Mobilities of Radical Cations and Anions, Dimer Radical Anions, and Relative Electron Affinities by Times of Flight in n-Hexane

Article abstract of DOI:10.1021/j100089a048

The mobilities of several radical cations and anions are measured in n-hexane using a thin-sheet time-of-flight (TOF) technique.We observe the radical cations of N,N,N',N'-tetramethyl-p-phenylenediamine, zinc tetraphenylporphine, and pyrene and the radical anions of perfluorobenzene, p-benzoquinone, anthraquinone, chloranil, buckminsterfullerene (C60), and octafluoronaphthalene.For all electron acceptors but C60, the dependence of the anionic TOF on acceptor concentration reveals the appearance of the homodimer radical anion at sufficiently high concentrations.The equilibrium constant for the monomer anion/monomer acceptor association reaction is obtained from the concentration studies.A Born-Haber cycle is then applied to estimate the difference between the electron affinities of the monomer and dimer molecules in the gas phase.