对苯二酚合成过程中酚醌物质的气相色谱法分析

采用气相色谱（GC）分析方法,以氢火焰离子化检测器（FID）和30 m×0.25 mm×0.25μm KB-5毛细管色谱柱,实现了苯酚为原料合成对苯二酚合成过程中对苯二酚,对苯醌,邻苯二酚及苯酚四种物质的同步定量。该方法操作简便,能准确、快捷的测定合成过程中各物质的含量,是对先前工作新的发展。     

Electrodeposition of PbO2 and Bi–PbO2 on Ebonex

Electrodeposition of PbO2 and Bi–PbO2 on Ebonex was carried out under various conditions, and the surfaces and coating/substrate interfaces examined by SEM, XPS and SIMS. Excellent adhesion to Ebonex was obtained with both crystalline and amorphous surfaces. Low plating temperatures resulted in dark grey, bright PbO2 and black, mirror-like Bi–PbO2 surfaces. Extrapolation of electrode lifetime test data indicated corrosion rates of 716 m yr–1 for PbO2 and 158 m yr–1 for Bi–PbO2.     

Electrochemical waste water treatment: Electrooxidation of acetaminophen

Oxidation of acetaminophen at boron-doped diamond (BDD) and at Ti/SnO₂ anodes in a plug-flow divided electrochemical reactor led to electrochemical combustion, whereas at Ti/IrO₂ benzoquinone was the exclusive product except at very long electrolysis times. The difference is explicable in terms of the different mechanisms of oxidation: direct oxidation at the anode for Ti/IrO₂ vs. indirect oxidation involving electrogenerated hydroxyl radicals at BDD and Ti/SnO₂. At BDD, at which the efficiency of degradation of acetaminophen was greatest, the rate of electrolysis at constant concentration was linearly dependent on the current, and at constant current linearly dependent on the concentration. Current efficiencies for mineralization up to 26% were achieved without optimization of the cell design.     

维生素K的合成及其废液处理

介绍了维生素Ｋ的合成路线，重点介绍了合成中含铬废液的处理方法。     

Poly(methacrylic acid)‐bound dihydroxybenzene units: Redox polymers

Poly(methacrylic acid) (PMAA) was functionalized with a hydroquinone/catechol under the reaction conditions of Minisci. Optimum conditions for maximum functionalization (52%) were found to be as follows: [benzoquinone]/[PMAA] ratio, 0.75; reaction time, 3 h; temperature, 75°C; and a nitrogen atmosphere. Redox properties of hydroquinone/catechol‐modified PMAA (PMAA‐HQ) were evaluated by their midpotentials potentiometrically estimated to be 898 mV at 20°C. At 35°C, a two‐stage oxidation was observed with a midpotential of 1000 mV. These midpotentials were found to be higher than those of hydroquinone, catechol, and a 1 : 1 hydroquinone‐catechol mixture, under the same conditions of potentiometric titration. Under the modification reaction conditions, the modified PMAA underwent severe degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 954–961, 2006     

Electrochemical Recycling of Benzoquinone in the Pd/Benzoquinone‐Catalyzed Heck‐Type Reactions from Arenes

Palladium(II ) acetate‐catalyzed Heck‐type reactions have been performed from the arene 1 and alkenes (n‐butyl acrylate, styrene) in acetic acid at room temperature, in the presence of a catalytic amount of benzoquinone or hydroquinone. The reactions have been made catalytic in benzoquinone [which is used to continuously oxidize the Pd(0) into to the active Pd(II) species able to activate the Ar H bond] by the electrochemical oxidation of hydroquinone, formed in the reaction, back to benzoquinone.     

Rational Molecular Design of Benzoquinone‐Derived Cathode Materials for High‐Performance Lithium‐Ion Batteries

p‐Benzoquinone (BQ) is a promising cathode material for lithium‐ion batteries (LIBs) due to its high theoretical specific capacity and voltage. However, it suffers from a serious dissolution problem in organic electrolytes, leading to poor electrochemical performance. Herein, two BQ‐derived molecules with a near‐plane structure and relative large skeleton: 1,4‐bis(p‐benzoquinonyl)benzene (BBQB) and 1,3,5‐tris(p‐benzoquinonyl)benzene (TBQB) are designed and synthesized. They show greatly decreased solubility as a result of strong intermolecular interactions. As cathode materials for LIBs, they exhibit high carbonyl utilizations of 100% with high initial capacities of 367 and 397 mAh g^?1, respectively. Especially, BBQB with better planarity presents remarkably improved cyclability, retaining a high capacity of 306 mAh g^?1 after 100 cycles. The cycling stability of BBQB surpasses all reported BQ‐derived small molecules and most polymers. This work provides a new molecular structure design strategy to suppress the dissolution of organic electrode materials for achieving high performance rechargeable batteries.     

介孔纳米孔道中单维交联酶策略固定青霉素酰化酶

为解决酶固定化过程中稳定性较差的问题,将单维交联酶策略引入青霉素酰化酶的固定化中,通过在介孔泡沫硅载体(MCFs)表面初步吸附作用将酶固定,再用对本醌对酶分子进行交联,从而制得单维交联酶聚体。实验结果显示:单维交联酶聚体(CLEA)的稳定性有明显提高,最适温度从游离酶的45℃上升到55℃,催化温度的适用范围更宽,在50℃下热处理25 h仍保持74.4%活力,在测试操作稳定性方面,连续操作15次,其酶活保持在61.9%。     

Seasonal Anointment with Millipedes in a Wild Primate: A Chemical Defense Against Insects?

Members of a wild group of wedge-capped capuchin monkeys (Cebus olivaceus) intentionally anoint themselves with millipedes (Orthoporus dorsovittatus). Chemical analysis revealed these millipedes secrete two benzoquinones, compounds known to be potently repellent to insects. We argue that the secretion that rubs off on the monkeys in the course of anointment provides protection against insects, particularly mosquitoes (and the bot flies they transmit) during the rainy season. Millipede secretion is so avidly sought by the monkeys that up to four of them will share a single millipede. The anointment must also entail risks, since benzoquinones are toxic and carcinogenic. We suggest that for capuchins the immediate benefits of anointment outweigh the long-range costs.     

苯酚催化氧化制对苯二酚的两步法工艺

以苯酚为原料,复合金属离子为催化剂,研究用气相氧化合成苯醌,用铁粉还原苯醌制对苯二酚的两步法工艺,考察了氧化过程中的工艺条件对反应的影响。实验结果表明,苯酚催化氧化制苯醌适宜的工艺条件是以甲醇为溶剂、摩尔比为1∶3的Cu(NO3)2和NaNO3为催化剂、催化剂加入量为苯酚质量的1/2、70℃、2.7 MPa、反应2.5 h。在此反应条件下,苯酚转化率可达90%,苯醌选择性达88%。以铁粉作还原剂,将苯醌还原为对苯二酚,苯醌可完全转化,对苯二酚的选择性可达99.5%。