| Abstract: | The crystalline‐state photoreaction of 1‐azido‐2‐nitrobenzene ( 1 ) was investigated by a combination of X‐ray crystallography, IR spectroscopy, electron‐spin resonance (ESR), and by means of theoretical calculations. Upon low‐temperature (80 K) photolysis of 1 , the formation of benzofuroxan ( 2 ) was directly observed by X‐ray single‐crystal analysis. ESR Measurements at 5 K suggested the presence of a triplet nitrene as an intermediate in the formation of the heterocycle. Temperature‐dependent IR spectroscopy also revealed that another intermediate, trans,trans‐1,2‐dinitrosobenzene, was produced at temperatures below 80 K. |
