Endohedral Nitrogen Fullerenes

Abstract

There is a remarkable molecule that can be said to be nature’s atomic trap. This molecule is called an endohedral nitrogen fullerene. Endohedral nitrogen fullerenes (ENFs) and related molecules are the subject of this chapter. Endohedral fullerenes were discovered almost as soon as their empty-cage equivalents. However, ENFs were only available for studies more than a decade after the discovery of fullerenes. A number of endohedral metallofullerenes have been made in significant amounts. However, there are only a handful of ENFs studied to date. ENFs are remarkable for another reason too. Nitrogen is one of the most reactive elements known to science. This is somewhat concealed by the relative inertness of the nitrogen molecule. The nitrogen-nitrogen triple bond is after all one of the strongest bonds in the universe. However atomic nitrogen retains its high reactivity. So how come atomic nitrogen is stable inside a fullerene molecule? Well, it turns out the nitrogen wave function just about “fits snugly” inside the fullerene cage. This chapter describes the different methods of production of ENFs. The properties and chemical functionalization of ENFs are also explored with the aim to summarize progress made towards applications. There is still some way to go before ENFs can be used in real-life applications. This chapter describes what progress has been made and what challenges lay ahead before nature’s atomic traps find their way in commercially available products.KeywordsFullerenesEndohedral fullerenesENFFunctionalizationElectron spinRelaxation timesQuantum computingAtomic clocks