The preparation and photolysis of 3-aryl-3H-diazirines

The preparation of a number of 3-aryl-3H-diazirines is reported. On irradiation, these materials undergo both photolytic fragmentation to the arylcarbene and photoisomerisation to the linear diazo-compound which is then itself photolysed. The existence of a second intermediate is also apparent from the spectral changes observed.