LJ isomerized azo compound is formed, besides the usual denitrogenated products, implies rupture of the weaker CN bond, leading to the caged diazenyl radical and allyl radical pair followed by recombination at the other allyl radical terminal prior to nitrogen loss from the diazenyl radical. Moreover, also for symmetrical bicyclic azo compounds, such thermal isomerizations have been documented2 to proceed via diazenyl diradicals (eq 2). ...