organic compounds
2,3-Diaminopyridinium 4-nitrobenzoate
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my
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 R22(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
|
Refinement
|
Data collection: APEX2 (Bruker, 2005); cell 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).
Supporting information
10.1107/S160053680902100X/tk2462sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S160053680902100X/tk2462Isup2.hkl
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.
All the H atoms were located from the difference Fourier map [N–H = 0.82 (3)–0.99 (3)Å and C–H = 0.91 (2)–0.99 (2) Å] and allowed to refine freely. In the absence of significant
effects, 2144 Friedel pairs were merged.Data collection: APEX2 (Bruker, 2005); cell
SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).Fig. 1. The molecular structures of the ions in (I), illustrating the primary mode of association between them, showing 50% probability displacement ellipsoids and the atom numbering scheme. Dashed lines indicate the hydrogen bonding. | |
Fig. 2. The crystal packing of (I). Dashed lines indicate the hydrogen bondings. |
C5H8N3+·C7H4NO4− | F(000) = 288 |
Mr = 276.26 | Dx = 1.504 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 2526 reflections |
a = 8.0827 (2) Å | θ = 2.8–31.7° |
b = 6.7365 (1) Å | µ = 0.12 mm−1 |
c = 11.4489 (3) Å | T = 100 K |
β = 101.967 (1)° | Block, brown |
V = 609.83 (2) Å3 | 0.25 × 0.17 × 0.10 mm |
Z = 2 |
Bruker SMART APEXII CCD area-detector diffractometer | 2808 independent reflections |
Radiation source: fine-focus sealed tube | 2155 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.045 |
ϕ and ω scans | θmax = 34.9°, θmin = 2.6° |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | h = −12→12 |
Tmin = 0.972, Tmax = 0.988 | k = −10→10 |
11659 measured reflections | l = −17→18 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.116 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0571P)2 + 0.026P] where P = (Fo2 + 2Fc2)/3 |
2808 reflections | (Δ/σ)max < 0.001 |
229 parameters | Δρmax = 0.43 e Å−3 |
1 restraint | Δρmin = −0.30 e Å−3 |
C5H8N3+·C7H4NO4− | V = 609.83 (2) Å3 |
Mr = 276.26 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 8.0827 (2) Å | µ = 0.12 mm−1 |
b = 6.7365 (1) Å | T = 100 K |
c = 11.4489 (3) Å | 0.25 × 0.17 × 0.10 mm |
β = 101.967 (1)° |
Bruker SMART APEXII CCD area-detector diffractometer | 2808 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 2155 reflections with I > 2σ(I) |
Tmin = 0.972, Tmax = 0.988 | Rint = 0.045 |
11659 measured reflections |
R[F2 > 2σ(F2)] = 0.052 | 1 restraint |
wR(F2) = 0.116 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | Δρmax = 0.43 e Å−3 |
2808 reflections | Δρmin = −0.30 e Å−3 |
229 parameters |
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K. |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
O1 | −0.0506 (2) | −0.7085 (2) | 0.85306 (17) | 0.0306 (4) | |
O2 | −0.04637 (19) | −0.7831 (2) | 0.66897 (16) | 0.0269 (4) | |
O3 | 0.35100 (19) | 0.1109 (2) | 0.60686 (14) | 0.0223 (3) | |
O4 | 0.35695 (19) | 0.1713 (2) | 0.79972 (14) | 0.0210 (3) | |
N4 | −0.0141 (2) | −0.6717 (3) | 0.75606 (18) | 0.0213 (4) | |
C1 | 0.1816 (2) | −0.1740 (3) | 0.82546 (19) | 0.0178 (4) | |
C2 | 0.1021 (2) | −0.3532 (3) | 0.8391 (2) | 0.0183 (4) | |
C3 | 0.0723 (2) | −0.4824 (3) | 0.7432 (2) | 0.0178 (4) | |
C4 | 0.1172 (2) | −0.4421 (3) | 0.6355 (2) | 0.0196 (4) | |
C5 | 0.1973 (2) | −0.2624 (3) | 0.6234 (2) | 0.0180 (4) | |
C6 | 0.2309 (2) | −0.1287 (3) | 0.71862 (19) | 0.0162 (4) | |
C7 | 0.3201 (2) | 0.0666 (3) | 0.70675 (18) | 0.0169 (4) | |
N1 | 0.5459 (2) | 0.4983 (2) | 0.80784 (16) | 0.0179 (3) | |
N2 | 0.5600 (2) | 0.4619 (3) | 0.60992 (18) | 0.0213 (4) | |
N3 | 0.7324 (2) | 0.8308 (3) | 0.62077 (18) | 0.0212 (4) | |
C8 | 0.5959 (2) | 0.5681 (3) | 0.71027 (19) | 0.0166 (4) | |
C9 | 0.6873 (2) | 0.7522 (3) | 0.72040 (19) | 0.0168 (4) | |
C10 | 0.7217 (2) | 0.8451 (3) | 0.8301 (2) | 0.0197 (4) | |
C11 | 0.6717 (2) | 0.7629 (3) | 0.9295 (2) | 0.0213 (4) | |
C12 | 0.5820 (2) | 0.5895 (3) | 0.91644 (19) | 0.0199 (4) | |
H1A | 0.201 (3) | −0.084 (4) | 0.887 (2) | 0.020 (6)* | |
H2A | 0.068 (3) | −0.384 (4) | 0.914 (2) | 0.020 (6)* | |
H4A | 0.089 (3) | −0.535 (5) | 0.569 (2) | 0.033 (7)* | |
H5A | 0.232 (3) | −0.233 (4) | 0.547 (2) | 0.021 (6)* | |
H10A | 0.782 (3) | 0.972 (5) | 0.834 (2) | 0.029 (7)* | |
H11A | 0.711 (3) | 0.821 (4) | 1.010 (2) | 0.027 (7)* | |
H12A | 0.540 (3) | 0.527 (4) | 0.978 (2) | 0.021 (6)* | |
H1N1 | 0.478 (3) | 0.375 (5) | 0.793 (3) | 0.038 (8)* | |
H1N2 | 0.497 (4) | 0.353 (5) | 0.608 (3) | 0.038 (8)* | |
H2N2 | 0.579 (3) | 0.496 (4) | 0.542 (2) | 0.017 (6)* | |
H1N3 | 0.735 (3) | 0.759 (5) | 0.560 (2) | 0.025 (7)* | |
H2N3 | 0.806 (4) | 0.917 (5) | 0.635 (3) | 0.037 (8)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0374 (9) | 0.0213 (8) | 0.0368 (10) | −0.0086 (6) | 0.0162 (8) | 0.0038 (7) |
O2 | 0.0274 (7) | 0.0170 (7) | 0.0348 (10) | −0.0058 (6) | 0.0027 (7) | −0.0027 (7) |
O3 | 0.0293 (7) | 0.0175 (6) | 0.0226 (8) | −0.0035 (5) | 0.0109 (6) | 0.0002 (6) |
O4 | 0.0281 (7) | 0.0164 (6) | 0.0199 (8) | −0.0056 (5) | 0.0083 (6) | −0.0023 (6) |
N4 | 0.0165 (7) | 0.0146 (7) | 0.0320 (10) | −0.0015 (6) | 0.0030 (7) | 0.0026 (8) |
C1 | 0.0213 (8) | 0.0139 (8) | 0.0187 (10) | −0.0012 (7) | 0.0053 (7) | −0.0008 (8) |
C2 | 0.0185 (8) | 0.0155 (8) | 0.0215 (10) | −0.0007 (6) | 0.0054 (7) | 0.0030 (8) |
C3 | 0.0166 (8) | 0.0116 (7) | 0.0255 (11) | −0.0015 (6) | 0.0053 (7) | 0.0010 (7) |
C4 | 0.0216 (8) | 0.0132 (8) | 0.0249 (11) | −0.0008 (6) | 0.0067 (8) | −0.0015 (8) |
C5 | 0.0205 (8) | 0.0146 (8) | 0.0196 (10) | −0.0010 (7) | 0.0056 (7) | −0.0018 (8) |
C6 | 0.0176 (8) | 0.0111 (8) | 0.0201 (10) | 0.0012 (6) | 0.0043 (7) | 0.0032 (7) |
C7 | 0.0180 (8) | 0.0128 (8) | 0.0208 (10) | 0.0003 (6) | 0.0058 (7) | 0.0008 (8) |
N1 | 0.0188 (7) | 0.0161 (7) | 0.0191 (9) | −0.0021 (6) | 0.0048 (6) | 0.0004 (7) |
N2 | 0.0300 (9) | 0.0176 (8) | 0.0182 (9) | −0.0056 (6) | 0.0094 (7) | −0.0014 (7) |
N3 | 0.0273 (8) | 0.0178 (7) | 0.0201 (9) | −0.0061 (7) | 0.0089 (7) | −0.0003 (8) |
C8 | 0.0158 (7) | 0.0136 (8) | 0.0208 (10) | −0.0012 (6) | 0.0046 (7) | 0.0007 (8) |
C9 | 0.0157 (7) | 0.0161 (8) | 0.0189 (9) | 0.0003 (6) | 0.0042 (6) | 0.0023 (8) |
C10 | 0.0199 (8) | 0.0168 (8) | 0.0228 (11) | −0.0021 (7) | 0.0055 (7) | −0.0018 (8) |
C11 | 0.0210 (8) | 0.0225 (9) | 0.0206 (11) | −0.0001 (7) | 0.0051 (7) | −0.0028 (8) |
C12 | 0.0201 (8) | 0.0223 (9) | 0.0176 (10) | −0.0010 (7) | 0.0045 (7) | 0.0004 (8) |
O1—N4 | 1.232 (2) | N1—C8 | 1.349 (3) |
O2—N4 | 1.232 (2) | N1—C12 | 1.363 (3) |
O3—C7 | 1.256 (2) | N1—H1N1 | 0.99 (3) |
O4—C7 | 1.260 (2) | N2—C8 | 1.333 (3) |
N4—C3 | 1.476 (2) | N2—H1N2 | 0.89 (3) |
C1—C2 | 1.391 (3) | N2—H2N2 | 0.85 (3) |
C1—C6 | 1.397 (3) | N3—C9 | 1.373 (3) |
C1—H1A | 0.92 (3) | N3—H1N3 | 0.85 (3) |
C2—C3 | 1.383 (3) | N3—H2N3 | 0.82 (3) |
C2—H2A | 0.98 (3) | C8—C9 | 1.435 (3) |
C3—C4 | 1.382 (3) | C9—C10 | 1.379 (3) |
C4—C5 | 1.394 (3) | C10—C11 | 1.399 (3) |
C4—H4A | 0.98 (3) | C10—H10A | 0.98 (3) |
C5—C6 | 1.396 (3) | C11—C12 | 1.367 (3) |
C5—H5A | 0.99 (3) | C11—H11A | 0.99 (3) |
C6—C7 | 1.520 (3) | C12—H12A | 0.94 (3) |
O2—N4—O1 | 123.84 (17) | C8—N1—C12 | 123.62 (17) |
O2—N4—C3 | 118.06 (18) | C8—N1—H1N1 | 113.8 (17) |
O1—N4—C3 | 118.10 (18) | C12—N1—H1N1 | 122.6 (17) |
C2—C1—C6 | 120.69 (19) | C8—N2—H1N2 | 119.0 (19) |
C2—C1—H1A | 119.4 (17) | C8—N2—H2N2 | 126.1 (17) |
C6—C1—H1A | 119.9 (17) | H1N2—N2—H2N2 | 114 (2) |
C3—C2—C1 | 117.7 (2) | C9—N3—H1N3 | 121 (2) |
C3—C2—H2A | 122.2 (16) | C9—N3—H2N3 | 114 (2) |
C1—C2—H2A | 120.1 (16) | H1N3—N3—H2N3 | 115 (3) |
C4—C3—C2 | 123.38 (18) | N2—C8—N1 | 118.49 (17) |
C4—C3—N4 | 118.44 (18) | N2—C8—C9 | 123.34 (19) |
C2—C3—N4 | 118.18 (18) | N1—C8—C9 | 118.16 (18) |
C3—C4—C5 | 118.21 (19) | N3—C9—C10 | 122.90 (18) |
C3—C4—H4A | 120.7 (17) | N3—C9—C8 | 119.10 (19) |
C5—C4—H4A | 121.1 (17) | C10—C9—C8 | 117.97 (18) |
C4—C5—C6 | 120.13 (19) | C9—C10—C11 | 121.58 (18) |
C4—C5—H5A | 118.6 (16) | C9—C10—H10A | 116.5 (16) |
C6—C5—H5A | 121.2 (16) | C11—C10—H10A | 121.9 (16) |
C5—C6—C1 | 119.87 (17) | C12—C11—C10 | 119.1 (2) |
C5—C6—C7 | 120.51 (17) | C12—C11—H11A | 120.1 (16) |
C1—C6—C7 | 119.62 (17) | C10—C11—H11A | 120.5 (16) |
O3—C7—O4 | 125.37 (18) | N1—C12—C11 | 119.6 (2) |
O3—C7—C6 | 118.35 (18) | N1—C12—H12A | 115.8 (16) |
O4—C7—C6 | 116.28 (17) | C11—C12—H12A | 124.6 (16) |
C6—C1—C2—C3 | −0.8 (3) | C1—C6—C7—O3 | −174.40 (17) |
C1—C2—C3—C4 | −0.1 (3) | C5—C6—C7—O4 | −174.72 (17) |
C1—C2—C3—N4 | −179.16 (16) | C1—C6—C7—O4 | 5.6 (2) |
O2—N4—C3—C4 | −1.9 (3) | C12—N1—C8—N2 | 177.00 (18) |
O1—N4—C3—C4 | 178.55 (18) | C12—N1—C8—C9 | −2.2 (3) |
O2—N4—C3—C2 | 177.21 (18) | N2—C8—C9—N3 | 3.9 (3) |
O1—N4—C3—C2 | −2.3 (3) | N1—C8—C9—N3 | −176.90 (17) |
C2—C3—C4—C5 | 0.4 (3) | N2—C8—C9—C10 | −177.88 (18) |
N4—C3—C4—C5 | 179.44 (17) | N1—C8—C9—C10 | 1.3 (2) |
C3—C4—C5—C6 | 0.2 (3) | N3—C9—C10—C11 | 178.94 (19) |
C4—C5—C6—C1 | −1.0 (3) | C8—C9—C10—C11 | 0.8 (3) |
C4—C5—C6—C7 | 179.32 (16) | C9—C10—C11—C12 | −2.1 (3) |
C2—C1—C6—C5 | 1.3 (3) | C8—N1—C12—C11 | 0.9 (3) |
C2—C1—C6—C7 | −179.02 (17) | C10—C11—C12—N1 | 1.3 (3) |
C5—C6—C7—O3 | 5.3 (3) |
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) | 176.9 (16) |
C11—H11A···O4iii | 0.99 (2) | 2.56 (2) | 3.216 (3) | 123.5 (19) |
Symmetry codes: (i) −x+1, y+1/2, −z+1; (ii) x+1, y+2, z; (iii) −x+1, y+1/2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C5H8N3+·C7H4NO4− |
Mr | 276.26 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 100 |
a, b, c (Å) | 8.0827 (2), 6.7365 (1), 11.4489 (3) |
β (°) | 101.967 (1) |
V (Å3) | 609.83 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.12 |
Crystal size (mm) | 0.25 × 0.17 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.972, 0.988 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11659, 2808, 2155 |
Rint | 0.045 |
(sin θ/λ)max (Å−1) | 0.805 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.116, 1.04 |
No. of reflections | 2808 |
No. of parameters | 229 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.43, −0.30 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
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) | 176.9 (16) |
C11—H11A···O4iii | 0.99 (2) | 2.56 (2) | 3.216 (3) | 123.5 (19) |
Symmetry codes: (i) −x+1, y+1/2, −z+1; (ii) x+1, y+2, z; (iii) −x+1, y+1/2, −z+2. |
Footnotes
‡Thomson Reuters ResearcherID: A-3561-2009.
Acknowledgements
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.
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107. CrossRef CAS Web of Science IUCr Journals Google Scholar
Jeffrey, G. A. (1997). In An Introduction to Hydrogen Bonding. Oxford University Press. Google Scholar
Jeffrey, G. A. & Saenger, W. (1991). In Hydrogen Bonding in Biological Structures. Berlin: Springer. Google Scholar
Katritzky, A. R., Rees, C. W. & Scriven, E. F. V. (1996). In Comprehensive Heterocyclic Chemistry II. Oxford: Pergamon Press. Google Scholar
Pozharski, A. F., Soldatenkov, A. T. & Katritzky, A. R. (1997). In Heterocycles in Life and Society. New York: Wiley. Google Scholar
Scheiner, S. (1997). In Hydrogen Bonding, A Theoretical Perspective. Oxford University Press. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
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.