Loss of hydroxyl radical from isomeric ethylnitrobenzenes

The loss of a hydroxyl radical from the molecular ions of o-, m- and p-ethylnitrobenzene has been studied by metastable ion and collisional activation techniques using electron impact and field ionization. It is shown that for the ortho isomer the mechanism of this reaction is unique, and is totally different from that of the meta and para isomers. The critical energies are also reported, and deuterium labelling is employed to access the role of the α-hydrogens in hydroxyl loss.