A synthetic route to potentially biocidal silsesquioxanes functionalized by quaternary pyridinium functionalities has been developed. N -Alkylation reactions of the precursor compounds 4-(2-(trimethoxysilyl)ethyl)-pyridine ( 5 ) and 4-(2-trichloro-silylethyl)pyridine ( 6 ) with iodomethane, n -hexylbromide, and n -hexadecylbromide cleanly afforded the corresponding N -alkylpyridinium salts ( 7 – 10 ). The synthesis of a 4-(2-ethyl)pyridine POSS derivative ( 2 ) was achieved by capping of the silsesquioxane trisilanol Cy 7 Si 7 O 9 (OH) 3 ( 1 ) via two different preparative routes. Attempts to use compound 2 as precursor for quaternary pyridinium salt-functionalized POSS derivatives were met with only partial success. Only the reaction with iodomethane cleanly afforded the new N -methylpyridinium salt 12 in high yield, whereas n -hexylbromide and n -hexadecylbromide failed to react with 2 even under forcing conditions.
Kostenko, N., Gottfriedsen, J., Hilfert, L., & Edelmann, F. T. (2012). A Synthetic Route to Quaternary Pyridinium Salt-Functionalized Silsesquioxanes. International Journal of Polymer Science, 2012, 1–9. https://doi.org/10.1155/2012/586594