Amination of energetic anions: High-performing energetic materials

Article abstract of DOI:10.1039/c2dt30684k

The new energetic materials 2-amino-5-nitrotetrazole (ANT, 1), 1-amino-3,4-dinitro-1,2,4-triazole (ADNT, 2), and both 1,1′-diamino-5, 5′-bistetrazole and 1,2′-diamino-5,5′-bistetrazole (11DABT, 3 and 12DABT, 4) have been prepared by the amination of the p

Full text of DOI:10.1039/c2dt30684k

View Online / Journal Homepage
Dalton
Transactions
Accepted Manuscript
This is an Accepted Manuscript, which has been through the RSC Publishing peer
review process and has been accepted for publication.
Dalton
Transactions
Volume 39 | Number 3 | 21 January 2010 | Pages 657–964
Accepted Manuscripts are published online shortly after acceptance, which is prior
to technical editing, formatting and proof reading. This free service from RSC
Publishing allows authors to make their results available to the community, in
citable form, before publication of the edited article. This Accepted Manuscript will
be replaced by the edited and formatted Advance Article as soon as this is available.
An international journal of inorganic chemistry
www.rsc.org/dalton
To cite this manuscript please use its permanent Digital Object Identifier (DOI®),
which is identical for all formats of publication.
More information about Accepted Manuscripts can be found in the
Information for Authors.
Please note that technical editing may introduce minor changes to the text and/or
graphics contained in the manuscript submitted by the author(s) which may alter
content, and that the standard Terms & Conditions and the ethical guidelines
that apply to the journal are still applicable. In no event shall the RSC be held
responsible for any errors or omissions in these Accepted Manuscript manuscripts or
any consequences arising from the use of any information contained in them.
ISSN 1477-9226
COMMUNICATION
PAPER
Bu et al.
Manzano et al.
Zinc(ii)-boron(iii)-imidazolate
Experimental and computational study framework (ZBIF) with unusual
of the interplay between C–H/p and
anion–p interactions
pentagonal channels prepared from
deep eutectic solvent
1477-9226(2010)39:1;1-K
www.rsc.org/dalton
Registered Charity Number 207890

Page 1 of 12
Dalton Transactions
Dynamic Article Links ►
Dalton Transactions
View Online
Cite this: DOI: 10.1039/c0xx00000x
www.rsc.org/Dalton Transactions
PAPER
Amination of Energetic Anions: High-Performing Energetic Materials
Thomas M. Klapötke,* Davin G. Piercey and Jörg Stierstorfer
Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
DOI: 10.1039/b000000x
5
The new energetic materials 2-amino-5-nitrotetrazole (ANT,1), 1-amino-3,4-dinitro-1,2,4-triazole
(ADNT, 2), and both 1,1’-diamino-5,5’-bistetrazole and 1,2’-diamino-5,5’-bistetrazole (11DABT, 3 and
12DABT, 4) have been prepared from the amination of the parent anion with O-tosylhydroxylamine. The
5-H-tetrazolate anion has also been aminated using hydroxylamine O-sulfonic acid to both 1-
aminotetrazole and 2-aminotetrazole (1AT, 5 and 2AT 6). The prepared materials have been
10 characterized chemically (XRD (1-4, 6·AtNO2, 8), multinuclear NMR, IR, Raman) and as explosives
(mechanical and electrostatic sensitivity) and their explosive performances calculated using the EXPLO5
computer code. The prepared N-amino energetic materials, which can also be used as new ligands for
high-energy capacity transition metal complexes, exhibit high explosive performances (in the range of
hexogen and octogen) and a range of sensitivities from low to extremely high
15
.
room temperature.15
Introduction
The design of new energetic materials is an intensely-pursued
research area in the chemical sciences, with a historical following
including such scientists as Liebig, Berzelius, and Gay-Lussac.1-8
50
20 The field of energetic materials research possesses a unique
combination of both academic and practical interest, where
working with metastable molecules on the edge of existence is
both valued militarily and industrially for their values as
explosives, and by scientists for their value in predicting factors
25 affecting molecular stability, and the unique synthetic reactions
that are mandated. Beyond these factors, one of the driving
forces of modern energetic materials research is that the produced
materials must be “green” by not causing an environmental or
toxicological hazard, while simultaneously increasing
30 performance.9,10
Traditional energetic materials include such quintessential
explosives such as RDX (1,3,5-trinitro-1,3,5-triazinane) and TNT
(2,4,6-trinitrotoluene) are based on the oldest strategy in energetic
materials design: the presence of fuel and oxidizer in the same
35 molecule. New strategies in energetic materials research include
high-nitrogen/high heat of formation compounds, those
possessing ring or cage strain, and combinations of all three
strategies.3,11,12
55
Figure 1: The Structures of TATB and FOX-7.
The N-amination of both electron-rich triazoles16 and tetrazoles17
have been known for some time, using the commercially
available hydroxylamine-O-sulfonic acid (HOSA), however
60 HOSA aminations unfortunately do not extend to electron poor
systems. The addition of an amino group to an energetic
molecule is advantageous in terms of stability, for example
amino-nitro compounds such as 1,3,5-triamino-2,4,6-
trinitrobenzene (TATB) or diaminodinitroethylene (FOX-7) are
65 low-sensitivity-high-performance explosives that are the standard
for insensitive explosives.18 (Figure 1) N-amino compounds have
the further advantage that their heats of formation (and as such
explosive performance) increase as a result of the additional N-N
single bond. In addition new donor sites and functionalities are
70 introduced by the NH2 groups yielding (for example) new
potential nitrogen ligands for high energy-capacity transition
metal complexes.
Possessing high heats of formation and ring strain, triazoles
40 and tetrazoles have been used for the preparation of high-
performance primary13 and secondary explosives.14 Triazoles and
tetrazoles occupy an intermediate position on the ‘stability versus
heat of formation’ continuum, where pyrazoles are stable but
O-Tosylhydroxylamine (THA)19,20 is a powerful amination
agent well known to aminate electron-poor systems. We have
75 used this reagent to aminate the electron poor 5-nitrotetrazolate,
3,5-dinitro-1,2,4-triazolate, and 5,5’-bistetrazolate anions
yielding 2-amino-5-nitrotetrazole (ANT, 1), 1-amino-3,4-dinitro-
possess
a poor heat of formation, but pentazoles, while
45 possessing a high heat of formation, are thermally unstable with
most members of this class of compounds decomposing below
This journal is © The Royal Society of Chemistry [year]
[journal], [year], [vol], 00–00 | 1

Dalton Transactions
Page 2 of 12
View Online
1,2,4-triazole (ADNT, 2), and both 1,1’-diamino-5,5’-bistetrazole
and 1,2’-diamino-5,5’-bistetrazole (11DABT, 3 and 12DABT, 4).
atoms were refined anisotropically and the hydrogen atoms were
located and freely refined. The absorptions were corrected by a
ANT and ADNT have been mentioned in the literature,21 but no 60 Scale3 Abspack multi-scan method.36
full synthetic procedure is available. The compounds were
characterized by X-ray diffraction, infrared and Raman
spcectroscopy, multinuclear NMR spectroscopy, elemental
analysis, and DSC. Computational calculations confirming the
CAUTION! All the following compounds are energetic materials
5
with sensitivity to various stimuli. While compounds 1-6 and 8
were handled without incident, proper protective measures (face
shield, ear protection, body armour, Kevlar® gloves and
high energetic performance was also performed. We furthermore 65 earthened equipment) should be used at all times. Compound 7 is
repeat the literature synthesis17 of 1-amino (5) and 2-
exceedingly sensitive and can spontaneously detonate even when
10 aminotetrazoles (6) with HOSA and report the full chemical and
energetic properties. Three derivatives of N-amino energetic
heterocycles have also been prepared, the first is the azo coupling
product of 1, 2,2’-azobis(5-nitrotetrazole), 7, a compound of
astounding sensitivity and performance. The condensation
15 product of 5 with trinitroethanol, 1-(trinitroethylamino)tetrazole
(8) and a cocrystal of 6 with nitriminotetrazole (6.ATNO2).
Compound 7 has been mentioned22 in a patent, however no
characterization was mentioned, not even the exceedingly high
sensitivity that we determined.
damp. Extreme caution is advised.
2-Amino-5-Nitrotetrazole (ANT,1)
0.95 g (3.69 mmol) of freshly prepared pulverized ethyl O-p-
70 tolylsulphonylacetohydroximate was added to 7.5 mL of 60%
perchloric acid at room temperature and was allowed to stir under
ambient conditions for two hours.
The now-free
tosylhydroxylamine suspension was poured into 80 mL of
ice/water slurry and after the ice was melted the mixture was
75 extracted with 7 x 10 mL portions of dichloromethane. The
combined dichloromethane extracts were dried over sodium
sulfate and then added in one portion to a solution of 0.50 g (3.54
mmol) of ammonium nitrotetrazolate hemihydrate in 250 mL
acetonitrile. The solution was stirred for two days under ambient
80 conditions, evaporated to dryness, and resuspended in ethyl
acetate. The suspension was filtered and the filtrate evaporated
and purified by silica chromatography using 4:4:2 ethyl
acetate:hexane:benzene as eluent yielding 0.230 g (50%) of 2-
20 Experimental
All reagents and solvents were used as received (Sigma-Aldrich,
Fluka, Acros Organics) if not stated otherwise. Ethyl-O-p-
tolylsulphonylacetohydroximate, ammonium nitrotetrazolate
hemihydrate, ammonium dinitrotriazolate, 5,5’-bistetrazole and
25 trinitroethanol were prepared according to the literature
procedures.19,23-25 Melting and decomposition points were
measured with a Linseis PT10 DSC using heating rates of 5 °C
min–1, which were checked with a Büchi Melting Point B-450
apparatus. 1H, 13C and 15N NMR spectra were measured with a
30 JEOL Eclipse 270, JEOL EX 400, or a JEOL Eclipse 400
instrument. All chemical shifts are quoted in ppm relative to
TMS (1H, 13C) or nitromethane (15N). Infrared spectra were
measured with a Perkin-Elmer Spektrum One FT-IR instrument.
Raman spectra were measured with a Perkin-Elmer Spektrum
35 2000R NIR FT-Raman instrument equipped with a Nd-YAG
laser (1064 nm) Elemental analyses were performed with a
Netsch STA 429 simultaneous thermal analyser. Sensitivity data
were determined using a BAM drophammer and a BAM friction
tester (method: 1 of 6). The electrostatic sensitivity tests were
40 carried out using an Electric Spark Tester ESD 2010 EN (OZM
Research) operating with the “Winspark 1.15” software package.
Electronic energies (CBS-4M method) were calculated with the
Gaussian09 (Revision A.02) software.26 Gas phase enthalpies of
formation were computed using the atomization method
45 numerously described recently.27 The gas phase enthalpies of
formation were converted to the solid state enthalpies of
formation by subtraction of sublimation enthalpy calculated
according to Troutons’ rule (ꢀHsub = 188·Tm, ꢀHvap = 108·Tb ).28
Detonation parameters were calculated with the EXPLO5.04
50 computer code.29
amino-5-nitrotetrazole. DSC (5 °C min–1): 102 (Tm), 140 (Tdec);
–1
˜
ν
85 IR (cm ) =3340 (m), 3255 (w), 3191 (w), 2945 (w), 2921 (w),
1729 (w), 1678 (w), 1622 (m), 1563 (s), 1529 (m), 1495 (m),
1473(s), 1454 (w), 1418 (m), 1340 (w), 1319 (s), 1249 (m), 1227
(w), 1190 (m), 1174(m), 1154 (m), 1144 (m), 1119 (m), 1049
(m), 1073 (m), 1030 (m), 954 (s), 912 (m), 893 (m), 840 (s), 711
90 (w), 696 (w), 652 (w). Raman (1064 nm, cm–1)
=3343 (5),
˜
ν
3258 (3), 3195 (8), 2985 (1), 2939 (3), 2915 (1), 1722 (2), 1679
(1), 1617 (4), 1567 (14), 1528 (2), 1497 (20), 1475 (31), 1457 (6),
1420 (100), 1394 (14), 1322 (16), 1252 (3), 1159 (19), 1074 (10),
1030 (86), 842 (8), 772 (11), 762 (3), 746 (17), 663 (1), 569 (8),
1
95 455 (8), 419 (6), 332 (3), 229 (6); H NMR (DMSO-d6) δ (ppm)
= 8.98; 13C NMR (DMSO-d6) δ (ppm) = 163.1 (s, 1C); m/z:
(DCI+) 131.07 (M+H) (CH2O2N6); EA (CH2O2N6, 130.07 g/mol)
calcd: C 9.23%, N 64.61%, H 1.55%, found:too sensitive for
measurement; BAM impact: <1 J; BAM friction: <5 N; ESD:
100 250 mJ.
1-Amino-3,5-dinitro-1,2,4-triazole (ADNT,2)
0.80 g (3.11 mmol) of freshly prepared pulverized ethyl O-p-
tolylsulphonylacetohydroximate was added to 7.5 mL of 60%
105 perchloric acid at room temperature and was allowed to stir under
ambient conditions for two hours.
The now-free
tosylhydroxylamine suspension was poured into 80 mL of
ice/water slurry and after the ice was melted the mixture was
extracted with 7 x 10 mL portions of dichloromethane. The
110 combined dichloromethane extracts were dried over sodium
sulfate and then added in one portion to a solution of 0.50 g (2.84
mmol) of ammonium dinitrotriazolate in 250 mL acetonitrile.
The solution was stirred for two days under ambient conditions,
evaporated to dryness, and resuspended in ethyl acetate. The
XRD was performed on a Oxford Xcalibur3 diffractometer with a
Spellman generator (voltage 50 kV, current 40 mA) and a
KappaCCD detector. The data collection and reduction was
carried out using the CRYSALISP
RO software.30 The structures
55 were solved either with SIR-9231 or SHELXS-9732, refined with
34
S
HELXL-9733 and finally checked using the PLATON software
integrated in the WINGX35 software suite. The non-hydrogen
2
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 3 of 12
Dalton Transactions
View Online
1395 (7), 1364 (1), 1348 (1), 1327 (7), 1221 (21), 1189 (10),
silica chromatography using 4:4:2 ethyl acetate:hexane:benzene 60 1126 (13), 1092 (1), 1062 (8), 1030 (43), 993 (3), 950 (4), 755
suspension was filtered and the filtrate evaporated and purified by
as eluent yielding 0.319 g (65%) of 1-amino-3,5-dinitro-1,2,4-
(5), 736 (1), 708 (7), 682 (1), 543 (1), 454 (2), 417 (3), 366 (9),
1
triazole. DSC (5 °C min–1): 118 (Tm) 165 (Tdec); IR (cm–1)
=
320 (5), 269 (4); H NMR (DMSO-d6) δ (ppm) = 8.59 (s, 2H),
˜
ν
5
3333 (m), 3278 (w), 3208 (w), 2924 (w), 1612 (w), 1578 (m),
1562 (s), 1512 (s), 1449 (w), 1425(w), 1392 (w), 1375 (w), 1338
7.35 (s, 2H); 13C NMR (DMSO-d6) δ (ppm) = 150.5 (s, 1C),
143.7 (s, 1C); m/z: (DCI+) 169.2 (C2H5N10); EA (C2H4N10,
(m), 1321 (s), 1256 (w), 1132 (m), 1032 (w), 991 (w), 974 (w), 65 168.12) calcd: C, 14.29; H, 2.40; N, 83.31%; found: C, 14.70; H,
934 (m), 883 (w), 856 (s), 828 (s), 771 (w), 755 (w), 731 (w), 673
2.33; N, 51.03%; BAM impact: 3 J; BAM friction: 10 N; ESD:
0.25 J.
(w); Raman (1064 nm, cm–1)
=3344 (2), 3280 (5), 3222 (1),
˜
ν
10 1914 (1), 1799 (1), 1621 (1), 1569 (10), 1518 (3), 1447 (100),
1393 (10), 1382 (30), 1345 (18), 1324 (9), 1281 (9), 1135 (9),
1033 (19), 993 (2), 937 (1), 862 (3), 831 (14), 772 (4), 757 (5),
734 (6), 477 (7), 394 (2), 383 (1), 357 (9), 318 (2), 250 (1), 221
5H-Tetrazole amination19
14.0 g (0.200 mol) of tetrazole was dissolved in 150 mL water
70 and 23.2 g (0.219 mol) of sodium carbonate was added followed
by heating to 75°C. 27.2 g (0.240 mol) of hydroxylamine-O-
sulfonic acid in 120 mL water was added dropwise over 20
minutes while maintaining the pH between 7 and 8 by periodic
addition of a saturated solution of sodium bicarbonate. Following
75 addition the solution was refluxed for 30 minutes and then
evaporated to 125 mL. This solution was continuously extracted
with ethyl acetate overnight, evaporation of the extract gave a
mixture of 1- and 2- aminotetrazoles, of which the 2-isomer could
be distilled at 2.2x10–2 mbar and 47 °C yielding a pure distillate
1
(2); H NMR (DMSO-d6) δ (ppm) = 8.26; 13C NMR (DMSO-d6)
15 δ (ppm) = 153.3 (s, 1C), 145.9 (s, 1C); m/z: (DEI+) 174.1 (M+)
(C2H2O4N6); EA (C2H2O4N6, 174.08 g/mol) calcd: C 13.80%, N
48.29%, H 1.16%, found: C 14.19%, N 47.97%, H 1.08%,; BAM
impact: 30 J; BAM friction: 240 N; ESD: 500 mJ.
20 5,5’-Bistetrazole amination
5,5’-Bistetrazole (1.00 g, 7.2 mmol) was dissolved in 20 mL of
distilled water, and to this was added 4.34 g (14.5 mmol) of 80 of 1.92 g (11%) 2-aminotetrazole, and a pure residue of 4.11 g
CsOH solution (50 wt.%); the solution was then evaporated and
the resulting residue was dissolved in 250 mL of acetonitrile and
25 100 mL of distilled water. 4.4 g (17.1 mmol) of ethyl O-p-
tolylsulphonylacetohydroximate was added to 40 mL of
(24%) 1-aminotetrazole.
1-Aminotetrazole (1AT, 5)
DSC (5 °C min–1): 130 °C (Tvap, onset); IR (cm–1) =3326 (m),
˜
ν
3282 (m), 3195 (m), 3144 (m), 1625 (m), 1491 (w), 1430 (w),
perchloric acid, stirred for 2 h at rt, poured on 100 mL of iced 85 1348 (w), 1286 (w), 1273 (w), 1184 (s), 1097 (s), 1013 (m), 962
water and stirred until the ice melted. Subsequently this mixture
was extracted with dichloromethane (5 x 10 mL). The extract was
30 added to the solution of bistetrazole and stirred overnight under
ambient conditions. The solution was evaporated and extracted
(s), 871 (m), 723 (w), 694 (w), 643 (s); Raman (1064 nm, cm–1):
˜
ν
= 3275 (5), 3212 (2), 3148 (24), 1622 (7), 1491 (11), 1430
(21), 1363 (1), 1342 (4), 1272 (42), 1187 (49), 1102 (18), 1016
1
(40), 957 (7), 723 (2), 697 (100), 646 (4), 422 (12), 270 (7); H
with ethyl acetate. The extract was filtered and the filtrate was 90 NMR (DMSO d6) δ (ppm) = 9.14 (s, 1H, C-H), 7.02 (s, 2H,
evaporated and purified by column chromatography (ethyl
acetate/benzene/petrol ether = 3/1/1) to yield 124 mg (10 %) of
35 1,1’-diamino-5,5’-bistetrazole and 72 mg (6 %) of 1,2’-diamino-
5,5’-diaminobistetrazole
NH2); 13C NMR (DMSO d6) δ (ppm) = 143.3 (s, 1C, CN4); m/z:
(FAB +) 86.0 (M+H+)); EA (CN5H3, 85.07 g mol–1) calcd: C
14.12, N 82.33, H 3.55 %, found C 14.46, N 82.33, H 3.48 %;
BAM impact: < 1 J, BAM friction: 64 N.
1,1’-Diamino-5,5’-bistetrazole (3): DSC (5 °C min–1): 145 °C 95 2-Aminotetrazole (2AT, 6)
–1
(mp), 185 °C (dec); IR (cm ) = 3292 (w), 3249 (w), 3140 (m),
DSC (5 °C min–1): 100 °C (Tvap, onset); IR (cm–1) v=3319 (m),
3271 (m), 3178 (m), 3147 (m), 3003 (w), 1611 (m), 1453 (m),
1386 (m), 1285 (s), 1218 (m), 1178 (m), 1138 (s), 1023 (s), 1006
(s), 948 (s), 883 (s), 703 (s), 667 (s); Raman (1064 nm, cm–1):
˜
ν
2361 (w), 2200 (w), 1612 (m), 1459 (w), 1406 (w), 1385 (w),
40 1330 (w), 1303 (w), 1274 (w), 1213 (w), 1193 (w), 1131 (m),
1065 (w), 1032 (s), 1008 (m), 973 (s), 956 (s), 924 (s), 816 (w),
˜
ν
716 (w), 705 (w), 681 (w), 666 (w); Raman (1064 nm): = 3330 100 3263 (12), 3147 (54), 1610 (7), 1452 (13), 1387 (37), 1286 (100),
(1), 3256 (1), 3177 (4), 2937 (1), 2859 (2), 2026 (1), 1626 (100),
1613 (10), 1502 (2), 1392 (1), 1334 (1), 1278 (27), 1206 (1),
45 1181 (2), 1130 (1), 1082 (26), 1044 (11), 983 (5), 927 (1), 752
1214 (5), 1182 (18), 1141 (36), 1026 (62), 1008 (22), 724 (82),
1
455 (9), 277 (6); H NMR (DMSO d6) δ (ppm) = 8.64 (s, 1H, C-
H), 7.97 (s, 2H, NH2); 13C NMR (DMSO d6) δ (ppm) = 151.5 (s,
(4), 742 (22), 706 (1), 579 (1), 550 (1), 406 (4), 388 (7), 324 (1),
1C, CN4); m/z: (FAB +) 86.0 (M+H+)); EA (CN5H3, 85.07 g mol-
1
290 (1), 256 (10); H NMR (DMSO-d6) δ (ppm) = 7.40 (s, 4H); 105 1) calcd: C 14.12, N 82.33, H 3.55 %, found C 14.30, N 81.15, H
13C NMR (DMSO-d6) δ (ppm) = 141.7 (s, 2C); m/z: (DCI+) 169.2
(C2H5N10); EA (C2H4N10, 168.12) calcd: C, 14.29; H, 2.40; N,
50 83.31%; found: C, 14.70; H, 2.33; N, 51.03%; BAM impact: 3 J;
BAM friction: 10 N; ESD: 0.25 J.
3.54 %; BAM impact: < 1 J, BAM friction: 36 N.
2,2’-Azobis(5-nitrotetrazole) (7)
1,2’-Diamino-5,5’-bistetrazole (4): DSC (5 °C min–1): 90 °C
0.13 g (1.00 mmol) of ANT (1) was dissolved in 4 mL of
o
–1
˜
110 acetonitrile and cooled to 0 C. To this was added dropwise a
ν
(mp), 170 °C (dec); IR (cm ) = 3299 (w), 3224 (w), 3143 (m),
solution of 0.225 g (0.88 mmol) sodium dichloroisocyanurate
dehydrate in 8 mL of water containing 0.25 mL of acetic acid.
The solution instantly turned yellow and was stirred in the ice
bath for 30 minutes followed by pouring into 100 mL of 2%
115 aqueous sodium bicarbonate solution. The precipitate was then
1634 (w), 1602 (m), 1591 (m), 1499 (w), 1429 (w), 1398 (w),
55 1348 (w), 1326 (w), 1216 (w), 1184 (m), 1114 (w), 1093 (w),
1064 (m), 993 (s), 953 (s), 822 (w), 733 (w), 718 (w), 704 (m),
˜
ν
682 (w); Raman (1064 nm): = 3229 (5), 3147 (3), 2944 (1),
2859 (2), 1635 (100), 1609 (4), 1501 (2), 1460 (10), 1434 (4),
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 3

Dalton Transactions
Page 4 of 12
View Online
Scheme 2: Amination of energetic heterocycles with THA
filtered during which time the filtercake spontaneously detonated.
˜
ν
Raman (1064 nm):
= 3073 (7), 2970 (3), 2910 (1), 2875 (1),
1604 (3), 1575 (4), 1530 (100), 1495 (44), 1395 (37), 1296 (23),
1257 (5), 1225 (3), 1176 (48), 1113 (3), 1062 (7), 1005 (27), 932
(62), 889 (4), 833 (3), 776 (8), 707 (3), 638 (2), 554 (1), 464 (1),
372 (1), 341 (4), 249 (2). (VERY WET MEASUREMENT) m/z:
Results and Discussion
5
60 Synthesis
–
(FAB–) 256 (M–), 114 (CN5O2 ))
O-Tosylhydroxylamine is unfortunately not stable in storage so
before each reaction it was prepared from ethyl O-p-
tolylsulphonylacetohydroximate by hydrolysis with 60
%
1-(Trinitroethylamino)tetrazole (8)
perchloric acid (Scheme 1). After hydrolysis it was poured into
65 ice water, extracted with dichloromethane, and the
dichloromethane solution dried over sodium sulfate. This
solution of O-tosylhydroxylamine was then added to an
acetonitrile solution of ammonium 5-nitrotetrazolate hemihydrate
or ammonium dinitrotriazolate. Salts of 5,5’-bistetrazole are of
70 very low solubility in acetonitrile, so acetonitrile/water was used
as solvent. (Scheme 2) The amination reactions were stirred for
two days under ambient conditions, evaporated to dryness and
extracted with ethyl acetate. After purification of the ethyl
acetate extract by column chromatography, 2-amino-5-
75 nitrotetrazole (ANT, 1), 1-amino-3,4-dinitro-1,2,4-triazole
(ADNT, 2), and both 1,1’-diamino-5,5’-bistetrazole and 1,2’-
diamino-5,5’-bistetrazole (11DABT, 3 and 12DABT, 4) were
obtained. Crystals of all four compounds were obtained by slow
evaporation of the desired column fractions.
10 0.25g 1-aminotetrazole (2.9 mmol) was dissolved in 10 mL
distilled water and to this was added 0.60 g of trinitroethanol (3.3
mmol) and the resultant solution was stirred overnight. After
filtration 0.52 g (72%) of colorless 1-(trinitroethylamino)-
tetrazole was obtained.
15 DSC (5 °C min–1): 116 °C(Tdec, onset); IR (cm–1) v=3203 (w),
3159 (w), 2991 (w), 2949 (w), 1597 (s), 1586 (s), 1512 (w), 1467
(w)1422 (w), 1386 (w), 1350 (w), 1300 (m) 1190 (w), 1182 (w),
1088 (m), 1039 (w), 999 (w), 956 (w), 907 (w), 889 (w), 856 (w),
833 (w), 803 (s), 776 (m), 719 (w), 672 (w); Raman (1064 nm,
20 cm–1)
= 3212 (4), 3159 (25), 2991 (25), 2953 (38), 2731 (2),
˜
ν
1609 (36), 1513 (5), 1466 (9), 1430 (36), 1389 (20), 1353 (36),
1304 (14), 1286 (47), 1184 (23), 1150 (4), 1116 (3), 1088 (15),
1041 (13), 997 (49), 957 (17), 906 (6), 858 (99), 807 (6), 778 (3),
724 (10), 674 (7), 640 (21), 547 (10), 496 (10), 418 (25), 396
1
25 (15), 380 (81), 322 (14), 278 (16), 237 (11); H NMR (DMSO
80
5H-tetrazole was aminated according to the literature
procedure by refluxing the anionic tetrazolate with HOSA in
water for 30 minutes. (Scheme 3) After reaction the solution was
subjected to continuous ethyl acetate extraction overnight
followed by distillation of 6 away from 5 under high vacuum
d6) δ (ppm) = 9.18 (s, 1H, tz C-H), 8.24 (t, 1H, N-H 3J=6.0 Hz),
3
5.47 (d, 2H, CH2, J=6 Hz); 13C NMR (acetone-d6) δ (ppm) =
143.4 (s, 1C, CN4), 127.1 (s, 1C, C(NO2)3) 53.1 (s, 1C, CH2);
m/z: (FAB +) 249.0 (M+H+); EA (C3N8O6H4, 248.11 g mol–1)
30 calcd: C 14.52, N 46.16, H 1.63 %, found C 14.81, N 44.72, H
1.56 %; BAM impact: 1 J; BAM friction: 20 N; ESD 0.080 J.
85 (behind a blast shield). Low temperature crystallization proved
unsuccessful so densities were measured via gas pycnometry.
35
90
Scheme 3: Amination of 5H-tetrazole with HOSA
40
95
Scheme 1: Synthesis of O-tosylhydroxylamine (THA) from ethyl-O-p-
Scheme 4: Azo coupling of 1 to 7.
tolylsulfonylacetohydroximate.
45
100
Scheme 5: Condensation of 5 with trinitroethanol to 8.
Crystallization of 6 was achieved as a cocrystal by evaporating a
solution of 6 with 5-nitriminotetrazole yielding a 1-to-1 cocrystal
(6.ATNO2)
50
We have previously described the azo coupling of 5 using
105 sodium dichloroisocyanurate and acetic acid.3 1 was dissolved in
acetonitrile and cooled, followed by adding an acidic solution of
sodium dichloroisocyanurate in water. (Scheme 4) After stirring
for 30 minutes and quenching the reaction in an aqueous sodium
bicarbonate solution a light yellow precipitate (7) was obtained.
55
4
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 5 of 12
Dalton Transactions
View Online
were performed at the DFT level of theory; the gradient-
During filtration the compound exploded while wet, sending
explosive-contaminated fragments of filter paper around the fume 60 correctedhybrid three-parameter B3LYP37,38 functional theory has
hood.
As the fragments of filter paper dried, several
been used with a correlation-consistent cc-pVDZ basis set.39-42
The experimental (calculated) spectrum of 7 possesses five high
intensity peaks at 1530 (1603), 1395 (1428), 1176 (1202), 1005
(972) and 776 (871) cm-1. However, the presence of several
spontaneously re-exploded, and all would explode when touched
with even the lightest force. Compound 7, while having a lower
number of cantenated nitrogen atoms (8) than our previously
5
reported 1,1’-azobis(tetrazole) with ten nitrogen atoms, is even 65 significant additional peaks (ex. 1495, 1257, 1062 cm-1) in the
more difficult to handle, for the measurement of Raman spectra, a
experimental spectrum suggests partial decomposition. The azo
N=N stretch occurs at 1530 cm-1, N3-N4 tetrazole ring
deformation at 1395 cm-1, N2-N3 tetrazole ring deformation(with
minor N2-azo stretching) at 1176 cm-1, tetrazole N1-N2-N3
very wet sample had to be used. The only mention of 7 in a
10 patent does not mention this extremely high sensitivity.22
5 was dissolved in water and trinitroethanol added. After
stirring overnight 1-(trinitroethylamino)tetrazole (8) had 70 asymetric stretching at 1005 cm-1, and N2-N3 stretching (with
precipitated. (Scheme 5) Compounds 1, 2 and 6 were also all
attempted to be reacted with trinitroethanol under these
15 conditions however only 5 yielded a product. Evaporation of a
tetrachloroethylene solution yielded crystals of 8.
minor C-NO2 symmetric stretching) at 776 cm-1.
Energetic Calculations
75 Bomb calorimetric measurements have not been carried out due
to the high nitrogen content of the compounds which oftentimes
leads to incorrect values due to explosion and incomplete
combustion. The heats of formation were calculated by the
atomization equation 1 using CBS-4M enthalpies.
80
Spectroscopy
Multinuclear NMR spectroscopy (1H, 13C) was used to
characterize all compounds with the exception of 7 which
20 decomposed with gas release in all solvents attempted (d6-
DMSO, d6-acetone, CDCl3).
The amine protons of ANT (1) resonate at 8.98 ppm and in the
13C spectra the single carbon at 163.1 ppm. This is in contrast to
the nitrotetrazolate anion where the 13C signal lies around 169
25 ppm depending on the counterion.
The amine protons of ADNT (2) resonate at 8.26 ppm, slightly
upfield compared to those of 1. In the 13C spectrum the
previously symmetrical dinitrotriazolate anion’s resonance at
around 163 ppm is shifted upfield to 153.3 and 145.9 ppm for
30 carbons C2 and C1 respectively.
ꢀfH°(g, M, 298) = H(M, 298) – ∑H°(Atoms, 298) + ∑ꢀfH°(Atoms, 298) (1)
The results are summarized in Table 2. All compounds are
formed endothermically with the highest value of 1092 kJ mol–1
85 calculated for 7. Due to the highly energetic character of the
compounds their detonation performance was computed with the
EXPLO5.04 computer code.29 The input is based on the sum
formula, heats of formation (see experimental section) and the
maximum densities according to their crystal structures at low
90 temperatures. EXPLO5.04 is based on the chemical equilibrium,
steadystate model of detonation. It uses the Becker-
Kistiakowsky- Wilson’s equation of state (BKW EOS) for
gaseous detonation products and Cowan-Fickett’s equation of
state for solid carbon. Compound 7 is also the one with the
95 highest sensitivities within this work. Of interest is its exceptional
high nitrogen/oxygen (%N+%O) content of 90.62 %. Its
calculated detonation parameters are the highest calculated for 1–
8. The lowest detonation parameters were calculated for the
liquids 5 and 6 because of their low density. All of the other
100 compounds show detonation velocities comparable to those
observed for RDX. Although academically interesting the
practical use of 1–8 is limited due to their low decomposition
temperature, the highest being observed for 3 (185 °C).
The detonation parameters of the aminated compounds are
105 higher than their corresponding methylated derivates (e.g.
VDet(ANT) = 9087 m s–1, VDet(2-methyl-5-nitrotetrazole): 8109 m
s–1)45. This is a reason of (i) a higher density (e.g. ρ(ANT): 1.791
g cm–3, ρ(2-methyl-5-nitrotetrazole): 1.668 g cm–3) and (ii) of a
higher heat of formation (e.g. ꢀfHm°(ANT): 376 kJ mol–1, ꢀfHm°
110 (2-methyl-5-nitrotetrazole): 247 kJ mol–1). Comparison of ANT
with neutral 5-nitrotetrazole shows (i) lower density for the
aminated compound (ρ(5-nitrotetrazole): 1.899 g cm–3)45, (ii)
higher heat of formation for ANT (ꢀfHm° (5-nitrotetrazole): 281
kJ mol–1) and (iii) lower detonation velocity VDet(5-
115 nitrotetrazole): 9457 m s–1). In comparison to the 2-hydroxy-5-
nitrotetrazole1 the amino compound shows lower values however
11DABT possesses 1H NMR resonances at 7.40 ppm, however
in 12DABT the four amino protons are no longer equivalent and
are split into two equivalent resonances at 7.35 ppm for the 1-
amino protons and 8.59 ppm for the 2-amino protons. The 13C
35 NMR of 11DABT shows an upfield shift to 141.7 ppm from the
~155 ppm shift in the bistetrazolate anion, however the 12DABT
carbon resonances are not equivalent at 150.5 and 143.7 ppm for
the 1- and 2-substituted tetrazole rings within.
1AT possesses resonances in the 1H NMR at 9.14 ppm for the
40 CH and 7.02 ppm for the NH2 protons. 2AT possesses resonances
in the 1H NMR at 8.64 ppm for the CH and 7.97 ppm for the NH2
protons. The CH protons of both 1 and 2AT are downfield
compared to the CH of tetrazole at 8.36, with the change less for
2AT as the structures would predict. In the 13C NMR the
45 resonances of 1AT and 2AT occur at 143.3 and 151.5 ppm
compared to the resonance of the tetrazolate anion at ~150 ppm.
8 possesses three resonances in the proton spectrum. The first
at 9.18 ppm arises from the tetrazole CH, the second at 8.24 ppm
from the NH proton, and finally at 5.47 ppm for the CH2 of the
50 trinitroethyl moiety. In the carbon spectrum three resonances are
also observed; at 143.4 ppm for the tetrazole carbon, at 127.1
ppm for the trinitromethyl carbon, and at 53.1 ppm for the CH2
group.
55
Compound 7, 2,2’-azobis(5-nitrotetrazole), was characterized
extensively via Raman spectroscopy. The observed spectrum was
assigned using frequency analysis from an optimized structure
(B3LYP/cc-pVDZ, using Gaussian09 software). All calculations
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 5

Dalton Transactions
Page 6 of 12
View Online
it must be mentioned that the neutral 2-hydroxy-5-nitrotetrazole
and 5-nitrotetrazole are strongly acidic and deliquescent and
cannot be used as single compounds at ambient conditions.
along the b axis formed by the bifurcated hydrogen bonds N6–
H6a···O1i and N6–H6b···O1i. The planar chains are connected
20 orthogonally by the hydrogen bonds N6–H6a···N4ii and N6–
H6b···O1iii; Symmetry codes: (i) x, –1+y, z, (ii) 1.5–x, –0.5+y, –
0.5+z, (iii) 2–x, –y, 0.5+z.
5
Single Crystal X-ray Structure Analysis.
Compounds 1-4, 6.AtNO2, and 8 were characterized by low
temperature (173 K) single crystal X-ray diffraction. Selected
data and parameter of the X-ray determinations are given in Table
3.
10 ANT (1) crystallizes in the orthorhombic space group Pna21 with
four formula units in the unit cell and a density of 1.791 g cm-3.
The molecular unit is depicted in Figure 2. Comparison to the
methylated sister compound 2-methyl-5-nitrotetrazole 45 yields no
significant difference. The hydrazine bond N2–N6 is shorter
15 (1.40 Å) than the corresponding methyl bond 1.46 Å.45 Of course
all tetrazole and triazole rings show planar geometry due to their
ADNT(2) crystallizes in the non-centrosymmetric triclinic space
25 group P1 with eight (!) different molecules in the unit cell and a
density of 1.885 g cm–3. One molecular unit is shown in Figure 3.
The molecular structure is very similar to analogously 1-methyl-
3,5-dinitrotriazole.46 The structure is dominated by numerous
47
Nitrogen-oxygen (mostly nitro-nitro interactions)
which must
30 be the reason of the extraordinary large asymmetric unit. These
interaction may also cause the highest density of 1.885 g cm-3
observed in this work.
aromaticity. The ANT molecules are arranged in planar chains
35
40 Table 2.
Explosive and detonation parameters of 1–8.
1
2
3
4
5
6
7
8
RDX
Formula
FW / g mol–1
ISa / J
CN6O2H2
130.07
<1
<5
0.25
64.61
–12.30
102 (Tm)
140 (Td)
1.791
C2H2N6O4
174.08
30
240
0.5
48.28
–9.19
118 (Tm)
165 (Td)
1.885
C2H4N10
168.12
3
10
0.5
83.31
–57.09
145 (mp),
185 (dec)
1.759
C2H4N10
168.12
3
10
0.25
83.31
–57.09
90 (mp),
175 (dec)
1.762
CH3N5
85.09
<1
64
N/A
82.32
–65.82
130 (Tvap
CH3N5
85.09
<1
36
N/A
82.32
–65.82
100 (Tvap
C2N12O4
256.10
<<<<1
<<<<5
ND
65.63
0
50 (mp)
C3H4N8O6
248.11
1
C3H6N6O7
222.12
7.5
120
0.1 - 0.2
37.84
FSb / N
20
ESDc / J
Nd / %
0.080
45.16
–12.9
116
e / %
TDec . / °C
–21.61
ꢀ
f
)
)
205 43
ρg / g cm–3
1.413
1.387
1.80*
1.825
1.858
(90K)44
896.346781
H°CBS4Mh / H
517.444682
446.9
70.5
376.4
2988.4
705.719973
331.8
73.5
258.3
1569.1
625.146143
176.5
78.6
797.9
4847.9
625.145978
176.9
68.3
808.7
4912.0
313.152993
449.0
313.165237
416.8
1032.454643
1153.0
60.8
1092.2
4341.6
1004.479332
450.7
53.0
397.7
1692.6
ꢀfH(g)i / kJ mol–1
176.2
89.9
ꢀ
subH°j / kJ mol–1
43.5§
40.3§
ꢀfHmk / kJ mol–1
ꢀfU°l / kJ kg–1
405.5
4881.7
376.5
4541.7
86.3 #
489.0 #
EXPLO5.04values:
–ꢀExU°m/ kJ kg–1
Tdetn/ K
6236
4698
368
9087
772
6188
4706
382
8981
701
5144
3611
326
8898
759
5208
3639
329
8934
759
5329
3571
216
7846
799
4996
3428
200
7629
799
6931
5855
390
9184
707
6606
4830
373
8938
711
6190
4232
380
8983
734
PCJo/ kbar
p
VDet . / m s–1
Voq / L kg–1
a impact sensitivity (BAM drophammer, 1 of 6), b friction sensitivity (BAM friction tester, 1 of 6), c sensitivity towards electrical discharge, d nitrogen content, e oxygen
balance (ꢁ = (xO–2yC–1/2zH)M/1600, f temperature of decomposition, g density, h CBS4M electronic enthalpy, i gas phase enthalpy of formation; j enthalpy of sublimation
according to Troutons’ rule, k heat of formation, l energy of formation, m heat of explosion, n temperature of detonation, o detonation pressure according to Chapmen-Jouguet,
p velocity of detonation, q volume of detonation gases, * estimated, # calculated (CBS-4M), § enthalpy of vaporization.
45 Table 3. X-ray data and parameters of materials 1-4 as well as 6 and 8.
compound
formula
ANT (1)
ADNT (2)
11DABT (3)
12DABT (4)
2AT.ATNO2
1ATTNE (8)
(6.ATNO2)
.
CH2N6O2
C2H2N6O4
C2H4N10
C2H4N10
CH3N5 CH2N6O2
C3H4N8O6
temperature [K]
crystal system
space group
a [Å]
b [Å]
c [Å]
173
orthorhombic
Pna21
173
Triclinic
P1
173
Triclinic
P–1
173
Orthorhombic
Pbca
173
monoclinic
P21/c
13.0616(9)
8.8579(6)
6.9023(5)
90
90.859 (17)
90
173
monoclinic
P21/c
9.9097(5)
7.7761(4)
117846(6)
90
96.124(5)
90
9.855(6)
78.082(4)
6.059 (4)
90
90
90
8.3125(7)
11.4102(8)
13.5629 (16)
78.074(8)
77.335(8)
89.873(6)
1226.8
6.2087(6)
9.9845(10)
10.6782(14)
90.106(9)
90.874(9)
106.336(9)
635.14(9)
10.2063(3)
6.2946(2)
19.7287(6)
90
90
90
α [°]
β [°]
γ [°]
volume [Å3]
482.6 (5)
1267.46(7)
798.49(10)
902.92(8)
6
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 7 of 12
Dalton Transactions
View Online
formula Z
4
4
8
8
4
4
8
8
4
4
4
4
space group Z
density calc. [g cm– 1.791
1.885
1.759
1.762
1.790
1.825
3
]
[mm–1]
0.162
0.177
704
0.139
344
0.140
688
0.154
0.172
504
ꢁ
F(000)
264
440
θ min–max [°]
4.1, 26.5
4.3, 26.5
4.3, 26.5
4.1, 26.5
4.6, 26.0
4.4,25.0
–12:7;–10:9;–
6:7
–10:10;–14:13;–
17:15
–7:7;–7:12;–
13:13
–12:12;–7:7;–
24:24
–15:16;–10:10;–8:8
–7:11;–9:9;–14:–
13
Dataset [h; k; l]
Reflections
Collected
Independent
Reflections
Rint
2405
9699
3443
12017
4024
1565
4041
543
5066
2592
1300
1574
0.130
398
0.030
4379
0.024
2034
0.032
1103
0.029
1133
0.022
1139
Observed
Reflections
No. Parameters
90
913
249
126
156
170
R1 / wR2 [all data]
R1 / wR2 [I > 2σ(I)]
0.0699/0.0984
0.0477/0.0861
1.001
0.0442/0.0769
0.0344/0.0709
1.024
0.0719/0.1370
0.0539/0.01260
1.104
0.0363/0.0813
0.0291/0.0770
1.055
0.0496/0.0656
0.0302/0.0625
0.898
0.0510/0.0862
0.0348/0.0819
0.973
S
CCDC
871736
871737
871738
871739
871734
871735
O2 125.7(3), O3–N5–O4 124.7(3), O3–N5–C2 119.2(3), O4–N5–
C2 116.1(3), N3–C1–N1 112.31(17), N3–C1–N4 123.73(17),
N1–C1–N4 123.96(17), N3–C2–N2 116.90(17), N3–C2–N5
25 122.88(18),.
11DABT (3) crystallizes in the triclinic space group P–1 with
four formula units in the unit cell and a density of 1.759 g cm–3.
Both planar tetrazole rings are twisted slightly (N1–C1–C2–N9=
30 –14.8(4)°) to each other. The C1–C2 (1.45 Å) is slightly shorter
than a typical C–C single bond at 1.54 Å. The amino hydrogen
atoms are directed to the other ring systems by two
intramolecular bifurcated hydrogen bonds (e.g. N5–H5B···N9:
0.85(2) Å, 2.73(2) Å, 3.08(2) Å, 106(3)°. The crystal structure is
35 strongly dominated by several classical hydrogen bonds
involving the NH groups. In addition also a non-classical
hydrogen bond can be found (N1–C1···N5: 0.91(2) Å, 2.62(2) Å,
3.43(9) Å, 135.7(1)°).
Figure 2: ORTEP plot of 1, non-hydrogen atom displacement
parameters are at the 50% level. Selected bond distances [Å]:
O2–N5 1.224(5), O1–N5 1.239(5), N1–C1 1.328(5), N1–N2
1.334(5), N4–C1 1.328(6), N4–N3 1.329(5), N6–N2 1.396(5),
N5–C1 1.439(5), N2–N3 1.322(5); Selected bond angles [°]: C1–
N1–N2 98.1(4), C1–N4–N3 104.6(4), O2–N5–O1 124.5(4), O2–
5
10 N5–C1 117.3(4), N3–N2–N1 115.9(4), N3–N2–N6 124.1(4), N1–
N2–N6 120.0(4), N4–C1–N1 116.2(4),.
40 Figure 4: ORTEP plot of 3, non-hydrogen atom displacement
parameters are at the 50% level. Selected bond distances [Å]:
N1–C1 1.343(3), N1–N2 1.345(3), N1–N5 1.404(3), N6–N7
1.335(3), N6–C2 1.343(3), N6–N10 1.396(3), N7–N8 1.293(3),
N4–C1 1.314(3), N4–N3 1.370(3), N3–N2 1.301(3), N8–N9
45 1.371(3), N9–C2 1.317(3), C2–C1 1.458(3); Selected bond angles
[°]: C1–N1–N5 133.4(2), N2–N1–N5 118.23(19), N7–N6–N10
119.3(2), C2–N6–N10 132.1(2).
15 Figure 3: ORTEP plot of 2, non-hydrogen atom displacement
parameters are at the 50% level. Selected bond distances [Å]:
O1–N4 1.208(4), O2–N4 1.229(4), O3–N5 1.213(4), O4–N5
1.232(4), N1–N2 1.339(4), N1–C1 1.352(3), N1–N6 1.405(3),
N2–C2 1.348(3), N3–C1 1.300(3), N3–C2 1.325(3), N4–C1
20 1.454(3), N5–C2 1.451(3); Selected bond angles [°]:N2–N1–N6
118.0(2), C1–N1–N6 133.2(2), C1–N3–C2 101.17(18), O1–N4–
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 7

Dalton Transactions
Page 8 of 12
View Online
12DABT (4), which is shown in Figure 5, crystallizes in the
1.3333(19).
orthorhombic space group Pbca with eight formula units in the
unit cell and a density of 1.762 g cm–3. Interestingly both amino
Single crystals of 1ATTNE (8), shown in Figure 7, were obtained
groups are directed to one side of the bistetrazole backbone. 45 from tetrachloroethylene. It crystallizes in the monoclinic space
5
Although having only one (but slightly stronger) intramolecular
hydrogen bond (N5–H5B···N6: 0.89(2)Å, 2.53(2)Å, 2.955(1)Å,
110(2)°) the rings are planar to each other (angle of torsion N1–
C1–C2–N6 = –0.12(18)°. The C1–C2 bond length is in the same
range (1.45 Å) as observed for 3. The bond lengths and angles
group P21/c with four formula units in the unit cell and a density
of 1.825 g cm-3. The trinitromethyl moiety is comparable to
corresponding derivatives described in the literature forming
weak nitro-nitro-groups interactions.47
10 within the tetrazole rings of 3 and 4 are similar to those observed
for 5,5-bistetrazole salts recently published.48
50
Figure 7: ORTEP plot of 8, non-hydrogen atom displacement
parameters are at the 50% level. Selected bond distances [Å]:
O5–N8 1.213(2), O6–N8 1.211(2), O4–N7 1.211(2), O3–N7
1.209(2), O2–N6 1.215(2), O1–N6 1.217(2), N8–C3 1.516(2),
55 N7–C3 1.529(2), N6–C3 1.517(2), N5–N1 1.399(2), N5–C2
1.459(2), N1–C1 1.327(2), N1–N2 1.350(2), N2–N3 1.297(2),
N3–N4 1.367(2), N4–C1 1.307(2), C3–C2 1.512(2); Selected
bond angles [°]: N1–N5–C2 114.23(15), C2–C3–N8 110.92(15),
C2–C3–N6 111.73(14), N8–C3–N6 107.40(14), C2–C3–N7
60 114.17(15), N8–C3–N7 105.72(13), N6–C3–N7 106.48(14), N5–
C2–C3 111.44(15).
Figure 5: ORTEP plot of 4, non-hydrogen atom displacement
parameters are at the 50% level. Selected bond distances [Å]:
15 N1–N2 1.3360(15), N1–C1 1.3415(15), N1–N5 1.4025(14), N2–
N3 1.3131(16), N3–N4 1.3487(16), N4–C1 1.3267(15), N6–N7
1.3204(13), N6–C2 1.3410(15), N7–N8 1.3175(14), N7–N10
1.3936(13), N8–N9 1.3350(14), N9–C2 1.3383(15), C1–C2
1.4514(17); Selected bond angles [°]: N2–N1–N5 121.96(10),
20 C1–N1–N5 128.64(10), N8–N7–N10 122.54(9), N6–N7–N10
121.93(9).
Since 1- and 2-aminotetrazole are liquids at room temperature
and their structure could not be determined even at lower
25 temperature they were derivatized with other energetic
compounds in order to provide structural data. Figure 6 depicts
the molecular moiety of the adduct 2AT.ATNO2 (6.ATNO2). It
crystallizes in the monoclinic space group P21/c with four
formula units in the unit cell and a density of 1.790 g cm–3. The
30 5-nitriminotetrazole molecule follows the structure observed for
the parent compound described in the literature.49 The hydrazine
bond length N8–N11 (1.39 Å) is again shorter than a typical N–N
bond (1.45 Å).
Sensitivities
For initial safety testing the impact, friction and electrostatic
65 discharge sensitivities of the prepared compounds were carried
out.50 The impact sensitivity tests were carried out according to
STANAG 448952 and were modified according to instruction53
using
a
BAM (Bundesanstalt für Materialforschung51)
drophammer.54 The Friction sensitivities were carried out
55
70 according to STANAG 2287 and were modified according to
instruction56 using a BAM friction tester. Compound 7 was
unable to be measured according to these protocols as it
spontaneously detonates when dry. Compounds 1,5,6,7,8 are
classified as “very sensitive” (2) according to the UN
75 Recommendations on the Transport of Dangerous Goods57
whereas 3 and 4 are “sensitive” and 2 is “less sensitive”. It is
likely that the insensitivity of 2 results from the low melting point
and amino-nitro group interactions. Electrostatic Sensitivity tests
were performed on all materials using a small scale electric spark
80 tester ESD2010EN (OZM Research58) operating with the
“Winspark 1.15” Software package.59 The human body can
generate up to 0.025 J of static energy which all measured
compounds are insensitive towards (3 and 4 cannot be measured
as they are liquids). Compound 7 was so sensitive that ESD
85 measurement was impossible.
35 Figure 6: ORTEP plot of 6.ATNO2, non-hydrogen atom
displacement parameters are at the 50% level. Selected bond
distances [Å]: N4–C1 1.3311(19), N4–N3 1.3502(17), C2–N7
1.317(2), C2–N10 1.346(2), N8–N9 1.3099(17), N8–N7
1.3289(17), N8–N11 1.3868(18), O1–N6 1.2350(15), O2–N6
40 1.2505(15), N3–N2 1.2783(17), N2–N1 1.3549(17), N5–N6
1.3444(17), N5–C1 1.3457(18), N9–N10 1.3252(17), N1–C1
8
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 9 of 12
Dalton Transactions
View Online
16. L. Salazar, M. Espada, C. Avendańo, J. Elguero, J. Het. Chem. 1990,
Conclusions
27, 1109-1110.
From this combined experimental and theoretical study the
following conclusions can be drawn:
17. R. Raap, Can. J. Chem., 1969, 47, 3677-3681.
18. W. A. Trzciński, S. Cudzilo, Z. Chylek, L. Szymańczyk, J. Haz. Mat.
2008, 157, 605-612.
Amination of nitrogen-rich anionic heterocycles with O-
tosylhydroxylamine yields the corresponding amino derivative,
the molecular structures of these materials have been determined
for the first time. These amino derivatives generally have a
higher density and heat of formation than their methylated
versions, but is lower in both compared to the protonated
60
65
70
5
19. E. E. Glover, K. T. Rowbottom, J. Chem. Soc. Perkin. Trans. 1.
1976, 4, 367-371.
20. L. A. Carpino, J. Am. Chem. Soc., 1960, 82, 3133-3135.
21. J. C. Bottaro, M. A. Petrie, P. E. Penwell, A. L. Dodge, R. Malhotra,
NANO/HEDM Technology: Late Stage Exploratory Effort. Report
No. A466714, SRI International: Menlo Park, CA, 2003,
DARPA/AFOSR funded, contract no. F49620-02-C-0030.
22. J. C. Bottaro, R. J. Schmitt, P. E. Penwell, US 5889161, 1999.
23. T. M. Klapötke, P. Mayer, C. M. Sabaté, J. M. Welch, Inorg Chem.
2008, 47, 6014-6027.
10 versions. The N-amino energetic are not acidic or hygroscopic
unlike their N-H or N-OH analogues. These amino-energetic
materials have the capability to be thermally-stable energetic
materials with a range of mechanical sensitivities (ranging from
sensitive to less-sensitive energetic materials). These compounds
15 are new nitrogen-rich ligands with multiple donor sites for being
used in (e.g.) novel high energy-capacity transition metal
complexes. The azo coupling of 1 yielding 7 has been achieved
however the 2,2’-azobis(5-nitrotetrazole) is EXCEEDINGLY
sensitive and was only characterized by Raman spectroscopy and
20 mass spectra. This compound is among the most sensitive
compounds we have handled exceeding our previously-reported
24. K. Y. Lee, C. B. Storm, M. A. Hiskey, M. D. Coburn, J. Energ. Mat.,
1994, 12, 223-235.
25. D. E. Chavez, M. A. Hiskey, D. L. Naud, J. Pyrotech. 1999,
10, 17-36.
75 26. Gaussian 09, Revision A.02, M. J. Frisch, G. W. Trucks, H.
B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, G.
Scalmani, V. Barone, B. Mennucci, G. A. Petersson, H.
Nakatsuji, M. Caricato, X. Li, H. P. Hratchian, A. F. Izmaylov, J.
Bloino, G. Zheng, J. L. Sonnenberg, M. Hada, M. Ehara, K.
80 Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y.
Honda, O. Kitao, H. Nakai, T. Vreven, J. A. Montgomery, Jr., J.
E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N.
Kudin, V. N. Staroverov, R. Kobayashi, J. Normand, K.
Raghavachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi,
85 M. Cossi, N. Rega, J. M. Millam, M. Klene, J. E. Knox, J. B.
Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E.
Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J. W.
Ochterski, R. L. Martin, K. Morokuma, V. G. Zakrzewski, G. A.
Voth, P. Salvador, J. J. Dannenberg, S. Dapprich, A. D. Daniels,
90 Ö. Farkas, J. B. Foresman, J. V. Ortiz, J. Cioslowski, and D. J.
Fox, Gaussian, Inc., Wallingford CT, 2009.
27. N. Fischer, T.M. Klapötke, J. Stierstorfer, C. Wiedemann,
Polyhedron 2011, 30, 2374-2386.
28. (a) M. S. Westwell, M. S. Searle, D. J. Wales, D. H.
95 Williams, J. Am. Chem. Soc. 1995, 117, 5013-5015; (b) F.
Trouton, Philos. Mag. 1884, 18, 54–57.
29. (a) Sucéska, M. EXPLO5.4 program; Zagreb, Croatia, 2010;
(b) Sucéska, M. Mater. Sci. Forum 2004, 465-466, 325–330.
30. CrysAlisPro Oxford Diffraction, Version 171.33.41, Oxford,
100 2009.
compound with exceedingly high sensitivity.3
1 and 2-
aminotetrazoles (5,6) have been structurally characterized for the
first time as their trinitroethyl condenstation product and
25 nitriminotetrazole cocrystal respectively (6.ATNO2, 8)
Notes
a Butenandtstrasse 5-13 (Haus D) D-81377 Munich, Germany Fax: +89
2180 77492; E-mail: tmk@cup.uni-muenchen.de
References
30 1. M. Göbel, K. Karaghiosoff, T. M. Klapötke, D. G. Piercey. J.
Stierstorfer, J. Am. Chem. Soc.,2010, 132, 17216-17226.
2. H. Gao, J. M. Shreeve, Chem. Rev., 2011, 111, 7377-7436.
3. T. M. Klapötke, D. G. Piercey, Inorg Chem., 2011, 50, 2732-2734.
4. T. M. Klapötke, D. G. Piercey, J. Stierstorfer., Chem. Eur. J., 2011,
35
17, 13068-13077.
5. V. Thottempudi, J. M. Shreeve, J. Am. Chem. Soc. 2011, 133, 19982-
19992.
6. J. L. Gay-Lussac, Ann. Chim. Phys., 1824, 27, 199.
7. J. Berzelius, Ann Chem. Pharm., 1844, 50, 426-429.
40 8. J. L.Gay-Lussac, J. Leibig, Kastners Archiv., 1824, II, 58-91.
9.P. Y. Robidoux, J. Hawari, G. Bardai, L. Paquet, G. Ampelman, S.
Thiboutot, G. Sunahara. Arch. Environ. Contam. Toxicol. 2002, 43,
379-388.
31. SIR-92, 1993, A program for crystal structure solution, A.
Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, J. Appl.
Cryst. 1993, 26, 343.
10. T. Altenburg, T. M. Klapötke, A. Penger, J. Stierstorfer, Z. Anorg.
45
Allg. Chem. 2010, 636, 463-471.
32. G. M. Sheldrick SHELXS-97, Program for Crystal Structure
105 Solution, Universität Göttingen, 1997.
11. M. –X. Zhang, P. E. Eaton, R. Gilardi, Angew. Chem. Int. Ed. 2000,
39, 401-404.
33. G. M. Sheldrick, SHELXL-97. Program for the Refinement
of Crystal Structures. University of Göttingen, Germany, 1997.
34. A. L. Spek, PLATON, A Multipurpose Crystallographic
Tool, Utrecht University, Utrecht, The Netherlands, 1999.
110 35. L. J. Farrugia, J. Appl. Cryst. 1999, 32, 837.
12. R. A. Carboni, J. C. Kauer, J. E. Castle, H. E. Simmons, J. Am.
Chem. Soc., 1967, 89, 2618-2625.
50 13. M. H. V. Huynh, M. A. Hiskey, T. J. Meyer, M. Wetzler, Proc. Nat.
Acad. Sci. U.S.A., 2006, 103, 5409-5412.
14. R. Boese, T. M. Klapötke, P. Meyer, V. Verma, Propellants, Explos.
Pyrotech., 2006, 31, 263-268.
36. SCALE3 ABSPACK - An Oxford Diffraction program
(1.0.4,gui:1.0.3) (C) 2005 Oxford Diffraction Ltd.
37. A. D. Becke, J. Chem. Phys. 1993, 98, 5648-5652.
15. P. Carlqvist, H. Ostmark, T. J. Brinck, J. Phys Chem. A., 2004, 108,
55
7463-7467.
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 9

Dalton Transactions
Page 10 of 12
View Online
38. C. Lee, W. Yang, R. G. Parr, Phys Rev. B. 1988, 37,785-789.
39. D. E. Woon, T. H. Dunning, R. J. Harrison, J. Chem.
Phys.,1993, 98, 1358-1371.
40. R. A. Kendall, T. H. Dunnings, R. J. Harrison, J. Phys.
Chem. 1992, 96, 6796-6806.
5
41. T. H. Dunning, J. Chem Phys. 1989, 90, 1007-1023.
42. K. A. Peterson, D. E. Woon, T. H. Dunning, J. Chem. Phys.,
1994, 100, 7410-7415.
43. J. P. Agrawal, in High Energy Materials, 1st edn., Wiley-
10 VCH, Weinheim, 2010. p.189.
44. P. Hakey, W. Ouellette, J. Zubieta and T. Korter, Acta Crystallogr.
2008, E64, o1428
45. T. M. Klapötke, C. M. Sabaté , J. Stierstorfer, New J. Chem. 2009,
33, 136-147.
15 46. G. L.Starova, O. V. Frank-Kamenetskaya and M. S. Pevzner, J.
Struct. Chem. 1988, 29, 162-165.
47. M. Göbel and T. M. Klapötke, Adv. Funct. Mater. 2009, 19, 347–
365.
48. N. Fischer, D. Izsàk,T. M. Klapötke, S. Rappenglück and J.
20 Stierstorfer, Chem. Europ. J. 2012, 18, 4051-4062.
49 T. M. Klapötke and J. Stierstorfer, Helv. Chim. Acta 2007, 90, 2132-
2150
50. Sućeska, M. Test Methods for Explosives; Springer: New
York, 1995; p 21 (impact), p 27 (friction).
25 51. www.bam.de
52. NATO standardization agreement (STANAG) on explosives,
impact sensitivity tests, no. 4489, Ed. 1, Sept. 17, 1999.
53. WIWEB-Standardarbeitsanweisung 4-5.1.02, Ermittlung der
Explosionsgefährlichkeit, hier der Schlagempfindlichkeit mit dem
30 Fallhammer, Nov. 8, 2002.
54. http://www.reichel-partner.de
55. NATO standardization agreement (STANAG) on explosives,
friction sensitivity tests, no. 4487, Ed. 1, Aug. 22, 2002.
56. WIWEB-Standardarbeitsanweisung 4-5.1.03, Ermittlung der
35 Explosionsgefährlichkeit oder der Reibeempfindlichkeit mit dem
Reibeapparat, Nov. 8, 2002.
57. Impact: Insensitive > 40 J, less sensitive ≥ 35 J, sensitive ≥ 4
J, very sensitive ≤ 3 J; Friction Insensitive > 360 N, less sensitive
= 360 N, sensitive < 360 N a. > 80N, very sensitive ≤ 80 N,
40 extremely sensitive
≤
10 N.
According to the UN
Recommendations on the Transport of Dangerous Goods.
58. D. Skinner, D. Olson, A. Block-Bolten, Propellants, Explos.,
Pyrotech. 1998, 23, 34-42.
59.
http://www.ozm.cz/testinginstruments/
small-scale-
45 electrostatic-discharge-tester.htm.
10 | Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 11 of 12
Dalton Transactions
View Online
100x100mm (200 x 200 DPI)

Dalton Transactions
Page 12 of 12
View Online
TOC phrase:
Several new highly energetic neutral nitrogen rich N-amino compounds were synthesized by
amination reactions and intensively characterized.