Nitrogen-Rich Bis-1,2,4-triazoles
FULL PAPER
ment like earthed shoes, leather coat, Kevlar gloves, ear protection, and
face shield is recommended for the handling of any energetic material.
3,3’-Dinitro-5,5’-bis(1H-1,2,4-triazole) (DNBT, 2): A solution of 1 (11.9 g,
72 mmol) in 20% sulfuric acid (140 mL) was added dropwise to a solu-
tion of sodium nitrite (98.8 g, 1.4 mol, 10 equiv) in water (140 mL) at
408C. The mixture was stirred at 508C for one hour. After cooling down
to room temperature the mixture was acidified with sulfuric acid (20%)
until no evolution of nitrogen dioxide could be observed. The precipitate
was collected by filtration and dissolved in boiling water. The hot solu-
tion was filtrated and allowed to cool to room temperature. Collection of
the pale green precipitate affords 2·2H2O (15.5 g, 59 mmol, 82%) as a
crystalline solid. 1H NMR (400 MHz, [D6]DMSO): d=9.68 ppm (s, 2H;
General: All chemical reagents and solvents were obtained from Sigma–
Aldrich or Acros Organics (analytical grade) and were used as supplied
without further purification. 1H, 13C{1H}, 14N{1H}, and 15N NMR spectra
were recorded on a JEOL Eclipse 400 instrument in [D6]DMSO at 258C.
The chemical shifts are given relative to tetramethylsilane (1H, 13C) or ni-
tromethane (14N, 15N) as external standards and coupling constants are
given in Hertz (Hz). Infrared (IR) spectra were recorded on a Perkin–
Elmer Spectrum BX FT-IR instrument equipped with an ATR unit at
258C. Transmittance values are qualitatively described as “very strong”
(vs), “strong” (s), “medium” (m), “weak” (w), and “very weak” (vw).
Raman spectra were recorded on a Bruker RAM II spectrometer equip-
ped with a Nd:YAG laser (200 mW) operating at l=1064 nm and a re-
flection angle of 1808. The intensities are reported as percentages of the
most intense peak and are given in parentheses. Elemental analyses
(CHNO) were performed with a Netzsch Simultaneous Thermal Ana-
lyzer STA 429. Melting and decomposition points were determined by
differential scanning calorimetry (Linseis PT 10 DSC, calibrated with
standard pure indium and zinc). Measurements were performed at a
heating rate of 58Cminꢀ1 in closed aluminum sample pans with a 1 mm
hole in the lid for gas release to avoid an unsafe increase in pressure
under a nitrogen flow of 20 mLminꢀ1 with an empty identical aluminum
sample pan as a reference.
H
Triazole); 13C NMR (100 MHz, [D6]DMSO): d=162.7, 145.6 ppm;
14N NMR (28.9 MHz, [D6]DMSO): d=ꢀ26 ppm ( NO2); 15N NMR
(40.5 MHz, [D6]DMSO): d=ꢀ27.8 (N4), ꢀ88.8 (N2), ꢀ141.7 (N3),
ꢀ156.1 ppm (N1); IR: n˜ =3599 (m), 3499 (m), 3052 (w), 2849 (w), 2747
(w), 2670 (m), 2621 (m), 2574 (m), 2530 (m), 2488 (m), 2419 (m), 1844
(w), 1609 (m), 1532 (vs), 1466 (w), 1416 (vs), 1314 (vs), 1245 (m), 1183
(m), 1024 (m), 953 (s), 837 (s), 690 (w), 690 cmꢀ1 (w); Raman (200 mW):
n˜ (rel. intensity)=3192 (3), 1641 (100), 1546 (28), 1519 (5), 1485 (75),
1468 (43), 1458 (95), 1413 (18), 1393 (97), 1365 (6), 1362 (6), 1345 (13),
1325 (27), 1306 (35), 1172 (58), 1062 (67), 1015 (31), 855 (4), 774 (8), 744
(5), 619 (4), 511 (4), 452 (5), 452 (5), 399 (9), 297 (9), 203 cmꢀ1 (6); MS
(FABꢀ): m/: 225.1 [C4HN8O4]ꢀ; elemental analysis (%) calcd for
C4H2N8O4: C 21.25, H 0.89, N 49.56; found: C 21.44, H 0.95, N 49.19;
sensitivities (grain size<100 mm): friction=360 N, impact=10 J, ESD=
0.1 J; DSC (onset, 58C minꢀ1): Tdecomp =2518C.
ꢀ
For initial safety testing, the impact and friction sensitivities as well as
the electrostatic sensitivities were determined. The impact sensitivity
tests were carried out according to STANAG 4489,[33] modified according
to the WIWEB instruction 4-5.1.02[34] by using a BAM[35] drop hammer.
The friction sensitivity tests were carried out according to
STANAG 4487[36] and modified according to the WIWEB instruction 4-
5.1.03[37] by using the BAM[35] friction tester. The electrostatic sensitivity
tests were accomplished according to STANAG 4490[38] by using an elec-
tric spark testing device ESD 2010EN (OZM Research).
3,3’-Dinitrimino-5,5’-bis(1H-1,2,4-triazole) (DNABT, 3): Compound
3
was synthesized according to a modified literature-known procedure:[12]
Nitric acid (100%, 3.0 mL) was added slowly to a solution of 1 (1.0 g,
6.0 mmol) in concentrated sulfuric acid (9.0 mL) at 08C. The mixture was
allowed to warm to room temperature and stirred for one hour. The
clear solution was poured on ice, the precipitate was collected by filtra-
tion and recrystallized from boiling water to yield 3·2H2O (1.35 g,
4.6 mmol, 77%) as yellow crystalline solid. 1H NMR (400 MHz,
[D6]DMSO): d=5.52 ppm (s, 2H; HTriazole); 13C NMR (100 MHz,
[D6]DMSO): d=153.1, 142.1 ppm; 14N NMR (28.9 MHz, [D6]DMSO):
Crystallographic measurements: The single-crystal X-ray diffraction data
of compounds 1, 2, 4, and 5 were collected by using an Oxford Xcalibur3
diffractometer equipped with a Spellman generator (voltage=50 kV, cur-
rent=40 mA) and a Kappa CCD detector. The data collection was un-
dertaken by using the Crysalis CCD software,[39] whereas the data reduc-
tion was performed with the Crysalis Red software.[40] Crystals of com-
pound 3c were investigated by using a Bruker–Nonius Kappa CCD dif-
fractometer equipped with a rotating molybdenum anode and Montel-
graded multilayered X-ray optics. The structures were solved with SIR-
92[41] or SHELXS-97[42] and refined with SHELXL-97[43] implemented in
the program package WinGX[44] and finally checked by using
PLATON.[45] CCDC-887530 (1), 864398 (2), 887531 (4), and 887532 (5)
contain the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge Crystallograph-
ꢀ
d=ꢀ21 ppm ( NO2); IR: n˜ =3165 (m), 3154 (m), 1565 (vs), 1508 (s),
1463 (s), 1446 (s), 1380 (m), 1298 (vs), 1229 (vs), 1140 (m), 1085 (m),
1054 (s), 989 (m), 947 (s), 849 (m), 778 (s), 766 (s), 751 (s), 708 cmꢀ1 (vs);
Raman (200 mW): n˜ (rel. intensity)=1655 (100), 1592 (60), 1568 (81),
1527 (14), 1288 (2), 1224 (7), 1123 (26), 1072 (2), 1019 (25), 992 (35), 851
(11), 764 (26), 691 (2), 558 (6), 520 (2), 440 (2), 417 (3), 407 (3), 226 cmꢀ1
(6); elemental analysis (%) calcd for C4H2N8O4: C 16.44, H 2.76, N
47.94; found: C 16.73, H 2.69, N 47.73; sensitivities (water-free com-
pound, grain size<100 mm): friction=108 N, impact=3 J, ESD=0.5 J;
DSC (onset, 58C minꢀ1): Tdecomp =1948C.
3,3’-Diazido-5,5’-bis(1H-1,2,4-triazole) (DAzBT, 4): A solution of sodium
nitrite (0.37 g, 5.4 mol, 3 equiv) in water (2.0 mL) was added dropwise to
a suspension of 1 (0.3 g, 1.8 mmol) in 20% sulfuric acid (20 mL,) at 08C.
The mixture was allowed to warm to room temperature and subsequently
stirred at 408C for one hour. After cooling down to room temperature, a
solution of sodium azide (5.9 g, 9.0 mmol, 5 equiv) in water (2.0 mL) was
added dropwise. (DANGER: EVOLUTION OF HN3!). The suspension
was stirred over night at room temperature to remove the excess of
sodium azide and extracted with ethyl acetate (3ꢄ20 mL). The solvent
was evaporated and the resulting solid was recrystallized from water.
Collection of the colorless precipitate affords 4·2H2O (0.25 g, 1.0 mmol,
56%) as crystalline needles. 1H NMR (400 MHz, [D6]DMSO): d=
14.86 ppm (s, 2H; HTriazole); 13C NMR (100 MHz, [D6]DMSO): d=157.7,
3,3’-Diamino-5,5’-bis(1H-1,2,4-triazole) (DABT, 1): Hydrochloric acid
(60 mL) was added to a stirred mixture of oxalic acid (20.0 g, 159 mmol)
and aminoguanidinium bicarbonate (45.4 g, 332 mmol). The reaction was
stirred at 708C for one hour and the precipitate was collected by filtra-
tion. The colorless solid was dissolved in water (240 mL) and alkalized
with sodium hydroxide to pH 14. The reaction mixture was heated to
reflux for one hour and subsequently acidified with acetic acid to pH 4.
The resulting precipitate was collected by filtration, washed with water
(ꢂ200 mL) and dried in air to yield 1 (18.6 g, 112 mmol, 70%) as a color-
less solid.1H NMR (400 MHz, [D6]DMSO): d=6.46 ppm (s, 2H; NH2);
13C NMR (100 MHz, [D6]DMSO): d=157.3, 149.3 ppm; IR: n˜ =3325 (m),
3116 (m), 2863 (m), 2784 (m), 1706 (s), 1668 (s), 1654 (s), 1618 (m), 1606
(m), 1484 (m), 1457 (m), 1267 (m), 1104 (vs), 1061 (s), 987 (w), 956 (w),
769 (w), 721 cmꢀ1 (s); Raman (200 mW): n˜ (rel. intensity)=1636 (62),
1614 (100), 1591 (67), 1575 (57), 1495 (13), 1439 (21), 1432 (21), 1361 (9),
1152 (24), 1143 (23), 1059 (23), 1042 (34), 1022 (22), 980 (27), 772 (18),
554 (7), 413 (11), 328 (12), 249 cmꢀ1 (16); MS (DEI+): m/z: 166.1
[C4H7N8]+; elemental analysis (%) calcd for C4H6N10: C 28.92, H 3.64, N
67.44; found: C 28.72, H 3.58, N 66.11.
145.9 ppm (C N3); 14N NMR (28.9 MHz, [D6]DMSO): d=ꢀ145 ppm
ꢀ
( N3); 15N NMR (40.5 MHz, [D6]DMSO): d=ꢀ115.3 (N2), ꢀ141.9 (N3),
ꢀ
ꢀ146.2 (N5), ꢀ153.0 (N6), ꢀ173.2 (N1), ꢀ295.2 ppm (N4); IR: n˜ =3141
(s), 3042 (s), 2876 (s), 2710 (s), 2655 (s), 2630 (m), 2571 (m), 2435 (m),
2362 (m), 2240 (m), 2228 (m), 2156 (vs), 2138 (vs), 2137 (vs), 1541 (vs),
1518 (s), 1483 (vs), 1457 (s), 1420 (vs), 1418 (vs), 1391 (s), 1333 (s), 1299
(m), 1299 (m), 1275 (s), 1241 (m), 1218 (m), 1188 (s), 1142 (s), 1122 (s),
1033 (vs), 1014 (m), 980 (vs), 958 (m), 846 (m), 799 (s), 780 (m), 729 (s),
714 (m), 661 (m), 532 cmꢀ1 (m); Raman (200 mW): n˜ (rel. intensity)=
2171 (14), 2142 (17), 1620 (56), 1605 (100), 1551 (17), 1551 (16), 1549
(17), 1548 (17), 1547 (17), 1515 (44), 1503 (24), 1501 (26), 1500 (27), 1423
Chem. Eur. J. 2012, 18, 16742 – 16753
ꢂ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
16751