Connectivity effects in isomeric naphthalenedinitrenes.

[figure: see text] UV-vis, FTIR, and ESR spectroscopic studies were carried out on samples of 1,4- and 1,5-naphthalenediazide that were photolyzed at cryogenic temperatures in argon and frozen solvent matrices. Mononitrenes and diiminediyl systems are produced. Spectral and computational results are consistent with quinonoidal singlet ground-state structures for the diiminediyls, rather than aromatic dinitrene structures.