In this study, the interactions between nitrile oxide (fulminic acid) and azide (hydrazoic acid) with the C20 fullerene were investigated and their priority in reacting and functionalizing surface of this fullerene were compared with each other. The results show that the 1,3-dipolar cycloaddition reaction between fulminic acid and C20 fullerene could occur faster than this reaction by hydrazoic acid. Therefore, nitrile oxide group as a dipole is much preferred compared to the azide functional group in reacting with the surface of C20 fullerene. In addition, the calculated adsorption energy and electronic density of state, DOS plots for the related species con¯rmed that the C20 fullerene can be used as sensors for sensing the hydrazoic acid and fulminic acid molecules.
