4-Aza-1-azoniabicyclo­[2.2.2]octa­ne–2-amino­benzoate–2-amino­benzoic acid (1/1/1)

Hadi D Arman; Trupta Kaulgud; Edward R T Tiekink

doi:10.1107/S1600536811041559

. 2011 Oct 12;67(Pt 11):o2933. doi: 10.1107/S1600536811041559

4-Aza-1-azoniabicyclo[2.2.2]octane–2-aminobenzoate–2-aminobenzoic acid (1/1/1)

Hadi D Arman ^a, Trupta Kaulgud ^a, Edward R T Tiekink ^b,^*

PMCID: PMC3247346 PMID: 22219964

Abstract

A 4-aza-1-azoniabicyclo[2.2.2]octane cation, a 2-aminobenzoate anion and a neutral 2-aminobenzoic acid molecule comprise the asymmetric unit of the title compound, C₆H₁₃N₂ ⁺·C₇H₆NO₂ ⁻·C₇H₇NO₂. An intramolecular N—H⋯O hydrogen bond occurs in the anion and in the neutral 2-aminobenzoic acid molecule. The cation provides a charge-assisted N—H⋯O hydrogen bond to the anion, and the 2-aminobenzoic acid molecule forms an O—H⋯N hydrogen bond to the unprotonated amino N atom in the cation. In this way, a three-component aggregate is formed. These are connected into a three-dimensional network by amino–carboxylate N—H⋯O hydrogen bonds. N—H⋯N hydrogen bonds are also observed.

Related literature

For related studies on co-crystal formation, see: Arman et al. (2010 ▶); Arman & Tiekink (2010 ▶); Wardell & Tiekink (2011 ▶). For examples of multi-component crystals containing the 2-aminobenzoate anion, see: Lynch et al. (1998 ▶); Chen & Peng (2011 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

C₆H₁₃N₂ ⁺·C₇H₆NO₂ ⁻·C₇H₇NO₂
M _r = 386.45
Monoclinic,
a = 9.285 (3) Å
b = 16.843 (5) Å
c = 12.660 (4) Å
β = 102.127 (6)°
V = 1935.7 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 98 K
0.34 × 0.17 × 0.07 mm

Data collection

Rigaku AFC12/SATURN724 diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.731, T _max = 1.000
16911 measured reflections
4440 independent reflections
3929 reflections with I > 2σ(I)
R _int = 0.054

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.128
S = 1.13
4440 reflections
268 parameters
7 restraints
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrystalClear (Molecular Structure Corporation & Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811041559/hb6440sup1.cif

e-67-o2933-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811041559/hb6440Isup2.hkl

e-67-o2933-Isup2.hkl^{(217.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811041559/hb6440Isup3.cml

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
O1—H1O⋯N3	0.84	1.77	2.597 (2)	168
N4—H5n⋯O3	0.93	1.64	2.546 (2)	166
N1—H2n⋯O2	0.88	2.03	2.725 (2)	135
N2—H3n⋯O3	0.88	2.04	2.696 (2)	131
N1—H1n⋯O4ⁱ	0.88	2.08	2.941 (2)	165
N2—H4n⋯N1ⁱⁱ	0.88	2.38	3.256 (2)	171

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

Acknowledgments

The Ministry of Higher Education, Malaysia, is thanked for the award of a research grant in crystal engineering (RG125/10AFR).

supplementary crystallographic information

Comment

As a part of on-going studies into co-crystallization experiments of carboxylic acids with N-containing molecules (Arman et al. 2010; Arman & Tiekink, 2010; Wardell & Tiekink, 2011), the 1:2 co-crystallization of 1,4-diazabicyclo[2.2.2]octane (DABCO) and 2-aminobenzoic was investigated, leading to the isolation of (I).

The crystallographic asymmetric unit of (I) comprises a 4-aza-1-azoniabicyclo(2.2.2)octane cation, Fig. 1, a 2-aminobenzoate anion, Fig. 2, and a neutral 2-aminobenzoic acid molecule, Fig. 3. While there are many examples of 4-aza-1-azoniabicyclo(2.2.2)octane cations and neutral 2-aminobenzoic acid molecules in the crystallographic literature (Allen, 2002), examples of 2-aminobenzoate anions are comparatively rare in all-organic molecules (Lynch et al., 1998; Chen & Peng, 2011). The ions and neutral benzoic acid derivative associate into a three-molecule aggregate via N⁺—H···O and O—H···N hydrogen bonds formed by and to the cation, Fig. 4 and Table 1; intramolecular N—H···O hydrogen bonds are also noted in the benzoate and benzoic acid species, Table 1.

The three component aggregates are connected into the three-dimensional architecture by hydrogen bonds involving the amino-H atoms not participating in intramolecular N—H···O interactions, Fig. 5 and Table 1.

Experimental

Colourless crystals of (I) were isolated from the 1:2 co-crystallization of 1,4-diazabicyclo[2.2.2]octane (Sigma-Aldrich, 0.089 mmol) and anthranilic acid (Sigma-Aldrich, 0.19 mmol) in chloroform solution (6 ml); M.pt. 427–430 K.