organic compounds
2-Amino-4-methylpyridinium 4-methoxybenzoate dihydrate
aResearch and Development Centre, Bharathiar University, Coimbatore 641 046, India, bDepartment of Physics, CPCL Polytechnic College, Chennai 600 068, India, cPost Graduate and Research Department of Physics, Govt Arts College for Men, Nandanam, Chennai 600 025, India, and dPost Graduate and Research Department of Physics, The American College, Madurai 625 002, India
*Correspondence e-mail: israel.samuel@gmail.com, chakkaravarthi_2005@yahoo.com
In the title hydrated molecular salt, C6H9N2+·C8H7O3−·2H2O, the cation is protonated at the pyridine N atom. The cation and anion are linked by a pair of N—H⋯O hydrogen bonds, which generates an R22(8) loop, and the dihedral angle between their ring planes is 16.07 (14)°. The ion pairs are linked by O—H⋯O hydrogen bonds involving the water molecules, generating a three-dimensional network. Weak C—H⋯O and aromatic π–π stacking [centroid-to-centroid distance = 3.5874 (17) Å] interactions are also observed.
Keywords: crystal structure; molecular salt; hydrogen bonding.
CCDC reference: 1547046
Structure description
We herewith report the synthesis and the ). The bond lengths are comparable with reported similar structures (Sivakumar et al., 2016a,b). The cation is protonated at the pyridine N atom and the dihedral angle between the pyridine (N1/C9–C13) and benzene (C2–C7) rings is 16.07 (14)°.
of the title hydrated molecular salt (Fig. 1In the B⋯O2 hydrogen bonds link the anion and cation and generate an (8) loop. The ion-pairs are further connected with the water molecules of crystallization through O4—H4A⋯O2 and O5—H5A⋯O1 hydrogen bonds (Fig. 1 and Table 1). Further O—H⋯O hydrogen bonds link the components into a three-dimensional network (Fig. 2). Weak C—H⋯O and π–π [Cg2⋯Cg2(−x, y, 1 − z) = 3.5874 (17) Å; Cg2 is the centroid of the N1/C9–C13 ring] interactions are also observed.
N1—H1⋯O1 and N2—H2Synthesis and crystallization
The title compound was prepared by mixing 4-methoxy benzoic acid (0.76 g) and 2-amino-4-methylpyridine (0.54 g) in an equimolar ratio in 20 ml acetone: the mixture was magnetically stirred for 3 h in a round-bottomed flask and then kept at room temperature for slow evaporation. After 30 days, colourless blocks were harvested.
Refinement
Crystal data, data collection and structure . The water H atoms were located in difference maps but DFIX and DANG commands were required to stabilize their and prevent unreasonable close contacts and the location of these atoms should be regarded as less certain.
details are summarized in Table 2
|
Structural data
CCDC reference: 1547046
https://doi.org/10.1107/S2414314617006496/hb4140sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617006496/hb4140Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314617006496/hb4140Isup3.cml
Data collection: APEX2 (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2016 (Sheldrick, 2015) and PLATON (Spek, 2009).C6H9N2+·C8H7O3−·2H2O | F(000) = 632 |
Mr = 296.32 | Dx = 1.276 Mg m−3 |
Monoclinic, C2 | Mo Kα radiation, λ = 0.71073 Å |
a = 13.6968 (12) Å | Cell parameters from 4368 reflections |
b = 12.1053 (10) Å | θ = 2.6–25.0° |
c = 9.6353 (7) Å | µ = 0.10 mm−1 |
β = 105.170 (3)° | T = 295 K |
V = 1541.9 (2) Å3 | Block, colourless |
Z = 4 | 0.28 × 0.24 × 0.20 mm |
Bruker Kappa APEXII CCD diffractometer | 2891 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.048 |
ω and φ scan | θmax = 31.0°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −19→19 |
Tmin = 0.694, Tmax = 0.746 | k = −17→17 |
15843 measured reflections | l = −11→13 |
4821 independent reflections |
Refinement on F2 | Hydrogen site location: mixed |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.046 | w = 1/[σ2(Fo2) + (0.060P)2 + 0.0879P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.133 | (Δ/σ)max < 0.001 |
S = 1.02 | Δρmax = 0.17 e Å−3 |
4821 reflections | Δρmin = −0.16 e Å−3 |
217 parameters | Extinction correction: SHELXL2016 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
10 restraints | Extinction coefficient: 0.0095 (18) |
Primary atom site location: structure-invariant direct methods |
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. The hydrogen atoms for the NH and NH2 groups were loacated from Fourier maps and refined with N—H distance restraints of 0.86 (1) Å. The C-bound H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C) for aromatic CH and C—H = 0.96 Å and Uiso(H) = 1.5Ueq(C) for CH3. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.2345 (2) | 0.6229 (2) | 0.2107 (3) | 0.0483 (6) | |
C2 | 0.27037 (19) | 0.6036 (2) | 0.0794 (3) | 0.0405 (5) | |
C3 | 0.2511 (2) | 0.5037 (2) | 0.0058 (3) | 0.0510 (6) | |
H3 | 0.213561 | 0.449829 | 0.037537 | 0.061* | |
C4 | 0.2863 (2) | 0.4830 (2) | −0.1125 (3) | 0.0537 (7) | |
H4 | 0.273219 | 0.415525 | −0.159883 | 0.064* | |
C5 | 0.34132 (19) | 0.5633 (2) | −0.1606 (3) | 0.0458 (6) | |
C6 | 0.3602 (2) | 0.6642 (2) | −0.0921 (3) | 0.0481 (6) | |
H6 | 0.396041 | 0.718693 | −0.125850 | 0.058* | |
C7 | 0.3245 (2) | 0.6827 (2) | 0.0280 (3) | 0.0458 (6) | |
H7 | 0.337494 | 0.750201 | 0.075218 | 0.055* | |
C8 | 0.4287 (3) | 0.6162 (3) | −0.3348 (4) | 0.0772 (10) | |
H8A | 0.389868 | 0.683038 | −0.354442 | 0.116* | |
H8B | 0.441904 | 0.589405 | −0.421898 | 0.116* | |
H8C | 0.491630 | 0.630678 | −0.265095 | 0.116* | |
C9 | 0.13362 (18) | 0.6428 (3) | 0.5632 (3) | 0.0484 (6) | |
C10 | 0.0920 (2) | 0.6643 (3) | 0.6788 (3) | 0.0550 (7) | |
H10 | 0.068893 | 0.606065 | 0.724535 | 0.066* | |
C11 | 0.0851 (2) | 0.7694 (3) | 0.7244 (3) | 0.0584 (7) | |
C12 | 0.1220 (3) | 0.8565 (3) | 0.6556 (4) | 0.0668 (8) | |
H12 | 0.118150 | 0.929002 | 0.685539 | 0.080* | |
C13 | 0.1631 (2) | 0.8337 (3) | 0.5456 (3) | 0.0606 (8) | |
H13 | 0.188020 | 0.890841 | 0.500152 | 0.073* | |
C14 | 0.0384 (3) | 0.7919 (4) | 0.8469 (4) | 0.0876 (12) | |
H14A | −0.006539 | 0.732559 | 0.854159 | 0.131* | |
H14B | 0.001103 | 0.859920 | 0.829460 | 0.131* | |
H14C | 0.090709 | 0.797567 | 0.935051 | 0.131* | |
N1 | 0.16822 (17) | 0.7284 (2) | 0.5012 (2) | 0.0500 (6) | |
H1 | 0.198 (2) | 0.718 (3) | 0.433 (3) | 0.077 (11)* | |
N2 | 0.1394 (2) | 0.5422 (2) | 0.5105 (3) | 0.0607 (7) | |
H2A | 0.123 (3) | 0.488 (2) | 0.558 (3) | 0.075 (11)* | |
H2B | 0.156 (3) | 0.533 (3) | 0.430 (2) | 0.071 (10)* | |
O1 | 0.26234 (15) | 0.70839 (18) | 0.2845 (2) | 0.0614 (6) | |
O2 | 0.1790 (2) | 0.5517 (2) | 0.2445 (3) | 0.0845 (8) | |
O3 | 0.37349 (16) | 0.5352 (2) | −0.2798 (2) | 0.0663 (6) | |
O4 | 0.0223 (2) | 0.4061 (2) | 0.1497 (3) | 0.0846 (8) | |
H4A | 0.068 (2) | 0.452 (3) | 0.171 (5) | 0.127* | |
H4B | −0.0250 (18) | 0.439 (4) | 0.0997 (15) | 0.127* | |
O5 | 0.43049 (16) | 0.84316 (18) | 0.3669 (2) | 0.0596 (5) | |
H5A | 0.383 (2) | 0.799 (3) | 0.340 (4) | 0.089* | |
H5B | 0.465 (3) | 0.859 (4) | 0.312 (4) | 0.089* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0507 (14) | 0.0501 (16) | 0.0493 (14) | −0.0098 (12) | 0.0220 (12) | −0.0039 (13) |
C2 | 0.0419 (12) | 0.0418 (13) | 0.0395 (13) | −0.0052 (10) | 0.0138 (10) | −0.0023 (10) |
C3 | 0.0596 (14) | 0.0461 (16) | 0.0529 (15) | −0.0147 (12) | 0.0249 (12) | −0.0041 (12) |
C4 | 0.0670 (17) | 0.0479 (15) | 0.0502 (15) | −0.0094 (13) | 0.0224 (13) | −0.0117 (12) |
C5 | 0.0434 (13) | 0.0543 (16) | 0.0413 (13) | −0.0038 (11) | 0.0143 (11) | −0.0042 (12) |
C6 | 0.0540 (15) | 0.0504 (16) | 0.0438 (14) | −0.0099 (12) | 0.0199 (11) | −0.0006 (11) |
C7 | 0.0513 (14) | 0.0414 (14) | 0.0480 (15) | −0.0094 (11) | 0.0186 (11) | −0.0062 (11) |
C8 | 0.082 (2) | 0.099 (3) | 0.0652 (19) | −0.016 (2) | 0.0454 (18) | −0.006 (2) |
C9 | 0.0411 (12) | 0.0630 (17) | 0.0408 (13) | 0.0006 (12) | 0.0099 (10) | 0.0049 (13) |
C10 | 0.0478 (14) | 0.075 (2) | 0.0431 (14) | −0.0046 (14) | 0.0139 (11) | 0.0086 (13) |
C11 | 0.0492 (15) | 0.083 (2) | 0.0456 (15) | −0.0021 (15) | 0.0165 (12) | −0.0088 (15) |
C12 | 0.075 (2) | 0.066 (2) | 0.0635 (19) | −0.0022 (16) | 0.0252 (16) | −0.0126 (17) |
C13 | 0.0670 (19) | 0.0617 (19) | 0.0565 (17) | −0.0098 (15) | 0.0226 (14) | −0.0036 (15) |
C14 | 0.086 (2) | 0.125 (3) | 0.063 (2) | −0.005 (2) | 0.0386 (19) | −0.021 (2) |
N1 | 0.0518 (12) | 0.0579 (14) | 0.0446 (13) | −0.0047 (10) | 0.0201 (10) | −0.0010 (11) |
N2 | 0.0752 (17) | 0.0586 (16) | 0.0549 (15) | 0.0007 (13) | 0.0289 (13) | 0.0080 (13) |
O1 | 0.0736 (13) | 0.0623 (12) | 0.0597 (12) | −0.0203 (10) | 0.0380 (10) | −0.0208 (10) |
O2 | 0.1166 (19) | 0.0796 (16) | 0.0798 (16) | −0.0489 (15) | 0.0659 (15) | −0.0271 (14) |
O3 | 0.0743 (13) | 0.0787 (14) | 0.0568 (11) | −0.0145 (11) | 0.0365 (10) | −0.0150 (11) |
O4 | 0.0782 (16) | 0.0847 (18) | 0.0918 (18) | −0.0235 (14) | 0.0238 (13) | −0.0047 (15) |
O5 | 0.0634 (13) | 0.0619 (13) | 0.0570 (12) | −0.0125 (10) | 0.0220 (10) | −0.0108 (10) |
C1—O2 | 1.247 (3) | C9—C10 | 1.401 (4) |
C1—O1 | 1.257 (3) | C10—C11 | 1.357 (5) |
C1—C2 | 1.491 (3) | C10—H10 | 0.9300 |
C2—C7 | 1.380 (3) | C11—C12 | 1.407 (5) |
C2—C3 | 1.391 (4) | C11—C14 | 1.508 (4) |
C3—C4 | 1.372 (4) | C12—C13 | 1.352 (4) |
C3—H3 | 0.9300 | C12—H12 | 0.9300 |
C4—C5 | 1.382 (4) | C13—N1 | 1.352 (4) |
C4—H4 | 0.9300 | C13—H13 | 0.9300 |
C5—O3 | 1.376 (3) | C14—H14A | 0.9600 |
C5—C6 | 1.381 (4) | C14—H14B | 0.9600 |
C6—C7 | 1.387 (3) | C14—H14C | 0.9600 |
C6—H6 | 0.9300 | N1—H1 | 0.870 (13) |
C7—H7 | 0.9300 | N2—H2A | 0.864 (14) |
C8—O3 | 1.422 (4) | N2—H2B | 0.868 (13) |
C8—H8A | 0.9600 | O4—H4A | 0.823 (14) |
C8—H8B | 0.9600 | O4—H4B | 0.805 (14) |
C8—H8C | 0.9600 | O5—H5A | 0.830 (14) |
C9—N2 | 1.330 (4) | O5—H5B | 0.822 (14) |
C9—N1 | 1.342 (4) | ||
O2—C1—O1 | 122.4 (2) | N1—C9—C10 | 118.3 (3) |
O2—C1—C2 | 118.2 (2) | C11—C10—C9 | 120.6 (3) |
O1—C1—C2 | 119.4 (2) | C11—C10—H10 | 119.7 |
C7—C2—C3 | 117.9 (2) | C9—C10—H10 | 119.7 |
C7—C2—C1 | 121.6 (2) | C10—C11—C12 | 119.0 (3) |
C3—C2—C1 | 120.5 (2) | C10—C11—C14 | 120.2 (3) |
C4—C3—C2 | 121.4 (2) | C12—C11—C14 | 120.8 (3) |
C4—C3—H3 | 119.3 | C13—C12—C11 | 119.4 (3) |
C2—C3—H3 | 119.3 | C13—C12—H12 | 120.3 |
C3—C4—C5 | 119.4 (2) | C11—C12—H12 | 120.3 |
C3—C4—H4 | 120.3 | C12—C13—N1 | 120.4 (3) |
C5—C4—H4 | 120.3 | C12—C13—H13 | 119.8 |
O3—C5—C6 | 123.8 (2) | N1—C13—H13 | 119.8 |
O3—C5—C4 | 115.4 (2) | C11—C14—H14A | 109.5 |
C6—C5—C4 | 120.8 (2) | C11—C14—H14B | 109.5 |
C5—C6—C7 | 118.6 (2) | H14A—C14—H14B | 109.5 |
C5—C6—H6 | 120.7 | C11—C14—H14C | 109.5 |
C7—C6—H6 | 120.7 | H14A—C14—H14C | 109.5 |
C2—C7—C6 | 121.8 (2) | H14B—C14—H14C | 109.5 |
C2—C7—H7 | 119.1 | C9—N1—C13 | 122.2 (2) |
C6—C7—H7 | 119.1 | C9—N1—H1 | 121 (3) |
O3—C8—H8A | 109.5 | C13—N1—H1 | 117 (3) |
O3—C8—H8B | 109.5 | C9—N2—H2A | 117 (2) |
H8A—C8—H8B | 109.5 | C9—N2—H2B | 121 (3) |
O3—C8—H8C | 109.5 | H2A—N2—H2B | 122 (4) |
H8A—C8—H8C | 109.5 | C5—O3—C8 | 117.3 (3) |
H8B—C8—H8C | 109.5 | H4A—O4—H4B | 105 (2) |
N2—C9—N1 | 118.3 (2) | H5A—O5—H5B | 119 (4) |
N2—C9—C10 | 123.4 (3) | ||
O2—C1—C2—C7 | 174.3 (3) | C5—C6—C7—C2 | −0.6 (4) |
O1—C1—C2—C7 | −7.1 (4) | N2—C9—C10—C11 | −177.7 (3) |
O2—C1—C2—C3 | −6.6 (4) | N1—C9—C10—C11 | 1.3 (4) |
O1—C1—C2—C3 | 172.0 (3) | C9—C10—C11—C12 | −1.1 (4) |
C7—C2—C3—C4 | 1.3 (4) | C9—C10—C11—C14 | 178.8 (3) |
C1—C2—C3—C4 | −177.9 (3) | C10—C11—C12—C13 | 0.2 (5) |
C2—C3—C4—C5 | −0.6 (5) | C14—C11—C12—C13 | −179.7 (3) |
C3—C4—C5—O3 | 180.0 (3) | C11—C12—C13—N1 | 0.4 (5) |
C3—C4—C5—C6 | −0.8 (4) | N2—C9—N1—C13 | 178.4 (3) |
O3—C5—C6—C7 | −179.5 (3) | C10—C9—N1—C13 | −0.7 (4) |
C4—C5—C6—C7 | 1.3 (4) | C12—C13—N1—C9 | −0.1 (5) |
C3—C2—C7—C6 | −0.7 (4) | C6—C5—O3—C8 | −0.4 (4) |
C1—C2—C7—C6 | 178.5 (2) | C4—C5—O3—C8 | 178.8 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.87 (1) | 1.87 (1) | 2.737 (3) | 175 (4) |
N2—H2B···O2 | 0.87 (1) | 1.91 (2) | 2.758 (3) | 165 (4) |
N2—H2A···O5i | 0.86 (1) | 2.10 (2) | 2.951 (3) | 169 (3) |
O4—H4A···O2 | 0.82 (1) | 1.92 (2) | 2.743 (3) | 173 (5) |
O4—H4B···O4ii | 0.81 (1) | 2.45 (2) | 2.788 (6) | 107 (1) |
O5—H5A···O1 | 0.83 (1) | 1.94 (2) | 2.764 (3) | 173 (4) |
O5—H5B···O4iii | 0.82 (1) | 2.01 (2) | 2.814 (3) | 168 (4) |
C6—H6···O4iv | 0.93 | 2.57 | 3.455 (4) | 160 |
Symmetry codes: (i) −x+1/2, y−1/2, −z+1; (ii) −x, y, −z; (iii) x+1/2, y+1/2, z; (iv) −x+1/2, y+1/2, −z. |
Acknowledgements
The authors acknowledge the SAIF, IIT, Madras, for the data collection.
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