Angewandte
Chemie
Table 1: Thermal and physical properties of the 5-azidotetrazoles 2a–g.[a]
[1] a) R. P. Singh, R. D. Verma, D. T.
Comp’d
Crystallization
M.p.[a]
[8C]
Td[a]
[8C]
Density[b]
DH8f[c]
DH8f
P[d]
[GPa]
D[d]
3347; c) R. P. Singh, H. Gao, D. T.
Meshri, J. M. Shreeve in High
Energy Density Materials (Ed.:
T. M. Klapötke), Springer, Heidel-
berg, 2007, pp. 35 – 83; d) T. M.
Klapötke in High Energy Density
Materials (Ed.: T. M. Klapötke),
Temp.[a] [8C]
[gcmÀ3
]
[kJmolÀ1
]
[kJgÀ1
]
[msÀ1
]
2a[e]
2b
–
–
–
–
–
165
163
149
166
162
153
155
1.43
1.24
1.36
1.20
1.18
1.39
1.26
820.5
750.6
730.3
719.4
651.8
752.7
730.7
5.94
4.52
4.39
3.99
2.76
3.65
3.32
21.86
13.03
16.45
11.83
11.68
15.99
12.42
7635
6691
7251
6473
6429
7138
6523
2c[f]
2d[g]
2e[g]
2 f[f]
2g[f]
67
15
À2
42
34
À41
À36
–
–
[a] DSC under nitrogen gas 108CminÀ1. [b] gas pycnometer. [c] calculated in Gaussian ’03. [d] calculated
using 83.68 kJmolÀ1 for the enthalpy of sublimation for each compound in Cheetah 5.0. [e] Measured as
viscous liquids for all compounds unless otherwise stated. [f] Solid sample obtained by recrystallization.
[g] see Supporting Information.
Springer,
Heidelberg,
2007,
pp. 85 – 122; e) R. N. Butler in
reactions (see Supporting Information). The enthalpy of an
Comprehensive Heterocyclic Chemistry II. A review of the
literature 1982–1985, Vol. 4 (Eds.: A. R. Katritzky, C. W. Rees,
E. F. Scriven), Pergamon, New York, 1996, pp. 897 – 904.
isodesmic reaction (DHr298) is obtained by combining the
MP2(full)/6-311 + G** energy difference for the reaction, the
scaled zero-point energies, and other thermal factors. All the
5-azidotetrazoles exhibit positive heats of formation with 2a
having the highest value (820.5 kJmolÀ1). By using the
experimental values for the densities of the new substituted
tetrazoles, 2a–g, the detonation pressures (P) and veloci-
ties (D) were calculated based on traditional Chapman–
Jouget thermodynamic detonation theory using Chee-
tah 5.0.[16] It can be seen that, with the exception of 2a, the
new 5-azidotetrazoles exhibit lower detonation pressures than
TNT (P = 20 GPa), attributed mainly to their lower densities.
[3] W. Friderich, K. Flick, US 2179783, 1939 [Chem. Abstr. 1940, 34,
11610].
912; b) A. Hammerl, T. M. Klapötke, H. Nöth, M. Warchhold, G.
Hammerl, T. M. Klapötke, P. Mayer, J. J. Weigand, Propellants
[5] a) A. H. Dinwoodie, R. N. Haszeldine, J. Chem. Soc. 1965, 2266 –
2268; b) S. P. Makarov, A. S. Filatov, A. Ya. Yakubovich, Zh.
Obshch. Khim. 1967, 37, 158 – 163; c) A. S. Filatov, S. P.
Makarov, A. Ya. Yakubovich, Zh. Obshch. Khim. 1967, 37,
837 – 841; d) S. P. Makarov, A. Ya. Yakubovich, A. S. Filatov,
M. A. Énglin, T. Ya. Nikiforova, Zh. Obshch. Khim. 1968, 38,
g) K. Charavorty, J. M. Pearson, M. J. Szearc, J. Phys. Chem.
[6] V. A. Ginsburg, A. Ya. Yakubovich, A. S. Filatov, G. E. Zelenin,
S. P. Makarov, V. A. Shpanskii, G. P. Kotel’nikova, L. F.
Segienko, L. L. Martynova, Dokl. Akad. Nauk SSSR 1962, 142,
354 – 357.
[7] 1a–g:NaN3 = 1:2–2.5 mmol and CH3CN (5 mL) were used unless
otherwise stated. Yield: 2a (1a:NaN3 = 1:1, 258C/24 h, 49%
yield, 63.8 mg), 2b (608C/8 h, 78%, 88.4 mg), 2c (558C/10 h,
99%, 131 mg), 2d (608C/8 h, 98%, 119 mg), 2e (258C/24 h,
74%, 125 mg), 2e (1e:(CH3)3SiN3 = 1:2, 258C/24 h, 75%,
92.4 mg), 2 f (608C/8 h, 89%, 110 mg), 2g (608C/8 h, 93%,
139 mg).
Experimental Section
Caution: When handling these energetic materials, small scale and
best safety practices (leather gloves, face shield) are strongly
encouraged. We experienced an explosion in handling 2a when the
stopcock with a ground joint was opened after drying on the vacuum
line. These 5-azidotetrazoles are very sensitive towards friction.
Impact sensitivities for 2b, 2c, 2e and 2 f were determined to be less
than 1 J (BAMFallhammer test).
2c: In a 50 mL Schlenk tube, 1c (0.111 g, 0.79 mmol) and NaN3
(0.127 g, 2.00 mmol) were taken up in CH3CN (5 mL). The resultant
solution was held at 558C for 10 h. The solvent was removed, and the
residue was extracted with chloroform which when evaporated to
leave a colorless liquid. Yield 99%, 131 mg. Crystals suitable for
single-crystal X-ray structure determination were obtained from
chloroform/n-hexane.
IR (liq. film): n˜ = = 2159 (s; nas(N3)), 1535 cmÀ1 (s; nas(N=C));
1H NMR (300 MHz, CDCl3, 258C, TMS): d = 1.30 (s, 3H), 2.13 ppm
(s, 3H); 13C NMR (75.5 MHz, CDCl3, 258C, TMS): d = 21.5 (q), 26.3
(q), 149.7 (s), 182.5 ppm (s); 15N NMR (50.7 MHz, CDCl3, 258C,
1
1
CH3NO2): d = À297.9 (d, J = 14.5 Hz, Na), À143.5 (dd, J = 14.5 Hz,
1J = 6.5 Hz, Nb), À137.9 (d, 1J = 6.5 Hz, Ng), À75.5 (ddd, 1J = 20.3 Hz,
2J = 1.6 Hz, 2J = 0.8 Hz, N4), À16.5 (dd, 1J = 16.3 Hz, 2J = 1.6 Hz, N2),
À4.3 ppm (dd, 1J = 20.3 Hz, 1J = 16.3 Hz, N3); MS (FAB; 3-nitro-
benzyl alcohol matrix): C4H6N8, 167.0320 (100) [M+ + H], 333.0907
(9) [2M+ + H].
Received: May 27, 2008
[9] A. F. Gonter, E. N. Glatov, A. S. Vinogradov, E. G. Bykhov-
skaya, I. L. Knunyants, Izv. Akad. Nauk SSSR Ser. Khim. 1985,
700 – 703.
Published online: August 1, 2008
[10] a) G. Köter, K. Seppelt, J. Am. Chem. Soc. 1979, 101, 347 – 349;
b) K. A. Petrov, A. A. Neimysheva, J. Gen. Chem. USSR (Engl.
Transl.) 1969, 29, 2135 – 2139.
À
Keywords: azo compounds · C F activation · hydrazones ·
nitrogen heterocycles · tetrazoles
.
Angew. Chem. Int. Ed. 2008, 47, 7087 –7090
ꢀ 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim