Stabilizing and Activating Nitrogen Catenates.

The remarkably stable catenated hexa-nitrogen chain in bis(benzotriazene-4-one) is structurally, theoretically, and spectroscopically characterized to illustrate the durability of the central N-N bond in this hexaazo chain. The reactions of this species illustrate the potential of these nitrogen catenates for the preparation of other condensed heterocycles, such as bispyrazolones, by thermal nitrogen exclusion or by trapping the single ring-opened Dimroth intermediates. In these latter reactions, 2-naphtholate anion condenses with bis(benzotriazene-4-one) to trap and retain a zwitterionic diazonium intermediate as an isolated diazo product, whereas transition metals ring effect ring-extrusion of dinitrogen from the Dimroth intermediate to generate chelating σ-aryls.