Synthesis, Thermolysis, and Mass Spectrometry of Perfluorinated Di- and Triazidopyridines

2,4-Diazido-3,5,6-trifluoropyridine and 2,4,6-triazido-3,5-difluoropyridine were obtained by the reaction of pentafluoropyridine with sodium azide in aqueous acetone. Under the action of electron impact the 2,4-diazidopyridine undergoes sequential fission of the azide groups in positions 2 and 4 of the pyridine ring and ring contraction with the formation of a characteristic [M-2N₂-F]⁺ ion. On the other hand thermolysis of the same diazide is accompanied by the selective decomposition of its -azide group with the formation of 4-amino-2-azido-3,5,6-trifluoropyridine. The effect of selective decomposition of the azide groups in 2,4-diazidopyridines on thermolysis and under electron impact is caused by the different distribution of bonding orbital density at the - and -azide groups respectively in the initial diazide and its radical cation. One of the routes of the triazide decomposition under electron impact is the form! ation of the [M-N₂2]⁺ ion due to decomposition of the -azide group.