Syntheses and Properties of Cyclopolysilanes with Well-defined Structures as Models for σ-Conjugation

作为 σ 共轭模型的具有明确结构的环聚硅烷的合成和性能

基本信息

批准号：
09304058
负责人：
MATSUMOTO Hideyuki
金额：
$ 25.41万
依托单位：
Gunma University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 2000
项目状态：
已结题

项目摘要

1. In a series of the anti isomers of the ladder polysilanes, the absorption maxima of the longest wavelength shift to the longer wavelength region as the number of cyclotetrasilane rings progressively increases. The shift is explained in terms of the stabilization of the lowest unoccupied molecular orbitals (LUMO) by the extension of the Si-Si σ-conjugation. The ladder polysilanes can be readily reduced by Na and K to generate the radical anions. The remarkable feature of the resulting radical anions is their unusual stability. For example, in the absence of dioxygen, the half-life of the pentacyclododecasilane is too long to be measured. The X-ray crystallography disclosed that the anti ladder polysilanes can be seen as silicon double helices, in which two linear polysilane chains screw in one way and are bridged by Si-Si bonds. Chiral symmetry breaking could be realized for anti-tricyclooctasilane. The crystallization gave one large crystal of each enantiomer M or P.The oxidation of … More the bicyclohexasilane with a deficient amount of m-chloroperbenzoic acid (MCPBA) resulted in the formation of 7-oxa compound, which shows stronger UV absorption and fluorescence. The domino oxidation predominates in the tri-, tetra-, and penta-oxidations of the tricyclooctasilane, tetracyclodecasilane, and pentacyclododecasilane with MCPBA, respectively.2. From the stereochemical results observed in the ring-opening of the cis, cis- and cis, transcyclotrisilane [Ph (Thex) Si]_3 (Thex=1, 1, 2-trimethylpropyl) with halogens, it is concluded that the cleavage of the Si-Si bonds occurs with retention -inversion of the configuration of the Si atoms.3. Octathexyloctagermacubane was synthesized to allow a comparison of chemical and physical properties of the alkyl-substituted octasilacubane with those of the corresponding octagermacubane. The octagermacubane is very stable to UV-Visible light, suggesting the unusual electronic and photochemical properties of the polyhedral germanium framework. Less

1。在一系列梯子多硅烷的抗异构体中，随着环甲硅烷环的数量逐渐增加，最长波长向更长的波长区域的吸收最大值。通过延伸Si-Siσ-偶联的扩展，用最低的无分子轨道（LUMO）的稳定来解释了这一移位。 Na和K可以很容易地减少梯子多硅烷，从而产生自由基阴离子。产生的自由基阴离子的显着特征是它们的异常稳定性。例如，在没有二恶英的情况下，五氯二苯二甲烷的半衰期太长而无法测量。 X射线晶体学揭示了抗梯子多硅烷被视为硅双螺旋，其中两个线性多多硅烷链螺钉以一种方式被Si-Si键桥接。可以实现手性对称性破裂，以实现抗三环链硅烷。结晶给出了每种映异构体M或P的一个大晶体。…更多的是含量不足的M-氯二苯甲酸（MCPBA）的双环己二硅烷（MCPBA），导致了7-oxa化合物的形成，这表现出强烈的UV吸收和荧光。 Domino氧化主要在三轮氯辛烷，四环氯二烷烷和McPBA的五氧化氧化和五氧化氧化中占主导地位。 From the stereochemical results Observed in the ring-opening of the cis, cis- and cis, transcyclotrisilane [Ph (Thex) Si]_3 (Thex=1, 1, 2-trimethylpropyl) with halogens, it is concluded that the cleavage of the Si-Si bonds occurs with retention -inversion of the configuration of the Si atoms.3.合成了八度二氧化糖核酸，以比较烷基取代的Octasilacubane的化学和物理性质与相应的八叶苯甲酰基的化学和物理性质。 octagermacubane非常稳定，可在紫外线可见光中稳定，这表明了多面部锗框架的异常电子和光化学特性。较少的