Identification of Butatrienedione, Its Radical Anion, and Its Radical Cation in the Gas Phase^†‡

Butatrienedione is also detectable mass spectroscopically: electron impact ionization of 1 affords, via elimination of CO₂ and Me₂CO, the radical anion OC₄O^•⊖, which can be converted by vertical charge reversal into the corresponding cation. In neutralization-reionization experiments, starting from both species it was possible to obtain the neutral molecule.