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 spe ctrometer were used to ''bracket'' the electron affinities of the fluo rinated fullerenes C-60 F-x (X = 44, 46) and C70Fy (y = 52, 54). By mo nitoring 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 in dicate that fluorination at this level increases the electron affiniti es of these fullerene derivatives by almost 1.5eV. It was also determi ned that the electron affinity of C70Fy (y = 52, 54) is slightly great er than that for C60Fx (x = 44, 46), which may be related to the highe r number of substituted fluorines and/or the fact that the EA(C-70) is also known to be greater than EA(C-60).