3-Benzyl-1-methyl­imidazolium picrate

Min Pi; Xiu-Ling Liu; Ji-Jun Xu; Chuan-Ming Jin

doi:10.1107/S1600536809035454

. 2009 Sep 9;65(Pt 10):o2386. doi: 10.1107/S1600536809035454

3-Benzyl-1-methylimidazolium picrate

Min Pi ^a, Xiu-Ling Liu ^a, Ji-Jun Xu ^a, Chuan-Ming Jin ^a,^*

PMCID: PMC2970314 PMID: 21577850

Abstract

In the title salt, C₁₁H₁₃N₂ ⁺·C₆H₂N₃O₇ ⁻, the dihedral angles between the benzene ring in the cation and the imidazolium ring and the benzene ring of the picrate anion are 113.7 (2) and 116.3 (2)°, respectively. The imidazolium ring is nearly parallel to the benzene ring of the picrate anion, the dihedral angle between the planes being 2.6 (1)°. The nitro groups in the picrate anions are disordered (occupancy ratio 0.54:0.46). The crystal packing is stabilized by weak C—H⋯O interactions between the cation–anion pairs.

Related literature

For civilian and military applications of energetic materials, see: Sikder & Sikder (2004 ▶). Heterocyclic organic salts with low melting points are a new class of energetic materials, which have attracted considerable interest because of their ‘green chemistry’ properties, see: Singh et al. (2006 ▶). Picric acid is a polynitrogen compound with explosive character and imidazolium-based cation picrate salts are good candidates for energetic ionic salts, see: Jin et al. (2005 ▶).

Experimental

Crystal data

C₁₁H₁₃N₂ ⁺·C₆H₂N₃O₇ ⁻
M _r = 401.34
Triclinic,
a = 9.1322 (6) Å
b = 10.2060 (7) Å
c = 10.8744 (7) Å
α = 63.6190 (10)°
β = 80.1660 (10)°
γ = 86.4820 (10)°
V = 894.52 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 298 K
0.20 × 0.10 × 0.10 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.986, T _max = 0.988
5623 measured reflections
3447 independent reflections
2610 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.144
S = 1.04
3447 reflections
320 parameters
15 restraints
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809035454/jj2007sup1.cif

e-65-o2386-sup1.cif^{(22.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809035454/jj2007Isup2.hkl

e-65-o2386-Isup2.hkl^{(169KB, 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
C17—H17C⋯O7ⁱ	0.96	2.42	3.346 (10)	162
C14—H14⋯O5ⁱⁱ	0.93	2.39	3.283 (11)	161
C17—H17A⋯O2ⁱⁱⁱ	0.96	2.32	3.205 (11)	153
C16—H16⋯O2ⁱⁱⁱ	0.93	2.39	3.159 (9)	140
C16—H16⋯O1ⁱⁱⁱ	0.93	2.19	3.021 (2)	149
C13—H13A⋯O1ⁱⁱⁱ	0.97	2.58	3.382 (3)	140
C17—H17C⋯O7ⁱ	0.96	2.42	3.346 (10)	162

Open in a new tab

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

Acknowledgments

We gratefully acknowledge the financial support of the National Science Funds for Distinguished Young Scholars of Hubei Province (grant No. 2006ABB038), the Outstanding Mid-young Scholars’ Programs, Hubei Provincial Department of Education (Q20072203) and the project sponsored by SRF for ROCS, SEM (200724).

supplementary crystallographic information

Comment

Energetic materials are used extensively for both civilian and military applications (Sikder & Sikder, 2004). Heterocyclic organic salts with low melting points are a new class of energetic materials that has attracted considerable interest because of their "green chemistry" properties (Singh et al., 2006). Picric acid is a polynitrogen compound with explosive character and imidazolium-based cation picrate salts are good candidates for energetic ionic salts (Jin et al., 2005). Based on our continued interest in these compounds, the title organic salt (scheme 1) was prepared and its structure is reported.

The asymmetric unit of the title compound contains one independent cation (1-methyl-3-benzenylimidazolium)-anion (picrate) pair (Fig. 1). The dihedral angle between the benzene ring in the cation and the imidazolium ring and the benzene ring of the picrate anion is 113.7 (2)° and 116.3 (2) °, respectively. The imidazolium ring is nearly parallel to the benzene ring of the picrate anion with the dihedral angle of separation being 2.6 (1)°. The oxygen atoms in the nitro groups of the picrate anion are disorderd with the o-NO₂ major components (O2, O3, O4, O5) being 0.54 occupied and the p-NO₂major components (O5, O6) at 0.58 occupancy . Crystal packing is stabilized by the weak C—H···O interactions between the cation-anion pairs (Fig. 2, Table 1).

Experimental

The title salt (C₁₁H₁₃N₂)⁺.(C₆H₂N₃O₇)^- was synthesized using a slightly modified literature mothod (Jin et al., 2005). It was crystallized by slow evaporation of an acetonitrile and methanol solution of the salt.