Carbosiloxandendrimere mit terminalen SiH-Bindungen
作者:Roy Buschbeck、Helga Sachse、Heinrich Lang
DOI:10.1016/j.jorganchem.2004.08.052
日期:2005.1
HOCH(Me)(CH2)4SiMe3 − nHn (4a: n = 1, 4b: n = 2, 4c: n = 3), which themselves are accessible by the hydrosilylation of MeCOCH2CH2CHCH2 (1) with the chlorosilanes HSiMe3 − nCln (2a: n = 1, 2b: n = 2, 2c: n = 3) and hydrogenation of the latter species with Li[AlH4]. Alcohols 4a–4c can be used as starting materials for the preparation of carbosiloxane dendrimers of the 1st–3rd generation. For the synthesis of the
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.