organic compounds
2-Amino-4-methylpyridinium 2-nitrobenzoate
aDepartment of Physics, Anna University, Chennai 600 025, India, and bCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India
*Correspondence e-mail: shirai2011@gmail.com
In the title molecular salt, C6H9N2+·C7H4NO4−, the original pyridine N atom of 2-amino-4-methylpyridine is protonated and the carboxylic acid group of nitrobenzoic acid is deprotonated. In the crystal, the ions are linked by N—H⋯O hydrogen bonds, forming chains propagating along [001]. The chains are linked via C—H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to the bc plane.
Related literature
For related structures, see: Navarro Ranninger et al. (1985); Luque et al. (1997); Qin et al. (1999); Jin et al. (2001); Albrecht et al. (2003); Kvick & Noordik (1977).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009).
Supporting information
10.1107/S1600536813012919/su2590sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813012919/su2590Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813012919/su2590Isup3.cml
2-amino-4-methylpyridine (C6H8N2) and 2-nitrobenzoic acid (C7H5N1O4) were mixed in an equimolar ratio (1:1) using ethanol as solvent and stirred well. The solution was filtered into a clean beaker and optimally closed. Colourless block-like crystals were obtained by slow evaporation at room temperature in 15 days.
The NH and NH2 H atoms were located in a difference Fourier map and freely refined. The C-bound H atoms were positioned geometrically and refined using a riding model: C—H = 0.93 and 0.96 Å for CH and CH3 H atoms, respectively, with Uiso(H) = 1.5Ueq(C) for CH3 H atoms and = 1.2Ueq(C) for other H atoms.
Data collection: APEX2 (Bruker, 2008); cell
SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).Fig. 1. The molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 30% probability level. | |
Fig. 2. The crystal packing of the title compound viewed along the a axis. The hydrogen bonds are shown as dashed lines (see Table 1 for details; C-bound H-atoms have been omitted for clarity). |
C6H9N2+·C7H4NO4− | F(000) = 576 |
Mr = 275.26 | Dx = 1.379 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3289 reflections |
a = 12.2049 (3) Å | θ = 1.8–28.4° |
b = 9.8463 (2) Å | µ = 0.11 mm−1 |
c = 11.5405 (2) Å | T = 293 K |
β = 107.106 (1)° | Block, colourless |
V = 1325.51 (5) Å3 | 0.30 × 0.25 × 0.20 mm |
Z = 4 |
Bruker SMART APEXII area-detector diffractometer | 3289 independent reflections |
Radiation source: fine-focus sealed tube | 2644 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
ω and ϕ scans | θmax = 28.4°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | h = −13→16 |
Tmin = 0.969, Tmax = 0.979 | k = −12→13 |
12523 measured reflections | l = −12→15 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.041 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.125 | w = 1/[σ2(Fo2) + (0.0582P)2 + 0.2995P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.004 |
3289 reflections | Δρmax = 0.26 e Å−3 |
195 parameters | Δρmin = −0.18 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.031 (3) |
C6H9N2+·C7H4NO4− | V = 1325.51 (5) Å3 |
Mr = 275.26 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.2049 (3) Å | µ = 0.11 mm−1 |
b = 9.8463 (2) Å | T = 293 K |
c = 11.5405 (2) Å | 0.30 × 0.25 × 0.20 mm |
β = 107.106 (1)° |
Bruker SMART APEXII area-detector diffractometer | 3289 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | 2644 reflections with I > 2σ(I) |
Tmin = 0.969, Tmax = 0.979 | Rint = 0.023 |
12523 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.125 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.26 e Å−3 |
3289 reflections | Δρmin = −0.18 e Å−3 |
195 parameters |
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 | ||
C1 | 0.61383 (11) | 0.04795 (13) | 0.39832 (12) | 0.0428 (3) | |
C2 | 0.53048 (13) | 0.13768 (17) | 0.40961 (15) | 0.0577 (4) | |
H2 | 0.4606 | 0.1437 | 0.3494 | 0.069* | |
C3 | 0.55274 (15) | 0.21813 (17) | 0.51177 (17) | 0.0631 (4) | |
H3 | 0.4979 | 0.2798 | 0.5202 | 0.076* | |
C4 | 0.65544 (15) | 0.20749 (16) | 0.60095 (15) | 0.0578 (4) | |
H4 | 0.6694 | 0.2605 | 0.6705 | 0.069* | |
C5 | 0.73827 (12) | 0.11780 (14) | 0.58743 (12) | 0.0469 (3) | |
H5 | 0.8076 | 0.1114 | 0.6484 | 0.056* | |
C6 | 0.72002 (10) | 0.03729 (12) | 0.48485 (10) | 0.0367 (3) | |
C7 | 0.81856 (11) | −0.04361 (12) | 0.46565 (11) | 0.0383 (3) | |
C8 | 0.87671 (12) | 0.30082 (14) | 0.40898 (11) | 0.0472 (3) | |
H8 | 0.8642 | 0.2544 | 0.3360 | 0.057* | |
C9 | 0.80301 (12) | 0.39954 (14) | 0.41863 (12) | 0.0483 (3) | |
H9 | 0.7407 | 0.4216 | 0.3526 | 0.058* | |
C10 | 0.82151 (11) | 0.46900 (13) | 0.52995 (12) | 0.0429 (3) | |
C11 | 0.91448 (12) | 0.43446 (13) | 0.62498 (11) | 0.0423 (3) | |
H11 | 0.9278 | 0.4794 | 0.6987 | 0.051* | |
C12 | 0.99021 (11) | 0.33137 (13) | 0.61202 (11) | 0.0399 (3) | |
C13 | 0.73825 (14) | 0.57626 (16) | 0.54149 (15) | 0.0597 (4) | |
H13A | 0.7559 | 0.6044 | 0.6246 | 0.090* | |
H13B | 0.6618 | 0.5403 | 0.5153 | 0.090* | |
H13C | 0.7437 | 0.6528 | 0.4920 | 0.090* | |
N1 | 0.58459 (11) | −0.04327 (14) | 0.29302 (11) | 0.0562 (3) | |
N3 | 0.96840 (10) | 0.26833 (11) | 0.50367 (9) | 0.0417 (3) | |
N4 | 1.08159 (12) | 0.29199 (15) | 0.70053 (11) | 0.0561 (3) | |
O1 | 0.53069 (14) | 0.00397 (18) | 0.19509 (11) | 0.0954 (5) | |
O2 | 0.61421 (12) | −0.16147 (12) | 0.30903 (11) | 0.0771 (4) | |
O3 | 0.83221 (9) | −0.04027 (11) | 0.36362 (9) | 0.0547 (3) | |
O4 | 0.88257 (8) | −0.10404 (11) | 0.55661 (8) | 0.0518 (3) | |
H4B | 1.0969 (15) | 0.3317 (18) | 0.7709 (17) | 0.059 (5)* | |
H4A | 1.1221 (15) | 0.2174 (19) | 0.6872 (16) | 0.065 (5)* | |
H3A | 1.0192 (15) | 0.2040 (18) | 0.4898 (16) | 0.064 (5)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0439 (7) | 0.0438 (6) | 0.0385 (6) | 0.0005 (5) | 0.0088 (5) | 0.0079 (5) |
C2 | 0.0448 (7) | 0.0628 (9) | 0.0619 (9) | 0.0129 (6) | 0.0101 (6) | 0.0191 (7) |
C3 | 0.0659 (10) | 0.0565 (9) | 0.0744 (11) | 0.0243 (7) | 0.0323 (9) | 0.0124 (8) |
C4 | 0.0738 (10) | 0.0519 (8) | 0.0533 (8) | 0.0144 (7) | 0.0272 (8) | −0.0016 (6) |
C5 | 0.0513 (7) | 0.0510 (7) | 0.0379 (6) | 0.0061 (6) | 0.0122 (6) | −0.0011 (5) |
C6 | 0.0409 (6) | 0.0363 (6) | 0.0334 (6) | 0.0026 (5) | 0.0118 (5) | 0.0053 (4) |
C7 | 0.0410 (6) | 0.0395 (6) | 0.0335 (6) | 0.0019 (5) | 0.0095 (5) | −0.0001 (5) |
C8 | 0.0572 (8) | 0.0520 (7) | 0.0299 (6) | 0.0070 (6) | 0.0089 (5) | −0.0020 (5) |
C9 | 0.0504 (7) | 0.0528 (7) | 0.0368 (6) | 0.0087 (6) | 0.0053 (5) | 0.0017 (5) |
C10 | 0.0460 (7) | 0.0396 (6) | 0.0435 (7) | 0.0020 (5) | 0.0139 (6) | 0.0008 (5) |
C11 | 0.0503 (7) | 0.0417 (6) | 0.0352 (6) | 0.0010 (5) | 0.0130 (5) | −0.0047 (5) |
C12 | 0.0460 (7) | 0.0416 (6) | 0.0321 (6) | 0.0010 (5) | 0.0115 (5) | 0.0005 (5) |
C13 | 0.0599 (9) | 0.0541 (8) | 0.0621 (9) | 0.0150 (7) | 0.0131 (7) | −0.0064 (7) |
N1 | 0.0510 (7) | 0.0649 (8) | 0.0446 (7) | −0.0082 (6) | 0.0016 (5) | −0.0002 (6) |
N3 | 0.0479 (6) | 0.0452 (6) | 0.0318 (5) | 0.0083 (5) | 0.0114 (4) | −0.0001 (4) |
N4 | 0.0627 (8) | 0.0625 (8) | 0.0355 (6) | 0.0192 (6) | 0.0026 (5) | −0.0050 (5) |
O1 | 0.1008 (11) | 0.1144 (12) | 0.0473 (7) | 0.0141 (9) | −0.0148 (7) | 0.0027 (7) |
O2 | 0.1014 (10) | 0.0528 (7) | 0.0671 (8) | −0.0131 (6) | 0.0094 (7) | −0.0113 (6) |
O3 | 0.0669 (7) | 0.0634 (6) | 0.0391 (5) | 0.0162 (5) | 0.0237 (5) | 0.0062 (4) |
O4 | 0.0522 (6) | 0.0648 (6) | 0.0372 (5) | 0.0209 (5) | 0.0111 (4) | 0.0079 (4) |
C1—C2 | 1.382 (2) | C9—C10 | 1.4137 (19) |
C1—C6 | 1.3880 (17) | C9—H9 | 0.9300 |
C1—N1 | 1.4682 (18) | C10—C11 | 1.3688 (18) |
C2—C3 | 1.379 (3) | C10—C13 | 1.4985 (19) |
C2—H2 | 0.9300 | C11—C12 | 1.4101 (18) |
C3—C4 | 1.372 (2) | C11—H11 | 0.9300 |
C3—H3 | 0.9300 | C12—N4 | 1.3295 (17) |
C4—C5 | 1.385 (2) | C12—N3 | 1.3505 (16) |
C4—H4 | 0.9300 | C13—H13A | 0.9600 |
C5—C6 | 1.3872 (18) | C13—H13B | 0.9600 |
C5—H5 | 0.9300 | C13—H13C | 0.9600 |
C6—C7 | 1.5122 (17) | N1—O2 | 1.2165 (18) |
C7—O3 | 1.2372 (15) | N1—O1 | 1.2203 (17) |
C7—O4 | 1.2585 (15) | N3—H3A | 0.933 (18) |
C8—C9 | 1.3510 (19) | N4—H4B | 0.871 (19) |
C8—N3 | 1.3526 (17) | N4—H4A | 0.923 (19) |
C8—H8 | 0.9300 | ||
C2—C1—C6 | 122.54 (13) | C10—C9—H9 | 120.3 |
C2—C1—N1 | 117.55 (13) | C11—C10—C9 | 118.75 (12) |
C6—C1—N1 | 119.83 (12) | C11—C10—C13 | 121.87 (12) |
C3—C2—C1 | 118.83 (14) | C9—C10—C13 | 119.37 (12) |
C3—C2—H2 | 120.6 | C10—C11—C12 | 120.57 (12) |
C1—C2—H2 | 120.6 | C10—C11—H11 | 119.7 |
C4—C3—C2 | 120.27 (14) | C12—C11—H11 | 119.7 |
C4—C3—H3 | 119.9 | N4—C12—N3 | 118.01 (12) |
C2—C3—H3 | 119.9 | N4—C12—C11 | 123.81 (12) |
C3—C4—C5 | 120.01 (15) | N3—C12—C11 | 118.18 (11) |
C3—C4—H4 | 120.0 | C10—C13—H13A | 109.5 |
C5—C4—H4 | 120.0 | C10—C13—H13B | 109.5 |
C4—C5—C6 | 121.40 (13) | H13A—C13—H13B | 109.5 |
C4—C5—H5 | 119.3 | C10—C13—H13C | 109.5 |
C6—C5—H5 | 119.3 | H13A—C13—H13C | 109.5 |
C5—C6—C1 | 116.90 (11) | H13B—C13—H13C | 109.5 |
C5—C6—C7 | 119.41 (11) | O2—N1—O1 | 124.08 (15) |
C1—C6—C7 | 123.29 (11) | O2—N1—C1 | 118.07 (12) |
O3—C7—O4 | 125.59 (12) | O1—N1—C1 | 117.84 (14) |
O3—C7—C6 | 117.46 (11) | C12—N3—C8 | 122.02 (11) |
O4—C7—C6 | 116.88 (10) | C12—N3—H3A | 120.8 (11) |
C9—C8—N3 | 121.08 (12) | C8—N3—H3A | 117.1 (11) |
C9—C8—H8 | 119.5 | C12—N4—H4B | 119.2 (11) |
N3—C8—H8 | 119.5 | C12—N4—H4A | 118.3 (11) |
C8—C9—C10 | 119.39 (12) | H4B—N4—H4A | 122.2 (16) |
C8—C9—H9 | 120.3 | ||
C6—C1—C2—C3 | −1.2 (2) | N3—C8—C9—C10 | −0.6 (2) |
N1—C1—C2—C3 | 175.64 (14) | C8—C9—C10—C11 | 0.4 (2) |
C1—C2—C3—C4 | −0.8 (2) | C8—C9—C10—C13 | −178.59 (14) |
C2—C3—C4—C5 | 1.4 (3) | C9—C10—C11—C12 | −0.1 (2) |
C3—C4—C5—C6 | 0.0 (2) | C13—C10—C11—C12 | 178.84 (13) |
C4—C5—C6—C1 | −1.9 (2) | C10—C11—C12—N4 | −179.53 (14) |
C4—C5—C6—C7 | 171.12 (13) | C10—C11—C12—N3 | 0.1 (2) |
C2—C1—C6—C5 | 2.48 (19) | C2—C1—N1—O2 | −137.16 (16) |
N1—C1—C6—C5 | −174.27 (12) | C6—C1—N1—O2 | 39.75 (19) |
C2—C1—C6—C7 | −170.21 (12) | C2—C1—N1—O1 | 41.9 (2) |
N1—C1—C6—C7 | 13.05 (18) | C6—C1—N1—O1 | −141.19 (15) |
C5—C6—C7—O3 | −134.09 (13) | N4—C12—N3—C8 | 179.29 (13) |
C1—C6—C7—O3 | 38.42 (18) | C11—C12—N3—C8 | −0.33 (19) |
C5—C6—C7—O4 | 43.01 (17) | C9—C8—N3—C12 | 0.6 (2) |
C1—C6—C7—O4 | −144.48 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···O4i | 0.933 (18) | 1.752 (19) | 2.6746 (16) | 169.5 (17) |
N4—H4A···O3i | 0.923 (19) | 1.972 (19) | 2.8734 (18) | 164.9 (17) |
N4—H4B···O4ii | 0.871 (19) | 2.033 (19) | 2.8937 (16) | 169.7 (18) |
C11—H11···O3iii | 0.93 | 2.58 | 3.3624 (16) | 142 |
Symmetry codes: (i) −x+2, −y, −z+1; (ii) −x+2, y+1/2, −z+3/2; (iii) x, −y+1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C6H9N2+·C7H4NO4− |
Mr | 275.26 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 12.2049 (3), 9.8463 (2), 11.5405 (2) |
β (°) | 107.106 (1) |
V (Å3) | 1325.51 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.30 × 0.25 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART APEXII area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2008) |
Tmin, Tmax | 0.969, 0.979 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12523, 3289, 2644 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.668 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.125, 1.06 |
No. of reflections | 3289 |
No. of parameters | 195 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.26, −0.18 |
Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···O4i | 0.933 (18) | 1.752 (19) | 2.6746 (16) | 169.5 (17) |
N4—H4A···O3i | 0.923 (19) | 1.972 (19) | 2.8734 (18) | 164.9 (17) |
N4—H4B···O4ii | 0.871 (19) | 2.033 (19) | 2.8937 (16) | 169.7 (18) |
C11—H11···O3iii | 0.93 | 2.58 | 3.3624 (16) | 142 |
Symmetry codes: (i) −x+2, −y, −z+1; (ii) −x+2, y+1/2, −z+3/2; (iii) x, −y+1/2, z+1/2. |
Acknowledgements
The authors thank the TBI X-ray facility, CAS in Crystallography and Biophysics, University of Madras, India, for the data collection. TS and DV thank the UGC (SAP–CAS) for the departmental facilties. TS also thanks DST Inspire for financial assistance.
References
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There are numerous examples of 2-amino-substituted pyridine compounds in which the 2-aminopyridines act as neutral ligands (Navarro Ranninger et al., 1985; Luque et al., 1997; Qin et al., 1999) or as protonated cations (Luque et al., 1997; Jin et al., 2001; Albrecht et al., 2003). In order to study hydrogen bonding interactions in such systems, we synthesized the title salt and report herein on its crystal structure.
In the title molecular salt, Fig. 1, the pyridine N atom of 2-amino-4-methylpyridine is protonated and the carboxyl group of nitrobenzoic acid is deprotonated. The amine attached with the pyridine ring deviates by -0.0098 (15) Å. The methyl carbon atom C13 attached with the pyridine ring deviates by -0.0261 (17) Å.
In the crystal, the pyridine ring (N3,C8-C12) makes a dihedral angle of 12.13 (7)° with the nitrobenzoate ring (C1-C6). The ions are linked by N–H···O hydrogen bonds forming chains propagating along [001]; see Table 1 and Fig. 2. These chains are linked via C–H···O hydrogen bonds forming two-dimensional networks lying parallel to the bc plane (Table 1).