Observation of difluorinated higher fullerene anions by Knudsen cell mass spectrometry and determination of electron affinities of C 60F 2 and C 70F 2

Abstract

Difluorinated higher fullerenes have been studied by Knudsen cell mass spectrometry. Thermal negative ions C n F 2 − ( n=60, 70, 72, 74, 76 and 78) were produced inside the effusion cell as well as the neutral molecules C 60F 2 and C 70F 2. From the equilibrium constants for the electron exchange reactions between difluorinated fullerenes and their parents electron affinity values were derived for C 60F 2 (2.74 eV) and C 70F 2 (2.80 eV).