organic compounds
2-Amino-5-methylpyridinium 3-aminobenzoate
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my
In the title compound, C6H9N2+·C7H6NO2−, the H atom of the N—H group and an H atom of the 2-amino group from the cation are involved in intermolecular N—H⋯O hydrogen bonds with the O atoms of the carboxylate group of the anion, forming an R22(8) ring motif. These ring motifs are, in turn, connected by further N—H⋯O hydrogen bonds, forming a two-dimensional network. The is further stabilized by π⋯π stacking interactions involving the benzene and pyridinium rings with a centroid–centroid distance of 3.7594 (8) Å.
Related literature
For background to the chemistry of substituted pyridines see: Pozharski et al. (1997); Katritzky et al. (1996). For related structures, see: Nahringbauer & Kvick (1977); Feng et al. (2005); Xuan et al. (2003); Jin et al. (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).
Experimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 2009); cell 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).
Supporting information
10.1107/S1600536810005180/lh2994sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810005180/lh2994Isup2.hkl
A hot methanol solution (20 ml) of 2-amino-5-methylpyridine (54 mg, Aldrich) and 3-aminobenzoic acid (68 mg, Merck) were mixed and warmed over a heating magnetic stirrer for a few minutes. The resulting solution was allowed to cool slowly at room temperature and crystals of the title compound appeared after a few days.
The methyl H atoms were positioned geometrically and were refined using a riding model, with Uiso(H) = 1.5Ueq(C). A rotating group model was used for the methyl group. The remaining H atoms were located in a difference map and refined freely [N–H = 0.92 (2)–1.02 (2)Å, C–H = 0.96–1.00 (2)Å].
Data collection: APEX2 (Bruker, 2009); cell
SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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 asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level. | |
Fig. 2. The crystal packing of the title compound, showing hydrogen-bonded (dashed lines) networks. |
C6H9N2+·C7H6NO2− | F(000) = 520 |
Mr = 245.28 | Dx = 1.341 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3778 reflections |
a = 10.0739 (2) Å | θ = 2.6–29.9° |
b = 10.9620 (2) Å | µ = 0.09 mm−1 |
c = 11.9641 (2) Å | T = 296 K |
β = 113.148 (1)° | Plate, brown |
V = 1214.83 (4) Å3 | 0.72 × 0.34 × 0.13 mm |
Z = 4 |
Bruker SMART APEXII CCD area-detector diffractometer | 3541 independent reflections |
Radiation source: fine-focus sealed tube | 2576 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.029 |
ϕ and ω scans | θmax = 30.1°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −10→14 |
Tmin = 0.936, Tmax = 0.988 | k = −15→13 |
13305 measured reflections | l = −16→16 |
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)] = 0.048 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.138 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0676P)2 + 0.1203P] where P = (Fo2 + 2Fc2)/3 |
3541 reflections | (Δ/σ)max = 0.001 |
212 parameters | Δρmax = 0.20 e Å−3 |
0 restraints | Δρmin = −0.26 e Å−3 |
C6H9N2+·C7H6NO2− | V = 1214.83 (4) Å3 |
Mr = 245.28 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.0739 (2) Å | µ = 0.09 mm−1 |
b = 10.9620 (2) Å | T = 296 K |
c = 11.9641 (2) Å | 0.72 × 0.34 × 0.13 mm |
β = 113.148 (1)° |
Bruker SMART APEXII CCD area-detector diffractometer | 3541 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 2576 reflections with I > 2σ(I) |
Tmin = 0.936, Tmax = 0.988 | Rint = 0.029 |
13305 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.138 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.20 e Å−3 |
3541 reflections | Δρmin = −0.26 e Å−3 |
212 parameters |
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) k. |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 | ||
N1 | 0.03024 (11) | 0.31395 (9) | 0.56765 (8) | 0.0363 (2) | |
N2 | −0.07229 (13) | 0.27732 (11) | 0.70650 (10) | 0.0477 (3) | |
C1 | 0.12267 (13) | 0.37351 (11) | 0.52889 (10) | 0.0377 (3) | |
C2 | 0.01813 (13) | 0.34187 (11) | 0.67327 (10) | 0.0364 (3) | |
C3 | 0.10505 (14) | 0.43720 (12) | 0.74341 (10) | 0.0418 (3) | |
C4 | 0.19709 (14) | 0.49686 (12) | 0.70412 (11) | 0.0430 (3) | |
C5 | 0.20896 (13) | 0.46594 (11) | 0.59348 (10) | 0.0390 (3) | |
C6 | 0.31252 (16) | 0.53099 (14) | 0.55236 (13) | 0.0546 (4) | |
H6A | 0.2979 | 0.5045 | 0.4719 | 0.082* | |
H6B | 0.4097 | 0.5128 | 0.6069 | 0.082* | |
H6C | 0.2964 | 0.6173 | 0.5519 | 0.082* | |
O1 | 0.74312 (11) | 0.37847 (9) | 1.02381 (8) | 0.0506 (3) | |
O2 | 0.87300 (12) | 0.35863 (9) | 0.91200 (8) | 0.0552 (3) | |
N3 | 0.44474 (16) | 0.75758 (13) | 0.87306 (15) | 0.0620 (4) | |
C7 | 0.61001 (13) | 0.58920 (11) | 0.90248 (10) | 0.0380 (3) | |
C8 | 0.54279 (13) | 0.69494 (11) | 0.84017 (11) | 0.0396 (3) | |
C9 | 0.57809 (14) | 0.73551 (12) | 0.74452 (11) | 0.0415 (3) | |
C10 | 0.67681 (15) | 0.67294 (12) | 0.71301 (11) | 0.0424 (3) | |
C11 | 0.74400 (14) | 0.56839 (12) | 0.77538 (10) | 0.0392 (3) | |
C12 | 0.70967 (12) | 0.52632 (10) | 0.87065 (9) | 0.0343 (3) | |
C13 | 0.78005 (13) | 0.41271 (11) | 0.94066 (9) | 0.0371 (3) | |
H1 | 0.1227 (15) | 0.3450 (13) | 0.4509 (14) | 0.049 (4)* | |
H3 | 0.0993 (15) | 0.4581 (13) | 0.8200 (13) | 0.048 (4)* | |
H4 | 0.2602 (17) | 0.5628 (15) | 0.7561 (14) | 0.061 (4)* | |
H7 | 0.5865 (15) | 0.5593 (13) | 0.9703 (13) | 0.046 (4)* | |
H9 | 0.5270 (16) | 0.8131 (14) | 0.6969 (14) | 0.056 (4)* | |
H10 | 0.7025 (16) | 0.7023 (13) | 0.6453 (14) | 0.053 (4)* | |
H11 | 0.8116 (16) | 0.5214 (14) | 0.7520 (13) | 0.050 (4)* | |
H1N1 | −0.0365 (17) | 0.2494 (16) | 0.5130 (15) | 0.062 (5)* | |
H1N2 | −0.1357 (17) | 0.2226 (15) | 0.6504 (14) | 0.056 (4)* | |
H2N2 | −0.0953 (16) | 0.3031 (14) | 0.7699 (15) | 0.055 (4)* | |
H1N3 | 0.4107 (18) | 0.7223 (17) | 0.9247 (17) | 0.067 (5)* | |
H2N3 | 0.395 (2) | 0.8179 (18) | 0.8245 (18) | 0.077 (6)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0421 (5) | 0.0357 (5) | 0.0327 (4) | −0.0030 (4) | 0.0163 (4) | −0.0047 (4) |
N2 | 0.0578 (7) | 0.0513 (7) | 0.0429 (5) | −0.0101 (6) | 0.0294 (5) | −0.0079 (5) |
C1 | 0.0405 (6) | 0.0398 (6) | 0.0341 (5) | −0.0004 (5) | 0.0162 (5) | −0.0022 (4) |
C2 | 0.0412 (6) | 0.0359 (6) | 0.0336 (5) | 0.0034 (5) | 0.0163 (4) | −0.0009 (4) |
C3 | 0.0457 (7) | 0.0433 (7) | 0.0359 (5) | 0.0016 (6) | 0.0156 (5) | −0.0092 (5) |
C4 | 0.0420 (7) | 0.0386 (6) | 0.0448 (6) | −0.0020 (5) | 0.0132 (5) | −0.0103 (5) |
C5 | 0.0372 (6) | 0.0371 (6) | 0.0421 (6) | 0.0004 (5) | 0.0148 (5) | −0.0003 (5) |
C6 | 0.0516 (8) | 0.0563 (9) | 0.0584 (8) | −0.0131 (7) | 0.0242 (6) | −0.0058 (6) |
O1 | 0.0655 (6) | 0.0505 (6) | 0.0456 (5) | 0.0114 (5) | 0.0323 (4) | 0.0126 (4) |
O2 | 0.0757 (7) | 0.0558 (6) | 0.0455 (5) | 0.0294 (5) | 0.0362 (5) | 0.0148 (4) |
N3 | 0.0660 (9) | 0.0531 (8) | 0.0837 (9) | 0.0201 (7) | 0.0475 (8) | 0.0152 (7) |
C7 | 0.0419 (6) | 0.0377 (6) | 0.0380 (5) | 0.0000 (5) | 0.0197 (5) | 0.0003 (5) |
C8 | 0.0363 (6) | 0.0370 (6) | 0.0461 (6) | −0.0003 (5) | 0.0169 (5) | −0.0025 (5) |
C9 | 0.0404 (7) | 0.0366 (6) | 0.0441 (6) | 0.0001 (5) | 0.0130 (5) | 0.0053 (5) |
C10 | 0.0463 (7) | 0.0442 (7) | 0.0387 (5) | −0.0021 (6) | 0.0187 (5) | 0.0062 (5) |
C11 | 0.0426 (7) | 0.0414 (7) | 0.0376 (5) | 0.0025 (5) | 0.0200 (5) | 0.0007 (5) |
C12 | 0.0378 (6) | 0.0339 (6) | 0.0308 (5) | −0.0006 (5) | 0.0130 (4) | −0.0014 (4) |
C13 | 0.0465 (7) | 0.0354 (6) | 0.0300 (5) | 0.0033 (5) | 0.0156 (4) | −0.0008 (4) |
N1—C2 | 1.3515 (14) | O1—C13 | 1.2490 (14) |
N1—C1 | 1.3593 (16) | O2—C13 | 1.2642 (15) |
N1—H1N1 | 1.018 (17) | N3—C8 | 1.3811 (18) |
N2—C2 | 1.3316 (16) | N3—H1N3 | 0.904 (19) |
N2—H1N2 | 0.938 (17) | N3—H2N3 | 0.89 (2) |
N2—H2N2 | 0.921 (17) | C7—C12 | 1.3888 (17) |
C1—C5 | 1.3607 (17) | C7—C8 | 1.4003 (17) |
C1—H1 | 0.984 (15) | C7—H7 | 0.986 (15) |
C2—C3 | 1.4090 (17) | C8—C9 | 1.3977 (18) |
C3—C4 | 1.3605 (19) | C9—C10 | 1.3771 (19) |
C3—H3 | 0.968 (14) | C9—H9 | 1.040 (16) |
C4—C5 | 1.4163 (17) | C10—C11 | 1.3897 (18) |
C4—H4 | 1.001 (16) | C10—H10 | 0.995 (15) |
C5—C6 | 1.4974 (19) | C11—C12 | 1.3933 (16) |
C6—H6A | 0.9600 | C11—H11 | 0.978 (15) |
C6—H6B | 0.9600 | C12—C13 | 1.5126 (16) |
C6—H6C | 0.9600 | ||
C2—N1—C1 | 122.40 (10) | H6B—C6—H6C | 109.5 |
C2—N1—H1N1 | 118.6 (9) | C8—N3—H1N3 | 119.2 (11) |
C1—N1—H1N1 | 118.9 (9) | C8—N3—H2N3 | 117.7 (13) |
C2—N2—H1N2 | 118.7 (10) | H1N3—N3—H2N3 | 119.6 (17) |
C2—N2—H2N2 | 120.4 (10) | C12—C7—C8 | 121.01 (11) |
H1N2—N2—H2N2 | 117.6 (13) | C12—C7—H7 | 119.6 (8) |
N1—C1—C5 | 122.30 (11) | C8—C7—H7 | 119.4 (8) |
N1—C1—H1 | 115.2 (8) | N3—C8—C9 | 121.04 (12) |
C5—C1—H1 | 122.5 (8) | N3—C8—C7 | 120.67 (12) |
N2—C2—N1 | 118.85 (11) | C9—C8—C7 | 118.28 (12) |
N2—C2—C3 | 123.65 (11) | C10—C9—C8 | 120.61 (11) |
N1—C2—C3 | 117.48 (11) | C10—C9—H9 | 120.8 (9) |
C4—C3—C2 | 119.94 (11) | C8—C9—H9 | 118.6 (9) |
C4—C3—H3 | 121.1 (8) | C9—C10—C11 | 121.03 (12) |
C2—C3—H3 | 119.0 (8) | C9—C10—H10 | 120.6 (9) |
C3—C4—C5 | 121.83 (11) | C11—C10—H10 | 118.4 (9) |
C3—C4—H4 | 119.0 (9) | C10—C11—C12 | 119.16 (12) |
C5—C4—H4 | 119.1 (9) | C10—C11—H11 | 121.8 (8) |
C1—C5—C4 | 116.05 (12) | C12—C11—H11 | 119.0 (8) |
C1—C5—C6 | 122.69 (11) | C7—C12—C11 | 119.91 (11) |
C4—C5—C6 | 121.25 (11) | C7—C12—C13 | 119.26 (10) |
C5—C6—H6A | 109.5 | C11—C12—C13 | 120.83 (11) |
C5—C6—H6B | 109.5 | O1—C13—O2 | 124.01 (11) |
H6A—C6—H6B | 109.5 | O1—C13—C12 | 117.84 (11) |
C5—C6—H6C | 109.5 | O2—C13—C12 | 118.15 (10) |
H6A—C6—H6C | 109.5 | ||
C2—N1—C1—C5 | −0.37 (18) | N3—C8—C9—C10 | 179.50 (12) |
C1—N1—C2—N2 | −178.35 (11) | C7—C8—C9—C10 | −0.18 (18) |
C1—N1—C2—C3 | 0.48 (17) | C8—C9—C10—C11 | −0.16 (19) |
N2—C2—C3—C4 | 178.51 (12) | C9—C10—C11—C12 | 0.43 (19) |
N1—C2—C3—C4 | −0.26 (18) | C8—C7—C12—C11 | 0.00 (18) |
C2—C3—C4—C5 | −0.1 (2) | C8—C7—C12—C13 | 179.81 (10) |
N1—C1—C5—C4 | 0.01 (18) | C10—C11—C12—C7 | −0.35 (18) |
N1—C1—C5—C6 | 179.17 (12) | C10—C11—C12—C13 | 179.84 (11) |
C3—C4—C5—C1 | 0.20 (19) | C7—C12—C13—O1 | 1.32 (17) |
C3—C4—C5—C6 | −178.97 (12) | C11—C12—C13—O1 | −178.87 (11) |
C12—C7—C8—N3 | −179.42 (12) | C7—C12—C13—O2 | −178.33 (10) |
C12—C7—C8—C9 | 0.26 (18) | C11—C12—C13—O2 | 1.48 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···O2i | 1.017 (17) | 1.682 (17) | 2.6901 (14) | 170.6 (17) |
N2—H1N2···O1i | 0.939 (16) | 1.886 (16) | 2.8207 (15) | 173.3 (14) |
N2—H2N2···O2ii | 0.920 (17) | 1.947 (17) | 2.8650 (16) | 175.3 (16) |
N3—H1N3···O1iii | 0.903 (19) | 2.18 (2) | 3.027 (2) | 156.0 (17) |
Symmetry codes: (i) x−1, −y+1/2, z−1/2; (ii) x−1, y, z; (iii) −x+1, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C6H9N2+·C7H6NO2− |
Mr | 245.28 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 296 |
a, b, c (Å) | 10.0739 (2), 10.9620 (2), 11.9641 (2) |
β (°) | 113.148 (1) |
V (Å3) | 1214.83 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.72 × 0.34 × 0.13 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.936, 0.988 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 13305, 3541, 2576 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.706 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.138, 1.07 |
No. of reflections | 3541 |
No. of parameters | 212 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.20, −0.26 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···O2i | 1.017 (17) | 1.682 (17) | 2.6901 (14) | 170.6 (17) |
N2—H1N2···O1i | 0.939 (16) | 1.886 (16) | 2.8207 (15) | 173.3 (14) |
N2—H2N2···O2ii | 0.920 (17) | 1.947 (17) | 2.8650 (16) | 175.3 (16) |
N3—H1N3···O1iii | 0.903 (19) | 2.18 (2) | 3.027 (2) | 156.0 (17) |
Symmetry codes: (i) x−1, −y+1/2, z−1/2; (ii) x−1, y, z; (iii) −x+1, −y+1, −z+2. |
Footnotes
‡Thomson Reuters ResearcherID: A-3561-2009
Acknowledgements
MH and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. MH thanks Universiti Sains Malaysia for a post-doctoral research fellowship.
References
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–S19. CrossRef Web of Science Google Scholar
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 (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Feng, H., Sun, C.-R., Li, L., Jin, Z.-M. & Tu, B. (2005). Acta Cryst. E61, o1983–o1984. Web of Science CrossRef IUCr Journals Google Scholar
Jeffrey, G. A. (1997). An Introduction to Hydrogen Bonding. Oxford University Press. Google Scholar
Jeffrey, G. A. & Saenger, W. (1991). Hydrogen Bonding in Biological Structures. Berlin: Springer. Google Scholar
Jin, Z.-M., Tu, B., He, L., Hu, M.-L. & Zou, J.-W. (2005). Acta Cryst. C61, m197–m199. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Katritzky, A. R., Rees, C. W. & Scriven, E. F. V. (1996). Comprehensive Heterocyclic Chemistry II. Oxford: Pergamon Press. Google Scholar
Nahringbauer, I. & Kvick, Å. (1977). Acta Cryst. B33, 2902–2905. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Pozharski, A. F., Soldatenkov, A. T. & Katritzky, A. R. (1997). Heterocycles in Life and Society. New York: Wiley. Google Scholar
Scheiner, S. (1997). 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
Xuan, R.-C., Wan, Y.-H., Hu, W.-X., Yang, Z.-Y., Cheng, D.-P. & Xuan, R.-R. (2003). Acta Cryst. E59, o1704–o1706. Web of Science CSD CrossRef 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-bond interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). The crystal structures of 2-amino-5-methylpyridine (Nahringbauer & Kvick, 1977), 2-amino-5-methylpyridinium phosphate (Feng et al., 2005), 2-amino-5-methylpyridinium 3-(4- hydroxy-3-methoxyphenyl)-2-propenoate monohydrate (Xuan et al., 2003) and 2-amino-5-methylpyridinium (2-amino-5-methylpyridine)trichlorozincate(II) (Jin et al., 2005) have been reported in the literature. In order to study some interesting hydrogen bonding interactions, the synthesis and structure of the title salt is presented here.
The asymmetric unit (Fig. 1) contains a 2-amino-5-methylpyridinium cation and a 3-aminobenzoate anion. The proton transfer from the carboxyl group to atom N1 of 2-amino-5-methylpyridine resulted in the widening of C2—N1—C1 angle of the pyridinium ring to 122.40 (10)°, compared to the corresponding angle of 117.4° (no standard uncertainty available) in neutral 2-amino-5-methylpyridine (Nahringbauer & Kvick, 1977). The 2-amino-5-methylpyridinium cation is essentially planar, with a maximum deviation of 0.002 (1)Å for atom N1. The bond lengths (Allen et al., 1987) and angles are within normal ranges.
In the crystal structure (Fig. 2), the protonated N1 atom and 2-amino group (N2) are hydrogen-bonded to the carboxylate oxygen atoms (O1 and O2) via a pair of N—H···O hydrogen bonds forming a ring motif R22(8) (Bernstein et al., 1995). The symmetry-related 3-aminobenzoate molecules are linked through N3—H1N3···O1(-x+1, -y+1, -z+2) hydrogen-bonding to form a R22(14) ring motif (Table 1). The cystal structure is further stabilized by π···π stacking interaction between the pyridine rings (C1–C5/N1) and benzene ring (C7–C12) with centroid- to-centroid distance of 3.7594 (8)Å [symmetry codes: 1-x, 1/2+y, 3/2-z and 1-x, -1/2+y, 3/2-z ].