键合型铕-十一烯酸-硅橡胶复合材料的合成及其荧光性能

以铕-十一烯酸配合物和含氢硅油为原料,在铂催化剂作用下制备稀土有机硅加成产物。对产物进行红外光谱和核磁共振分析。结果表明,配合物键接在有机硅高分子主链上,加成产物为一种键合型的铕-十一烯酸-硅橡胶复合材料。荧光光谱分析确定复合材料的最佳激发波长为393 nm;最强发射波长为616 nm,为铕离子的特征发射。同时,随着铕离子浓度的增大,复合材料没有荧光猝灭现象。     

Cyclolinear polysiloxanes. II. Crosslinking and characterization

The synthesis and characterization of two groups of novel networks prepared from cyclolinear polysiloxanes are described. The first group of networks from cyclolinear polysiloxanes (N‐CLPSs) was synthesized by the hydrosilation of vinyl‐terminated cyclolinear polyorganosiloxanes [prepared from diacetoxydiethyltetramethylcyclotetrasiloxane (D₄Et₂OAc₂) or diacetoxytriethylpentamethylcyclopentasiloxane (D₅Et₃OAc₂)] with a copolymer of dimethylsiloxane and methylhydrosiloxane as the crosslinking agent. Hydrosilation was effected with a platinum carbonyl catalyst with a cyclovinylsiloxane moderator. The second group of networks (N‐eCLPSs) was prepared similarly with extended cyclolinear polysiloxanes. The mechanical properties of the novel networks were comparable to those of polydimethylsiloxane networks (N‐PDMS). The oxygen permeabilities were similar to or slightly higher than that of N‐PDMS. The glass‐transition temperatures of D₄Et₂OAc₂‐ and D₅Et₃OAc₂‐based N‐CLPSs were ?67.8 and ?90.8 °C, respectively, whereas the incorporation of polydimethylsiloxane spacers into similar N‐eCLPSs lowered their glass‐transition temperatures to ?109.7 and ?115.0 °C. Upon heating to 800 °C in air, N‐CLPSs yielded more residue than N‐eCLPSs, which in turn yielded more residue than N‐PDMS. These results may have been due to the presence of T units in the cyclic siloxane units, which may have inhibited chain degradation or the formation of volatile products. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4053–4062, 2006     

Application of chiral thiazolidine ligands to asymmetric hydrosilation

Seven chiral thiazolidines bound rhodium complexes were synthesized and their catalytic asymmetric hydrosilation properties were investigated It was found through investigation that the configuration of newly formed chiral centre C2 of substituted chiral thiazolidines prepared from L-cysteine or its esters has no effect on the final results of catalytic asymmetric hydrosilation.The direct reason for causing this phenomenon is reported by the present quantitative results for the first time:the rapid racemation of chiral center C2 of chiral thiazolidine ligands takes place under the catalysis of rhodium(Ⅰ) complex [Rh(COD)CI]2     

The synthesis and cationic polymerization of multifunctional silicon-containing epoxy monomers and oligomers

Several series of multifunctional silicon-containing epoxide monomers and oligomers have been prepared using rhodium catalyzed hydrosilation reactions. Dialkyl and diarylsilanes can be condensed with vinyl epoxides to give high yields of the desired diepoxides while the hydrosilation of alkyl and aryl silanes yields a mixture of di and tri epoxy substituted products. The condensation of αω,? Si? H difunctional compounds with vinyl epoxides can be carried out regioselectively to give α-hydrogen-ω-epoxy intermediates, which can be further reacted with di and tri olefins bearing terminal double bonds to give a series of well characterized epoxy functional oligomers. An investigation of the photoinitiated cationic polymerization of the monomers and oligomers, which were prepared during the course of these studies, was carried out. © 1994 John Wiley & Sons, Inc.     

Regioselective hydrosilations. III. The synthesis and polymerization of ambifunctional silicon-containing epoxy monomers

Silicon-containing epoxide compounds bearing Si ? H groups can be readily prepared in high yields by the regioselective rhodium-catalyzed monohydrosilation of α,ω-dihydrogen functional siloxanes and silanes with vinyl epoxides. The remaining Si ? H groups in these compounds can be further selectively hydrosilated with unsaturated epoxides to give a series of unique ambifunctional monomers containing two different epoxide groups in the same molecule. The photopolymerization of these monomers has been studied using analytical techniques including real time infrared spectroscopy and differential scanning photocalorimetry. On photopolymerization, the new monomers yield interesting networks. © 1993 John Wiley & Sons, Inc.     

End‐capped carbosilane dendrimers with benzoxazole,quinoline, and pyrone derivatives

Dendritic carbosilanes containing benzoxazole, quinoline, and pyrone derivatives on the periphery were prepared. The parent dendrimers in the inner shell were prepared by the use of iterative hydrosilation and alkenylation cycles. The end generations were obtained by the reaction of terminal Si? Cl groups on each periphery with HOR [HOR = 2‐(2‐hydroxyphenyl)‐benzoxazole, 8‐hydroxyquinoline, and 3‐hydroxy‐2‐methyl‐4‐pyrone] in the presence of amine. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2308–2314, 2001     

Comparison of octadecyl bonded titania phases

Summary The structure of a C₁₈ phase based on titania (C₁₈-A), synthesized by the method of solution polymerization, is investigated by diffuse reflectance infrared Fourier transform (DRIFT) and solid-state nuclear magnetic resonance (NMR) spectroscopy. The findings are compared with the results of a second C₁₈ phase based on titania (C₁₈-B) which was synthesized by the method of surface hydrosilation. The dynamic behavior of both phases is examined by¹H MAS NMR detection of spinlattice relaxation times in the rotating frame (T_1pH) and conventional spin-lattice relaxation times (T₁). Due to a smaller ligand density, phase C₁₈-A appears to be a somewhat more mobile than phase C₁₈-B. The chromatographic capability of the phase C₁₈-A is demonstrated by the separation of samples containing benzene derivates or anilines. The elution order is analogous to the phase C₁₈-B, but for both test mixtures the polarity of the mobile phase has to be increased. Phase C₁₈-A is classified as being polymeric by the Sander and Wise test, whereas phase C₁₈-B shows intermediate retention behavior.     

硅氢加成反应用铂催化剂的研究进展

系统综述了铂催化剂体系研究的几个主要发展阶段及目前存在的问题;介绍了铂催化烯烃硅氢加成反应合成有机硅的机理.指出有机硅产品在我们的生活和生产中越来越重要,是不可或缺的化工材料;不饱和烃的硅氢加成反应是合成有机硅的重要途径之一,主要利用过渡金属作为催化剂进行加成.     

γ-(甲基丙烯酰氧)丙基三甲氧基硅烷的合成研究

通过酯化法高产率地合成甲基丙烯酸烯丙酯(AMA)，并合成了一种用于硅氢加成合成γ-(甲基丙烯酰氧)丙基三甲氧基硅烷的新的催化剂，与所有已申请专利的合成方法采用的Speier催化剂相比，具有更高的催化活性，提高了产率且缩短了反应时间．讨论了在该催化剂作用下硅氢加成的各种影响因素．     

Synthesis of (+)-obtusenyne

An enantioselective synthesis of the halogenated medium-ring ether natural product (+)-obtusenyne is reported which uses the ring expansion of a seven-membered ketene acetal by means of a Claisen rearrangement to construct the core nine-membered oxygen heterocycle. The trans substituents across the ether linkage were established by using a transition-metal-catalyzed intramolecular hydrosilation reaction of an exo-cyclic enol ether. In addition, a formal synthesis of ent-obtusenyne from 2-deoxy-D-ribose is reported. A number of interesting points regarding the chemistry of medium-ring oxygen heterocycles are highlighted.