Synthesis of Octacarboxy Spherosilicate

Abstract

feasible new preparation was reported for an octacarboxylphenyl functionalized spherosilicate, octakis[(pcarboxyphenyl) dimethylsilyl]silicate, which was a versatile monomer leading to other functional spherosilicate derivatives. The synthesis was started from octakis[dimethyl(p-methylphenyl)silyl]silicate. Octakis[dimethyl(pmethylphenyl) silyl]silicate was brominated by NBS to produce octakis[dimethyl(4-tribromomethylphenyl)silyl]silicate. Finally, octakis[dimethyl(4-tribromomethylphenyl)silyl]silicate was hydrolyzed in the presence of AgNO3 and formic acid to give the desired compound. Octakis[(pcarboxyphenyl) dimethylsilyl]silicate was fully characterized by FTIR, 1H NMR, 13C NMR, 29Si NMR spectra, ESI-MS, and elemental analysis.

Thermodynamic study of POSS-based ionic liquids with various numbers of ion pairs

“…[17][18][19][20][21][22][23][24] In polar solvents, POSS can form a globular conformation and create a distinct hydrophobic space around the POSS core. [25][26][27][28] Such structural features can contribute to reduce the packing density and isolating the distal ion pairs.…”

Direct alkoxysilylation of alkoxysilanes for the synthesis of explicit alkoxysiloxane oligomers

“…Although a Q 3 signal (ca. À100 ppm, OSi(OSi) 3 ) and small T 1 signal besides main T 1 R = t Bu, -CHPh 2 R 1 = H, Me, Ph, -CH=CH 2 , -(CH 2 ) 3 …”

An Efficient Approach to Monophenyl‐Functionalized Octasilsesquioxanes

“…[26] Although an octacarboxyl spherosilicate was successfully prepared through complete bromination of an octatolyl-tethered spherosilicate following hydrolysis, [25] all attempts to prepare monocarboxy-functionalized T 8 via 5 by following a similar method failed. This failure was due to the production of a mixture of monobromo, dibromo, and tribromo derivatives and the inability to purify the crude product, which should be ascribed to the low reactivity of the tolyl group in 5 due to steric hindrance of the large cage core.…”

“…As a model compound, it will play a different, but also very important role in basic and applied research, comparable to that of an octacarboxyl cage. [25] We report here the first preparation of monocarboxyphenyl-functionalized T 8 and some other T 8 compounds (Scheme 2 and Scheme 3) based on a novel synthetic concept for the selective bromination of trichloro(p-tolyl)silane. Scheme 3.…”