Siloxane and Carbosiloxane Based Dendrimers: Synthesis, Reaction Chemistry, and Potential Applications

Abstract

This article focuses on recent developments made in the field of siloxane and carbosiloxane dendrimers with the silicon atoms as the branching (1 → 2, 1 → 3, or 1 → 4) points. It attempts to treat in a comprehensive way the divergent growth method for the synthesis of Si–O‐ and Si–O–C‐based dendrimers, including their reaction chemistry, their theoretical and physical descriptions, as well as their potential applications in the area of materials science.

Photodimerization of Coumarin‐Derived Pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane to Fabricate a Three‐Dimensional Organic–Inorganic Hybrid Material

“…In the synthesis of the coumarin-derived octasiloxane, the reaction of 1, 3,5,7,9,11,13,15-octakis(dimethylsiloxy)pentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxane (1) and 8 equivalents of 7-allyloxycoumarin in the presence of Pt(dvs) (platinum(0) 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex) catalyst was employed (Scheme 1). [14,30±32] This reaction proceeded quantitatively at room temperature to afford compound 2.…”

“…[1±4] On the other hand, covalent bonds are also applied to produce stronger structures and materials, when monomers bearing reactive sites are used as building blocks. Recently, pentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxanes have been the subject of studies for fabricating novel materials. [5±9] In particular, polyhedral oligomeric silsesquioxanes (POSS) are actively employed.…”

“…[5±9] In particular, polyhedral oligomeric silsesquioxanes (POSS) are actively employed. [10±12] Pentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxanes with substituents at the eight corners of the pseudo-cubic cores create a new field of this technology. [13±16] Hydrosilylation of octasiloxanes often contributes to the cross-linking reaction.…”

“…[13±16] Hydrosilylation of octasiloxanes often contributes to the cross-linking reaction. [13±16] A representative example of this process was reported by Laine et al, in which polymers were prepared from octahydrosilyl-and octavinylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxanes. [14] Furthermore, some non-catalytic reactions were also utilized in this process.…”

“…[30] On the other hand, this reaction has not been extended to the fabrication of nanostructures from multifunctional molecules, although this process provides a new type of polymerization and fabrication methodology for three-dimensional nanostructure materials. In this paper, we report on the crosslinking behaviors of a pentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxane bearing eight coumarin groups induced by photodimerization, and the fabrication of a novel organic±inorganic hybrid material.…”