Size and Shape Dependence of Organo‐Interconnected Silsesquioxanes through Hydrolysis‐Condensation Reaction Conditions: Nanotubes, Spheres and Films

Abstract

International audienceA tris-silylated urea-based compound, 1,3,5-tris(triethoxysilylpropylureido)benzene has been synthesized. Hybrids materials with different shapes (films, spheres and tubes) are obtained upon base-catalyzed hydrolytic condensation of this compound. A self-templating process is demonstrated using electron microscopy (SEM and TEM) and X-ray diffraction (SAXS and WAXS) techniques. We show the formation of nanometer size hollow tubes according to the size of the self-templating crystalline precursor. The possibility for this self-templating to occur is due to a favored dissolution of the self-assembled molecules of the precursor in a preferential direction parallel to the cross-section of the crystal

Luminescent Triazine‐Containing Bridged Polysilsesquioxanes Activated by Lanthanide Ions

“…9-11°m ay be attributed to a periodic arrangement of the monomer during the sol-gel processing. [29] The addition of Eu 3+ ions can affect the periodicity structure of the materials, as evidenced by the decreased d value (from 9.2 to 7.9 Å) of the first XRD pattern as indicated by the arrow in Figure 3. Figure 4 shows the SEM images of MICPTES-Hb and MICPTES-Hb-Eu.…”

The Influence of Arylene and Alkylene Units on the Structuring of Urea‐Based Bridged Silsesquioxanes

“…(10-Isocyanodecyl)triethoxysilane, [16,22] (11-aminoundecyl)triethoxysilane, [23] 1,3,5-triisocyanobenzene [21] and 1,3,5-tris{ [3-(triethoxysilyl)propyl]ureido}benzene [15] (P5) were synthesised as reported previously. (10-Isocyanodecyl)triethoxysilane, [16,22] (11-aminoundecyl)triethoxysilane, [23] 1,3,5-triisocyanobenzene [21] and 1,3,5-tris{ [3-(triethoxysilyl)propyl]ureido}benzene [15] (P5) were synthesised as reported previously.…”

“…[15] These reactions were performed at room temperature in CH 2 Cl 2 under argon and led to bis-or tris(urea)-based precursors P1-6 with yields of up to 75 %. of (3-isocyanopropyl)triethoxysilane or (10-isocyanodecyl)triethoxysilane (Scheme 2).…”

“…[15] These reactions were performed at room temperature in CH 2 Cl 2 under argon and led to bis-or tris(urea)-based precursors P1-6 with yields of up to 75 %. The symmetry of the organic units was found to control the dimensionality of the hybrid nanostructure.…”

Self-assembly of bridged silsesquioxanes incorporated with conjugated organic functionalities

“…Table 1 structures of some bridged silsesquioxanes [5,[10][11][12][13][14][15][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. However, the embedded organic components are mainly limited to passive functional groups, such as methylene, ethane, ethylene, dodecane, and benzene.…”