A SPECTROSCOPIC STUDY OF THE PHOTODECOMPOSITION OF DIAZOMETHANE

Abstract— The decomposition of diazomethane by photolytic means has been studied both in inert gas matrices near 4°K and in the gas phase near 295°K. The direct detection of the diazomethyl radical, HCNN and DCNN, and evidence for the participation of methanal azine, H₂C=‐N=CH₂, by vibrational spectroscopy proved that both species play a significant role in the decomposition schemes under the conditions of investigation. The present results make possible the reinterpretation of the data from earlier published experiments to conform to these schemes. The isomerisation of diazomethane is also discussed, and evidence is presented for the production of both diazirine and isodiazomethane under certain photolytic conditions, the former by an intramolecular process and the latter by the recombination of the diazomethyl radical with a hydrogen atom. The vibronic absorption spectra of gaseous diazomethane at 295°K are presented, and deductions concerning photochemical processes are drawn.