DETERMINATION OF THE ELECTRON-AFFINITIES OF FLUORINATED FULLERENES (C60F44,46, C70F52,54) BY FOURIER-TRANSFORM MASS-SPECTROMETRY

Negative ion charge exchange reactions in a Fourier transform mass spectrometer were used to ''bracket'' the electron affinities of the fluorinated fullerenes C-60 F-x (X = 44, 46) and C70Fy (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(C60F44,46) = 4.06 +/- 0.25 eV and EA(C70F52,54) = 4.06 +/- 0.25 eV. These results indicate that fluorination at this level increases the electron affinities of these fullerene derivatives by almost 1.5eV. It was also determined that the electron affinity of C70Fy (y = 52, 54) is slightly greater than that for C60Fx (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).