Homolytic Reactive Mass Spectrometry of Fullerenes: Peculiarities of the Reactions of C^sub 60^ with Aromatic Compounds in the Ionization Chambers of Mass Spectrometers and in Solution

• Published in: Journal of the American Society for Mass Spectrometry 2013-04, Vol.24 (4), p.579
• Main Authors: Lyakhovetsky, Yury I, Shilova, Elena A, Belokon, Alexander I, Panz, Larisa I, Tumanskii, Boris L
• Format: Article
• Language: English
• Subjects: Adducts; Aromatic compounds; Benzene; Benzyl bromide; Buckminsterfullerene; Fullerenes; Ionization chambers; Ions; Mass spectrometers; Mass spectrometry; Radicals; Reaction mechanisms; Scientific imaging; Spectrometers; Spectroscopy; Toluene
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1007/s13361-012-0550-4

C60 reacted with PhH, PhCl, BnH, BnNH2, and o-C2H2B10H10 in the electron impact (EI) ion source of a mass spectrometer at 300 °C forming phenyl, benzyl, and o-carboranyl adducts, respectively, stabilized by hydrogen addition and loss. Besides, the additions to C60 of methyl and phenyl radicals for toluene, and a phenyl radical for benzylamine were observed. A homolytic reaction mechanism was suggested involving the reaction of the radicals formed from the aromatics under EI with C60 at the ionization chamber walls. While the ion/molecule reaction of C60 with benzene performed by Sun et al. under chemical ionization conditions at 200 °C afforded the complex C60•PhH+•, quite a different isomer, HC60Ph+•, was detected in the present study as a sequence of the different reaction mechanisms. C60 also reacted with benzyl bromide in the laser desorption/ionization (LDI) source of a mass spectrometer to give C60CPh+. Phenyl and benzyl derivatives of C60 were found, respectively, when the reactions of the fullerene with PhCl, BnH, and BnBr were performed in solution under ultra violet irradiation. For the reaction with toluene, the strong chemically induced dynamic electron polarization of the intermediate benzylfullerenyl radical with the reverse phase effect was found. The coincidence of the results of the mass spectrometry and solution reactions of C60 with aromatics, even though incomplete, additionally supports the hypothesis, formulated earlier, that the former results can predict the latter ones to a significant extent and shows that this conclusion is valid for both EI and LDI initiated reactions in mass spectrometers. [Figure not available: see fulltext.]