High-yield synthesis of amido-functionalized polyoctahedral oligomeric silsesquioxanes by using acyl chlorides.

Homosubstituted amido-functionalized polyoctahedral oligomeric silsesquioxanes (POSS) have been synthesized by using acyl chlorides in high yields (ca. 95%). The method proved to be superior over "conventional" syntheses applying carboxylic acids or acid anhydrides, which are much less efficient (ca. 60% yield). A palette of aryl and alkyl groups has been used as side-chains. The structures of the resulting amide-POSS are supported by multinuclear (1)H, (13)C, (29)Si NMR and FTIR spectroscopy and their full conversion into octasubstituted derivatives was confirmed using mass spectrometry. We also demonstrate that the functionalized silsesquioxanes with bulky organic side-chains attached to cubic siloxane core form spherical-like, well-separated nanoparticles with a size of approximately 5 nm.