The electron affinity of tetracyanoethylene and other organic electron acceptors

Information on the molecular structure of tetracyanoethylene and its mononegative ion is used to derive the electron affinity of tetracyanoethylene from the experimentally determined threshold energy for photodetachment of electrons from the negative ions. The resultant electron affinity of 2.3(± 0.3) eV is 0.6(± 0.4) eV less than a value derived by the magnetron surface ionization technique. Relative electron affinities for the strong electron acceptor organic molecules, which are known from charge-transfer spectra, are placed on an absolute scale using the photodetachment result for tetracyanoethylene.