1,2-Branched 1st to 4th Generation Carbosiloxane Dendrimers with a Me2SiO2 or MeSiO3 Core
作者:Roy Buschbeck、Karin Brüning、Heinrich Lang
DOI:10.1055/s-2001-18446
日期:——
A straightforward method for the preparation of 1 → 2-branched carbosiloxane dendrimers of the 1st to 4th generation with a Me2SiO2 or a MeSiO3 core by applying repetitive hydrosilylation-alcoholysis cycles is described. All dendrimers prepared contain as repeated units SiOCH2CH2CH2 entities and feature SiMe2Cl, SiMeCl2 or Si(OCH2CH=CH2) end-grafted moieties. Depending on the different initiator cores MeSi(OCH2CH=CH2)3 (MeSiO3) (17) and Me2Si(OCH2CH=CH2)2 (Me2SiO2) (1), 1,2-branched carbosiloxane dendrimers up to the 3rd (17) or 4th (1) generation are accessible. However, further hydrosilylation of the latter molecules only results in the formation of irregular structured species, due to increasing steric congestions on the respective dendrimer surface. The formation of analytically pure and uniform carbosiloxane dendritic molecules is based on elemental analyses, IR, 1H, 13C1H} and 29Si1H} NMR spectroscopic studies. From selected examples gel permeation chromatography was carried out.
描述了通过重复氢化硅烷化-醇解循环制备具有 Me2SiO2 或 MeSiO3 核的第一代至第四代 1→2-支链碳硅氧烷树枝状聚合物的简单方法。制备的所有树枝状聚合物均含有重复单元 SiOCH2CH2CH2 实体,并具有 SiMe2Cl、SiMeCl2 或 Si(OCH2CH=CH2) 末端接枝部分。根据不同的引发剂核心 MeSi(OCH2CH=CH2)3 (MeSiO3) (17) 和 Me2Si(OCH2CH=CH2)2 (Me2SiO2) (1),1,2-支链碳硅氧烷树枝状聚合物最多为第 3 个 (17) 或第 4 个(1)代可访问。然而,由于相应树枝状聚合物表面上的空间拥挤增加,后一分子的进一步氢化硅烷化仅导致不规则结构物质的形成。分析纯且均匀的碳硅氧烷树枝状分子的形成基于元素分析、IR、1H、13C1H} 和 29Si1H} NMR 光谱研究。从选定的实施例中进行凝胶渗透色谱法。