Abstract The nitration of 5-amino-1H-tetrazole (1), 5-amino-1-methyl-1H-tetrazole (3), and 5- amino-2-methyl-2H-tetrazole (4) with HNO 3 (100%) was undertaken, and the corresponding products 5-(nitrimino)-1H-tetrazole (2), 1-methyl-5-(nitrimino)-1H-tetrazole (5), and 2-methyl-5-(nitramino)-2H-tetrazole (6) were characterized comprehensively using vibrational (IR and Raman) spectroscopy, multinuclear (1 H, 13 C, 14 N, and 15 N) NMR ...