Determination of the electron affinities of fluorinated fullerenes (C 60F 44,46, C 70F 52,54) by Fourier transform mass spectrometry

Abstract

Negative ion charge exchange reactions in a Fourier transform mass spectrometer were used to “bracket” the electron affinities of the fluorinated fullerenes C 60F x ( x = 44,46) and C 70F y ( y = 52,54). By monitoring the occurrence of charge exchange reactions between negative ions and gas phase neutrals of fluorinated fullerenes and a variety of reagents, electron affinities were determined to be EA(C 60F 44,46) = 4.06±0.25 eV and EA(C 70F 52,54) = 4.06±0.25 eV. These results indicate that fluorination at this level increases the electron affinities of these fullerene derivatives by almost 1.5 eV. It was also determined that the electron affinity of C 70F y ( y = 52, 54) is slightly greater than that for C 60F x ( x = 44, 46), which may be related to the higher number of substituted fluorines and/or the fact that the EA(C 70) is also known to be greater than EA(C 60)