Self-assembly of fluoride-encapsulated polyhedral oligomeric silsesquioxane (POSS) nanocrystals

Abstract

The self-assembly and crystal packing of a unique series of nanocrystalline fluoride ion-encapsulated polyhedral oligomeric silsesquioxane (F-POSS) compounds, with substituted electron-withdrawing group (EWG) perfluorinated alkyl chain arms of varying lengths, were investigated.

Sol–gel processing of polyhedral oligomeric silsesquioxanes: nanohybrid materials incorporating T8 and T10 cages

“…Samples were prepared by deposition on Lacey/Carbon 300 Mesh TEM grids (LC325-Cu-25). 29 Si and 13 C solid-state NMR spectra were performed using magic-angle spinning techniques (MAS) or cross-polarization and magic-angle spinning techniques (CP-MAS) on a Varian VNMR 300 MHz spectrometer. Liquid 1 H, 13 C and 29 Si NMR spectra were recorded on a Bruker Avance 400 MHz spectrometer in CDCl3 at room temperature and at concentrations of around 10 mg/mL.…”

“…29 Si and 13 C solid-state NMR spectra were performed using magic-angle spinning techniques (MAS) or cross-polarization and magic-angle spinning techniques (CP-MAS) on a Varian VNMR 300 MHz spectrometer. Liquid 1 H, 13 C and 29 Si NMR spectra were recorded on a Bruker Avance 400 MHz spectrometer in CDCl3 at room temperature and at concentrations of around 10 mg/mL. 13 C and 29 Si NMR spectra were proton decoupled and all chemical shifts (δ) were calibrated against the signal of tetramethylsilane as internal standard.…”

“…Liquid 1 H, 13 C and 29 Si NMR spectra were recorded on a Bruker Avance 400 MHz spectrometer in CDCl3 at room temperature and at concentrations of around 10 mg/mL. 13 C and 29 Si NMR spectra were proton decoupled and all chemical shifts (δ) were calibrated against the signal of tetramethylsilane as internal standard.…”

“…The functionalized cage silsesquioxanes ((R-SiO1.5)n, where n=8, 10, 12, etc), have been of particular interest [7,8], with n=8 being the most widely studied. In addition to porous materials [3,9] in which the porosity can either arise from the voids between the cages or cage's central void (0.3 nm) [3], selforganized systems [10][11][12][13], POSS micelles and templated POSS systems leading to mesoporous materials with T8 cages embedded with the walls [14], and organic polymer-based nanohybrids [15][16][17][18][19][20] can be obtained by modulating the properties of the functional organic moieties.…”

Post-synthesis modification of functionalised polyhedral oligomeric silsesquioxanes with encapsulated fluoride – enhancing reactivity of T8-F POSS for materials synthesis

“…[15][16][17][18] A diverse range of applications for Tn cage systems have now been investigated, including bio/nanomedicine, [19][20][21][22][23][24][25] catalysis, [26][27][28][29] optoelectronics, 30 polymer chemistry, [31][32][33] and optical and sensing applications. [33][34][35][36] Postfunctionalised Tn compounds have also been incorporated into self-organised systems, [37][38][39][40][41] organic polymer-based nanohybrids, 31,33,[42][43][44][45] POSS micelles and templated POSS systems leading to mesoporous materials with embedded T8 cages. [46][47][48] In 2003, Bassindale's group reported a new T8 cage silsesquioxane, in which a fluoride anion was entrapped within the central T8 void, leading to the emergence of the T8-F POSS family.…”