Free-Radical Mechanism Of The Sonochemical Reaction Of Fullerenes C-60 And C-70 With Ethylene Glycol In The Presence Of Naoh

The mechanism of the heterogeneous sonochemical reaction of fullerenes C-60 and C-70 with ethylene glycol in the presence of NaOH was studied using EPR and UV spectroscopies. As found, the reaction occur via a free-radical mechanism. For the first time in sonochemistry, the signal of the radical NaOCH2CH2O center dot (a(Na) = a(4H) = 0.061 mT, g = 1.9802; the lifetime in air is 0.5 hours) was registered by the direct EPR method. The kinetics of the NaOCH2CH2O center dot decay was studied using acceptors of radicals of different nature: DPPH (2,2-diphenyl-1-picrylhydrazyl), galvinoxyl and CCl4. The EPR method revealed that 5,5-dimethyl-1-pyrroline N-oxide (DMPO) does not react with NaOCH2CH2O center dot. At the sonolysis of the C-60 and C-70 solutions in CCl4 with ethylene glycol in the presence of NaOH, only the spin adduct DMPO/CCl3 was registered. The effect of NaOH, nature of the solvent and dissolved gases, reaction temperature and intensity of ultrasonic radiation on the synthesis of dioxane monoadducts C-60 and C-70 are discussed.