On the knowledge of the Lewis amphoteric tris(pentafluoroethyl)silanolate ion and its derivatives [Si(C2F5)3E]- (E = O, NR and CR2)

关于路易斯两性三(五氟乙基)硅烷醇根离子及其衍生物[Si(C2F5)3E]- (E = O、NR和CR2)的认识

• 批准号: 440653279
• 负责人: Professor Dr. Berthold Hoge
• 金额: --
• 依托单位: Arbeitsgruppe Anorganische Chemie II
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/440653279?language=en
• 关键词: knowledge; Lewis; amphoteric; tris; pentafluoroethyl

Utilizing the strong electron-withdrawing effect of the pentafluoroethyl group, we are able to realize a LEWIS amphoteric character in the tris(pentafluoroethyl)silanide ion, [Si(C2F5)3]¬–, on the one hand, and to stabilize negative charges in alpha-position to the Si(C2F5)3 unit, such as in [(C2F5)3Si-CR2]– or [(C2F5)3Si-NR]– derivatives, on the other hand. We would like to study the LEWIS amphoteric behavior of the [Si(C2F5)3]– ion based on its reactions with polar multiple as well as single bonds. In this context, we expect further unusual reactions as observed for example in the oxidative addition of Ph2PCl. This reaction subsequently leads to a reductive coupling with another equivalent of Ph2PCl yielding in the formation of Ph2P-PPh2 and the oxidation of the silanide ion to the dichlorosilicate [Si(C2F5)3Cl2]–. The generation of carbanionic species, such as the [(C2F5)3Si-CH2]– ion, also leads to some unusual secondary products: The nucleophilic attack of [(C2F5)3Si-CH2]– on a second equivalent of the substrate, (C2F5)3Si-CH3, leads, after the elimination of C2F5H, to the anionic species [(C2F5)3Si-CH-Si(C2F5)2CH3]–, in which the negative charge on the central C atom is stabilized by two silane units. We would like to employ two tris(pentafluoroethyl)silanyl units for the stabilization of isolobal carbodiphosphorane systems and, of course, investigate in detail the reactivity of the dianionic compound [(C2F5)3Si=C=Si(C2F5)2]2–.

利用五氟乙基的强吸电子效应，我们一方面能够在三（五氟乙基）硅烷离子[Si（C2 F5）3]-中实现刘易斯两性特征，另一方面能够稳定Si（C2 F5）3单元的α-位的负电荷，例如在[（C2 F5）3Si-CR2]-或[（C2 F5）3Si-NR]-衍生物中。我们想研究[Si（C_2F_5）_3]-离子与极性多键和单键反应的刘易斯两性行为。在这种情况下，我们预期进一步的不寻常的反应，例如在Ph 2 PCl的氧化加成中观察到的。该反应随后导致与另一当量的Ph 2 PCl的还原偶联，产生Ph 2 P-PPh 2的形成和硅烷离子氧化成二氯硅酸盐[Si（C2 F5）3Cl 2]-。碳负离子物质的产生，如[（C2 F5）3Si-CH 2]-离子，也会导致一些不寻常的次级产物：[（C2 F5）3Si-CH 2]-对第二当量底物（C2 F5）3Si-CH 3的亲核攻击在消除C2 F5 H之后导致阴离子物质[（C2 F5）3Si-CH-Si（C2 F5）2CH 3]-，其中中心C原子上的负电荷被两个硅烷单元稳定。我们想采用两个三（五氟乙基）硅烷单元的稳定isolobal正膦系统，当然，详细研究的双阴离子化合物[（C2 F5）3Si=C=Si（C2 F5）2]2-的反应性。