New protocol for functionalization of fullerene soot with dinitrobenzene groups from a non-diazonium resource

Abstract

The nitrobenzene functionalized fullerene soot has been considered as a potentially energetic material. In our previous study, the in situ produced nitrobenzene diazonium ions have been used for the synthesis of 2-nitrobenzene, 4-nitrobenzene and 2,4-dinitrobenzene functionalized fullerene soot nanoparticles with moderate oxygen (14.91 wt%) and nitrogen (6.27 wt%) contents. In the present study, a new protocol for the functionalization of fullerene soot with 3,5-dinitrobenzene groups from a non-diazonium resource is reported. The functionalization of fullerene soot is performed through Ag(I)-catalyzed decarboxylative oxidation of 3,5-dinitrobenzoic acid (DNBA) under conventional heating or microwave irradiation. The effects of various parameters such as the oil bath temperature and the amounts of substrate (DNBA), catalyst (AgNO3) and oxidant (K2S2O8) on these reactions are evaluated. The synthesized compounds are characterized by FT-IR, Raman, XRD, SEM-EDX and elemental mapping analysis, FE-SEM and TEM along with particle size analysis, as well as TGA-DSC. The DSC thermograms of functionalized fullerene soot show a single exothermic peak attributed to the exothermic decomposition of 3,5-dinitrobenzene groups. Some of these compounds have up to 82.16 wt% oxygen and 6.10 wt% nitrogen contents. These findings are important for development of the energetic materials with improved oxygen content.