为分离柱,以0.15%甲酸溶液(含5mmol·L-1乙酸铵溶液)-乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源及多反应监测模式进行测定。各化合物的质量浓度在20.0μg·L-1以内呈线性,方法的测定下限(10S/N)均为0.5μg·kg-1。对空白样品进行加标回收试验,回收率在62.6%~108%之间,测定值的相对标准偏差(n=6)在2.0%~14%之间。方法用于鱼肉和虾肉样品的检测,结果与国家标准方法的测定值一致。     

One‐Pot Synthesis of Aliphatic Nitro Compounds by Michael/retro‐Claisen Fragmentation Domino Reaction

A novel and concise method for the construction of γ‐nitro ketones and 1,3‐dinitro compounds with chemoselective acyl transfer has been presented under basic conditions via one‐pot reactions. These reactions feature high atom‐ and step‐economic possess, mild condition and simple operation for one‐pot synthesis of aliphatic nitro compounds. This protocol provides the products in good yields. The possible reaction mechanism has also been proposed.     

高效液相色谱法测定化妆品中5种荧光增白剂

采用高效液相色谱法测定化妆品中5种荧光增白剂的含量。样品经甲醇超声提取,以C18色谱柱为分离柱,以甲醇和5mmol·L-1四丁基硫酸氢铵溶液以不同比例混合的溶液为流动相进行梯度洗脱,用荧光检测器测定。5种荧光增白剂在一定的质量浓度范围内与其峰面积呈线性关系,方法的测定下限(10S/N)在0.1~2.0μg·g-1之间。以空白样品为基体进行加标回收试验,所得回收率在85.1%~97.1%之间,测定值的相对标准偏差(n=6)在1.4%~5.7%之间。     

Quantum-chemical study on the catalytic activity of TinRumO2(1 1 0) surfaces on chlorine evolution

Based on the generalized gradient approximation (GGA), Perdew-Wang-91 (PW91) combined with a periodic slab model has been applied to study the catalytic activity of chlorine evolution on TinRumO2(1 1 0) surface. Metal oxide model TinRumO2 has been established with pure TiO2 and RuO2 on the basis set of Double Numerical plus polarization (DNP), in which the proportion of n:m was 3:1, 1:1, or 1:3. Analysis on the reaction activity in the electrochemical reaction and the electrochemical desorption reaction was based on Frontiermolecular orbital theory. The results show that the TinRumO2 with a ratio of Ti:Ru at 3:1 is best facilitates the electrochemical reaction and electrochemical desorption reaction to produce M-Clads intermediate and precipitate Cl2. In addition, the adsorption energy of Cl on the surface of Ti3Ru1O2 possesses the minimum value of 2.514 eV, and thus electrochemical desorption reaction could occur most easily.     

搅拌速率对β-PbO_2-CeO_2-ZrO_2复合电极材料电化学性能的影响

为了提高三价铬镀铬工艺中阳极材料的性能,采用阳极氧化法制备了掺杂纳米颗粒的β-Pb O2-Ce O2-Zr O2复合电极材料。通过扫描电化学显微镜和析氧极化曲线的测量,考察了不同搅拌速率条件下制备的复合电极材料在硫酸盐体系三价铬镀液中的电催化活性,利用塔菲尔曲线考察了复合电极材料的耐蚀性,并辅以扫描电镜表征了电极材料的微观形貌。结果表明:当施镀搅拌速率为350 r·min-1时,所制备的复合电极材料具有结构致密、电催化活性高、耐蚀性强等特点。     

Guapsidial A and Guadials B and C: Three New Meroterpenoids with Unusual Skeletons from the Leaves of Psidium guajava

A novel sesquiterpene‐based Psidium meroterpenoid, possessing an unusual coupling pattern, and two new monoterpene‐based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava. Their structures and absolute configurations were elucidated by spectroscopic, X‐ray diffraction, and computational methods. The plausible biosynthetic pathway of these meroterpenoids as well as their cytotoxicities toward HepG2 and HepG2/ADM cells were also discussed.     

Highly Segregated Lamello‐Columnar Mesophase Organizations and Fast Charge Carrier Mobility in New Discotic Donor–Acceptor Triads

Four new donor–acceptor triads (D–A–D) based on discotic and arylene mesogens have been synthesized by using Sonogashira coupling and cyclization reactions. This family of triads consists of two side‐on pending triphenylene mesogens, acting as the electron‐donating groups (D), laterally connected through short lipophilic spacers to a central perylenediimide (PI), benzo[ghi]perylenediimide (BI), or coronenediimide (CI) molecular unit, respectively, playing the role of the electron acceptor (A). All D–A–D triads self‐organize to form a lamello‐columnar oblique mesophase, with a highly segregated donor–acceptor (D–A) heterojunction organization, consequent to efficient molecular self‐sorting. The structure consists in the regular alternation of two disrupted rows of triphenylene columns and a continuous row of diimine species. High‐resolution STM images demonstrate that PI‐TP2 forms stable 2D self‐assembly nanostructures with some various degrees of regularity, whereas the other triads do not self‐organize into ordered architectures. The electron‐transport mobility of CI‐TP2, measured by time‐of‐flight at 200 °C in the mesophase, is one order of magnitude higher than the hole mobility. By means of this specific molecular designing idea, we realized and demonstrated for the first time the so‐called p–n heterojunction at the molecular level in which the electron‐rich triphenylene columns act as the hole transient pathways, and the coronenediimide stacks form the electron‐transport channels.     

On the Extreme Oxidation States of Iridium

It has recently been suggested that the oxidation states of Ir run from the putative ?III in the synthesized solid Na₃[Ir(CO)₃] to the well‐documented +IX in the species IrO₄⁺. Furthermore, [Ir(CO)₃]^3? was identified as an 18‐electron species. A closer DFT study now finds support for this picture: The orbitals spanned by the 6s,6p,5d orbitals of the iridium are all occupied. Although some have considerable ligand character, the deviations from 18 e leave the orbital symmetries unchanged. The isoelectronic systems from Os^?IV to Au^?I behave similarly, suggesting further possible species. To paraphrase Richard P. Feynmann “there is plenty of room at the bottom”.     

Monodisperse AgSbS2 Nanocrystals: Size‐Control Strategy,Large‐Scale Synthesis,and Photoelectrochemistry

We report an efficient approach to the synthesis of AgSbS₂ nanocrystals (NCs) by colloidal chemistry. The size of the AgSbS₂ NCs can be tuned from 5.3 to 58.3 nm with narrow size distributions by selection of appropriate precursors and fine control of the experimental conditions. Over 15 g of high‐quality AgSbS₂ NCs can be obtained from one single reaction, indicative of the up‐scalability of the present synthesis. The resulting NCs display strong absorptions in the visible‐to‐NIR range and exceptional air stability. The photoelectrochemical measurements indicate that, although the pristine AgSbS₂ NC electrodes generate a cathodic photocurrent with a relatively small photocurrent density and poor stability, both of them can be significantly improved subject to CdS surface modification, showing promise in solar energy conversion applications.