The exact structure of the compound was not known at the time, although it was known to crystallize as a monohydrate. The correct structural formula was published in 1901 by Arthur Hantzsch, who obtained it from the reaction between cyanamide and hydrazoic acid.[4]
To avoid direct handling of the problematic hydrazoic acid, a mixture of sodium azide and hydrochloric acid has been used to give the monohydrate at 73% yield.[5]
In a more efficient and controllable one-pot synthesis, cyanamide is treated with hydrazine hydrochloride to give aminoguanidine hydrochloride, which is then diazotized as in Thiele's original process. Addition of ammoniaorsodium hydroxide followed by heat-induced cyclization gives the anhydrous product in 74% yield.[6][7]
The structure of 5-aminotetrazole has been determined several times by X-ray crystallography, both as the anhydrous[8] and monohydrated forms.[9] The structures are very similar, consisting of a planar molecule, including the amino group.
The N-4 is basic as indicated by its binding to metal halides, such as the coordination complex[CoCl2(aminotetrazole)4.[11]
The compound has a particularly high nitrogen content of 80%. Partly for this reason, the compound is prone to decomposition to nitrogen gas (N2). It has been widely investigated for gas-generating systems, such as airbags and blowing agents.[12]
^Hiroshi Fujihisa, Kazumasa Honda, Shigeaki Obata, Hiroshi Yamawaki, Satoshi Takeya, Yoshito Gotoha, Takehiro Matsunaga "Crystal structure of anhydrous 5-aminotetrazole and its high-pressure behavior" CrystEngComm, 2011, volume 13, pp. 99-102. doi:10.1039/C0CE00278J
^D. D. Bray and J. G. White "Refinement of the structure of 5-aminotetrazole monohydrate" Acta Crystallogr. (1979). B35, pp. 3089-3091.doi:10.1107/S0567740879011493
^MIHINA, JOSEPH S.; HERBST, ROBERT M. (1950-09-01). "The Reaction of Nitriles with Hydrazoic Acid: Synthesis of Monosubstituted Tetrazoles". The Journal of Organic Chemistry. 15 (5): 1082–1092. doi:10.1021/jo01151a027. ISSN0022-3263.
^US 5424449, Rothgery, Eugene F. & Knollmueller, Karl O., "Process for the preparation of 5-aminotetrazole", published 1995-06-13, issued 1995-06-13
^US 5594146, Murotani, Masahiro; Mura, Hajime & Takeda, Makoto et al., "Process for producing 5-aminotetrazole", published 1997-01-14, issued 1997-01-14
^Fujihisa, Hiroshi; Honda, Kazumasa; Obata, Shigeaki; Yamawaki, Hiroshi; Takeya, Satoshi; Gotoh, Yoshito; Matsunaga, Takehiro (2011). "Crystal structure of anhydrous 5-aminotetrazole and its high-pressure behavior". CrystEngComm. 13: 99–102. doi:10.1039/c0ce00278j.
^Bray, D. D.; White, J. G. (1979). "Refinement of the structure of 5-aminotetrazole monohydrate". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 35 (12): 3089–3091. doi:10.1107/S0567740879011493.
^Zhao, Fang-Hua; Che, Yun-Xia; Zheng, Ji-Min; Grandjean, Fernande; Long, Gary J. (2012). "Two Acentric Mononuclear Molecular Complexes with Unusual Magnetic and Ferroelectric Properties". Inorganic Chemistry. 51 (8): 4862–4868. doi:10.1021/ic300394c. PMID22480292.
^Lesnikovich, A. I.; Ivashkevich, O. A.; Levchik, S. V.; Balabanovich, A. I.; Gaponik, P. N.; Kulak, A. A. "Thermal decomposition of aminotetrazoles" Thermochimica Acta 2002, vol. 388, pp. 233-251. doi:10.1016/S0040-6031(02)00027-8
