Designing low-ionization potential analogs of tetrakis-dimethylamino-ethylene using density functional calculations

A number of analogs of the photosensitive molecule TMAE (tetrakis-dimethylamino-ethylene) have been investigated computationally with the goal of lowering the vertical ionization potential (IPv). This is of importance in UV-photodetectors based on gas photoionization and multiplication. The low IPv of TMAE, 6.11 eV, is shown to be due to resonance stabilization of the cation. N-substitution of phenyl groups and p-substitution of tertiary amines on the latter are found to be efficient ways of lowering IPv. The compound trans-bis-(p-dimethylaminophenyl, methyl)aminoethylene is calculated to have a IPv considerably lower than TMAE (∼ 5.5–5.7 eV) and appears to be a promising synthetic target.