3-Nitro-1H-1,2,4-triazole

Madhukar Hemamalini; Hoong-Kun Fun

doi:10.1107/S1600536810049287

. 2010 Dec 4;67(Pt 1):o15. doi: 10.1107/S1600536810049287

3-Nitro-1H-1,2,4-triazole

Madhukar Hemamalini ^a, Hoong-Kun Fun ^a,^*,^‡

PMCID: PMC3050167 PMID: 21522657

Abstract

The asymmetric unit of the title compound, C₂H₂N₄O₂, contains two crystallographically independent molecules in which the triazole rings are essentially planar, with maximum deviations of 0.003 (1) Å in both molecules. The dihedral angle between the two 1H-1,2,4-triazole rings is 56.58 (5)°. In the crystal, molecules are linked via intermolecular N—H⋯N and C—H⋯O hydrogen bonds, forming a supramolecular chain along the b axis.

Related literature

For details and applications of 1H-1,2,4-triazole derivatives, see: Desenko (1995 ▶); Vos et al. (1983 ▶); van Albada et al. (1984 ▶); Al-Kharafi et al. (1986 ▶); Gupta & Bhargava (1978 ▶); Jones et al. (1965 ▶); Bennur et al. (1976 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂H₂N₄O₂
M _r = 114.08
Monoclinic,
a = 8.7818 (1) Å
b = 10.0726 (2) Å
c = 9.9703 (1) Å
β = 107.081 (1)°
V = 843.03 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.16 mm⁻¹
T = 100 K
0.48 × 0.33 × 0.30 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.928, T _max = 0.954
11450 measured reflections
3081 independent reflections
2768 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.092
S = 1.05
3081 reflections
153 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.50 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810049287/is2634sup1.cif

e-67-00o15-sup1.cif^{(15.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810049287/is2634Isup2.hkl

e-67-00o15-Isup2.hkl^{(148.1KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2A—H1N1⋯N1Aⁱ	0.885 (15)	1.995 (15)	2.8540 (9)	163.4 (15)
N2B—H1N2⋯N1Bⁱⁱ	0.857 (16)	2.057 (16)	2.9128 (10)	176.0 (16)
C1A—H1AA⋯O2Aⁱⁱⁱ	0.93	2.50	3.1129 (10)	124
C1B—H1BA⋯O2Bⁱⁱ	0.93	2.51	3.0451 (11)	117

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

MH and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University grant No. 1001/PFIZIK/811160. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

1H-1,2,4-Triazole ring systems are typical planar six-π-electron partially aromatic systems, and are used, along with their derivatives, as starting materials for the synthesis of many heterocycles (Desenko, 1995). Substituted 1H-1,2,4-triazoles have also been actively studied as bridging ligands coordinating through their vicinal N atoms and some have special structures with interesting magnetic properties (Vos et al., 1983; van Albada et al., 1984). Studies also indicate that the 1H-1,2,4-triazole system is associated with anticorrosion (Al-Kharafi et al., 1986) and anti-inflammatory action (Gupta & Bhargava, 1978) and other pharmacological activities by exhibiting antiviral, anti-asthmatic, diuretic, analgesic, antimicrobial, antidepressant and antifungal effects (Jones et al., 1965; Bennur et al., 1976).

The asymmetric unit of the title compound consists of two crystallographically independent 3-nitro-1H-1,2,4-triazole molecules (A & B) with very similar geometry (Fig. 1). The 1H-1,2,4-triazole units are essentially planar with maximum deviations of 0.003 (1) Å for atom N1A (molecule A) and 0.003 (1) Å for atom C2B (molecule B). The dihedral angle between the two 1H-1,2,4-triazole (N1A—N3A/ C1A–C2A) and (N1B—N3B/C1B–C2B) rings is 56.58 (5)°.

In the crystal structure (Fig. 2), molecules are connected via N2A—H1N1···N1A, N2B—H1N2···N1B, C1A—H1AA···O2A and C1B—H1BA···O2B (Table 1) hydrogen bonds to form a one-dimensional supramolecular chain along the b-axis.

Experimental

Hot methanol solution (20 ml) of 3-nitro-1H-1,2,4-triazole (57 mg, Aldrich) was warmed over a heating magnetic stirrer for 5 minutes. The resulting solution was allowed to cool slowly at room temperature. Crystals of the title compound appeared from the mother liquor after a few days.