Hydrogen bond system generated by nitroamino rearrangement: New character for designing next generation energetic materials

Article abstract of DOI:10.1039/d0cc07101c

A new hydrogen bond system is formed by the transfer of a proton from nitroamino to form nitroimino. The proton and the oxygen in nitroimino form an intramolecular hydrogen bond and two intermolecular hydrogen bonds that shorten the distance between molecules both vertically and horizontally leading to higher density. This journal is

Full text of DOI:10.1039/d0cc07101c

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Hydrogen bond system generated by nitramino rearrangement:
new character for designing next generation energetic materials
a
b
a
Lu Hu, Richard J. Staples and Jean’ne M. Shreeve*
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
A new hydrogen bond system is formed by the transfer of a proton salts which is a reasonable way to realize higher detonation
1
4, 15
from nitroamino to form nitroimino. The proton and the oxygen in performance and lower sensitivities.
However, compounds with
nitroimino form an intramolecular hydrogen bond and two the dinitroamino group almost always exhibit higher sensitivities to
intermolecular hydrogen bonds that shorten the distance between impact and friction stimuli and traditionally have lower thermal
1
6-18
molecules both vertically and horizontally leading to higher density. stabilities.
Additionally, most of them show good solubility in
water and must be extracted with low polarity solvents, which results
in low yield and precludes large scale syntheses making them unlikely
candidates for practical use.
Designing new energetic materials for practical use is a long-term
goal in the energetics field. New energetic compounds are required
to possess similar or better properties than commonly used
energetics, such as the benchmarks, RDX (1,3,5-trinitro-1,3,5-
triazinane) and HMX (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-
19
Hydrogen bonds (HBs) play an important role in the design of
energetic compounds because of their positive influence on both
20, 21
physical and chemical properties.
Intramolecular hydrogen
1
hexaazaisowurtzitane). These compounds must have a high density
bonds often observed in energetic materials are generated from
interaction of a nitro moiety with a neighboring amino group and are
exemplified in such stable compounds as 1,3,5-triamino-2,4,6-
trinitrobenzene (TATB) and 2,2-dinitroethylene-1,1-diamine (FOX-7)
which will result in a significant increase of the detonation
performance and good thermal stabilities and low sensitivities
enhancing safe syntheses, transfer, and storage.2 However, while
there are a fair number of high energetic density materials (HEDMs)
, 3
(Figure 1). The presence of HBs can increase the density of a
4
-7
that possess such properties, not many of them can be reduced to
practical use due to the high cost of a large-scale synthesis and the
low overall yield. For safety reasons, most compounds are
synthesized initially in small quantities and scale-up to multiple gram
compound resulting from closer packing and decreasing sensitivity
22
through the formation of a better stacking style. Both TATB and
FOX-7 contain many intermolecular HB systems with neighboring
23
molecules, which result in higher density and lower sensitivity.
8
quantities often becomes costly. Therefore, in order to synthesize
the new candidate as an energetic material easily and cheaply in
large-scale, it is helpful if the starting material is commercially
available at a very low price. Additionally, the product should be
2
, 9
obtained in a few steps in excellent yield.
The nitroamino group (-NHNO ) is one of the most often used
2
energetic groups in the design of HEDMs.10-13 The introduction of a
nitroamino moiety can significantly increase density and heat of
formation which can lead to compounds possessing superior
detonation properties. In addition, the nitroamino group can behave
as an anion to combine with an energetic cation to form energetic
a. Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343,
United States.
b.
Department of Chemistry, Michigan State University, East Lansing, MI 48824,
United States..
Electronic Supplementary Information (ESI) available: [NMR spectra for all
compounds
and
Single-crystal
X-ray
diffraction
analysis].
See
Figure 1. The HBs and layer structures of FOX-7, TATB and compound
DOI: 10.1039/x0xx00000x
3
.
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Journal Name
However, relative to the nitro group, the nitroamino group has a monohydride (3N) in isopropanol leading toView4A-rtcicylaenOonl-in5e-
smaller proclivity to form intramolecular HBs, which makes it less carbamidrazone imidazole (1) followed by DriOngI: 1c0lo.1s0u3r9e/Dw0CitCh0a7c1e01tiCc
likely to contribute to the practical use of the material. Now we acid to give pure 2 in a good yield of 92%. When reacted with fuming
report a new kind of hydrogen bond system which was generated by nitric acid, the two amino groups in 2 are converted to nitroamino
the rearrangement of a nitroamino group bonded to a pyridazine ring moieties followed by a structural rearrangement where a hydrogen
to form a nitroimino functionality by the transfer of the proton to the from one nitroamino group transfers to the pyridazine ring. Because
ortho nitrogen of the pyridazine ring. That proton forms an of poor solubility in water, 3 can be obtained easily in moderate yield
intramolecular hydrogen bond with the nitroimino oxygen moiety. (62%) by filtration. Since there is only one nitroamino group with an
Additionally, the proton and the oxygen form head-to-head acidic hydrogen, it was not possible to form a disalt when 3 is reacted
intermolecular hydrogen bonds with a neighboring molecule to give with ammonia, hydroxylamine or hydrazine. However, when 3 is
a parallelogram of hydrogen bonds. This HB system connects these reacted with sodium hydroxide, the disodium salt (8) is obtained
molecules in one layer to form face-to-face stacking which is (Scheme 1).
characteristic of high-energy materials with low sensitivity. This
The new compounds were fully characterized using H and 13C
1
hydrogen bond system reduces the amount of free space between NMR spectral data, and infrared spectroscopy as well as elemental
1
molecules which helps to increase the thermal stability, to lower the analysis. The H NMR signal shift for the C-H in the imidazole group
solubility and to enhance the density. These improve the ease and of 3 is found at δ 8.73 ppm (Figure S1). When a monocation is formed,
1
yield of syntheses which may have a positive impact on industrial the H NMR signal shifts to δ 8.42 ppm for 4; δ 8.45 ppm for 5 and 7;
production.
and δ 8.49 ppm for 6. In the disodium salt, the signal is at δ 7.99 ppm
Therefore, a series of new compounds which contain this HB (Figure S13). When attempts were made to synthesize diammonium,
1
13
system based on the imidazolo[4,5-d]pyridazine fused ring and its dihydrazinium and dihydroxylammonium disalts, H and C NMR
salts were synthesized. The 4,7-diamino-imidazolo[4,5-d]pyridazine signal shifts occurred compared with the monosalts, but none of the
fused ring (2) was obtained in high yield and purity by using low cost compounds passed elemental analysis as disalts. For example, the
commercial 4,5-dicyanoimidazole (Scheme 1). By reacting 2 with hydrazinium derivative which was obtained at high temperature has
1
13
fuming nitric acid, the two amino groups on the fused ring are a single H NMR signal at δ 8.32 ppm and a group of C NMR signals
1
oxidized to nitroamino groups to give 4-nitroamino-7-nitroimino-6- at δ 134.1, 148.3, 149.1 ppm ( H NMR for di and mono sodium salts
1
3
dihydro -imidazolo[4,5-d]pyridazine imidazolo[4,5-d]pyridazine are δ 7.99 and δ 8. 45; C NMR for di and mono sodium salts are δ
where a hydrogen atom is transferred from one of the nitroamino 137.3, 150.5, 152.8 ppm and δ 132.8, 145.3, 148.7 ppm), but the
moieties to the pyridazine ring to form a nitroimine group. The elemental analysis supports the presence of only 1.5 hydrazinium
intramolecular HBs reduce the amount of free space in 3 which groups. With a single H NMR signal and three C NMR signals it is
decreases water solubility making it easily obtainable by filtration not a mixture of monosalt and disalt, but rather the hydrazinium
after adding ice. Because of the presence of intramolecular HBs, the group is evenly distributed between the anions. The disodium salt
proton on the pyridazine ring is not as active as the proton on a can be obtained largely because the sodium hydroxide is a strong
nitroamino group, which can leave easily to form an anion. Therefore, base with a pKb of –0.56, while hydrazine and ammonia are weak
1
13
only energetic monosalts were obtained by reacting 3 with bases.
,7-Diamino-imidazo[4,5-d]pyridazine (2) was obtained by much weaker with a pKb of 7.97. None of these is strong enough to
reacting 4,5-dicyanoimidazole with aqueous hydrazine give the disalts.
bases with pKb of 5.9 and 4.75, respectively, and hydroxylamine is
4
2
4
monohydride as reactant and solvent with acetic acid as catalyst.
Crystals of 3 were obtained from a mixture of water and DMSO,
Since the method found in the literature uses a large amount of which resulted in the unit cell containing one water and two DMSO
aqueous hydrazine which is a potential carcinogen, and to reach the molecules. It crystallized in the triclinic space group with P-1 (Z = 4)
-
3
pure product requires multiple recrystallizations resulting in a yield symmetry, with a crystal density of 1.63 g cm at 173 K. The single-
of only 21%, a new method to obtain 2 was adopted. crystal X-ray structures and data are given in Figure 2 and Table S1,
Commercial 4,5-dicyanoimidazole was reacted with hydrazine
respectively. The value of Z’ is two, indicating that there are two
independent molecules (molecules A and B) in the asymmetric unit.
As shown in Figure 2a, the N-H on imidazole is on the same side
NH2
NH2
H
H
N
2
H N
H
N
NC
NC
NH2NH2 •H2O
°C to rt
N
CH3COOH
80 °C
N
N
N
0
N
N
NC
N
NH2
1
100% HNO3
°C to rt
2
0
O2N
2Na
O2N
Cation
=
NH4
4
N
N
O2N
H
N
H
N
N
N
H
N
2
N H
N
N
NaOH
80 °C
HN
N
Base
rt
5
HN
N
5
N
N
NH OH
3
N
N
HN
6
Na
7
NO2
NO2
NO2
8
3
Figure 2. (a) Single-crystal X-ray structures of 3 (molecules A and B).
(b) Face-to-face stacking.
Scheme 1. Synthesis of 1-4.
2
| J. Name., 2012, 00, 1-3
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molecule A. The HBs and face-to-face π-π interactions can be easily
View Article Online
DOI: 10.1039/D0CC07101C
observed by analysis of the relationship between the quantum-
mechanical electron density (ρ) and the reduced density gradient (s
=
1/2(3π2)1/3)|∇ρ|/ρ4/3). As shown in Figures 3b and 3d, the
noncovalent interaction (NCI) plots of 3 unit cells can be obtained in
real space where the differences between HBs, van der Waals
interactions, and repulsive steric clashes can be observed. As shown
in Figure 3b, the Z type interaction between two molecules (head-to-
head) indicates strong intramolecular and intermolecular HBs. In
Figure 3d, the NCI domains are abundant between the parallel layers,
resulting in a short interlayer distance of 2.87 Å, which indicate a
strong conjugated system between layers. In this structure, the NCI
domains not only exist on the parallel part of the fused rings, but also
2
between the C-NNO group because of the C−N and N-N distance
both are 1.35 Å, which indicate double bonds suggesting an obvious
conjugation effect (Figure 3d).
Figure 3. (a) Head-to-head intermolecular HBs in 3; (b) Hydrogen
bond system in NIC plots of gradient isosurfaces (s = 0.5 au) of the
unit cells of 3; (c) Two different layers in 3; (d) π-π stacking in NIC
plots of gradient isosurfaces (s = 0.5 au) of the unit cells of 3.
The density and heats of formation (HOF) values of a compound
are closely related to the detonation performance. The HOFs of the
new energetic materials were calculated by the Gaussian03 (Revision
25
D.01) suite of programs. As shown in Table 1, the neutral
-3
compound (3) has the highest density at 1.82 g cm , and has the
with the nitroamino in molecule A, but on the side of nitroimino in
molecule B (red circles).
For one nitroamino group, one proton transfers to the pyridazine
ring and forms an intramolecular HB with the oxygen in the
nitroimino group, which causes this nitroimino group to be almost
planar with the fused ring which have the torsion angles of C2-N7-
-1
lowest HOF at 355.2 kJ mol . The ammonium salt (4) has the lowest
-3
-1
density of 1.75 g cm and a HOF of 412.8 kJ mol . The hydrazinium
5) and hydroxylammonium (6) salts have the same density at 1.78 g
(
-3
-1
cm , but the HOF of the hydrazinium salt (561.4 kJ mol ) is a little
higher than that of hydroxylammonium salt (461.3 kJ mol ). Based
-1
on the density and HOF of those new energetic compounds, the
detonation performance was obtained by using the EXPLO5 (v6.01)
N8-O4
= 176.06(14)ᵒ, C2-N7-N8-O3 = -4.1(2)ᵒ, N8-N7-C2-C3
=179.75(14)ᵒ, N8-N7-C2-N2 = -3.2(3)ᵒ in molecule A, and N6A-N5A-
26
program. Because of having the highest HOF, the hydrazinium salt
C1A-C5A = 178.06(14)ᵒ, C1A-N5A-N6A-O1A = -0.1(2)ᵒ, C1A-N5A-N6A-
O2A = -179.2(14)ᵒ in molecule B. However, the other nitroamino
moiety is totally twisted out of the plane with N6-N5-C1-N1 = 117.5ᵒ
and N6-N5-C1-C5 = 66.9ᵒ for molecule A, and N8A-N7A-C2A-N2A = -
-1
(
5) has the highest detonation velocity at 8782 m s and a detonation
pressure of 30.6 GPa, which approach those of RDX. These are
followed by the hydroxylammonium (6) and ammonium (4) salts,
-1
-1
with detonation velocities of 8673 m s and 8425 m s , respectively.
1
27.7ᵒ, N8A-N7A-C2A-C3A = 59.0ᵒ for molecule B. Because of the
Because of the lowest HOF, 3 also has the lowest detonation velocity
proton transfer to the pyridazine ring, a head to head HB system is
formed, in which there is one intramolecular HB and HBs between
oxygen in nitroimino and proton in the pyridazine ring. This HB
system is in the same plane, making those molecules planar which
results in face to face stacking (Figure 2b). As shown in Figure 3a, the
proton of the nitroamino group in molecule A forms an HB with the
oxygen in water, while in molecule B, the HB was formed with an in
oxygen in DMSO. An intermolecular HB formed between the proton
the imidazole of molecule B and the nitrogen in the imidazole of
-1
of 8360 m s .
Both thermal stability and sensitivity are key properties in the
decision about practical application. As seen in Figure S19, all
compounds exhibit a sharp exothermic peak, with good
decomposition temperatures (onset temperature) > 150 ᵒC. For the
nitroamino compound, the trigger bonds are the N−NO
2
bonds. The
-
bond dissociation enthalpy (BDE) for the nitroimino is 205.8 kJ mol
1
,
which is much larger than that for the nitroamino (127.1 kJ
−
1
m
o
l
)
.
Table 1. Physical properties of 4-nitroamino-7-nitroimino-6-dihydro-imidazole [4,5-d]pyridazine and its derivatives (3) .
Na
T
b
d c
(g cm )
Δ
H
d
v e
(m s-1)
p f
(GPa)
IS g
(J)
FS h
(N)
Compound
dec
f
-3
-1
-1
(%)
(ᵒ C)
(kJ mol /kJ g )
3
4
46.7
49.0
51.5
46.2
37.8
32. 6
166
212
228
199
204
350
1.82
1.75
1.78
1.78
1.80
1.93
355.2/1.48
412.8/1.61
561.4/2.06
461.3/1.69
70.3/0.32
8360
8425
8782
8673
8795
8504
29.0
27.8
30.6
31.1
34.9
31.7
32
24
16
18
7.5
50
120
240
120
160
120
353
5
6
RDXi
TATBj
-154.2/-0.6
-1
a) Nitrogen content; b) Thermal decomposition temperature (DSC, 5 °C min ; c) Measured density, gas pycnometer (25 °C); d) Calculated
heat of formation; e) and f) Calculated detonation velocity and detonation pressure; g) and h) Impact and friction sensitivity. i) and j) Ref. 22
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
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and 23.
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DOI: 10.1039/D0CC07101C
4
5
6
7
8
9
1
1
1
1
1
1
Y. Tang, C. He, G. H. Imler, D. A. Parrish and J. M. Shreeve, ACS
Appl. Energy Mater., 2019, 2, 2263-2267.
P. Yin, J. Zhang, G. H. Imler, D. A. Parrish and J. M. Shreeve, Angew.
Chem. Int. Ed., 2017, 56, 8834-8838.
T. Yan, H. Yang and G. Cheng, ACS Appl. Energy Mater., 2020, 3,
6492-6500.
J. Zhang, P. Yin, G. Pan, Z. Wang, J. Zhang, L. A. Mitchell, D. A.
Parrish and J. M. Shreeve, New J. Chem, 2019, 43, 12684-12689.
J. L. Gottfried, T. M. Klapötke and T. G. Witkowski, Propellants
Explos. Pyrotech., 2017, 42, 353-359.
T.M. Klapötke and C.M. Sabaté, Chem. Mater., 2008, 20, 3629–
3637.
0 J. Ma, G. Cheng, X. Ju, Z. Yi, S. Zhu, Z. Zhang and H. Yang, Dalton
Trans, 2018, 47, 14483-14490.
1 S. Chen, Y. Jin, H. Xia, K. Wang, Y. Liu and Q. Zhang, Energetic
Materials Frontiers, 2020, 1, 16-25.
2 G. Wang, T. Lu, G. Fan, H. Yin and F. Chen, New J. Chem., 2019,
43, 1663-1666.
Therefore, compared with the traditional nitroamino group, the
rearranged nitroimino group has better thermal stability. Although
the neutral compound has the lowest decomposition temperature at
1
66 ᵒC, it is still higher than most dinitroamino compounds. The
hydrazinium salt (5) has the highest decomposition temperature at
28 ᵒC. The ammonium (4) and hydroxylammonium (6) salts
2
decompose at 212 and 199 ᵒC, respectively.
The impact (IS) and friction (FS) sensitivities of all the new
compounds were determined by standard BAM drop hammer and
2
7
friction tester techniques. All compounds are less impact sensitive
than RDX. Compared with the salts, molecule 3 has the
lowest sensitivity to impact which may arise from the special face to
face stacking. However, because one nitroamino moiety is twisted
out from the planar structure, the friction sensitivity is similar to that
of RDX. Among the salts, the ammonium salt (4) possesses the lowest
sensitivities, with an impact sensitivity of 24 J, and friction sensitivity
of 240 N. Next is the hydrazinium (5) (16 J, 120 N) and
hydroxylammonium salts (6) (18 J, 160 N), which are less impact
sensitive than RDX.
3 L. Hu, C. He, G. Zhao, G. H. Imler, D. A. Parrish and J. M. Shreeve,
ACS Appl. Energy Mater. 2020, 1, 16-25..
4 J. Ma, J. Tang, H. Yang, Z. Yi, G. Wu, S. Zhu, W. Zhang, Y. Li and G.
Cheng, Appl. Mater. Interfaces, 2019, 11, 26053-26059.
5 Y. Tang, C. He, L. A. Mitchell, D. A. Parrish and J. M. Shreeve, Chem.
Eur. J. 2016, 22, 11846-11853.
In conclusion, a series of new energetic materials based on the
imidazolo[4,5-d]pyridazine fused ring and its salts were synthesized
and characterized by IR, and NMR spectroscopy, and elemental
analysis. Compound 3 was also characterized by single crystal X-ray
structure analysis showing a proton of the nitroamino was
1
1
6 P. Yin and J. M. Shreeve, Angew. Chem. 2015, 127, 14721 –14725.
7 Y. Tang, J. Zhang, L. A. Mitchell, D. A. Parrish and J. M. Shreeve, J.
Am. Chem. Soc., 2015, 137, 15984-15987.
1
8 J. Zhang and J. M. Shreeve, J. Am. Chem. Soc., 2014, 136, 4437-
4
445.
transferred to the pyridazine ring to form a head-to-head HB system 19 L. Hu, P. Yin, G. Zhao, C. He, G. H. Imler, D. A. Parrish, H. Gao and
J. M. Shreeve, J. Am. Chem. Soc., 2018, 140, 15001-15007.
with a neighboring molecule. By analysis, the noncovalent
interaction (NCI) plots, strong π-π interactions can be found between
both the fused rings but also the HB system. With this special HB
system, compound 3 possesses face-to-face packing style, resulting
2
2
0 J. Li, S. Wang, L. Liao, Q. Ma, Z. Zhang and G. Fan, New J. Chem,
2
019, 43, 10675-10679.
1 Y. Xiong, Y. Ma, X. He, X. Xue and C. Zhang, Phys. Chem. Chem.
Phys., 2019, 21, 2397-2409.
-3
in a moderately high density of 1.82 g cm and low impact sensitivity 22 L. Hu, P. Yin, G. H. Imler, D. A. Parrish, H. Gao and J. M. Shreeve,
-1
Chem. Commun., 2019, 55, 8979-8982.
of 32 J. The hydrazinium salt has a detonation velocity of 8782 m s
2
2
3 Y. Ma, A. Zhang, C. Zhang, D. Jiang, Y. Zhu and C. Zhang, Cryst.
Growth Des., 2014, 14, 4703-4713.
and impact and friction sensitivity (16 J, 120 N) somewhat like RDX.
This special HB system reduces the free space in molecules, and
unlike most water soluble dinitroamino compounds, all new
4 T. Suzuki, N. Katou and K. Mitsuhashi, J. Heterocyclic Chem., 1978,
1
5, 1451-1453..
compounds have poor solubility in water, which makes them easy to 25 M. J. Frisch, G. W. Trucks, H. G. Schlegel, G. E. Scuseria, M. A. Robb,
J. A. Montgomery, Jr, T. Vreven, K. N. Kudin, J. C. Burant, J. M.
Millam, S. S. Iyengar, J. B. Tomasi, V., B. C. Mennucci, M., G.
Scalmani, N. Rega, G. A. Petersson, H. Nakatsuji, M. Hada, M.
Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima,
Y. Honda, O. Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P.
Hratchian, 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, P. Y. M. Ayala, K., G. A. Voth, P. Salvador,
J. J. Dannenberg, V. G. Zakrzewski, S. Dapprich, A. D. Daniels, M.
C. Strain, O. Farkas, D. K. Malick, A. D. Rabuck, K. Raghavachari, J.
B. Foresman, J. V. Ortiz, Q. Cui, A. G. Baboul, S. Clifford, J.
Cioslowski, B. B. Stefanov, A. L. G. Liu, P. Piskorz, I. Komaromi, R.
L. Martin, D. J. Fox, T. Keith, M. A. Al-Laham, C. Peng, A.
Nanayakkara, M. Challacombe, P. M. W. Gill, B. Johnson, W. Chen,
M. Wong, C. Gonzalez and J. A. Pople, Gaussian 03, revision D.01;
Gaussian, Inc.: Wallingford, CT, 2004.
recover after reaction. The synthesis of the neutral compound is
extremely cost effective and can be obtained on large scale (5 g),
which means it may be suitable for industrial production. This new
kind of HB system provides a promising pathway to design HEDMs
which is available for industrial production and practical application.
The Rigaku Synergy S Diffractometer was purchased with support
from National Science Foundation MRI (Grant No. 1919565).
Conflicts of interest
There are no conflicts to declare.
2
2
6 M. Suceska, EXPLO5, v6.01; Brodarski Institute: Zagreb, Croatia,
2013.
Notes and references
7 Tests were conducted according to the UN Recommendations on
the Transport of Dangerous Goods, Manual of Tests and Criteria,
1
2
3
H. Gao, Q. Zhang and J. M. Shreeve, J. Mater. Chem A., 2020, 8,
4
193-4216.
5
th rev. edn, United Nations Publication, New York, 2009.
T. M. Klapötke, P. C. Schmid, S. Schnell and J. Stierstorfer, J. Mater.
Chem. A, 2015, 3, 2658-2668.
T. M. Klapötke and C. M. Sabaté, New J. Chem, 2009, 33, 1605.
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DOI: 10.1039/D0CC07101C
Hydrogen bond systems stabilize molecules and shorten intermolecular distances to give higher
density and lower sensitivity.