organic compounds
2-Amino-4-methylpyridinium 3-chlorobenzoate
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my
In the title salt, C6H9N2+·C7H4ClO2−, the 2-amino-4-methylpyridinium cation is almost planar, with a maximum deviation of 0.010 (1) Å. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R22(8) ring motif. The ion pairs are further connected via N—H⋯O and C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane.
Related literature
For details of non-covalent interactions, see: Remenar et al. (2003); Aakeroÿ et al. (2001); Sokolov et al. (2006). For related structures, see: Kvick & Noordik (1977); Shen et al. (2008); Hemamalini & Fun (2010a,b). 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). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).
Experimental
Crystal data
|
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/S160053681002444X/hb5503sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S160053681002444X/hb5503Isup2.hkl
A hot methanol solution (20 ml) of 2-amino-4-methylpyridine (54 mg, Aldrich) and 3-chlorobenzoic acid (78 mg, Merck) were mixed and warmed over a heating magnetic-stirrer hotplate for a few minutes. The resulting solution was allowed to cool slowly at room temperature and colourless needles of (I) appeared after a few days.
All hydrogen atoms were positioned geometrically [C–H = 0.93 or 0.96 Å] and were refined using a riding model, with Uiso(H) = 1.2 or 1.5 Ueq(C). A rotating group model was used for the methyl group. 1860 Friedel pairs were used to determine the absolute configuration.
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).C6H9N2+·C7H4ClO2− | F(000) = 276 |
Mr = 264.70 | Dx = 1.432 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 6601 reflections |
a = 7.9930 (6) Å | θ = 3.9–35.1° |
b = 6.8608 (5) Å | µ = 0.31 mm−1 |
c = 11.2148 (9) Å | T = 100 K |
β = 93.526 (2)° | Needle, colourless |
V = 613.84 (8) Å3 | 0.28 × 0.17 × 0.10 mm |
Z = 2 |
Bruker APEXII DUO CCD diffractometer | 4207 independent reflections |
Radiation source: fine-focus sealed tube | 4076 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.019 |
ϕ and ω scans | θmax = 32.5°, θmin = 3.9° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −12→12 |
Tmin = 0.919, Tmax = 0.971 | k = −10→10 |
9325 measured reflections | l = −16→16 |
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)] = 0.029 | H-atom parameters constrained |
wR(F2) = 0.117 | w = 1/[σ2(Fo2) + (0.0801P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.22 | (Δ/σ)max < 0.001 |
4207 reflections | Δρmax = 0.64 e Å−3 |
164 parameters | Δρmin = −0.54 e Å−3 |
1 restraint | Absolute structure: Flack (1983), 1860 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: −0.01 (4) |
C6H9N2+·C7H4ClO2− | V = 613.84 (8) Å3 |
Mr = 264.70 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 7.9930 (6) Å | µ = 0.31 mm−1 |
b = 6.8608 (5) Å | T = 100 K |
c = 11.2148 (9) Å | 0.28 × 0.17 × 0.10 mm |
β = 93.526 (2)° |
Bruker APEXII DUO CCD diffractometer | 4207 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 4076 reflections with I > 2σ(I) |
Tmin = 0.919, Tmax = 0.971 | Rint = 0.019 |
9325 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | H-atom parameters constrained |
wR(F2) = 0.117 | Δρmax = 0.64 e Å−3 |
S = 1.22 | Δρmin = −0.54 e Å−3 |
4207 reflections | Absolute structure: Flack (1983), 1860 Friedel pairs |
164 parameters | Absolute structure parameter: −0.01 (4) |
1 restraint |
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 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 > 2σ(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 | ||
Cl1 | 0.03584 (4) | 1.13218 (6) | 0.91629 (3) | 0.02460 (10) | |
O1 | 0.36548 (12) | 0.41445 (16) | 0.66474 (7) | 0.01744 (18) | |
O2 | 0.36855 (12) | 0.47553 (16) | 0.86099 (7) | 0.01876 (19) | |
C7 | 0.18473 (15) | 0.7570 (2) | 0.61091 (10) | 0.0158 (2) | |
H7A | 0.2131 | 0.6782 | 0.5478 | 0.019* | |
C8 | 0.09543 (15) | 0.9288 (2) | 0.58796 (11) | 0.0197 (2) | |
H8A | 0.0654 | 0.9648 | 0.5096 | 0.024* | |
C9 | 0.05103 (16) | 1.0466 (2) | 0.68188 (12) | 0.0195 (2) | |
H9A | −0.0078 | 1.1618 | 0.6671 | 0.023* | |
C10 | 0.09626 (15) | 0.9890 (2) | 0.79852 (10) | 0.0159 (2) | |
C11 | 0.18604 (14) | 0.8195 (2) | 0.82290 (10) | 0.0148 (2) | |
H11A | 0.2155 | 0.7838 | 0.9014 | 0.018* | |
C12 | 0.23182 (14) | 0.70259 (19) | 0.72825 (10) | 0.01258 (19) | |
C13 | 0.32902 (14) | 0.51628 (19) | 0.75345 (10) | 0.0131 (2) | |
N1 | 0.53373 (13) | 1.07928 (17) | 0.70756 (8) | 0.01350 (18) | |
H1A | 0.4786 | 1.1863 | 0.6979 | 0.016* | |
N2 | 0.53701 (13) | 1.1268 (3) | 0.91147 (8) | 0.0185 (2) | |
H2B | 0.4837 | 1.2344 | 0.8986 | 0.022* | |
H2C | 0.5638 | 1.0902 | 0.9835 | 0.022* | |
C1 | 0.57797 (14) | 1.01721 (19) | 0.82012 (10) | 0.0133 (2) | |
C2 | 0.66378 (14) | 0.8378 (2) | 0.83484 (10) | 0.0144 (2) | |
H2A | 0.6936 | 0.7919 | 0.9112 | 0.017* | |
C3 | 0.70348 (14) | 0.73057 (19) | 0.73661 (10) | 0.0141 (2) | |
C4 | 0.65921 (14) | 0.8046 (2) | 0.62099 (10) | 0.0152 (2) | |
H4A | 0.6878 | 0.7364 | 0.5535 | 0.018* | |
C5 | 0.57458 (14) | 0.9762 (2) | 0.60956 (9) | 0.0143 (2) | |
H5A | 0.5441 | 1.0239 | 0.5337 | 0.017* | |
C6 | 0.79035 (16) | 0.5371 (2) | 0.75110 (12) | 0.0195 (2) | |
H6A | 0.9016 | 0.5472 | 0.7239 | 0.029* | |
H6B | 0.7286 | 0.4404 | 0.7048 | 0.029* | |
H6C | 0.7964 | 0.5002 | 0.8338 | 0.029* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.02597 (15) | 0.02386 (18) | 0.02371 (15) | 0.00755 (12) | −0.00058 (10) | −0.00950 (12) |
O1 | 0.0271 (4) | 0.0139 (4) | 0.0114 (3) | 0.0054 (3) | 0.0016 (3) | −0.0014 (3) |
O2 | 0.0299 (4) | 0.0157 (5) | 0.0104 (3) | 0.0044 (4) | −0.0002 (3) | 0.0000 (3) |
C7 | 0.0166 (4) | 0.0184 (6) | 0.0123 (4) | 0.0012 (4) | 0.0013 (3) | 0.0016 (4) |
C8 | 0.0203 (5) | 0.0227 (7) | 0.0160 (5) | 0.0047 (5) | 0.0006 (4) | 0.0050 (5) |
C9 | 0.0189 (5) | 0.0184 (7) | 0.0213 (5) | 0.0041 (4) | 0.0007 (4) | 0.0019 (5) |
C10 | 0.0147 (4) | 0.0158 (6) | 0.0173 (4) | 0.0005 (4) | 0.0016 (3) | −0.0023 (4) |
C11 | 0.0159 (4) | 0.0148 (6) | 0.0135 (4) | 0.0000 (4) | 0.0007 (3) | −0.0009 (4) |
C12 | 0.0131 (4) | 0.0126 (5) | 0.0121 (4) | −0.0009 (4) | 0.0013 (3) | 0.0007 (4) |
C13 | 0.0175 (4) | 0.0108 (5) | 0.0109 (4) | −0.0016 (4) | 0.0013 (3) | 0.0000 (4) |
N1 | 0.0177 (4) | 0.0123 (5) | 0.0106 (4) | −0.0005 (3) | 0.0009 (3) | 0.0017 (3) |
N2 | 0.0292 (5) | 0.0162 (5) | 0.0100 (4) | 0.0049 (4) | 0.0009 (3) | −0.0003 (4) |
C1 | 0.0164 (4) | 0.0130 (5) | 0.0104 (4) | −0.0015 (4) | 0.0017 (3) | 0.0018 (4) |
C2 | 0.0175 (4) | 0.0135 (6) | 0.0123 (4) | 0.0005 (4) | 0.0012 (3) | 0.0027 (4) |
C3 | 0.0138 (4) | 0.0133 (6) | 0.0152 (4) | −0.0010 (4) | 0.0016 (3) | 0.0007 (4) |
C4 | 0.0161 (4) | 0.0164 (6) | 0.0130 (4) | −0.0008 (4) | 0.0012 (3) | −0.0014 (4) |
C5 | 0.0169 (4) | 0.0161 (6) | 0.0099 (4) | −0.0021 (4) | 0.0012 (3) | 0.0001 (4) |
C6 | 0.0199 (5) | 0.0158 (6) | 0.0228 (5) | 0.0032 (4) | 0.0024 (4) | 0.0010 (4) |
Cl1—C10 | 1.7383 (13) | N1—H1A | 0.8600 |
O1—C13 | 1.2643 (14) | N2—C1 | 1.3280 (18) |
O2—C13 | 1.2593 (14) | N2—H2B | 0.8600 |
C7—C8 | 1.3934 (19) | N2—H2C | 0.8600 |
C7—C12 | 1.3972 (16) | C1—C2 | 1.4138 (18) |
C7—H7A | 0.9300 | C2—C3 | 1.3779 (16) |
C8—C9 | 1.3909 (19) | C2—H2A | 0.9300 |
C8—H8A | 0.9300 | C3—C4 | 1.4170 (16) |
C9—C10 | 1.3927 (17) | C3—C6 | 1.5019 (19) |
C9—H9A | 0.9300 | C4—C5 | 1.3599 (18) |
C10—C11 | 1.3849 (19) | C4—H4A | 0.9300 |
C11—C12 | 1.3968 (17) | C5—H5A | 0.9300 |
C11—H11A | 0.9300 | C6—H6A | 0.9600 |
C12—C13 | 1.5134 (18) | C6—H6B | 0.9600 |
N1—C1 | 1.3582 (14) | C6—H6C | 0.9600 |
N1—C5 | 1.3636 (15) | ||
C8—C7—C12 | 120.35 (12) | C1—N2—H2B | 120.0 |
C8—C7—H7A | 119.8 | C1—N2—H2C | 120.0 |
C12—C7—H7A | 119.8 | H2B—N2—H2C | 120.0 |
C9—C8—C7 | 120.21 (11) | N2—C1—N1 | 118.49 (12) |
C9—C8—H8A | 119.9 | N2—C1—C2 | 122.93 (11) |
C7—C8—H8A | 119.9 | N1—C1—C2 | 118.57 (11) |
C8—C9—C10 | 118.87 (12) | C3—C2—C1 | 120.36 (10) |
C8—C9—H9A | 120.6 | C3—C2—H2A | 119.8 |
C10—C9—H9A | 120.6 | C1—C2—H2A | 119.8 |
C11—C10—C9 | 121.68 (12) | C2—C3—C4 | 118.91 (11) |
C11—C10—Cl1 | 119.30 (9) | C2—C3—C6 | 120.86 (11) |
C9—C10—Cl1 | 119.01 (10) | C4—C3—C6 | 120.22 (11) |
C10—C11—C12 | 119.26 (11) | C5—C4—C3 | 119.42 (11) |
C10—C11—H11A | 120.4 | C5—C4—H4A | 120.3 |
C12—C11—H11A | 120.4 | C3—C4—H4A | 120.3 |
C11—C12—C7 | 119.63 (12) | C4—C5—N1 | 121.04 (11) |
C11—C12—C13 | 119.90 (10) | C4—C5—H5A | 119.5 |
C7—C12—C13 | 120.47 (11) | N1—C5—H5A | 119.5 |
O2—C13—O1 | 125.07 (12) | C3—C6—H6A | 109.5 |
O2—C13—C12 | 117.52 (10) | C3—C6—H6B | 109.5 |
O1—C13—C12 | 117.41 (10) | H6A—C6—H6B | 109.5 |
C1—N1—C5 | 121.66 (11) | C3—C6—H6C | 109.5 |
C1—N1—H1A | 119.2 | H6A—C6—H6C | 109.5 |
C5—N1—H1A | 119.2 | H6B—C6—H6C | 109.5 |
C12—C7—C8—C9 | −0.62 (19) | C11—C12—C13—O1 | 179.10 (11) |
C7—C8—C9—C10 | −0.5 (2) | C7—C12—C13—O1 | 0.27 (16) |
C8—C9—C10—C11 | 0.9 (2) | C5—N1—C1—N2 | 178.68 (11) |
C8—C9—C10—Cl1 | −178.18 (10) | C5—N1—C1—C2 | −2.06 (17) |
C9—C10—C11—C12 | −0.32 (18) | N2—C1—C2—C3 | −179.79 (12) |
Cl1—C10—C11—C12 | 178.81 (9) | N1—C1—C2—C3 | 0.98 (17) |
C10—C11—C12—C7 | −0.79 (17) | C1—C2—C3—C4 | 0.97 (17) |
C10—C11—C12—C13 | −179.62 (10) | C1—C2—C3—C6 | −178.29 (10) |
C8—C7—C12—C11 | 1.26 (18) | C2—C3—C4—C5 | −1.91 (17) |
C8—C7—C12—C13 | −179.91 (11) | C6—C3—C4—C5 | 177.35 (11) |
C11—C12—C13—O2 | −1.50 (17) | C3—C4—C5—N1 | 0.90 (17) |
C7—C12—C13—O2 | 179.67 (11) | C1—N1—C5—C4 | 1.13 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O1i | 0.86 | 1.83 | 2.6921 (16) | 175 |
N2—H2B···O2i | 0.86 | 1.93 | 2.786 (2) | 177 |
N2—H2C···O2ii | 0.86 | 1.96 | 2.8146 (14) | 173 |
C5—H5A···O1iii | 0.93 | 2.50 | 3.1707 (13) | 129 |
Symmetry codes: (i) x, y+1, z; (ii) −x+1, y+1/2, −z+2; (iii) −x+1, y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C6H9N2+·C7H4ClO2− |
Mr | 264.70 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 100 |
a, b, c (Å) | 7.9930 (6), 6.8608 (5), 11.2148 (9) |
β (°) | 93.526 (2) |
V (Å3) | 613.84 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.31 |
Crystal size (mm) | 0.28 × 0.17 × 0.10 |
Data collection | |
Diffractometer | Bruker APEXII DUO CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.919, 0.971 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9325, 4207, 4076 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.756 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.117, 1.22 |
No. of reflections | 4207 |
No. of parameters | 164 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.64, −0.54 |
Absolute structure | Flack (1983), 1860 Friedel pairs |
Absolute structure parameter | −0.01 (4) |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008), SHELXTL (Sheldrick, 2008 and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O1i | 0.86 | 1.83 | 2.6921 (16) | 175 |
N2—H2B···O2i | 0.86 | 1.93 | 2.786 (2) | 177 |
N2—H2C···O2ii | 0.86 | 1.96 | 2.8146 (14) | 173 |
C5—H5A···O1iii | 0.93 | 2.50 | 3.1707 (13) | 129 |
Symmetry codes: (i) x, y+1, z; (ii) −x+1, y+1/2, −z+2; (iii) −x+1, y+1/2, −z+1. |
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 also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.
References
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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.
Recently, much attention has been devoted to the design and synthesis of supramolecular architectures assembled via various weak noncovalent interactions, such as hydrogen bonds, π···π stacking and C—H···π interactions (Remenar et al., 2003; Aakeroÿ et al., 2001; Sokolov et al., 2006). 2-Aminopyridine and its derivatives are used in the manufacture of pharmaceuticals, hair dyes and other dyes. They are often involved in hydrogen-bond interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). The crystal structures of 2-amino-4-methyl pyridine (Kvick & Noordik, 1977) and 2-amino-4-methylpyridinium 4-aminobenzoate (Shen et al., 2008) have been reported. We have recently reported the crystal structures of 2-amino-4-methylpyridinium 4-nitrobenzoate (Hemamalini & Fun, 2010a) and 2-Amino-4-methylpyridinium trifluoroacetate (Hemamalini & Fun, 2010b) from our laboratory. In continuation of our studies of pyridinium derivatives, the crystal structure determination of the title salt has been undertaken.
The asymmetric unit of the title compound, (Fig 1), contains a protonated 2-amino-4-methylpyridinium cation and a 3-chlorobenzoate anion. The 2-amino-4-methylpyridinium cation is planar, with a maximum deviation of 0.010 (1) Å for atom C1. The protonated N1 atom has lead to a slight increase in the C1—N1—C5 angle to 121.66 (11)°, compared to the corresponding angle of 117.3 (1)° in neutral 2-amino-4-methylpyridine (Kvick & Noordik, 1977). The bond lengths (Allen et al., 1987) and angles are normal.
In the crystal packing, (Fig. 2), the protonated N atom and 2-amino group (N2) is hydrogen-bonded to the carboxylate oxygen atoms (O1 and O2) via a pair of N—H···O hydrogen bonds leading to the formation of a R22(8) ring (Bernstein et al., 1995). Furthermore, these motifs are connected via N2—H2C···O2 and C5—H5A···O1 hydrogen bonds to form two-dimensional networks parallel to the bc-plane.