Identification of Free Radicals in Flash Photolysis

McGrath and Morrow 1 have recently reported on a spectrum near 3290 Å obtained in the flash photolysis of fulminic acid which they ascribe to the free CNO radical. It appears that this spectrum is the same as that found independently by Jennings and Linnett 2 and ourselves 3 . The spectrum has recently been analysed in detail and shown to be due to the free NCN radical 4 . All the strong bands listed by McGrath and Morrow agree with strong NCN bands listed in our paper and relative intensities are roughly the game. We believe that on the basis of the observed intensity alternation and the observed triplet splitting, there can be no doubt that our identification of this spectrum is correct.