Preparation and crystallographic characterization of 1H-tetrazole/NaClO₄ energetic cocrystal

Cocrystallization is a promising method for generating new energetic materials with improved performances. Herein, a novel energetic cocrystal composed of 1H-tetrazole/sodium perchlorate was prepared using the solvent evaporation method. This cocrystal is characterized as containing organic azole derivatives and an ionic perchlorate salt, which is used as an oxidizer in pyrotechnics. The crystal structure was determined via single-crystal X-ray diffraction. The as-prepared crystal exhibited a lamellar structure consisting of 1H-tetrazole and sodium perchlorate layers. A molecular structure comparison between the cocrystal and pristine ingredients revealed variations in the bond lengths and angles owing to the cocrystallization. The hydrogen bond formed by adjacent tetrazole rings was strengthened. The 1H-tetrazole/sodium perchlorate cocrystal was structurally compared with crystals previously reported to the Cambridge Structural Database including sodium perchlorate in lamellar structures. The lamellar structure of the cocrystal exhibited weak layer-to-layer interactions compared with those of the other crystals. Fourier transform infrared and Raman spectroscopy analyses were conducted, and the relationship between the spectroscopy results and the crystal/molecular structure are discussed. The results of the spectroscopic analyses exhibited peak shifts that indicate structural changes in bond lengths and angles owing to the cocrystallization.

Computing details

Data collection: CrysAlis PRO 1.171.40.66a (Rigaku OD, 2019); cell refinement: CrysAlis PRO 1.171.40.66a (Rigaku OD, 2019); data reduction: CrysAlis PRO 1.171.40.66a (Rigaku OD, 2019); program(s) used to solve structure: SHELXT 2018/2 (Sheldrick, 2018); program(s) used to refine structure: SHELXL 2018/3 (Sheldrick, 2015); molecular graphics: Olex2 1.5 (Dolomanov et al., 2009); software used to prepare material for publication: Olex2 1.5 (Dolomanov et al., 2009).

(I)

Crystal data

CH2ClN4NaO4	F(000) = 192
Mr = 192.51	Dx = 2.012 Mg m^−3
Monoclinic, P121/m1	Cu Kα radiation, λ = 1.54184 Å
a = 4.9250 (1) Å	Cell parameters from 1359 reflections
b = 6.9281 (1) Å	θ = 4.7–74.8°
c = 9.5661 (2) Å	µ = 5.90 mm^−1
β = 103.171 (2)°	T = 295 K
V = 317.82 (1) Å^3	Plate, clear colourless
Z = 2	0.1 × 0.05 × 0.1 mm

Data collection

XtaLAB AFC12 (RINC): Kappa dual home/near diffractometer	680 independent reflections
Radiation source: micro-focus sealed X-ray tube, Rigaku (Cu) X-ray Source	665 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.027
Detector resolution: 5.8140 pixels mm^-1	θmax = 74.9°, θmin = 4.8°
ω scans	h = −6→5
Absorption correction: multi-scan CrysAlisPro 1.171.40.66a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −4→8
Tmin = 0.385, Tmax = 1.000	l = −11→11
1576 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.039	w = 1/[σ^2(Fo^2) + (0.0612P)^2 + 0.1719P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.104	(Δ/σ)max < 0.001
S = 1.14	Δρmax = 0.40 e Å^−3
680 reflections	Δρmin = −0.33 e Å^−3
71 parameters	Extinction correction: SHELXL-2018/3 (Sheldrick 2018), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.157 (11)
Primary atom site location: dual

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
Cl1	0.12579 (13)	0.750000	0.88736 (7)	0.0265 (4)
Na2	0.2166 (3)	0.250000	0.85142 (13)	0.0333 (4)
N6	0.7589 (6)	0.250000	0.5090 (3)	0.0327 (7)
N7	0.7429 (6)	0.250000	0.6471 (3)	0.0318 (7)
N8	0.4813 (5)	0.250000	0.6466 (3)	0.0316 (7)
O4	−0.1511 (6)	0.750000	0.9064 (3)	0.0663 (11)
N9	0.3264 (5)	0.250000	0.5096 (3)	0.0353 (7)
O5	0.1738 (6)	0.5861 (3)	0.8076 (3)	0.0660 (8)
O3	0.3029 (6)	0.750000	1.0255 (3)	0.0780 (13)
C10	0.5046 (7)	0.250000	0.4272 (4)	0.0366 (8)
H10	0.468 (8)	0.250000	0.336 (5)	0.033 (10)*
H6	0.907 (10)	0.250000	0.489 (5)	0.042 (12)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0267 (5)	0.0343 (5)	0.0197 (5)	0.000	0.0075 (3)	0.000
Na2	0.0383 (8)	0.0375 (8)	0.0247 (7)	0.000	0.0085 (5)	0.000
N6	0.0214 (14)	0.0534 (17)	0.0266 (13)	0.000	0.0120 (10)	0.000
N7	0.0259 (13)	0.0458 (16)	0.0236 (13)	0.000	0.0055 (10)	0.000
N8	0.0232 (13)	0.0482 (16)	0.0244 (13)	0.000	0.0075 (10)	0.000
O4	0.0285 (14)	0.136 (3)	0.0369 (14)	0.000	0.0121 (11)	0.000
N9	0.0205 (14)	0.0625 (19)	0.0237 (13)	0.000	0.0065 (10)	0.000
O5	0.115 (2)	0.0357 (12)	0.0644 (14)	−0.0023 (11)	0.0561 (14)	−0.0066 (9)
O3	0.0417 (16)	0.154 (4)	0.0299 (15)	0.000	−0.0085 (13)	0.000
C10	0.0258 (16)	0.066 (2)	0.0195 (16)	0.000	0.0075 (12)	0.000

Geometric parameters (Å, º)

Cl1—Na2^i	3.3180 (15)	Na2—O5^iv	2.367 (2)
Cl1—O4	1.416 (3)	Na2—O3^v	2.391 (3)
Cl1—O5	1.418 (2)	N6—N7	1.341 (4)
Cl1—O5^ii	1.418 (2)	N6—C10	1.317 (5)
Cl1—O3	1.408 (3)	N6—H6	0.80 (5)
Na2—N7^iii	2.681 (3)	N7—N8	1.288 (4)
Na2—N8	2.589 (3)	N8—N9	1.358 (4)
Na2—O4^i	2.411 (3)	N9—C10	1.307 (4)
Na2—O5	2.367 (2)	C10—H10	0.85 (5)
O4—Cl1—Na2^i	39.99 (12)	O5—Na2—O5^iv	159.34 (14)
O4—Cl1—O5	110.66 (13)	O5—Na2—O3^v	97.21 (8)
O4—Cl1—O5^ii	110.66 (13)	O5^iv—Na2—O3^v	97.21 (8)
O5—Cl1—Na2^i	125.55 (9)	O3^v—Na2—Cl1^i	104.18 (9)
O5^ii—Cl1—Na2^i	125.55 (9)	O3^v—Na2—N7^iii	163.42 (11)
O5—Cl1—O5^ii	106.41 (18)	O3^v—Na2—N8	76.13 (10)
O3—Cl1—Na2^i	66.78 (14)	O3^v—Na2—O4^i	82.01 (11)
O3—Cl1—O4	106.77 (19)	N7—N6—H6	120 (3)
O3—Cl1—O5^ii	111.20 (14)	C10—N6—N7	109.0 (3)
O3—Cl1—O5	111.20 (14)	C10—N6—H6	131 (3)
N7^iii—Na2—Cl1^i	92.40 (7)	N6—N7—Na2^vi	118.8 (2)
N8—Na2—Cl1^i	179.69 (8)	N8—N7—Na2^vi	135.0 (2)
N8—Na2—N7^iii	87.29 (9)	N8—N7—N6	106.2 (3)
O4^i—Na2—Cl1^i	22.17 (7)	N7—N8—Na2	132.3 (2)
O4^i—Na2—N7^iii	114.57 (10)	N7—N8—N9	110.2 (2)
O4^i—Na2—N8	158.14 (11)	N9—N8—Na2	117.50 (18)
O5^iv—Na2—Cl1^i	95.37 (6)	Cl1—O4—Na2^i	117.84 (17)
O5—Na2—Cl1^i	95.37 (6)	C10—N9—N8	106.0 (3)
O5^iv—Na2—N7^iii	80.98 (8)	Cl1—O5—Na2	135.35 (14)
O5—Na2—N7^iii	80.98 (8)	Cl1—O3—Na2^v	142.6 (2)
O5^iv—Na2—N8	84.59 (6)	N6—C10—H10	124 (3)
O5—Na2—N8	84.59 (6)	N9—C10—N6	108.6 (3)
O5^iv—Na2—O4^i	98.30 (6)	N9—C10—H10	127 (3)
O5—Na2—O4^i	98.30 (6)
Na2^i—Cl1—O5—Na2	−27.5 (3)	O4—Cl1—O3—Na2^v	180.000 (1)
Na2^i—Cl1—O3—Na2^v	180.000 (2)	O5—Cl1—O4—Na2^i	121.15 (12)
Na2^vi—N7—N8—Na2	0.000 (2)	O5^ii—Cl1—O4—Na2^i	−121.15 (12)
Na2^vi—N7—N8—N9	180.000 (1)	O5^ii—Cl1—O5—Na2	169.67 (8)
Na2—N8—N9—C10	180.000 (1)	O5^ii—Cl1—O3—Na2^v	−59.19 (11)
N6—N7—N8—Na2	180.000 (1)	O5—Cl1—O3—Na2^v	59.19 (11)
N6—N7—N8—N9	0.000 (1)	O3—Cl1—O4—Na2^i	0.000 (1)
N7—N6—C10—N9	0.000 (1)	O3—Cl1—O5—Na2	48.4 (3)
N7—N8—N9—C10	0.000 (1)	C10—N6—N7—Na2^vi	180.000 (1)
N8—N9—C10—N6	0.000 (1)	C10—N6—N7—N8	0.000 (1)
O4—Cl1—O5—Na2	−70.1 (3)

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