One-pot strategy for synthesis of open-cage silsesquioxane monomers
One-pot strategy for synthesis of open-cage silsesquioxane monomers
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DOI：
10.1039/c9py00036d
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发表时间：
2019-05-14
影响因子：
4.6
通讯作者：
Naka, Kensuke
中科院分区：
文献类型：
--
作者：
Katoh, Ryoichi;Imoto, Hiroaki;Naka, Kensuke
元素嵌段是由多种元素组成的可聚合的功能单元，在构建先进的有机-无机杂化聚合物材料方面越来越受到关注。在这种背景下，多面体低聚倍半硅氧烷(POSS)是很有希望的元素块，因为它们的无机核心被有机取代基覆盖。然而，由于POSS结构的高度对称性，已有的主链型POSS聚合物很难合成；八角的等效反应性使得获得双功能POSS单体变得困难。本工作利用不完全缩合POSS(IC-POSS)一锅法合成了POSS单体。引入了空间受阻的三苯基硅基，将三个硅醇基中的一个封闭在开放结构中，其余两个硅醇基转化为可聚合的官能团。值得注意的是，所得聚合物的材料性质不仅受共聚单体控制，还受IC-POSS上的取代基控制。这种简单易行、用途广泛的POSS单体分子设计将为复杂元素嵌段聚合物材料开辟新的途径。
Element blocks, which are polymerizable functional units composed of diverse elements, have increasingly attracted attention to construct advanced organic-inorganic hybrid polymer materials. Polyhedral oligomeric silsesquioxanes (POSSs) are, in this context, promising element blocks because their inorganic core is covered with organic substituents. However, well established main-chain type POSS polymers are difficult to be synthesized due to the highly symmetrical structure of POSS; equivalent reactivity of the eight corners makes it difficult to obtain bi-functional POSS monomers. In this work, a one-pot synthesis of POSS monomers has been attained by utilizing incompletely condensed POSS (IC-POSS). A sterically hindered triphenylsilyl group was introduced to cap one of the three silanol groups in the open structure, and the remaining two silanol groups were converted to polymerizable functional groups. Notably, material properties of the resulting polymers were controlled not only by the comonomers but also by the substituents on the IC-POSS. This facile and versatile molecular design of POSS monomers will open a new avenue to sophisticated element block polymer materials.