4-Carbamoylpiperidinium 2-carb­oxy­benzoate–benzene-1,2-dicarb­oxy­lic acid (1/1)

Graham Smith; Urs D Wermuth

doi:10.1107/S1600536811003825

. 2011 Feb 5;67(Pt 3):o566. doi: 10.1107/S1600536811003825

4-Carbamoylpiperidinium 2-carboxybenzoate–benzene-1,2-dicarboxylic acid (1/1)

Graham Smith ^a,^*, Urs D Wermuth ^b

PMCID: PMC3052136 PMID: 21522329

Abstract

The asymmetric unit of the title salt adduct, C₆H₁₃N₂O⁺·C₈H₅O₄ ⁻·C₈H₆O₄, comprises one isonipecotamide cation, a hydrogen phthalate anion and a phthalic acid adduct molecule. These form a two-dimensional hydrogen-bonded network through head-to-tail cation–anion–adduct molecule interactions which include a cyclic heteromolecular amide–carboxylate motif [graph set R ₂ ²(8)], conjoint cyclic R ₂ ²(6) and R ₃ ³(10) piperidinium N—H⋯O_carboxyl associations, as well as strong carboxyl O—H⋯O_carboxyl hydrogen bonds.

Related literature

For structural data on isonipecotamide salts, see: Smith et al. (2010 ▶); Smith & Wermuth (2010a ▶,b ▶,c ▶,d ▶, 2011 ▶). For the crystal structure of o-phthalic acid, see: Ermer (1981 ▶). For hydrogen-bonding graph-set analysis, see: Etter et al. (1990 ▶).

Experimental

Crystal data

C₆H₁₃N₂O⁺·C₈H₅O₄ ⁻·C₈H₆O₄
M _r = 460.43
Triclinic,
a = 8.7857 (4) Å
b = 11.7907 (6) Å
c = 12.3188 (6) Å
α = 62.496 (5)°
β = 85.916 (4)°
γ = 82.604 (4)°
V = 1122.36 (11) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 200 K
0.40 × 0.30 × 0.18 mm

Data collection

Oxford Diffraction Gemini-S CCD-detector diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.923, T _max = 0.980
13586 measured reflections
4401 independent reflections
3444 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.094
S = 1.07
4401 reflections
326 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) within WinGX (Farrugia, 1999 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811003825/wn2419sup1.cif

e-67-0o566-sup1.cif^{(24.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811003825/wn2419Isup2.hkl

e-67-0o566-Isup2.hkl^{(211.2KB, 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
N1C—H11C⋯O21A	0.932 (19)	1.911 (19)	2.8287 (18)	167.7 (16)
N1C—H12C⋯O12Aⁱ	0.953 (18)	2.077 (17)	2.8519 (16)	137.4 (14)
N1C—H12C⋯O12Bⁱ	0.953 (18)	2.204 (17)	2.9606 (16)	135.6 (14)
N41C—H41C⋯O22Bⁱⁱ	0.979 (19)	1.994 (19)	2.9494 (17)	164.5 (16)
N41C—H42C⋯O11Bⁱⁱⁱ	0.930 (18)	2.120 (19)	3.0122 (17)	160.3 (16)
O11A—H11A⋯O12B	1.00 (2)	1.57 (2)	2.5635 (15)	173 (2)
O21B—H21B⋯O41C^iv	0.99 (2)	1.58 (2)	2.5644 (14)	171 (2)
O22A—H22A⋯O11Bⁱ	0.90 (2)	1.65 (2)	2.5363 (17)	170.8 (18)

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

Acknowledgments

The authors acknowledge financial support from the Australian Research Council, the Faculty of Science and Technology and the University Library, Queensland University of Technology and the School of Biomolecular and Physical Sciences, Griffith University.

supplementary crystallographic information

Comment

The amide piperidine-4-carboxamide (isonipecotamide, INIPA) has provided the structures of proton-transfer compounds with a range of organic acids, mainly aromatic (Smith & Wermuth, 2010a,b,c,d, 2011; Smith et al., 2010). The title compound, the salt adduct, C₆H₁₃N₂O⁺ C₈H₅O₄^- . C₈H₆O₄, was obtained from the 1:1 stoichiometric reaction of phthalic acid with INIPA in methanol and the crystal structure is reported here; it represents the first example of a salt–adduct of INIPA.

The asymmetric unit (Fig. 1) comprises an isonipecotamide cation, (C), a hydrogen phthalate anion (B) and a phthalic acid adduct molecule (A), which together form a two-dimensional hydrogen-bonded network through head-to-tail cation–anion–adduct molecule interactions (Table 1). These include a cyclic heteromolecular amide–carboxylate motif [graph set R₂²(8) (Etter et al., 1990)], conjoint cyclic R₂²(6) and R₃³(10) piperidinium N—H···O_carboxyl associations, as well as strong carboxylic acid O—H···O_carboxyl hydrogen bonds (Fig. 2). There is no occurrence of the cyclic homomolecular amide–amide dimer motif association, such as is found in the INIPA salts of the 2-nitro-, 4-nitro- and 3,5-dinitrobenzoic acids (Smith & Wermuth, 2010b) or of biphenyl-4,4'-disulfonic acid (Smith et al., 2010).

In the hydrogen phthalate anion (B) and the phthalic acid adduct molecule (A), the carboxyl substituent groups are rotated by differing degrees out of the planes of the benzene rings [torsion angles C1—C2—C21—O22 and C2—C1—C11—O11: -147.67 (6) and 52.9 (2)° [for B)] and -117.75 (15) and -157.57 (14)° [for A)], which compare with 20.3 (1)° for the parent acid molecule which has two-fold rotational symmetry (Ermer, 1981).

Experimental

The title compound was synthesized by heating together under reflux for 10 minutes, 1 mmol quantities of piperidine-4-carboxamide (isonipecotamide) and phthalic acid in 50 ml of methanol. After concentration to ca 30 ml, partial room temperature evaporation of the hot-filtered solution gave colourless plates of the title compound, from which a specimen was cleaved for the X-ray crystallographic analysis.