Deazetation of a bicyclic azo compound: product and mechanistic studies

Abstract

In the deazetation of 7,8-diazabicyclo[4.2.Z]dec-7-ene 2, the product distributions from direct and sensitised photolyses are different, as would be expected if a spin correlation effect operates. A larger difference, however, is found between the distributions from the two nominally singlet processes, thermolysis and the direct photolysis. Several trivial explanations for this are ruled out, and two explanations are put forward, involving the intermediacy of either a diazenyl biradical or two singlet electronic states of the tetramethylene biradical, cyclooctanediyl.