The Azo(Azoxy) Functionality as a π₂ Component in Photo [2+2] cycloadditions ‘<i>syn</i>’‐ and ‘<i>anti</i>’‐3,4‐diazatricyclo[4.2.2.2^2,5]dodeca‐3,7‐diene, syntheses, photolyses, X‐ray‐structure analysis, and PE spectra

Abstract

Abstract The propensity of the NN bond to undergo photo [2 + 2] cycloadditions has been further explored. In the specifically designed 1,5‐azo/enes 1–3 , no [2 + 2] cycloaddition has been observed upon either direct or sensitized excitation with light of various wave lengths at temperatures down to 77 K, in line with expectations based on X‐ray ( 1 : d = 2.71 Å, ω = 129°) and PE measurements ( 1 : I 1 = 8.0 0 , I 2 = 9.0 5 eV; 2 ; I 1 = 8.0 0 , I 2 = 9.2 5 eV). The steric/stereoelectronic demands for the participation of the NN bond in pericyclic reactions are clearly more stringent than those for the CC bond.