2,3-Diamino­pyridinium 4-nitro­benzoate

Kasthuri Balasubramani; Hoong-Kun Fun

doi:10.1107/S160053680902100X

. 2009 Jun 6;65(Pt 7):o1511–o1512. doi: 10.1107/S160053680902100X

2,3-Diaminopyridinium 4-nitrobenzoate

Kasthuri Balasubramani ^a, Hoong-Kun Fun ^a,^*,^‡

PMCID: PMC2969435 PMID: 21582806

Abstract

In the title salt, C₅H₈N₃ ⁺·C₇H₄NO₄ ⁻, the pyridine N atom of the 2,3-diaminopyridine molecule is protonated. The protonated N atom and one of the two 2-amino groups are hydrogen bonded to the 4-nitrobenzoate anion through a pair of N—H⋯O hydrogen bonds, forming an R ₂ ²(8) ring motif. The carboxylate mean plane of the 4-nitrobenzoate anion is twisted by 3.77 (5)° from the attached ring and the nitro group is similarly twisted by 2.28 (10)°. In the crystal, the molecules are linked by N—H⋯O and C—H⋯O interactions into sheets parallel to (100).

Related literature

For substituted pyridines, see: Pozharski et al. (1997 ▶); Katritzky et al. (1996 ▶); Jeffrey & Saenger (1991 ▶); Jeffrey (1997 ▶); Scheiner (1997 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₅H₈N₃ ⁺·C₇H₄NO₄ ⁻
M _r = 276.26
Monoclinic,
a = 8.0827 (2) Å
b = 6.7365 (1) Å
c = 11.4489 (3) Å
β = 101.967 (1)°
V = 609.83 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 100 K
0.25 × 0.17 × 0.10 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.972, T _max = 0.988
11659 measured reflections
2808 independent reflections
2155 reflections with I > 2σ(I)
R _int = 0.045

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.116
S = 1.04
2808 reflections
229 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTLsoftware used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680902100X/tk2462sup1.cif

e-65-o1511-sup1.cif^{(17.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680902100X/tk2462Isup2.hkl

e-65-o1511-Isup2.hkl^{(135KB, 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
N1—H1N1⋯O4	0.99 (3)	1.70 (3)	2.671 (2)	167 (3)
N2—H1N2⋯O3	0.89 (3)	2.01 (3)	2.901 (2)	178 (5)
N2—H2N2⋯O3ⁱ	0.86 (2)	2.06 (2)	2.903 (2)	171 (2)
N3—H1N3⋯O3ⁱ	0.85 (3)	2.14 (3)	2.951 (3)	159 (2)
N3—H2N3⋯O2ⁱⁱ	0.82 (3)	2.34 (3)	3.140 (2)	165 (3)
C10—H10A⋯O1ⁱⁱ	0.98 (3)	2.53 (3)	3.507 (2)	177 (2)
C11—H11A⋯O4ⁱⁱⁱ	0.99 (2)	2.56 (2)	3.216 (3)	124 (2)

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

Acknowledgments

HKF and KBS thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. KBS thanks Universiti Sains Malaysia for a post–doctoral research fellowship. HKF also thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

Pyridine and its derivatives play an important role in heterocyclic chemistry (Pozharski et al., 1997; Katritzky et al., 1996). Pyridine and its substituted derivatives are often involved in hydrogen bonding interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). In order to study some interesting hydrogen bonding interactions, the synthesis and structure of the title salt (I) is presented here.

The asymmetric unit of (I), Fig. 1, contains a protonated 2,3-diaminopyridinium cation and a 4-nitrobenzoate anion. In the 2,3-diaminopyridinium cation, a wide angle (123.62 (17)°) is subtended at the protonated N1 atom. The 2,3-diaminopyridinium cation is planar, with a maximum deviation of 0.005 (2)Å for atom C1. The carboxylate group is twisted slightly from the ring; the dihedral angle between C1—C6 and O3/O4/C7/C6 planes is 5.41 (10)°. The nitro group is also slightly twisted away from its attached benzene ring by 2.28 (10)°.

In the crystal packing, Fig. 2, the protonated N1 atom and the 2-amino group (N2) is hydrogen-bonded to the carboxylate oxygen atoms (O3 and O4) via a pair of N—H···O hydrogen bonds forming a ring motif, R₂²(8) (Bernstein et al., 1995). The 2-amino groups (N2 and N3) are involved in N—H···O3 hydrogen bonding interactions to form a R¹₂(7) ring motif. One of the amino group hydrogen atoms, H2N3, and the ring hydrogen atom, H10A, are connected to the 4-nitro group oxygen atoms (O1 and O2) to form an R₂²(8) ring motif (Table 1 and Fig. 2). These molecules are linked by these interactions into sheets parallel to (100). The crystal structure is further stabilized by a π-π stacking interactions between the aminopyridine- and carboxylate-rings with centroid-to-centroid distances of 3.8343 (10) Å.

Experimental

Hot methanol solutions (20 ml) of 2,3-diaminopyridine (27 mg, Aldrich) and 4-nitrobenzoic acid (42 mg, Merck) were mixed and warmed over a heating magnetic stirrer for 5 minutes. The resulting solution was allowed to cool slowly at room temperature. Crystals of (I) appeared from the mother liquor after a few days.