Carbosilane and carbosiloxane dendrimers

Abstract

This review focuses on novel carbosilane dendrimers containing branches with Si-C and Si-O-C bonds. Introduction of organic moieties into the dendrimers is performed by hydrosilation of carbon-carbon double/triple bonds. Versatile organic or organometallic moieties are introduced onto the peripheral regions of dendrimers by coupling and complexation reactions, which clearly demonstrates their potential for variation.

Figure 1

Cores for ethynylsilane (A) and siloxane tetramer cores (B).

Scheme 1

Overview of the increasing generation process of ethynylsilane dendrimers.

Figure 2

Limit generations for ethynylsilane dendrimers emanating from the (PhC≡C)₄Si core (left) and the (PhC≡C)₂Me₂Si core (right).

Scheme 2

Preparation method for the 1st generation of benzoxazole and benzothiazole dendrimer and the suggested possible coordination mechanism for higher generation of the dendrimers (below).

Scheme 3

Synthetic procedure for ethynylsilane dendrimers based on a 1,3,5- tris(dimethylvinysilyl)benzene core molecule.

Scheme 4

Schematic view of tetrahedrane dendrimers zeroth to 2^nd generation.

Scheme 5

Planar view of 1st to 4th generation silafluorene dendrimers, their GPC chromatogram and photographs of their photoluminescent properties.

Scheme 6

General preparation method of siloxane dendrimers.

Scheme 7

Planar view of DA products with benzoquinone (3rd generations with 24 BQ) on the dendritic periphery.