Synthesis, thermal stability and impact stability of novel tetranitro-dipyridotetraazapentalene derivatives

The synthetic details for the construction of three new dipyridotetraazapen talene derivatives, 5H-pyrido[3",4":4',5'] [1,2,3]triazolo[1',2':1,2][1,2,3 ]triazolo[5,4-b]pyridin-6-ium inner salt (8), 5H-pyrido [3",2":4',5'][1,2,3 ]triazolo[1',2':1,2][1,2,3]triazolo[5,4-b]-pyridin-6-ium inner salt (15) an d 5H-pyrido[2",3":4',5'] [1,2,3]-triazolo[1',2':1,2][1,2,3]triazolo[4,5-b]p yridin-6-ium inner salt (16) are presented. Nitration of (8) and (15) affor ded the novel tetranitrodipyridotetraazapentalene derivatives, 2,4,8,10-tet ranitro-5H-pyrido[3",4":4',5'][1,2,3]triazolo[1',2':1,2][1,2,3]-triazolo[5, 4-b]-pyridin-6-ium inner salt (3) and 2,4,8,10-tetranitro-5N-pyrido [3", 2" :4',5][1,2,3]triazolo[1',2':1,2][1,2,3]-triazolo[5,4-b]-pyridin-6-ium inner salt (4) in good yields. Both isomers, (3) and (4), exhibited high thermal stability (differential scanning calorimetric analysis and thermal gravime tric analysis) and were insensitive to impact (hammer/anvil test).