Fullerene cyanation does not always increase electron affinity: an experimental and theoretical study

Abstract

The electron affinities of C₇₀ derivatives with trifluoromethyl, methyl and cyano groups were studied experimentally and theoretically using low-temperature photoelectron spectroscopy (LT PES) and density functional theory (DFT). The electronic effects of these functional groups were determined and found to be highly dependent on the addition patterns. Substitution of CF₃ for CN for the same addition pattern increases the experimental electron affinity by 70 meV per substitution. The synthesis of a new fullerene derivative, C₇₀(CF₃)₁₀(CN)₂, is reported for the first time.