Dumbbell‐Shaped T₈‐POSS with Functional Organic Linkers

Abstract

New dumbbell-shaped octasilsesquioxanes (T 8 -POSS) are obtained by the condensation of organobridged silane precursors with partially condensed T 7 -triol. The synthesis based on corner-capping proceeds under mild reaction conditions (60°C in toluene) upon a nucleophilic fluoride-catalyzed condensation of the T 7 -triol with the alkoxysilyl organics. Two

Interlayer Silylation of Layered Octosilicate with Organoalkoxysilanes: Effects of Tetrabutylammonium Fluoride as a Catalyst and the Functional Groups of Silanes

“…Indeed, the fluoride ion of TBAF attacks the Si atom of alkoxysilanes, forming hypervalent silicon intermediates, which increases the nucleophilicity of Si and hence the reactivity. [23][24][25][26] Here we found that the degree of silylation of layered silicate using C 8 TES was increased in the presence of TBAF for the first time. The catalytic effect of TBAF on the silylation reaction was verified with other organoalkoxysilanes, confirming the superiority of this method.…”

“…[13] Here, we discuss the reaction mechanism of the promotion of silylation by the addition of fluoride ion (TBAF) on the basis of the sol-gel reaction of alkoxysilanes catalyzed by fluoride ions (Scheme 2). [23][24][25][26] A) An XPS peak [34] due to the F 1s orbital at 687 eV, attributed to the SiÀ F bond, [35] was observed (Figure S6), indicating the formation of unidentified Si species with an SiÀ F bond; this, in turn, indicates the nucleophilic attack on the silylating agent. [36] B) It is plausible that the oxygen atom of the SiÀ OH group at the surfaces of the layers undergoes nucleophilic attack on the Si atom that has become electrophilic due to the formation of SiÀ F bonds, resulting in the formation of a hexacoordinated state with SiÀ OÀ Si.…”

Sulfonic Acid-Grafted Hybrid Porous Polymer Based on Double-Decker Silsesquioxane as Highly Efficient Acidic Heterogeneous Catalysts for the Alcoholysis of Styrene Oxide

“…These signals suggest that the sulfonic groups are successfully grafted to PCS-DDSQ-SO 3 H-x. 48 The chemical structure of DDSQ and PCS-DDSQ was also confirmed by 1 H, 13 C, and 29 Si NMR spectra (Figure S1). 32 As shown in Figure 2a, the broad peak around 130 ppm in PCS-DDSQ, indicating the overlap of aromatic carbons arising from DDSQ, confirms the formation of a porous network.…”

“…The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.2c17732. Material characterization; 1 H NMR, 13 C NMR, and 29 ■ AUTHOR INFORMATION…”

“…Recently, double-decker-type SQ (DDSQ) has attracted extensive attention . Similar to cubic silsesquioxane T 8 , DDSQ provides good heat resistance, oxidation resistance, mechanical properties, and dielectric properties. − In addition, DDSQ can be easily functionalized with various organic substituents. ,,, More importantly, phenyl-DDSQ precursors can be prepared in high yield with a simple synthetic method and have better solubility in organic solvents. Furthermore, the Scholl coupling reaction has made important progress in organic reactions in recent years and plays an important role in the formation of C–C bonds in π-conjugated frameworks using a Lewis acid such as AlCl 3 as a catalyst, , and porous structures can be effectively constructed by this reaction.…”