Benzofuroxans: A Possible +100 Years Old Misunderstanding?

Area of Science:

• Organic Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Benzofuroxans have been traditionally characterized by a fused bicyclic structure involving a benzene ring and a pentatomic heterocycle.
• This structure, specifically benzo[1,2-c]1,2,5-oxadiazole N-oxide, has been the accepted model since 1912.

Purpose of the Study:

• To investigate the electronic structure and molecular topology of 4,6-dinitro-benzofuroxan derivatives.
• To challenge the long-held assumptions about the molecular architecture of benzofuroxans.

Main Methods:

• Quantum chemical calculations were employed to model the electronic structure.
• Vibrational spectroscopic data (e.g., IR, Raman) were utilized to probe molecular vibrations.
• Experimental electronic spectra were analyzed.

Main Results:

• Computational and spectroscopic data raise fundamental questions about the established electronic structure.
• An alternative interpretation of the molecular topology is proposed.
• The proposed interpretation is supported by experimental vibrational and electronic spectra.

Conclusions:

• The traditional fused ring model for benzofuroxans, particularly dinitro derivatives, may require revision.
• This work provides new insights into the electronic and structural properties of benzofuroxan compounds.
• Further research is warranted to fully elucidate the molecular topology of this class of compounds.