No-Solvent Synthesis of Siloxanes and Silicone Nanotube

在本项目中，我们致力于合成高度可调控的硅烷醇，并通过无溶剂反应转化为纳米管状硅氧烷等新型硅氧烷。通过这项研究，我们获得了以下新结果并发表了它们：1)我们发明的立体定向新反应使合成六元硅醇、环三硅氧烷三醇(两种异构体)和八元硅醇、环四硅氧烷四元醇(所有四种异构体)成为可能。这些都是新化合物，尤其是环四硅氧烷四醇是合成梯形倍半硅氧烷的很好的前体。以环四硅氧烷四醇为起始原料，合成了五环、七环、非开环和多环阶梯硅氧烷。这些都是具有低介电常数的下一代耐热材料。我们目前正在研究其应用。2)通过对起始化合物和试剂的研究，我们可以将无溶剂反应扩展到普通的合成硅氧烷。例如，硅烷醇与对甲苯磺酸反应生成了通常不能通过溶液反应得到的应变硅氧烷。此外，氢溴酸和氢碘酸是制备溶剂反应难以获得的硅氧烷的良好添加剂。有了这些结果，我们就可以利用硅氧烷的无溶剂反应，节省成本，环境友好。

In this project, we aimed the syntheses of highly regulated silanols, and transformation to the novel siloxanes like nano-tube siloxanes by means of no-solvent reaction.Through this research, we obtained the following new result and published them.1)The stereospecific new reaction we invented made possible the synthesis of six-membered silanol, cyclotrisiloxanetriols (all two isomers) and eight-membered silanol, cyclotetrasiloxanetetraols (all four isomers). These are all new compounds, and especially cyclotetrasiloxanetetraols are very good precursors of ladder silsesquioxanes. Starting cyclotetrasiloxanetetraols, we obtained pentacyclic, heptacyclic, nonacyclic, and polycyclic laddersiloxanes. These are next-generation thermostable materials with low dielectric constant. We are currently investigation the application.2)By investigating starting compounds and reagents, we could extend the no-solvent reaction to the common synthesis of siloxanes. For example, the reaction of silanols with p-toluenesulfonic acid afforded strained siloxanes those could not be obtained by usual solution reaction. Additionally, hydrobromic acid and hydroiodic acid are good additives for the preparation of siloxanes inaccessible by solvent reactions. With these results, we can utilize cost-saving environmental-friendly no-solvent reaction of siloxanes.