Photoelectron Spectroscopy of C60Fn- and C60Fm2- (n=17, 33, 35, 43, 45, 47; m=34, 46) in the Gas Phase and the Generation and Characterization of C1-C60F47- and D2-C60F44 in Solution

A photoelectron spectroscopy investigation of the fluorofullerene anions C60Fn- (n = 17, 31, 35, 43, 45, 47) and the doubly charged anions C60F342- and C60F462- is reported. The first electron affinities for the corresponding neutral molecules, C60Fn, were directly measured and were found to increase as n increased, reaching the extremely high value of 5.66 +/- 0.10 eV for C60F47. Density functional calculations suggest that the experimentally observed species C60F17-, C60F35-, and C60F47- were each formed by reductive defluorination of the parent fluorofullerene, C-3n-C60F18, C60F36 (a mixture of isomers), and D-3-C60F48, respectively, without rearrangement of the remaining fluorine atoms. The DFT-predicted stability of C60F47- was verified by its generation by chemical reduction from D-3-C60F48 in chloroform solution at 25 degrees C and its characterization by mass spectrometry and F-19 NMR spectroscopy. Further reductive defluorination of C60F47- in solution resulted in the selective generation of a new fluorofullerene, D-2-C60F44, which was also characterized by mass spectrometry and F-19 NMR spectroscopy.