2-Amino-5-chloro­pyridinium 2-carb­oxy­acetate

Madhukar Hemamalini; Hoong-Kun Fun

doi:10.1107/S1600536810019677

. 2010 May 29;66(Pt 6):o1496–o1497. doi: 10.1107/S1600536810019677

2-Amino-5-chloropyridinium 2-carboxyacetate

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

PMCID: PMC2979552 PMID: 21579558

Abstract

The title salt, C₅H₆ClN₂ ⁺·C₃H₃O₄ ⁻, contains two cations and two anions in the asymmetric unit. Both 2-amino-5-chloropyridinium ions are protonated at their pyridine N atoms and both hydrogen malonate ions feature an intramolecular O—H⋯O hydrogen bond, which generates an S(6) ring motif and results in a folded conformation. In the crystal structure, the cations and anions are linked via N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds, forming chains propagating in [010], which are cross-linked by further C—H⋯O interactions.

Related literature

For background to the chemistry of substituted pyridines, see: Amr et al. (2006 ▶); Bart et al. (2001 ▶); Shinkai et al. (2000 ▶); Klimesôva et al. (1999 ▶). For related structures, see: Pourayoubi et al. (2007 ▶); Janczak & Perpétuo (2009 ▶); Akriche & Rzaigui (2005 ▶). For details of hydrogen bonding, see: Jeffrey & Saenger (1991 ▶); Jeffrey (1997 ▶); Scheiner (1997 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For bond-length data, see: Allen et al. (1987 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₅H₆ClN₂ ⁺·C₃H₃O₄ ⁻
M _r = 232.62
Monoclinic,
a = 15.6971 (19) Å
b = 16.866 (2) Å
c = 7.4662 (10) Å
β = 94.518 (3)°
V = 1970.5 (4) Å³
Z = 8
Mo Kα radiation
μ = 0.38 mm⁻¹
T = 100 K
0.22 × 0.14 × 0.07 mm

Data collection

Bruker APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.921, T _max = 0.973
22474 measured reflections
5811 independent reflections
4314 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.097
S = 1.01
5811 reflections
343 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.29 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/S1600536810019677/hb5466sup1.cif

e-66-o1496-sup1.cif^{(21.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810019677/hb5466Isup2.hkl

e-66-o1496-Isup2.hkl^{(278.8KB, 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
N1A—H1NA⋯O1A	0.93 (2)	1.68 (2)	2.5982 (17)	171 (2)
N2A—H2NA⋯O2A	0.95 (2)	2.01 (2)	2.9518 (19)	169.1 (18)
N2A—H3NA⋯O3Bⁱ	0.87 (2)	2.07 (2)	2.9333 (18)	178 (2)
N1B—H1NB⋯O1B	0.92 (2)	1.69 (2)	2.5980 (17)	169 (2)
N2B—H2NB⋯O2B	0.88 (2)	2.08 (2)	2.9538 (19)	175 (2)
N2B—H3NB⋯O3Aⁱⁱ	0.93 (2)	2.04 (2)	2.9598 (19)	175 (2)
O4A—H1OA⋯O2A	0.94 (2)	1.58 (2)	2.4835 (16)	158 (2)
O4B—H1OB⋯O2B	0.93 (3)	1.57 (3)	2.4752 (16)	162 (3)
C1A—H1A⋯O3Bⁱⁱⁱ	0.960 (18)	2.458 (18)	3.374 (2)	159.6 (14)
C1B—H1B⋯O3Aⁱⁱⁱ	0.98 (2)	2.46 (2)	3.417 (2)	166.1 (18)
C7A—H7AB⋯O1Bⁱⁱⁱ	0.97 (2)	2.31 (2)	3.2509 (19)	162.6 (18)
C7B—H7BB⋯O4A^iv	0.96 (2)	2.55 (2)	3.440 (2)	155.7 (16)
C4A—H4A⋯O4Bⁱ	0.95 (2)	2.32 (2)	3.264 (2)	171.6 (18)
C4B—H4B⋯O4Aⁱⁱ	0.94 (2)	2.30 (2)	3.237 (2)	177.4 (17)

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

Acknowledgments

MH and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

Pyridine and its derivatives continue to attract great interest due to the wide variety of interesting biological activities observed for these compounds, such as anticancer, analgesic, antimicrobial, and antidepressant activities (Amr et al., 2006; Bart et al., 2001; Shinkai et al., 2000; Klimesôva et al., 1999). They are often involved in hydrogen-bond interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). The crystal structures of 2-amino-5-chloropyridine (Pourayoubi et al., 2007), 2-amino-5-chloropyridinium trichloroacetate (Janczak & Perpétuo, 2009) and bis(2-amino-5-chloropyridinium)dihydrogendi phosphate (Akriche & Rzaigui, 2005) have been reported. Since our aim is to study some interesting hydrogen-bonding interactions, the crystal structure of the title salt, (I), is presented here.

The asymmetric unit of the title salt consists of two crystallographically independent 2-amino-5-chloropyridinium cations and two hydrogen malonate anions, with atom labelling suffixes of A & B (Fig. 1). Each 2-amino-5-chloropyridinium cation is planar, with a maximum deviation of 0.002 (1) Å for C5A atom (molecule A) and 0.009 (1) Å for atom N1B (molecule B). In the cations, protonation at atoms N1A and N1B lead to slight increases in the C1A—N1A—C5A [123.22 (13)°] and C1B—N1B—C5B [122.97 (14)°] angles compared to those observed in an unprotonated structure (Pourayoubi et al., 2007). The bond lengths (Allen et al., 1987) and angles are normal.

In the crystal structure, (Fig. 2), the ionic units are linked by N1A—H1NA···O1A; N2A—H2NA···O2A; N2A—H3NA···O3B; N1B—H1NB···O1B; N2B—H2NB···O2B; N2B—H3NB···O3A; C1A—H1A···O3B; C1B—H1B···O3A; C4A—H4A···O4B and C4B—H4B···O4A (Table 1) hydrogen bonds, forming one-dimensional chains along the b-axis. Furthermore, these chains are inter-connected by intermolecular C7A—H7AB···O1B and C7B—H7BB···O4A hydrogen bonds. There are intramolecular O4A—H1OA···O2A and O4B—H1OB···O2B hydrogen bonds in the hydrogen malonate anions, which generate S(6) (Bernstein et al., 1995) ring motifs, resulting in folded conformation.

Experimental

A hot methanol solution (20 ml) of 2-amino-5-chloropyridine (64 mg, Aldrich) and malonic acid acid (52 mg, Merck) were mixed and warmed over a heating magnetic stirrer hotplate for a few minutes. The resulting solution was allowed to cool slowly at room temperature and colourless needles of (I) appeared after a few days.