The low-lying triplet state in p-nitrobenzaldimide

Abstract Ion–molecule reactions show that p -nitrobenzaldimide, the conjugate-base anion of the benzaldimine, has a low-lying triplet state that is accessible under thermal conditions. Whether it is the ground state or a low-lying excited state cannot be determined, and both possibilities have computational support. Reactivity studies indicate that imide anions with weaker π-donors have singlet ground states, with no evidence for an accessible triplet.