The low-lying triplet state in p-nitrobenzaldimide

Photoelectron Spectroscopy Study of Quinonimides

“…Whereas 3p reacts with NO merely by addition, 2p reacts by addition and by a novel, N–O exchange reaction to form the semiquinone radical anion, as shown in eq . The observed differences in reactivity were attributed to differences in the electronic structures. The addition reaction that occurs with 3p is consistent with what is expected for the closed-shell, imide anion . In contrast, the N–O exchange reaction has been observed previously with nitrene radical anions and is interpreted as indicating an open-shell electronic structure .…”

“…The addition reaction that occurs with 3p is consistent with what is expected for the closed-shell, imide anion. 56 In contrast, the N−O exchange reaction has been observed previously with nitrene radical anions 57 and is interpreted as indicating an open-shell electronic structure. 58 Consequently, our previous study indicates that while 3p has a robust ground-state singlet, 2p is either a ground-state triplet or a singlet with a thermally accessible triplet state.…”

Mass spectrometry studies of nitrene anions

“…However, nitrene character can be introduced into the ion by the addition of electron withdrawing groups. For example, Rau and Wenthold (2015) have shown that benzaldimide (deprotonated benzaldimine), formed by reaction of trimethylsilybenzaldimine with fluoride, Equation ( 4), has an open-shell σπ electronic structure if there is a sufficiently electron-withdrawing group on the aromatic ring. However, most imide anions have negligible nitrene character.…”

“…The nitrene character of these molecules can be confirmed through ion/molecule reactions with NO and CS 2 which have distinct reactivities towards open‐shell and the closed‐shell nitrenes (Rau et al, 2013). Using these reagents, Rau and Wenthold (2015) examined the reactivities of substituted benzaldimide anions (Equation ). …”

“…In addition to providing valuable insights into the nature of neutral nitrenes, nitrene anions have their own unique properties as reactants, which can also be investigated using mass spectrometry. Anionic derivatives have been shown to be capable of tuning the reactivity of nitrenes, and their products have been explored using ion/molecule reactions (McDonald & Chowdhury, 1980a, 1980b, 1981, 1982, 1983; McDonald et al, 1981; Pellerite & Brauman, 1981; Rau & Wenthold, 2015; Wijeratne & Wenthold, 2007a). In this study, we review advancements in the field of nitrene anion chemistry, from their formal synthesis and reactivity to their characterization via spectroscopy and mass spectrometry, and characterization of the thermochemical properties of nitrenes.…”