1,4-Diazo­niabicyclo­[2.2.2]octane bis­(2,4,6-trinitro­phenolate)

Weiwei SiMa

doi:10.1107/S1600536810021021

. 2010 Jun 5;66(Pt 7):o1584. doi: 10.1107/S1600536810021021

1,4-Diazoniabicyclo[2.2.2]octane bis(2,4,6-trinitrophenolate)

Weiwei SiMa ^a,^*

PMCID: PMC3006919 PMID: 21587824

Abstract

In the title compound, C₆H₁₄N₂ ²⁺·2C₆H₂N₃O₇ ⁻, the cation possesses crystallographically imposed twofold rotation symmetry. In the crystal structure, the cation and anions are linked into a trimeric aggregate by intermolecular N—H⋯O hydrogen bonds. The trimeric units are further connected by π–π interactions [centroid–centroid distances = 3.507 (2)–3.660 (3) Å], forming layers parallel to the bc plane.

Related literature

For a discussion on hydrogen bonding in in the title crystal, see: Kumai et al. (2007 ▶); Horiuchi et al. (2005 ▶). For related structures, see: Dabros et al. (2007 ▶); Jin et al. (2004 ▶); Glidewell et al. (1999 ▶); Chen et al. (2009 ▶).

Experimental

Crystal data

C₆H₁₄N₂ ²⁺·2C₆H₂N₃O₇ ⁻
M _r = 570.40
Monoclinic,
a = 15.3808 (11) Å
b = 7.1520 (5) Å
c = 25.3527 (14) Å
β = 125.496 (2)°
V = 2270.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.15 mm⁻¹
T = 93 K
0.1 × 0.1 × 0.1 mm

Data collection

Rigaku SCXmini diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.857, T _max = 1.000
10700 measured reflections
2590 independent reflections
2218 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.098
S = 1.07
2590 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.59 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear (Rigaku, 2005 ▶); data reduction: CrystalClear (Rigaku, 2005 ▶); 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: PRPKAPPA (Ferguson, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810021021/rz2442sup1.cif

e-66-o1584-sup1.cif^{(16.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810021021/rz2442Isup2.hkl

e-66-o1584-Isup2.hkl^{(127.3KB, 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
N4—H4A⋯O1	0.93	1.69	2.589 (2)	161
N4—H4A⋯O2	0.93	2.42	2.954 (2)	117

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Acknowledgments

The author is grateful to the starter fund of Southeast University for financial support to buy the X-ray diffractometer.

supplementary crystallographic information

Comment

The co-crystals of 1,4-diazabicyclo[2.2.2]octane (DABCO) and phenols are typically characterized by the presence of N—H···O or O—H···N hydrogen-bonded adducts (Kumai et al. (2007); Horiuchi et al., 2005). Many of this type of co-crystals have been designed by employing crystal-engineering strategies, and their structures have been studied extensively (Dabros et al., 2007; Jin et al., 2004; Glidewell et al., 1999). As a continuation of a study of phase transitions in hydrogen-bonded co-crystalline compounds between phenols and tertiary amines as N–H···O-type systems (Chen et al., 2009), the crystal structure of the 1:2 co-crystal of DABCO and 2,4,6-trinitrophenol obtained by a single-crystal X-ray analysis is reported herein. The compound shows no dielectric irregularity in the temperature range of 93–373K.

The title compound (Fig. 1) was obtained from the reaction of 1,4-diazabicyclo[2.2.2]octane and 2,4,6-trinitrophenol. The cation has crystallographically imposed twofold rotation symmetry. The two protonated N atoms in the cation are almost equivalent with very close C–N bond lengths [1.4930 (19) to 1.4952 (18) Å] and C–N–C angles [109.79 (11)° to 110.72 (11)°]. Within the benzene ring of the 2,4,6-trinitrophenol anion, the C–C–C bond angles of the three nitro-connected C atoms are in the range 121.92 (13)–126.76 (13)°, and are a little larger than the remaining three C–C–C bond angles. In the crystal structure (Fig. 2), cation and anions are linked into a trimeric aggregate by intermolecular N—H···O hydrogen bonds (Table 1). The trimeric units are further connected by π–π interactions (centroid-to-centroid distance = 3.507 (2)–3.660 (3) Å) to form layers parallel to the bc plane.

Experimental

1,4-Diazabicyclo[2.2.2]octane (DABCO) (2.5 mmol) was dissolved in ethanol (10 ml).The clear solution obtained was added to a solution of 2,4,6-trinitrophenol(5 mmol) in ethanol (20 ml). The formed precipitate was then filtered and the obtained yellow solid was redissolved in DMF (15 ml). Yellow co-crystals of the title compound suitable for X-ray diffraction analysis were obtained by slow evaporation of the mixture at room temperature after 7 days.