New azidation methods for the functionalization of silicon nitride and application in copper-catalyzed azide-alkyne cycloaddition (CuAAC)

In this study, a new direct functionalization method of silicon nitride (Si3N4) using azidation and click chemistry is presented. First, amino groups (NHx) were created on a Si3N4 substrate by fluoride etching. These NHx-terminated Si3N4 surfaces were analyzed by chemical derivatization X-ray photoelectron spectroscopy with 4-trifluoromethylbenzaldehyde, and a derivatization yield of 20% was concluded. In the second step, freshly prepared NHx surfaces were transformed into azides, which were used immediately in a click reaction with halogenated alkynes. The presented combination of amination, azidation, and click reaction is a promising alternative for common silane-based Si3N4 functionalization methods. Copyright (c) 2016 John Wiley & Sons, Ltd.