1, 2-Diaza-2, 4, 6, 8-cyclooctatetraene

1,2-Diazocine is prepared from 7,8-diazatetracyclo[3.3.0.0^2.4.0^3,6]oct-7-ene by four methods that excite the precursor into its triplet state of lowest energy. The ¹H NMR spectrum shows its structure to be 2 and not 2a and its conformation to be 12. When heated it gives benzene and pyridine, and when irradiated with ultraviolet light it gives only benzene. Reasons are discussed why pyridine is formed in the one reaction and not in the other. The kinetics are recorded for the thermal reaction. Evidence that its double-bond and valence isomers are destabilized because lone pairs of electrons on adjacent nitrogens repel each other is sought in 2's reduction potential, but it cannot be recognized. Valence tautomers 7-11 are not detected in 2 by NMR spectroscopy.