金属有机配位聚合物的合成

金属有机配位聚合物(金属聚合物)由于整合了金属和聚合物的诸多优点而在清洁能源、智能响应材料、高性能器件制备方面具有广泛的应用潜力。本文综述了近十年金属聚合物合成进展,主要从聚合物形成和金属中心引入的顺序,如先合成聚合物再引入金属中心、先合成含金属单体后引发聚合以及一步法合成金属聚合物等方面进行论述,重点介绍合成方法、金属聚合物链结构和性能之间的关系,分析了不同合成方法的优缺点,探讨了金属聚合物合成的研究趋势。     

双金属在掺硼金刚石表面电化学共沉积-共溶出模型

采用微分脉冲阳极溶出伏安法, 研究了Ag+、Cu2+、Pb2+、Sn2+、Cd2+等多种共存金属离子在掺硼金刚石(BDD)表面双金属共沉积-共溶出电化学行为. 结果表明, 双金属在掺硼金刚石膜表面的共沉积-共溶出模型是由金属本身的析出电位, 金属之间的相互作用, 金属离子和溶液间的相互作用等多种因素决定的. 微分阳极溶出法的研究结果表明, 双金属在掺硼金刚石电极上的共沉积-共溶出过程表现出金属1溶出-金属2溶出、金属1溶出-析氢-金属2溶出、金属1溶出-金属合金溶出-金属2溶出、金属1溶出-析氢-金属2络合物形成-金属2溶出等四种模型.     

金属蒸气合成在金属有机合成中的应用

本文简要地介绍了金属蒸气合成法的基本原理、仪器和实验技术, 并按金属原子分别与炔、单烯、多烯、环烯、芳烃体系、卤代烃、有机混和物的反应及有机金属硼化合物的合成, 对金属蒸气合成法在金属有机合成中的应用进行了讨论。     

含硅金属化合物的研究进展

近年来,含硅金属化合物由于在催化工业等领域的广泛应用受到了化学工作者的重视。本文综述了以硅原子或硅杂链为配体的桥形成的金属络合物、金属硅氧烷、硅-金属化合物、金属不饱和硅化物、含硅多金属络合物五种含硅金属化合物的研究进展。最后,并对该领域的研究方向提出了展望。     

骨架具有金属-金属键的链状分子研究进展

以金属-金属键为骨架的链状分子,具有离域的σ电子,由于其特殊的光、电、磁及催化性能,引起了科学家们的广泛关注。本文根据金属-金属成键的方式,对近年来报道的金属链状分子进行了综述。文中总结了三大类型的金属链状分子:金属聚合物聚锡和聚锗、非配体桥连的过渡金属-金属键骨架链状分子以及多吡啶胺配体支撑的多核过渡金属-金属键骨架链状分子。最后对金属-金属键骨架链状分子结构进行了展望,为设计新型功能分子材料提供了思路。     

含硅金属化合物

近年来,含硅金属化合物由于在催化工业等领域的广泛应用受到了化学工作者的重视.本文综述了以硅原子或硅杂链为配体的桥形成的金属络合物、金属硅氧烷、硅-金属化合物、金属不饱和硅化物和含硅多金属络合物5种含硅金属化合物的研究进展,并对该领域的研究方向提出了展望.     

磺化酞菁金属的聚集及对催化氧化硫醇性能影响

磺化酞菁金属主要用作液化气脱硫醇过程碱液氧化再生催化剂。为研究磺化酞菁金属易于失活的影响因素,对比探讨了5种磺化酞菁金属(Fe、Co、Ni、Cu、Zn )在相同溶剂以及不同溶剂中的聚集作用,并研究了聚集对催化氧化硫醇活性的影响。结果表明,磺化酞菁金属聚集受溶剂影响较大,溶剂极性越强,聚集越严重;磺化酞菁金属溶液放置时间越长,磺化酞菁金属聚集体粒径越大;金属种类不同,对磺化酞菁金属聚集也有影响。聚集导致CoSPc、CuSPc催化氧化硫醇活性显著降低20%左右。     

中国金属有机化学的进展

本文综述了中国金属有机化学的进展。第一部分是主族元素金属有机化学,它包括有机硅、硼、砷和锡的化学。第二部分是过渡金属有机化学,包括过渡金属有机络合物的合成、结构和反应;过渡金属有机络合物在有机合成中的应用;均相催化和小分子活化。综述引用文献383篇。     

二氧化碳与不饱和烃的还原羧化反应

过渡金属催化CO₂参与的不饱和烃还原羧化反应是合成羧酸及丙烯酸类化合物的重要途径, 具有重要的研究价值和工业应用潜力．过渡金属试剂与不饱和烃、CO₂生成稳定的金属杂环内酯或金属羧酸盐．还原剂能够与金属杂环内酯或金属羧酸盐发生转金属作用, 重新生成活泼催化剂, 从而实现催化剂的循环利用．本文总结了还原剂, 包括有机金属试剂、硅烷、硼烷、金属粉末、甲醇和氢气等在不饱和烃与CO₂的还原羧化反应中的应用, 并着重描述其反应特点和反应机理.     

联三吡啶配体组装及其金属络合物性能*

金属-配体间的配位作用是超分子化学中最重要的相互作用之一,寡聚吡啶配体可以与许多过渡金属离子配位,形成具有独特磁、光物理和电化学性质的过渡金属配合物,因此联三吡啶配体过渡金属配合物性能研究引起化学家的广泛关注。本文系统综述了联三吡啶配体及其衍生物的组装策略及其过渡金属配合物的光化学与光物理性能,包括单极、二极及多极配体以及由这类配体组装得到的各种拓扑结构的单核、多核过渡金属配合物,如线型金属寡聚物、金属聚合物、金属大环化合物、有机金属树枝状化合物等,并介绍这些配合物在该领域研究和应用前景。     

Book Reviews

Abstract

HANDBOOK FOR ESTIMATING PHYSICOCHEMICAL PROPERTIES OF ORGANIC COMPOUNDS, by M. Reinhard and A. Drefal, 228 pages, J. Wiley, New York (1999). ISBN 0—471—172634. UK £ 210.00

THE CHEMISTRY OF POLLUTION, by G. Fellenberg, 192 pp. J. Wiley & Sons, Chichester, U.K. (1999). ISBN 0—471—980889. UK£ 24,95.

NATURAL ATTENUATION OF FUELS AND CHLORINATED SOLVENTS IN THE SUBSURFACE, by T.H. Wiedemeier, H.S. Rifai, C.J. Newell and J.T. Wilson, 617 pages, J. Wiley, New York (1999). ISBN 0—471—19749—1. UK £ 58.50

UNDERSTANDING OUR ENVIRONMENT, 3^rd, edition, edited by R.M. Harrison, 445 pages, The Royal Society of Chemistry, Cambridge (UK) (1999). ISBN 0—85404—584—8. UK£ 19.95

ENDOCRINE DISRUPTING CHEMICALS, Vol. 12 of Issues in Environmental Science and Technology, edited by R.E. Hester and R.H. Harrison, 152 pages, Royal Society of Chemistry, Cambridge (U.K.) (1999). ISBN 0—85404—255—5. UK£ 25,00

METHOD PERFORMANCE STUDIES FOR SPECIATION ANALYSIS. by P. Quevauviller, 271 pages, The Royal Society of Chemistry, Cambridge (U.K.) (1998). ISBN 0—85404—467—1. UK£ 59.50

GLOBAL AQUATIC AND ATMOSPHERIC ENVIRONMENT, by H.D. Kumar and D.P. Häder, 393 pages, Springer, Berlin (1999). ISBN 3—540—65369—4. USD 229.00

BIOACCUMULATION. New Aspects and Developments, edited by B. Beek, 284 pages, Springer, Heidelberg, 2000. ISBN 3—540—62575. USD 143.00

INTERLABORATORY STUDIES AND CERTIFIED REFERENCE MATERIALS FOR ENVIRONMENTAL ANALYSIS. The BCR approach, by Ph. Quevauviller and E.A. Maier, 558 pages, Elsevier Science, Amsterdam NL, (1999). ISBN 0—444—82389—1. USD 251.50 (Euro 224.62).     

Environmentally Friendly Techniques and Their Comparison in the Extraction of Natural Antioxidants from Green Tea,Rosemary, Clove,and Oregano

Many current food and health trends demand the use of more ecological, sustainable, and environmentally friendly techniques for the extraction of bioactive compounds, including antioxidants. However, extraction yields and final antioxidant activities vary between sources and are highly influenced by the given extraction method and nature and ratio of the employed solvent, especially for total polyphenols, flavonoids, and anthocyanins, which are well recognized as natural antioxidants with food applications. This review focused on the most common extraction techniques and potential antioxidant activity in the food industry for various natural antioxidant sources, such as green tea, rosemary, clove, and oregano. Green extraction techniques have been proven to be far more efficient, environmentally friendly, and economical. In general, these techniques include the use of microwaves, ultrasound, high hydrostatic pressure, pulsed electric fields, enzymes, and deep eutectic solvents, among others. These extraction methods are described here, including their advantages, disadvantages, and applications.     

石墨烯纤维：制备、性能与应用

石墨烯纤维是一种由石墨烯片层紧密有序排列而成的一维宏观组装材料。通过合理的结构设计和可控制备,石墨烯纤维能够将石墨烯在微观尺度的优异性能有效传递至宏观尺度,展现出优异的力学、电学、热学等性能,从而应用于功能织物、传感、能源等领域。目前,石墨烯纤维主要通过湿法纺丝、限域水热组装等方法制备得到,其性能可以通过对材料体系和制备工艺的优化而进一步提升。本文首先介绍了石墨烯纤维的制备方法,然后详细阐述了石墨烯纤维的性能,讨论了其性能提升策略,并总结了石墨烯纤维的应用,最后对石墨烯纤维的未来发展、挑战和前景进行了展望。     

Dynamics of phase separation and critical phenomena in polymer mixtures

The phenomenological mean-field theory for statics and dynamics of polymer mixtures is described, generalizing the approaches of Flory-Huggins, Cahn-Hilliard and de Gennes. Predictions are made for critical behavior, spinodal decomposition and homogeneous nucleation. The validity of the mean-field approximations is discussed with Ginzburg criteria. The results of the theory are compared to computer simulations and recent experiments.Invited talk delivered at the Tagung der Deutschen Physikalischen Gesellschaft, Fachausschu\ Polymerphysik, Kaiserslautern, 12–14 March 1986, and at the Gordon Research Conference on Polymer Physics, Andover, New Hampshire, 14–18 July 1986.The author is grateful to Dieter W. Heermann, Alla Sariban, Harry L. Frisch, Josef JÄckie and Thomas Schichtel for their fruitful collaboration on this research described in this review. He thanks them and Arthur BaumgÄrtner for allowing to present partially unpublished material, and for stimulating discussions. Furthermore the author has benefitted from discussions with P. G. de Gennes, P. Pincus, H. Sillescu and G. R. Strobl. This research is supported in part by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 41.     

石墨烯基二氧化碳电化学还原催化剂的研究进展

利用电催化技术将CO₂转化为小分子燃料或高值化学品是实现原子经济、构建人工碳循环的绿色能源技术之一。电催化还原CO₂ (ECR)的反应条件温和、产物多样(C₁、C₂和C₂₊),有极大的发展潜力。然而,ECR技术面临一些需要解决的挑战性问题,包括电极过电势高、C₂及C₂₊产物选择性低、伴随析氢反应等。解决这些问题的关键在于创制低成本、高性能电催化剂。近年来,石墨烯基电催化剂的研究成为ECR领域的热点之一,原因包括：1)在电化学环境中稳定性好;2)表面原子、电子结构可调,进而实现材料催化活性的调控;3)维度可调,易暴露较大的比表面积和形成层次孔结构;4)耦合石墨烯的高导电性与特定材料的高活性,可协同提升ECR催化性能。本文评述了石墨烯基材料在ECR中的研究进展,详述了石墨烯基电催化剂的构筑方法,探讨并梳理了石墨烯的点/线缺陷、表面官能团、掺杂原子构型、金属单原子种类、材料表界面性质等与ECR性能之间的本征构效关系。最后展望了石墨烯基催化剂在ECR领域中的挑战和未来发展。     

甘油催化氢解制备精细化学品的研究进展

随着生物柴油产业的快速发展,作为副产物的甘油大量过剩,因而有效利用甘油既能促进生物柴油产业的良性发展,又能节约大量石油资源。通过甘油催化氢解的方式来制备高附加值化学品丙二醇、乙二醇和丙醇等是甘油转化研究中最有潜在应用价值的路径之一,甘油氢解反应易于实现连续化生产,且目标产物附加值高、选择性高,因而具有良好的经济效益。本文首先简要介绍了甘油化学,深入探讨了甘油的氢解机理,然后重点综述了甘油氢解制备1, 2-丙二醇、1, 3-丙二醇、乙二醇和丙醇高效催化剂的研究进展,并对甘油氢解未来的研究方向和发展趋势作了进一步展望。     

液体弹珠：制备策略、物理性质及应用探索

Liquid marbles (LMs) are liquid droplets coated with a layer of lyophobic particles at the air-liquid interface. Since the pioneering work by Aussillous et al. in 2001, LMs have attracted significant attention owing to their facile fabrication, flexibility in the choice of the constituent particles and liquids, intriguing properties such as non-wetting and non-adhesive nature, satisfactory elasticity and stability, as well as promising applications in microfluidics, sensors, controlled release, and microreactors. The classical strategy for the preparation of LMs involves rolling a small volume of a droplet on a lyophobic powder bed for complete encapsulation of the liquid by the particles. In addition, various innovative methods, including electrostatic and coalescent approaches, have been developed for preparing special LMs with a complicated structure or morphology. Diverse materials such as water, surfactant solutions, liquid metals, reagents, blood, and even viscous adhesives have been employed as the internal liquid for the fabrication of LMs. Theoretically, any particulates such as lycopodium, polytetrafluoroethylene, Fe₃O₄, SiO₂, and graphite grains can be employed as the outer coating, but they are usually required to be lyophobic with sizes of less than hundreds of microns. The unique structure of the particle-covered droplet and the dual solid-liquid characteristics endow LMs with some unique and interesting properties, especially the non-wetting and non-adhesive nature. As the lyophobic coating particles restrain the internal liquid from contacting the substrate, LMs can move easily across either solid or liquid surfaces, neither wetting the substrate nor contaminating the internal liquid. An equally fascinating property of LMs is their satisfactory stability, which is necessary for most of their applications. The high stability of LMs stems from the protection of the coating powders and is embodied in both good mechanical stability (remaining intact after being released from a certain height or under a certain compression) and long lifetime (greatly suppressing the evaporation of the internal liquid). These extraordinary properties make LMs promising candidates for use in multitudinous fields, especially droplet microfluidics and microreactors. The potential application of LMs in microfluidics is ascribed to their non-wetting, non-adhesive nature and other features such as an ability to float on a liquid surface, coalescence, split, a small force of rolling friction, and response to external forces. Notably, LMs hold great promise for applications in microreactions, because they can create a confined reaction microenvironment, minimize reagent usage, facilitate unhindered gas exchange between the internal liquid medium and the surrounding environment, and allow the entry/exit of the reactants/products. We herein review the recent advances in LMs, such as manufacturing techniques, formation mechanisms, physical properties, and emerging applications. In particular, much attention is paid to the factors affecting the stability of LMs and the potential strategies to increase their stability. Moreover, this review discusses the challenges in the future development of LMs, suggests several possible ways of addressing these challenges, and forecasts the future development directions. We believe that this review can help researchers gain a better understanding of LMs and promote their further advances.     

ICP–AES法测定稀土硅铁球化剂和孕育剂中钙、镁、铝、锰、镧、铈

建立了电感耦合等离子体原子发射光谱法(ICP–AES)测定稀土硅铁球化剂和孕育剂中Ca,Mg,Al,Mn,La,Ce等元素含量的方法。通过基体匹配消除了铁基体的干扰,Ca,Mg,Al,Mn,La,Ce的分析谱线分别为317.933,279.553,394.401,257.610,333.749,456.236 nm。各元素标准曲线的线性相关系数均在0.999以上,检出限在0.000 1%~0.000 4%之间。方法的加标回收率为99.4%~102.8%,测定结果的相对标准偏差均小于3%(n=11)。用该方法测定标准样品,测定结果与认证值相吻合。该法适用于稀土硅铁球化剂和孕育剂中钙、镁、铝、锰、镧、铈的测定。     

Cellulose nanocrystals and related nanocomposites: Review of some properties and challenges

Cellulosic nanoparticles with high Young's modulus, crystallinity, specific surface area, and aspect ratio can be found in the natural structure of plant fibers. Indeed, lignocellulosic fibers consist of semicrystalline cellulose nanofibrils embedded in an amorphous matrix mainly composed of lignin and hemicelluloses. These nanostructures give the mechanical strength to higher plant cells, and are biodegradable, renewable, resistant, and widely available to produce nanocomposites with low density, and improved and controlled mechanical, optical, and barrier properties. Nanoparticles can be extracted from cellulose using a top‐down mechanically or chemically assisted deconstructing strategy, and owing to their highly reactive surface ensuing nanomaterials can be chemically modified to tailor their properties for a wide range of applications. This review is limited to cellulose chemically extracted nanocrystals and aims to provide an overview about several aspects that involve this material, including sources, properties, challenges, and perspectives. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 791–806     

三唑类药物研究新进展

三唑类化合物作为药物广泛应用于临床,是目前药物研究开发的重点领域之一．越来越多的高活性、低毒性、不良反应少、多药耐药性小、生物利用率高、药代动力学性质好、药物靶向性强、给药方式多样化、广谱、高疗效的三唑类化合物作为候选药物或药物用于临床医治多种疾病,显示出了三唑类化合物在医药领域的巨大开发价值和潜在的宽广应用．本文结合自己的工作,参考国内外近五年文献系统地综述了三唑类化合物作为药物在整个医药领域的研究与开发近况,包括抗真菌、抗细菌、抗结核、抗癌、抗病毒、抗炎镇痛、抗惊厥等,并展望其发展趋势与前景．希望该评论有助于为高活性低毒性三唑类医药合理设计提供新思路．