organic compounds
2-Amino-4-methylpyridinium 4-aminobenzoate
aDepartment of Chemistry, Zhejiang University, People's Republic of China
*Correspondence e-mail: xudj@mail.hz.zj.cn
In the structure of the title salt, C6H9N2+·C7H6NO2−, the 4-aminobenzoate anions are linked to adjacent anions and 2-amino-4-methylpyridinium cations via N—H⋯O hydrogen bonds, forming a three-dimensional supramolecular structure. The also shows a weak C—H⋯O hydrogen bond between adjacent anions. Within the 4-aminobenzoate anion, the carboxylate group is twisted by 14.0 (4)° with respect to the benzene ring.
Related literature
For general background, see: Choudhury et al. (2007); Halvorson et al. (1987); Geiser et al. (1986); Geiser & Willett (1984). For related structures, see: Kaabi & Khedhiri (2004); Chtioui et al. (2006). For a description of the Cambridge Structural Database, see Allen (2002).
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: PROCESS-AUTO (Rigaku, 1998); cell PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
10.1107/S1600536808014839/ng2457sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808014839/ng2457Isup2.hkl
2-Amino-4-methyl-pyridine (0.054 g, 0.5 mmol) and 4-amino-benzoic acid (0.069 g, 0.5 mmol) were dissolved in ethanol (5 ml) at room temperature. The solution was filtered and light brown single crystals were obtained from the filtration after 2 weeks.
H atoms bonded to N atoms were located in a difference Fourier map and were refined as riding in as-found relative positions, with Uiso(H) = 1.5Ueq(N). Methyl H atoms were placed in calculated positions with C—H = 0.96 Å and the torsion angle was refined to fit the electron density, Uiso(H) = 1.5Ueq(C). Aromatic H atoms were placed in calculated positions with C—H = 0.93 Å, and refined in riding mode with Uiso(H) = 1.2Ueq(C). In the absence of significant
effects, Friedel pairs were merged.Data collection: PROCESS-AUTO (Rigaku, 1998); cell
PROCESS-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).Fig. 1. The molecular structure of the title compound with 30% probability displacement (arbitrary spheres for H atoms). Dashed lines indicate hydrogen bonding. |
C6H9N2+·C7H6NO2− | F(000) = 520 |
Mr = 245.28 | Dx = 1.307 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 2654 reflections |
a = 5.5734 (14) Å | θ = 2.0–25.2° |
b = 8.8154 (16) Å | µ = 0.09 mm−1 |
c = 25.374 (5) Å | T = 295 K |
V = 1246.6 (5) Å3 | Chunk, light brown |
Z = 4 | 0.46 × 0.38 × 0.30 mm |
Rigaku R-AXIS RAPID IP diffractometer | 1126 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.059 |
Graphite monochromator | θmax = 26.0°, θmin = 1.6° |
Detector resolution: 10.00 pixels mm-1 | h = −6→6 |
ω scans | k = −10→10 |
14099 measured reflections | l = −30→29 |
1451 independent reflections |
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)] = 0.037 | H-atom parameters constrained |
wR(F2) = 0.095 | w = 1/[σ2(Fo2) + (0.0449P)2 + 0.1505P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max = 0.001 |
1451 reflections | Δρmax = 0.13 e Å−3 |
165 parameters | Δρmin = −0.12 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: 0.015 (3) |
C6H9N2+·C7H6NO2− | V = 1246.6 (5) Å3 |
Mr = 245.28 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 5.5734 (14) Å | µ = 0.09 mm−1 |
b = 8.8154 (16) Å | T = 295 K |
c = 25.374 (5) Å | 0.46 × 0.38 × 0.30 mm |
Rigaku R-AXIS RAPID IP diffractometer | 1126 reflections with I > 2σ(I) |
14099 measured reflections | Rint = 0.059 |
1451 independent reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.095 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.13 e Å−3 |
1451 reflections | Δρmin = −0.12 e Å−3 |
165 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 | ||
N1 | −0.5107 (5) | 0.2323 (3) | 0.74214 (9) | 0.0710 (7) | |
H1A | −0.4459 | 0.1947 | 0.7712 | 0.106* | |
H1B | −0.6362 | 0.1981 | 0.7267 | 0.106* | |
N2 | 0.5736 (4) | 0.8834 (2) | 0.61196 (7) | 0.0520 (6) | |
H2N | 0.4548 | 0.8231 | 0.6256 | 0.078* | |
N3 | 0.4308 (5) | 0.8308 (3) | 0.52906 (8) | 0.0660 (7) | |
H3A | 0.4443 | 0.8528 | 0.4934 | 0.099* | |
H3B | 0.3098 | 0.7766 | 0.5454 | 0.099* | |
O1 | 0.0737 (4) | 0.6432 (2) | 0.57815 (6) | 0.0692 (6) | |
O2 | 0.2584 (3) | 0.6999 (2) | 0.65310 (6) | 0.0562 (5) | |
C1 | −0.0644 (4) | 0.5269 (3) | 0.65687 (9) | 0.0451 (6) | |
C2 | −0.0117 (4) | 0.4843 (3) | 0.70832 (9) | 0.0497 (6) | |
H2 | 0.1249 | 0.5233 | 0.7244 | 0.060* | |
C3 | −0.1565 (5) | 0.3857 (3) | 0.73617 (9) | 0.0523 (7) | |
H3 | −0.1139 | 0.3568 | 0.7702 | 0.063* | |
C4 | −0.3654 (5) | 0.3295 (3) | 0.71361 (9) | 0.0488 (6) | |
C5 | −0.4210 (5) | 0.3741 (3) | 0.66250 (10) | 0.0581 (7) | |
H5 | −0.5612 | 0.3388 | 0.6468 | 0.070* | |
C6 | −0.2727 (5) | 0.4694 (3) | 0.63474 (10) | 0.0550 (7) | |
H6 | −0.3129 | 0.4960 | 0.6004 | 0.066* | |
C7 | 0.0980 (5) | 0.6303 (3) | 0.62688 (9) | 0.0479 (6) | |
C8 | 0.5886 (5) | 0.9037 (3) | 0.55940 (9) | 0.0482 (6) | |
C9 | 0.7670 (5) | 1.0014 (3) | 0.53990 (10) | 0.0520 (6) | |
H9 | 0.7815 | 1.0156 | 0.5037 | 0.062* | |
C10 | 0.9189 (5) | 1.0757 (3) | 0.57306 (10) | 0.0551 (7) | |
C11 | 0.8960 (6) | 1.0501 (3) | 0.62760 (11) | 0.0668 (8) | |
H11 | 0.9977 | 1.0989 | 0.6512 | 0.080* | |
C12 | 0.7262 (6) | 0.9547 (3) | 0.64526 (10) | 0.0636 (8) | |
H12 | 0.7131 | 0.9372 | 0.6813 | 0.076* | |
C13 | 1.1031 (6) | 1.1849 (3) | 0.55251 (12) | 0.0742 (8) | |
H13A | 1.1123 | 1.1766 | 0.5148 | 0.111* | |
H13B | 1.2567 | 1.1615 | 0.5676 | 0.111* | |
H13C | 1.0582 | 1.2865 | 0.5619 | 0.111* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0621 (14) | 0.0843 (17) | 0.0664 (14) | −0.0162 (14) | −0.0039 (12) | 0.0169 (13) |
N2 | 0.0637 (14) | 0.0562 (12) | 0.0360 (11) | 0.0004 (12) | 0.0035 (11) | 0.0007 (9) |
N3 | 0.0751 (15) | 0.0825 (16) | 0.0403 (11) | −0.0200 (16) | 0.0037 (12) | −0.0003 (11) |
O1 | 0.0800 (14) | 0.0940 (14) | 0.0336 (9) | −0.0151 (13) | −0.0001 (10) | 0.0088 (9) |
O2 | 0.0660 (11) | 0.0651 (10) | 0.0374 (9) | −0.0093 (11) | 0.0020 (10) | 0.0024 (8) |
C1 | 0.0495 (14) | 0.0509 (13) | 0.0350 (12) | 0.0068 (13) | 0.0035 (12) | 0.0009 (10) |
C2 | 0.0508 (14) | 0.0590 (14) | 0.0391 (13) | −0.0028 (13) | −0.0028 (11) | 0.0011 (12) |
C3 | 0.0537 (16) | 0.0673 (16) | 0.0360 (12) | −0.0002 (14) | −0.0013 (11) | 0.0086 (13) |
C4 | 0.0489 (15) | 0.0536 (14) | 0.0440 (14) | 0.0021 (13) | 0.0023 (12) | 0.0017 (12) |
C5 | 0.0525 (15) | 0.0734 (18) | 0.0484 (15) | −0.0043 (16) | −0.0046 (14) | −0.0018 (13) |
C6 | 0.0599 (17) | 0.0668 (17) | 0.0383 (14) | 0.0070 (16) | −0.0040 (13) | 0.0035 (12) |
C7 | 0.0559 (16) | 0.0525 (14) | 0.0354 (13) | 0.0065 (14) | 0.0036 (12) | 0.0021 (11) |
C8 | 0.0554 (15) | 0.0498 (13) | 0.0395 (13) | 0.0042 (14) | 0.0032 (12) | 0.0006 (11) |
C9 | 0.0635 (16) | 0.0517 (13) | 0.0409 (13) | 0.0048 (15) | 0.0058 (13) | 0.0019 (11) |
C10 | 0.0574 (16) | 0.0479 (14) | 0.0598 (16) | 0.0027 (14) | 0.0011 (15) | 0.0004 (12) |
C11 | 0.076 (2) | 0.0692 (18) | 0.0554 (17) | −0.0099 (18) | −0.0100 (16) | −0.0047 (14) |
C12 | 0.082 (2) | 0.0698 (18) | 0.0387 (14) | 0.0010 (19) | −0.0040 (15) | −0.0012 (13) |
C13 | 0.0708 (19) | 0.0678 (18) | 0.084 (2) | −0.0106 (19) | 0.0038 (18) | −0.0001 (16) |
N1—C4 | 1.384 (3) | C3—H3 | 0.9300 |
N1—H1A | 0.8846 | C4—C5 | 1.390 (3) |
N1—H1B | 0.8568 | C5—C6 | 1.373 (4) |
N2—C8 | 1.348 (3) | C5—H5 | 0.9300 |
N2—C12 | 1.354 (3) | C6—H6 | 0.9300 |
N2—H2N | 0.9167 | C8—C9 | 1.405 (4) |
N3—C8 | 1.334 (3) | C9—C10 | 1.361 (4) |
N3—H3A | 0.9287 | C9—H9 | 0.9300 |
N3—H3B | 0.9252 | C10—C11 | 1.408 (4) |
O1—C7 | 1.249 (3) | C10—C13 | 1.501 (4) |
O2—C7 | 1.272 (3) | C11—C12 | 1.343 (4) |
C1—C6 | 1.385 (4) | C11—H11 | 0.9300 |
C1—C2 | 1.390 (3) | C12—H12 | 0.9300 |
C1—C7 | 1.494 (3) | C13—H13A | 0.9600 |
C2—C3 | 1.381 (3) | C13—H13B | 0.9600 |
C2—H2 | 0.9300 | C13—H13C | 0.9600 |
C3—C4 | 1.389 (3) | ||
C4—N1—H1A | 115.4 | C1—C6—H6 | 119.3 |
C4—N1—H1B | 117.1 | O1—C7—O2 | 123.4 (2) |
H1A—N1—H1B | 125.7 | O1—C7—C1 | 119.6 (2) |
C8—N2—C12 | 121.1 (2) | O2—C7—C1 | 117.0 (2) |
C8—N2—H2N | 119.7 | N3—C8—N2 | 117.8 (2) |
C12—N2—H2N | 119.2 | N3—C8—C9 | 124.0 (2) |
C8—N3—H3A | 114.1 | N2—C8—C9 | 118.3 (2) |
C8—N3—H3B | 118.1 | C10—C9—C8 | 121.1 (2) |
H3A—N3—H3B | 127.2 | C10—C9—H9 | 119.4 |
C6—C1—C2 | 117.3 (2) | C8—C9—H9 | 119.4 |
C6—C1—C7 | 121.7 (2) | C9—C10—C11 | 118.3 (3) |
C2—C1—C7 | 121.0 (2) | C9—C10—C13 | 121.3 (2) |
C3—C2—C1 | 121.8 (2) | C11—C10—C13 | 120.4 (3) |
C3—C2—H2 | 119.1 | C12—C11—C10 | 119.5 (3) |
C1—C2—H2 | 119.1 | C12—C11—H11 | 120.3 |
C2—C3—C4 | 120.2 (2) | C10—C11—H11 | 120.3 |
C2—C3—H3 | 119.9 | C11—C12—N2 | 121.7 (2) |
C4—C3—H3 | 119.9 | C11—C12—H12 | 119.1 |
N1—C4—C3 | 119.7 (2) | N2—C12—H12 | 119.1 |
N1—C4—C5 | 122.2 (2) | C10—C13—H13A | 109.5 |
C3—C4—C5 | 118.1 (2) | C10—C13—H13B | 109.5 |
C6—C5—C4 | 121.1 (3) | H13A—C13—H13B | 109.5 |
C6—C5—H5 | 119.4 | C10—C13—H13C | 109.5 |
C4—C5—H5 | 119.4 | H13A—C13—H13C | 109.5 |
C5—C6—C1 | 121.4 (2) | H13B—C13—H13C | 109.5 |
C5—C6—H6 | 119.3 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O2i | 0.89 | 2.19 | 3.021 (3) | 157 |
N2—H2N···O2 | 0.92 | 1.69 | 2.606 (3) | 174 |
N3—H3A···O1ii | 0.93 | 1.95 | 2.844 (3) | 160 |
N3—H3B···O1 | 0.92 | 1.95 | 2.872 (3) | 174 |
C3—H3···O2i | 0.93 | 2.52 | 3.301 (3) | 142 |
Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) x+1/2, −y+3/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C6H9N2+·C7H6NO2− |
Mr | 245.28 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 295 |
a, b, c (Å) | 5.5734 (14), 8.8154 (16), 25.374 (5) |
V (Å3) | 1246.6 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.46 × 0.38 × 0.30 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID IP diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14099, 1451, 1126 |
Rint | 0.059 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.095, 1.04 |
No. of reflections | 1451 |
No. of parameters | 165 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.13, −0.12 |
Computer programs: PROCESS-AUTO (Rigaku, 1998), CrystalStructure (Rigaku/MSC, 2002), SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O2i | 0.89 | 2.19 | 3.021 (3) | 157 |
N2—H2N···O2 | 0.92 | 1.69 | 2.606 (3) | 174 |
N3—H3A···O1ii | 0.93 | 1.95 | 2.844 (3) | 160 |
N3—H3B···O1 | 0.92 | 1.95 | 2.872 (3) | 174 |
C3—H3···O2i | 0.93 | 2.52 | 3.301 (3) | 142 |
Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) x+1/2, −y+3/2, −z+1. |
Acknowledgements
The work was supported by the ZIJIN project of Zhejiang University, China.
References
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The presence of the outside lone-pair electrons on the pyridine-N atom suggests that 2-amino-4-methyl-pyridine is an appropriate ligand for preparing metal complexes. However a search of the Cambridge Structure Database (November 2007 update; Allen, 2002) shows that in the most cases the 2-amino-4-methyl-pyridine presents as a counter cation but does not coordinate to the metal ion (Choudhury et al., 2007; Halvorson et al., 1987; Geiser et al., 1986; Geiser & Willett, 1984). This implies that the 2-amino-4-methyl-pyridine, as a weak base, is easy to be protonated in acid condition. The crystal structures of two inorganic salt of 2-amino-4-methyl-pyridine, 2-amino-4-methyl-pyridinium phosphate (Kaabi & Khedhiri, 2004) and 2-amino-4-methyl-pyridinium arsenate (Chtioui et al., 2006), have been reported previously. Recently we prepared the title organic salt of 2-amino-4-methyl-pyridine, and its crystal structure is reported here.
The crystal of the title compound consists of 2-amino-4-methyl-pyridinium cations and amino-benzoate anions (Fig. 1). The smaller difference in C—O bond distances of the carboxyl group (Table 1) indicates the carboxyl group is deprotonated in the crystal. Within the anion the carboxyl group is twisted with respect to the benzene ring by a dihedral angle of 14.0 (4)°. In the crystal, the aminobenzoate anions are linked with both of adjacent aminobenzoate anions and aminomethylpyridinium cations via N—H···O hydrogen bonding, to form the three dimensional supramolecular structure. The crystal structure also contains weak C—H···O hydrogen bonding between adjacent anions.