Abstract
Abstract Since 1912 benzofuroxans have been believed to exhibit a molecular structure characterised by the presence of two fused rings, i. e. a benzene ring and a pentatomic heterocycle containing a N−O−N fragment wherein one of the two N atoms is involved in a further N O bond, namely benzo[1,2‐c]1,2,5‐oxadiazole N‐oxide. In this work, quantum chemical calculation results along with vibrational spectroscopic data raise fundamental questions about the electronic structure and the molecular topology of some 4,6‐dinitro‐derivatives of this class of compounds. An alternative interpretation is offered corroborated by the experimental vibrational and electronic spectra.