Synthesis of Carbosilane Dendrimers with Variable Distance between Branching Nodes

Abstract

A principal possibility to synthetically control the distance between the branching nodes of poly(propenylsilane) dendrimer molecules has been shown. This was achieved by performing a relatively simple procedure—adding to the classic dendrimer building process a stage involving a bifunctional reagent: dimethylchlorosilane. As a result two series of carbosilane dendrimers with doubled node-to-node distance, from previously achieved, were synthesized which differed by the distribution pattern of terminal allyl groups. A sixth generation dendrimer with varied node-to-node distance in the core and periphery had been synthesized. These compounds were isolated by preparative LC and were characterized by 1H, 13C, and 29Si NMR, mass spectroscopy, and GPC. Their characteristic viscosities and hydrodynamic diameters were identified. A comparative analysis of properties of synthesized dendrimers and their counterparts from half the distance between the branch nodes had been performed.