饱和、不饱和(N-杂环化)低聚硅烷的结构和光谱性质

用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)对线型(饱和N-杂环化)和(苯并N-杂环化)低聚硅烷的电子结构和吸收光谱性质以及溶剂效应进行了比较研究.对各体系的基态电子结构在B3LYP/6-31G(d,p)水平上进行了全优化,讨论了电荷分布和前线分子轨道性质.在获得基态稳定构型的基础上,用B3LYP/6-311+G(d)方法计算了电子吸收光谱的性质,探讨了主链的线型增长和溶剂对电子吸收光谱的影响.结果表明,随着主链的增长,低聚硅烷的电子结构发生明显扭曲,在(苯并N-杂环化)聚硅烷中形成了邻近苯并N-杂环之间π-π堆积作用,有利于结构的稳定.两类低聚硅烷的吸收光谱都随着主链的增长而发生明显的红移,(苯并N-杂环化)聚硅烷最大吸收光谱红移幅度要比(饱和N-杂环化)聚硅烷大得多.溶剂效应使得光谱略向短波长移动,溶剂的极性改变对吸收波长的影响不明显.     

二氧化硅-聚硅氧烷负载硫杂-15-冠-5铂、铑配合物的合成及其催化硅氧化性能

6－(ω'-十一碳烯氧甲基)-1-硫杂-4,7,1O,13-四氧杂环十五烷与三乙氧基硅烷进行硅氢加成,产物依次以气相法二氧化硅固载、氯亚铂酸钾或三氯化铑络合,合成了相应的二氧化硅-聚硅氧烷负载硫杂-15-冠-5-铂、铑配合物,并研究了它们在烯烃与三乙氧基硅烷的硅氢加成反应中的催化性能.结果表明,二者均为硅氢加成反应的高效催化剂.     

主链含杂氮硅三环的聚醚的合成及其抗肿瘤活性研究

通过乙二醇或多缩乙二醇双缩水甘油醚与氨基乙醇开环聚合,然后与γ-氨基丙基三乙氧基硅烷反应,合成了四种主链含γ-氨基丙基杂氮硅三环的聚醚聚合物。将这四种聚醚聚合物与芳香醛反应,合成了十二种主链含有γ-芳亚甲氨基丙基杂氮硅三环的聚醚聚合物。用IR、UV、~1HNMR和元素分析对它们的结构进行了验证。用体外细胞培养法测定了这些聚合物的抗肿瘤活性。     

聚合物冠醚的合成与性能——Ⅶ.梳形聚醚的合成及络合、催化性能

近年来通过非冠醚单体的聚合以合成聚合物冠醚,国内外都有一些新的进展.环氧化合物开环聚合时可得到具有乙撑氧链的聚醚,我们选用含环氧基团的化合物作为聚合单体,同时在环氧基团上又引入另外的乙撑氧链,经过开环聚合得到相应的梳形聚醚的主链和侧链都含有乙撑氧链,具有开链冠醚的结构特点,尚未见报道.     

氟取代聚芳醚酮低温合成及其结构研究

通过傅克酰基化反应合成4,4'-二(4-氟苯甲酰基)二苯醚、4,4'-二(五氟苯甲酰基)二苯醚、4,4'-二(4-氟苯甲酰基)二苯硫醚以及4,4'-二(五氟苯甲酰基)二苯醚4种长链双卤单体,并进一步制备了含二氮杂萘酮聚芳醚酮聚合物.通过多氟取代双卤单体在含二氮杂萘酮聚芳醚酮聚合物主链中引入氟原子.多氟取代双卤单体具有多...     

主链含吡啶环的聚合物

介绍了国内外有关主链含吡啶环聚酰胺、聚酰亚胺、聚苯并咪唑、聚吡咙、聚酯以及聚氨酯等芳杂环或杂链高分子的研究，特别着重于含吡啶环的二元酚、二元酸、二元胺、四元胺类单体以及主链含吡啶环聚合物的分子设计、合成反应、结构与性能表征等。     

结构规整支化聚合物的制备方法

结构规整支化聚合物可以通过主链引发法，大分子单体聚合法和主链－支链偶联法来合成，对结构较为规整的支化聚合物的制备进行总结和评述。     

含糖聚合物的酶促合成

介绍含糖聚合物的酶促催化合成研究进展，主要包括主链含糖聚糖酯，支链含糖聚合物，中心为糖的星形取合物，硅烷主链含糖聚合物等。主链含糖聚合物直接由酶促催化酯化或酯交换作用制得；支链含糖聚合物由酶促合成糖酯单体及单体的化学聚合两步制得。     

环硅氧烷阴离子开环均聚及共聚研究进展

聚硅氧烷是一类典型的有机/无机杂化聚合物,具有耐高低温、优异的环境适应性等突出性能,在航空航天、国防科技等领域应用广泛.环硅氧烷单体阴离子开环聚合是制备不同链结构及功能化聚硅氧烷的重要途径,也是推动有机硅聚合物发展的重要研究领域之一.本文以阴离子开环聚合制备聚硅氧烷所涉及的环硅氧烷单体为线索,梳理了与不同化学结构环硅氧烷单体均聚及共聚相匹配的引发体系、聚合条件,以及聚合产物状态,并对相关研究工作做了论述介绍.此外,本文基于此线索对代表性研究体系做了简明罗列,便于高效检索及整体对比认知.     

含多面低聚倍半硅氧烷新型杂化聚合物的合成

基于多面低聚倍半硅氧烷（POSS）的杂化聚合物是近年发展起来的一类新型有机/无机杂化材料，性能独特，应用前景广阔。本文综述了含POSS新型杂化聚合物的合成研究进展，涉及自由基溶液聚合、可控活性聚合、开环易位聚合、缩聚和配位聚合。     

Block interrupt polysilane derivatives

High molecular weight block interrupt polysilane derivatives have been prepared by the condensation of a number of α,ω-dichloropolysilanes with some aromatic bis silanols. In this manner, polymers containing polysilane blocks of 2, 4, or 6 catenated silicon atoms have been prepared. The materials are thermally stable and the UV spectroscopic properties mimic those of the corresponding monomers. Although these materials bleach upon irradiation in the deep UV, surprisingly, the block interrupt polysilanes behave as negative resists upon exposure to 254 nm radiation. This behavior contrasts with that of standard polysilane homopolymers which usually function in a positive lithographic mode.     

Block interrupt polysilane derivatives

High molecular weight block interrupt polysilane derivatives have been prepared by the condensation of a number of α,ω-dichloropolysilanes with some aromatic bis silanols. In this manner, polymers containing polysilane blocks of 2, 4, or 6 catenated silicon atoms have been prepared. The materials are thermally stable and the UV spectroscopic properties mimic those of the corresponding monomers. Although these materials bleach upon irradiation in the deep UV, surprisingly, the block interrupt polysilanes behave as negative resists upon exposure to 254 nm radiation. This behavior contrasts with that of standard polysilane homopolymers which usually function in a positive lithographic mode.     

Synthesis of poly(γ-methoxypropylmethylsilylene) and poly(γ-methoxypropylmethylsilylene-co-di-n-hexylsilylene)

The synthesis of γ;-methoxypropylmethyldichlorosilane, and its subsequent polymerization and copolymerization with di;-n;-hexyldichlorosilane through the reductive coupling with sodium has been accomplished. The resulting polymers contain methyl ether side groups that allow further synthetic transformations on the polysilane backbone. For poly (γ;-methoxypropylmethylsilylene) these groups impart solubility characteristics different than typical alkyl and aryl substituted polysilanes. These new polymers and copolymers have been characterized by GPC and ¹H-, ¹³C-, and ²⁹Si-NMR. © 1994 John Wiley & Sons, Inc.     

Structurally and conformationally defined small methyl polysilanes

Possessing the property of sigma-bond electron delocalisation, polysilanes are a class of compounds with unique properties. In recent years major progress has been achieved in the theoretical understanding and the synthesis of polysilanes. Much insight into the connection between conformation and electronic properties has been gained from studies of defined small polysilane molecules. The transition from Wurtz type coupling reactions to the stepwise construction of polysilane molecules employing silyl anions as key intermediates has permitted access to defined compounds with a higher degree of structural complexity. Besides this, several methods have been developed to control the conformational properties and thus gain control over the electronic properties of polysilanes.     

液体聚硅烷的合成与交联

采用具有不同有机取代基的二氯硅烷与甲基二苯基氯硅烷为原料,在甲苯中以金属钠共缩合的方法,合成了可流动的聚硅烷。这些聚硅烷可用灌注、浇铸、涂敷等方法制成各种形状,并能在多乙烯基硅烷存在下,以紫外光辐照进行交联。本文还讨论了这些聚硅烷的分子量分布以及红外、紫外、核磁共振等光谱性质。     

含N、S官能基聚硅烷*

综述了近年来含N、S官能基聚硅烷的研究进展。介绍了吡啶、联吡啶、吡咯等含N官能基与噻吩、硫代官能团等含S官能基取代聚硅烷的制备和光电性能表征,概括了含N,S官能团聚硅烷的分子设计、物理性能与应用领域。最后展望了含N、S官能团聚硅烷研究的发展方向与应用前景。     

Asymmetrically tilted alignment of rigid-rod helical polysilanes on a rubbed polyimide surface

The homogeneous alignments of helical rod-like polysilanes on a rubbed polyimide alignment layer were investigated by polarized optical microscopy (POM) and atomic force microscopy (AFM) analyses. The POM and AFM observations determined that polysilanes with a series of aliphatic side chains helically arranged around the main chains were tilted to the right and left by 33° from the rubbing direction when the handedness of the side-chain helical array is left and right, respectively. It is interesting to note that the side-chain arrays run perpendicular to the rubbing direction on the polyimide surface, which is different from intuitive "knob and hole" packing of the extended polyimide chain and the helical grooves between the side-chain arrays surrounding the polysilane backbone. More surprisingly, both right- and left-tilting smectic domains were simultaneously observed with an equal probability for an achiral polysilane, which apparently has the interconverting right- and left-handed helical segments separated by helical reversals. This might be the first observation of the chiral segregation of dynamic helical polymers.     

Cyclic polymers: Synthetic strategies and physical properties

Syntheses of cyclic polymers including cyclic homopolymers, cyclic block copolymers, sun‐shaped polymers, and tadpole polymers are discussed on the basis of a differentiation between synthetic methods and synthetic strategies (e.g., polycondensation, ring–ring equilibration, or ring‐expansion polymerization). Furthermore, all synthetic methods are classified as kinetically or thermodynamically controlled reactions. Characteristic properties of cyclic polymers such as smaller hydrodynamic volume, lower melt viscosities, and higher thermostabilities are compared to the properties of their linear counterparts. Furthermore, the nanophase separation of cyclic diblock copolymers is discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 251–284, 2010     

聚硅烷高分子化学的发展及应用

本文介绍了聚硅高分子的合成方法、紫外吸收、光敏性、导电性等一系列特殊性质,聚硅烷高分子的化学反应以及聚硅烷材料的应用.     

聚硅烷研究进展 (1)聚硅烷的合成及应用

聚硅烷的合成及应用因可溶性聚硅烷的发现而成为聚合物研究的又一热点。本文综述了聚硅烷合成与应用的近期发展。