The crystal structures of three salts of anionic 5-aminotetrazole are described. The tetramethylammonium salt (P[Formula: see text]) forms hydrogen-bonded ribbons of anions which accept weak C-H⋯N contacts from the cations. The cystamine salt (C2/c) shows wave-shaped ribbons of anions linked by hydrogen bonds to screw-shaped dications. The tetramethylguanidine salt (P21/c) exhibits layers of anions hydrogen-bonded to the cations.
Keywords: 5-aminotetrazole; cystamine; tetramethylammonium; tetramethylguanidine.