The antiarene 1 is remarkably stable. It was prepared as the first kinetically stabilized (electronically pure) azacyclobutadiene. 1 tolerates several days' heating at 100°C in toluene! The valence isomerism 1A⇄1B is immediately detectable by temperature-dependent 13C-NMR spectroscopy.
No takes yet. Share an insight, caveat, or question.
Vogelbacher et al. (1986) studied this question.
Synapse has enriched 2 closely related papers on similar clinical questions. Consider them for comparative context: