Ultrasound-assisted Bromination. Part 1: Bromination of C-60 and C-70

作者：Cataldo Franco^*; Ursini Ornella; Ragni Pietro

来源：Fullerenes, Nanotubes, and Carbon Nanostructures, 2013, 21(4): 346-356.

DOI：10.1080/1536383X.2011.613544

• Fullerenes
• bromination
• sonication
• ultrasound
• bromofullerenes
• thermal properties

Fullerenes C-60 and C-70 were brominated with liquid bromine either at room temperature with prolonged stirring or by sonication (ultrasound-assisted bromination) of the fullerene/bromine mixtures. The resulting bromofullerenes were studied by FT-IR. The amount of bromine content was determined by thermogravimetric analysis (TGA), and the thermal transitions and the decomposition temperatures of all fullerenes were measured by differential thermogravimetry (DTG) and differential thermal analysis (DTA). Depending on the conditions adopted the ultrasound assisted bromination of C-60 yields C60Br12 or C60Br14. However, mechanical stirring of C-60/Br-2 mixtures also yields similar products. The highly brominated fullerene derivative C60Br24 cannot be synthesized by sonication but only by stirring C-60/Br-2 mixture for a couple of days. The sonication stops the bromination at C60Br12 or C60Br14 level. The brominated derivatives of C-70 synthesized either with the aid of ultrasound or without sonication consists always C70Br12 or C70Br14. Through the thermal analysis it was found that the decomposition of bromofullerenes is always an exothermic process irrespective for the bromine content and the decomposition temperature of the bromofullerenes either C-60 or C-70 increases with the amount of their bromine content.

• 出版日期2013