The Prato reaction on nanodiamond: Surface functionalization by formation of pyrrolidine rings

The Prato reaction is a highly valued reaction for the functionalization of fullerenes and carbon nanotubes. It uses the generation of pyrrolidine rings from azomethine ylides in the formation of a covalent grafting of functional moieties. Here we present the first application of this reaction on thermally annealed nanodiamond as a way for the grafting of a multitude of functional moieties. We used two types of azomethine ylides (aliphatic and pyridine derived) to show the broad applicability of the reaction for the surface modification of nanodiamond. The possibility to attach glycol units or alkyl chains, both with or without reactive terminal groups opens the way to tune the surface properties of such “Prato-functionalized” diamond in a very flexible way.

Research Highlights
► Nanodiamond has been functionalized using the Prato reaction.
► The nanodiamond surface can be flexibly terminated using different azomethine ylides.
► The Prato reaction allows for biocompatible functionalization of nanodiamond.
► Pyrrolidine rings on diamond surfaces are formed with sp2 carbon from thermal annealing.