Crystallographic study of the energetic salt 1,2,4-triazolium perchlorate

The mol­ecular and crystal structure of 1H-1,2,4-triazolium perchlorate, C₂H₄N₃⁺·ClO₄⁻, was determined as detailed crystallographic data had not been available previously. The structure has monoclinic (P2₁/m) symmetry. It is of inter­est in the field of energetic com­pounds because nitro­gen-rich azoles are the backbone of high-density energetic com­pounds, and salt-based energetic materials can exhibit preferential energy-release behaviour. The bond angles of the 1,2,4-triazolium cation in this study were similar to those of a cationic triazole ring reported previously and were different from those of the neutral triazole ring. This study contributes to the available data that can be used to analyse the relationship between the structures and properties of energetic materials.

Computing details

Data collection: CrysAlis PRO (Rigaku OD, 2018); cell refinement: CrysAlis PRO (Rigaku OD, 2018); data reduction: CrysAlis PRO (Rigaku OD, 2018); program(s) used to solve structure: olex2.solve (Bourhis et al., 2015); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015) and OLEX2 (Dolomanov et al., 2009); molecular graphics: Mercury (Macrae et al., 2020); software used to prepare material for publication: publCIF (Westrip, 2010).

1H-1,2,4-Triazolium perchlorate

Crystal data

C2H4N3^+·ClO4^−	F(000) = 344
Mr = 169.53	Dx = 1.911 Mg m^−3
Monoclinic, P21/m	Cu Kα radiation, λ = 1.54184 Å
a = 5.1859 (1) Å	Cell parameters from 2328 reflections
b = 11.8497 (1) Å	θ = 4.6–73.1°
c = 9.6461 (1) Å	µ = 5.54 mm^−1
β = 96.153 (1)°	T = 223 K
V = 589.35 (1) Å^3	Plate, clear pale yellow
Z = 4	1 × 0.6 × 0.3 mm

Data collection

XtaLAB AFC12 (RINC) Kappa dual home/near diffractometer	1217 independent reflections
Radiation source: micro-focus sealed X-ray tube, Rigaku (Cu) X-ray Source	1136 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.030
ω scans	θmax = 73.3°, θmin = 4.6°
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2018)	h = −6→6
Tmin = 0.838, Tmax = 1.000	k = −13→14
3611 measured reflections	l = −11→11

Refinement

Refinement on F^2	Primary atom site location: iterative
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.035	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.094	w = 1/[σ^2(Fo^2) + (0.0523P)^2 + 0.1864P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max < 0.001
1217 reflections	Δρmax = 0.27 e Å^−3
108 parameters	Δρmin = −0.75 e Å^−3
0 restraints

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl10	0.85233 (11)	0.750000	0.42804 (6)	0.0232 (2)
O11	0.8685 (4)	0.750000	0.28056 (18)	0.0319 (5)
O12	0.5866 (4)	0.750000	0.4563 (2)	0.0416 (5)
O13	0.9799 (3)	0.65063 (13)	0.48852 (15)	0.0388 (4)
N1	0.5121 (3)	0.43779 (14)	0.83520 (17)	0.0277 (4)
H1	0.477 (5)	0.391 (2)	0.888 (3)	0.044 (7)*
N2	0.3322 (3)	0.51339 (16)	0.7827 (2)	0.0429 (5)
N4	0.6962 (3)	0.53346 (15)	0.69127 (17)	0.0297 (4)
H4	0.808 (6)	0.561 (3)	0.648 (3)	0.052 (8)*
C3	0.4530 (4)	0.57112 (19)	0.6944 (2)	0.0384 (5)
H3	0.379350	0.631209	0.640211	0.046*
C5	0.7300 (4)	0.44967 (17)	0.7816 (2)	0.0288 (4)
H5	0.881871	0.406992	0.803017	0.035*
Cl6	1.03081 (10)	0.250000	0.06220 (5)	0.0209 (2)
O7	0.7698 (4)	0.250000	−0.0070 (2)	0.0327 (5)
O8	1.0241 (4)	0.250000	0.21008 (18)	0.0319 (5)
O9	1.1632 (3)	0.34949 (12)	0.02056 (13)	0.0313 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl10	0.0243 (3)	0.0267 (3)	0.0191 (3)	0.000	0.0053 (2)	0.000
O11	0.0459 (12)	0.0308 (11)	0.0195 (9)	0.000	0.0058 (8)	0.000
O12	0.0244 (10)	0.0558 (15)	0.0464 (12)	0.000	0.0116 (9)	0.000
O13	0.0447 (8)	0.0410 (9)	0.0318 (7)	0.0131 (7)	0.0096 (6)	0.0121 (6)
N1	0.0313 (8)	0.0227 (8)	0.0304 (8)	−0.0006 (7)	0.0089 (7)	0.0045 (7)
N2	0.0234 (8)	0.0329 (10)	0.0742 (13)	0.0036 (7)	0.0138 (8)	0.0147 (9)
N4	0.0288 (8)	0.0331 (9)	0.0286 (8)	−0.0067 (7)	0.0093 (7)	0.0019 (7)
C3	0.0275 (9)	0.0327 (11)	0.0529 (13)	−0.0024 (8)	−0.0047 (9)	0.0169 (10)
C5	0.0232 (9)	0.0276 (10)	0.0356 (10)	0.0017 (7)	0.0036 (7)	−0.0011 (8)
Cl6	0.0233 (3)	0.0212 (3)	0.0184 (3)	0.000	0.0034 (2)	0.000
O7	0.0242 (9)	0.0308 (11)	0.0416 (11)	0.000	−0.0044 (8)	0.000
O8	0.0456 (12)	0.0307 (11)	0.0207 (9)	0.000	0.0091 (8)	0.000
O9	0.0359 (7)	0.0309 (8)	0.0279 (7)	−0.0098 (6)	0.0070 (5)	0.0023 (6)

Geometric parameters (Å, º)

Cl10—O11	1.4341 (18)	N4—C3	1.341 (3)
Cl10—O12	1.433 (2)	N4—C5	1.321 (3)
Cl10—O13^i	1.4428 (15)	C3—H3	0.9400
Cl10—O13	1.4428 (15)	C5—H5	0.9400
N1—H1	0.78 (3)	Cl6—O7	1.4438 (19)
N1—N2	1.352 (2)	Cl6—O8	1.4305 (18)
N1—C5	1.299 (2)	Cl6—O9	1.4428 (14)
N2—C3	1.303 (3)	Cl6—O9^ii	1.4427 (14)
N4—H4	0.82 (3)
O11—Cl10—O13	109.15 (8)	N2—C3—N4	111.04 (19)
O11—Cl10—O13^i	109.15 (8)	N2—C3—H3	124.5
O12—Cl10—O11	110.38 (13)	N4—C3—H3	124.5
O12—Cl10—O13	109.38 (8)	N1—C5—N4	106.52 (17)
O12—Cl10—O13^i	109.38 (8)	N1—C5—H5	126.7
O13—Cl10—O13^i	109.40 (14)	N4—C5—H5	126.7
N2—N1—H1	120 (2)	O8—Cl6—O7	109.84 (12)
C5—N1—H1	127 (2)	O8—Cl6—O9^ii	109.92 (7)
C5—N1—N2	111.94 (17)	O8—Cl6—O9	109.92 (7)
C3—N2—N1	103.41 (17)	O9^ii—Cl6—O7	108.77 (8)
C3—N4—H4	127 (2)	O9—Cl6—O7	108.77 (7)
C5—N4—H4	126 (2)	O9^ii—Cl6—O9	109.60 (12)
C5—N4—C3	107.08 (16)
N1—N2—C3—N4	0.2 (3)	C5—N1—N2—C3	0.2 (3)
N2—N1—C5—N4	−0.5 (2)	C5—N4—C3—N2	−0.5 (3)
C3—N4—C5—N1	0.6 (2)

Symmetry codes: (i) x, −y+3/2, z; (ii) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···O13	0.818	2.141	2.921	159.61
N1—H1···O9	0.787	2.230	2.874	139.46
N—H1···O7	0.787	2.407	2.936	125.59
N4—H4···O8	0.818	2.719	3.049	106.14