基于荧光共轭聚电解质的生物分子检测*

共轭聚电解质综合了传统共轭聚合物的光电性质和聚电解质的水溶性特点,使其在新一代化学生物荧光传感器中获得多种应用。本文总结了近五年来报道的共轭聚电解质（聚芴、聚噻吩、聚苯撑乙烯、聚苯撑乙炔等）用于检测生物分子的研究进展,并对共轭聚电解质的应用前景进行了展望。     

齐聚苯撑乙烯-二氧化硅复合膜的制备及其光电性质研究

聚苯撑乙烯（PPV）及其复合物由于光致发光效率高及电荷传输性能好,故在光电器件方面的应用已受到广泛重视,但聚合物材料有自身的局限性,主要是：（1）在矣合时残留杂质影响器件的稳定性;（2）聚合物结构复杂多变使其发光机理与微观结构模糊不清。因此具有化学结构,化学纯度高的剂聚苯撑乙烯（oligo-PV)及其复合物的合成和理论研究吸引了许多研究者。     

锂电池阴极材料多硫代聚苯撑的制备及电化学性能

采用阴极材料结构改性的新方法,即以导电的聚苯撑作为骨架,将多硫链以侧链形式连接在主链上.通过苯的聚合、聚苯撑氯代,氯代聚苯撑(PPPCl)的硫代三步合成了多硫代聚苯撑(PPPS),产物结构经¹³CNMR谱、IR光谱、Raman光谱和元素分析进行了鉴定,其中IR谱中461和615cm^-1及Raman谱中470和666cm^-1峰分别表明存在S-S键和C-S键,结合其它鉴定结果,证明终产物为多硫代聚苯撑.组装成电池进行充放电性能测试表明,材料在80mA/g的电流密度下放电,比容量为987mA·h/g;在400mA/g下放电,比容量为776mA·h/g.在这两种电流密度下的利用率分别为83.5%和65.7%,具有较高的利用率和较好的大电流性能.在400mA/g的电流密度下放电时,经过25个循环的容量为307mA·h/g.     

高分子电致发光材料研究进展

综述了近几年来国内外关于高分子聚合物在电致发光材料领域的研究进展,重点介绍了聚苯撑乙烯、聚芴类、聚噻吩类聚合物及其衍生物的相关研究成果,并讨论了当前高分子电致发光材料存在的关键问题及应用前景.     

荧光共轭聚合物传感器用于病原体检测的研究进展

以共轭聚合物为基础的传感器用于检测病原体是现代临床医学发展的一个新方向. 综述了近十年来聚二乙炔(PDA)以及聚苯撑乙炔撑(PPE)等共轭聚合物传感器用于病原体检测的研究进展.     

聚苯撑基硅氧烷交联毛细管柱的研究

使用静态涂渍法,在毛细管柱内壁涂渍新型苯撑基色谱固定液,通过原位交联,提高了液膜不可抽提性及稳定性。苯基通常被连接在聚硅氧烷硅原子的侧链上,如果两个硅原子之间通过苯联结而不是通过氧原子联结,则可形成聚苯撑基硅氧烷［１］,这种聚硅氧烷的弹性好。采用含５０％聚苯撑基硅氧烷研制出交联毛细管柱,并对制备过程重复程度进行了考察,评价了柱子的综合性能,简单介绍了柱子的极性及适用范围。     

聚对苯撑乙烯齐聚物及其衍生物电子结构和发光机理的理论研究

运用量子化学从头算ab initio HF方法对聚对苯撑乙烯剂聚物及其衍生物的几何结构进行了优化,分析了前线分子轨道成分,确认了电子光谱的跃迁轨道。计算结果表明,聚苯撑乙烯剂聚物及衍生物的电子云分布与其结构密切相关,不同取代基修饰下的二聚苯撑乙烯的电子光谱发生红移,且随取代基推电子能力加强红移显。电子光谱跃迁主要是最高占据轨道向最低空轨道之间的π－π^*跃迁,计算结果和实验吻合得很好。     

聚苯撑醚砜缩聚过程的研究

本文报导了聚苯撑醚砜碱法缩聚动力学的研究。首先合成了有关的单体及二聚体的模拟化合物,然后进行了反应速率常数的测定。其结果是:(1)两组带有取代基的苯衍生物相互作用时,其反应速率常数等于不带取代基的苯衍生物和带取代基的反应速率常数以及取代基组成相反的另一组速率常数的乘积。(2)对于聚苯撑醚砜缩聚反应必须采用多个反应速率常数来计算动力学过程。     

稀土掺杂聚苯撑ER流体的研究

选用CeCl4和FeCl3等对自制的对苯撑进行掺杂,将制得的高介电聚苯撑粉末加入到硅油中得到电流变体流体,测量了在电场作用下粘度和漏电流密度,以及相关的物理常数。讨论了电场强度、粒子浓度与粘度和漏电流密度的关系,粘度变化的响应速度和恢复时间,并探讨了其相关机制。     

PPV-PDMeOPV共聚物发光性质的实验和理论研究

具有优良电致发光性能的有机聚合物材料的研制及其发光性能和应用的研究是９０年代新兴的高科技领域．聚对苯乙炔［Ｐｏｌｙ（ｐ－ｐｈｅｎｙｌｅｎｅｖｉｎｙｌｅｎｅ）,缩写为ＰＰＶ,又称聚苯撑乙烯］是这一领域最先研制出来的具有代表性的材料［１,２］．为改变ＰＰ...     

Pyrene as chromophore and electrophore: encapsulation in a rigid polyphenylene shell

Starting from the fourfold ethynyl-substituted chromophore 1,3,6,8-tetraethynylpyrene as core, a series of polyphenylene dendrimers was prepared in high yield by combining divergent and convergent growth methods. The fluorescence quantum yields (Q(f)>0.92) of the encapsulated pyrene chromophore were independent of the size of the polyphenylene shell. Fluorescence quenching studies and temperature-dependent fluorescence spectroscopy were performed to investigate the site isolation of the core. They indicate that a second-generation dendrimer layer is needed to efficiently shield the encapsulated pyrene and prevent aggregate formation. Alkali-metal reduction of the encapsulated pyrene core was carried out to afford the corresponding pyrene radical anions, for which hampered electron transfer to the core was observed with increasing dendrimer generation, which is further proof of the site isolation due to the polyphenylene shell. To improve film formation and solubility of the material, solubilizing alkyl chains were introduced on the periphery of the spherical particles. Furthermore, highly transparent films obtained by a simple drop-casting method showed blue emission mainly from the unaggregated species. The materials presented herein combine high quantum efficiency, good solubility, and improved film-forming properties, which make them possible candidates for several applications in electronic devices.     

Wear-Resistant composite coatings with increased chemical resistance,produced by electrodeposition on a cathode

The formation and properties of coatings produced by electrodeposition on a cathode on the basis of an amine-containing oligomeric film-forming?ent modified with highly dispersed polytetrafluoroethylene, polyphenylene sulfide, and fluorine rubber were studied. A procedure is suggested for introduction of powdered polyphenylene sulfide into a formulation for cathodic electrodeposition. It was found that polyphenylene sulfide and polytetrafluoroethylene form a separate phase in a coating; during electrodeposition on a cathode, fluorine rubber SKF-264B enters into a chemical interaction with the amine-containing oligomeric film-forming agent; a scheme of this interaction is suggested. A formulation was created with a triple modification of the amine-containing oligomeric film-forming agent with polytetrafluoroethylene, polyphenylene sulfide, and fluorine rubber. This formulation forms a wear-resistant coating with increased chemical and corrosion resistance.     

Single-crystal structures of polyphenylene dendrimers

A series of first-generation polyphenylene dendrimers based on three different cores were prepared by Diels-Alder cycloaddition and their single-crystal structures were determined. Consisting exclusively of interlocked, twisted phenyl rings, these polyphenylene nanostructures have exciting structural and dynamic properties. Single crystals of dendrimers, suitable for X-ray structure analysis, were grown from different solvent mixtures by slow evaporation at room temperature. It should be pointed out that one of the described polyphenylene dendrimers represents up to now the biggest oligophenylene nanostructure from which crystallographic data is available.     

Synthesis and optical properties of polyphenylene dendrimers based on perylenes

A series of polyphenylene-dendronized perylenes have been synthesized, and their physical and mesoscopic properties have been investigated. The attached polyphenylene dendrons have significant effects on the physical properties of the perylenes. They increase the solubility of perylenes in common organic solvents, suppress significantly the aggregation of the perylene core, and lead to red-shifted absorption and emission. The polyphenylene dendrons give rise to a strong absorption band in the UV region and exhibit efficient intramolecular energy transfer to the perylene moiety. The functionalization of perylenes with polyphenylene dendrons allows the preparation of films by spin-coating.     

Polyphenylene dendrimers with different fluorescent chromophores asymmetrically distributed at the periphery

A new synthetic approach leading to asymmetrically substituted polyphenylene dendrimers is presented. Following this method, polyphenylene dendrimers decorated with an increasing number of chromophores at the periphery have been obtained up to the second generation. Especially the synthesis of a polyphenylene dendrimer bearing three donor chromophores and one acceptor chromophore has been realized. Intramolecular energy transfer within this molecule is demonstrated by applying absorption and fluorescence measurements.     

Two-dimensional polymer formation on surfaces: insight into the roles of precursor mobility and reactivity

We report on a combined scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) study on the surface-assisted assembly of the hexaiodo-substituted macrocycle cyclohexa-m-phenylene (CHP) toward covalently bonded polyphenylene networks on Cu(111), Au(111), and Ag(111) surfaces. STM and XPS indicate room temperature dehalogenation of CHP on either surface, leading to surface-stabilized CHP radicals (CHPRs) and coadsorbed iodine. Subsequent covalent intermolecular bond formation between CHPRs is thermally activated and is found to proceed at different temperatures on the three coinage metals. The resulting polyphenylene networks differ significantly in morphology on the three substrates: On Cu, the networks are dominated by "open" branched structures, on the Au surface a mixture of branched and small domains of compact network clusters are observed, and highly ordered and dense polyphenylene networks form on the Ag surface. Ab initio DFT calculations allow one to elucidate the diffusion and coupling mechanisms of CHPRs on the Cu(111) and Ag(111) surfaces. On Cu, the energy barrier for diffusion is significantly higher than the one for covalent intermolecular bond formation, whereas on Ag the reverse relation holds. By using a Monte Carlo simulation, we show that different balances between diffusion and intermolecular coupling determine the observed branched and compact polyphenylene networks on the Cu and Ag surface, respectively, demonstrating that the choice of the substrate plays a crucial role in the formation of two-dimensional polymers.     

Toward nanoamphiphiles: efficient synthesis of desymmetrized polyphenylene dendrimers

A new synthetic approach for the desymmetrization of polyphenylene dendrimers (PPDs) is described. Tetrakis(4-ethynylphenyl)methane undergoes facile Diels-Alder cycloaddition with substoichiometric quantities of tetraphenylcyclopentadienones bearing one polar functional group. A single ethynyl group is thereby converted to a rigid, selectively functionalized polyphenylene moiety, which serves as a focal point for further transformations or interfacial anchoring. This is the key feature for the design of desymmetrized monodisperse macromolecules with a spherical shape. The remaining unreacted ethynyl groups provide a trifold core for the stepwise elaboration of first- and second-generation polyphenylene dendrons, which may, in turn, bear specific numbers of different peripheral functional groups at their terminae. Moreover, the resulting macromolecules exhibit the characteristic shape-persistence and monodispersity of PPDs. This approach is an important achievement in nanosciences, especially for tailoring new nanoamphiphiles. It is also of synthetic importance, as it enables the separation of two regioisomeric polyphenylene dendrimers for the first time.     

Dendronized perylenetetracarboxdiimides with peripheral triphenylamines for intramolecular energy and electron transfer

Novel perylene-3,4,9,10-tetracarboxdiimides (PDI) dyes functionalized with polyphenylene dendrimers attached at the bay region are reported. Derivatives of PDI bearing polyphenylene dendrimers up to the second generation, substituted with an increasing number of triphenylamine (TPA) moieties at the periphery, as well as a related nondendronized model compound were prepared. Intramolecular energy transfer was demonstrated by the observation of PDI emission on excitation of the triphenylamines, and electron transfer was detected by comparing photoluminescence quenching in solvents of different polarity.     

A Polyphenylene Support for Pd Catalysts with Exceptional Catalytic Activity

We describe a solid polyphenylene support that serves as an excellent platform for metal‐catalyzed reactions that are normally carried out under homogeneous conditions. The catalyst is synthesized by palladium‐catalyzed Suzuki coupling which directly results in formation of palladium nanoparticles confined to a porous polyphenylene network. The composite solid is in turn highly active for further Suzuki coupling reactions, including non‐activated substrates that are challenging even for molecular catalysts.     

Properties of polyphenylene films deposited electrochemically in an HF-benzene system

Free-standing polyphenylene films, prepared by the electrochemical oxidation of benzene in an HF-benzene, two-phase system, were investigated. From electron microscope pictures, x-ray diffraction patterns, and infrared (IR) spectra of polyphenylene films and commercial polyphenylene powder it is concluded that the films, which are largely para linked, contain in addition a substantial amount of meta and possibly ortho linkages and are amorphous in nature. Doping with AsF₅ increases the electrical conductivity of the otherwise insulating films to 10^?4?10^?2ohm^?1cm^?1; doped films are relatively stable in air. The lower conductivity of doped films with respect to reported values for chemically synthesized poly-p-phenylene appears to be the result of the amorphous nature of the films.