Synthesis and Characterization of Functionalizable Silsesquioxanes with Ladder-type Structures

Abstract

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Synthesis, Characterization, and Reaction of Divinyl‐substituted Laddersiloxanes

“…Along these lines, we recently reported the preparation of tricyclic ladder silsesquioxanes with 6-8-6 fused rings bearing four reactive vinyl or allyl substituents on the D-group silicon atoms. The latter ones could be easily transformed into the corresponding tetrachloro- [27] or tetramercapto- [28] laddersiloxanes through hydrosilylation or thiol-ene reactions, respectively. Some of us also reported the functionalization of phenyl-substituted 8-8-8-laddersiloxanes through Friedel-Crafts acylation to prepare nanoporous materials for water-treatment, which shows the potential of hybrid materials based on laddersiloxanes [26].…”

Synthesis of Tricyclic Laddersiloxane with Various Ring Sizes (Bat Siloxane)

“…[ 3 ] Following the first proposal of laddersiloxane structures by Brown et al., [ 4,5 ] we developed various tricyclic, [ 6 ] pentacyclic, [ 7 ] heptacyclic, [ 8 ] nonacyclic, [ 9 ] and polycyclic [ 10 ] laddersiloxanes as well as tricyclic laddersiloxanes with reactive organic substituents. [ 11 ] All of these laddersiloxanes have significant thermal stability, and the laddersiloxane structure has shown the highest refractive index and Abbe number among linear, cyclic, and cage silsesquioxanes. [ 12 ] In addition, we recently reported the application of tricyclic laddersiloxanes to porous materials for the removal of dyes and heavy metal ions from water.…”

“…DOI: 10.1002/marc.202000608 example, catalyst support materials, [14,15] electronic materials, [16] and hybrid organic-inorganic semiconducting fragments. [17] Tricyclic laddersiloxanes with syn-and anti-structures, which are depend on the structure of starting precursors, have typically been prepared through the base-catalyzed cleavage of cage hexasilsesquioxanes, [18] condensation of cyclic silanols with dichlorosilane, [6,11,19,20] or isocyanate-substituted siloxanes with silanols, [21,22] and oxidation of ladder oligosilanes. [23] To the best of our knowledge, tricyclic laddersiloxanes have been limited to 6-8-6-and 8-8-8-membered-ring systems.…”

“…[23] To the best of our knowledge, tricyclic laddersiloxanes have been limited to 6-8-6-and 8-8-8-membered-ring systems. [3,11] According to earlier work, several studies indicated that siloxane bond can be formed by the coupling of silyl hydride in the presence of water mediated by B(C 6 F 5 ) 3 , [24] since B(C 6 F 5 ) 3 can coordinate with water. [25] Here we developed a new synthetic method for tricyclic laddersiloxanes involving B(C 6 F 5 ) 3 -catalyzed intramolecular cyclization of an extended Janus ring, as shown in Scheme 1A.…”

“…Significant variance in the SiOSi bond angles from 138.27 (11) Reaction condition: a 200 mg of Janus ring, 10 mol% catalyst, 4 mL hexane, 4 mL water, vigorous stirring, products were isolated by GPC using CHCl 3 as eluents. Table 2.…”