organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoIUCrDATA
ISSN: 2414-3146

2-Amino-4-methyl­pyridinium 4-meth­­oxy­benzoate dihydrate

CROSSMARK_Color_square_no_text.svg

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

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 15 April 2017; accepted 30 April 2017; online 5 May 2017)

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 ππ stacking [centroid-to-centroid distance = 3.5874 (17) Å] inter­actions are also observed.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

We herewith report the synthesis and the crystal structure of the title hydrated mol­ecular salt (Fig. 1[link]). The bond lengths are comparable with reported similar structures (Sivakumar et al., 2016a[Sivakumar, P., Sudhahar, S., Israel, S. & Chakkaravarthi, G. (2016a). IUCrData, 1, x160747.],b[Sivakumar, P., Sudhahar, S., Gunasekaran, B., Israel, S. & Chakkaravarthi, G. (2016b). IUCrData, 1, x160817.]). 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)°.

[Figure 1]
Figure 1
The mol­ecular structure of the title mol­ecular salt, with 30% probability displacement ellipsoids. Hydrogen bonds are shown as dashed lines.

In the asymmetric unit, N1—H1⋯O1 and N2—H2B⋯O2 hydrogen bonds link the anion and cation and generate an [R_{2}^{2}](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[link] and Table 1[link]). Further O—H⋯O hydrogen bonds link the components into a three-dimensional network (Fig. 2[link]). Weak C—H⋯O and ππ [Cg2⋯Cg2(−x, y, 1 − z) = 3.5874 (17) Å; Cg2 is the centroid of the N1/C9–C13 ring] inter­actions are also observed.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+1]; (ii) -x, y, -z; (iii) [x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]; (iv) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z].
[Figure 2]
Figure 2
The crystal packing of the title mol­ecular salt viewed along a axis. Hydrogen bonds are shown as dashed lines. H atoms not involving in hydrogen bonds have been omitted for clarity.

Synthesis 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 refinement details are summarized in Table 2[link]. The water H atoms were located in difference maps but DFIX and DANG commands were required to stabilize their refinement and prevent unreasonable close contacts and the location of these atoms should be regarded as less certain.

Table 2
Experimental details

Crystal data
Chemical formula C6H9N2+·C8H7O3·2H2O
Mr 296.32
Crystal system, space group Monoclinic, C2
Temperature (K) 295
a, b, c (Å) 13.6968 (12), 12.1053 (10), 9.6353 (7)
β (°) 105.170 (3)
V3) 1541.9 (2)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.10
Crystal size (mm) 0.28 × 0.24 × 0.20
 
Data collection
Diffractometer Bruker Kappa APEXII CCD
Absorption correction Multi-scan (SADABS; Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.694, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections 15843, 4821, 2891
Rint 0.048
(sin θ/λ)max−1) 0.725
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.046, 0.133, 1.02
No. of reflections 4821
No. of parameters 217
No. of restraints 10
H-atom treatment H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.17, −0.16
Computer programs: APEX2 and SAINT (Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2016 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. A71, 3-8.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Structural data


Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: 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).

2-Amino-4-methylpyridinium 4-methoxybenzoate dihydrate top
Crystal data top
C6H9N2+·C8H7O3·2H2OF(000) = 632
Mr = 296.32Dx = 1.276 Mg m3
Monoclinic, C2Mo Kα radiation, λ = 0.71073 Å
a = 13.6968 (12) ÅCell parameters from 4368 reflections
b = 12.1053 (10) Åθ = 2.6–25.0°
c = 9.6353 (7) ŵ = 0.10 mm1
β = 105.170 (3)°T = 295 K
V = 1541.9 (2) Å3Block, colourless
Z = 40.28 × 0.24 × 0.20 mm
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2891 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.048
ω and φ scanθmax = 31.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 1919
Tmin = 0.694, Tmax = 0.746k = 1717
15843 measured reflectionsl = 1113
4821 independent reflections
Refinement top
Refinement on F2Hydrogen site location: mixed
Least-squares matrix: fullH 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 = 1.02Δρmax = 0.17 e Å3
4821 reflectionsΔρmin = 0.16 e Å3
217 parametersExtinction correction: SHELXL2016 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
10 restraintsExtinction coefficient: 0.0095 (18)
Primary atom site location: structure-invariant direct methods
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.2345 (2)0.6229 (2)0.2107 (3)0.0483 (6)
C20.27037 (19)0.6036 (2)0.0794 (3)0.0405 (5)
C30.2511 (2)0.5037 (2)0.0058 (3)0.0510 (6)
H30.2135610.4498290.0375370.061*
C40.2863 (2)0.4830 (2)0.1125 (3)0.0537 (7)
H40.2732190.4155250.1598830.064*
C50.34132 (19)0.5633 (2)0.1606 (3)0.0458 (6)
C60.3602 (2)0.6642 (2)0.0921 (3)0.0481 (6)
H60.3960410.7186930.1258500.058*
C70.3245 (2)0.6827 (2)0.0280 (3)0.0458 (6)
H70.3374940.7502010.0752180.055*
C80.4287 (3)0.6162 (3)0.3348 (4)0.0772 (10)
H8A0.3898680.6830380.3544420.116*
H8B0.4419040.5894050.4218980.116*
H8C0.4916300.6306780.2650950.116*
C90.13362 (18)0.6428 (3)0.5632 (3)0.0484 (6)
C100.0920 (2)0.6643 (3)0.6788 (3)0.0550 (7)
H100.0688930.6060650.7245350.066*
C110.0851 (2)0.7694 (3)0.7244 (3)0.0584 (7)
C120.1220 (3)0.8565 (3)0.6556 (4)0.0668 (8)
H120.1181500.9290020.6855390.080*
C130.1631 (2)0.8337 (3)0.5456 (3)0.0606 (8)
H130.1880200.8908410.5001520.073*
C140.0384 (3)0.7919 (4)0.8469 (4)0.0876 (12)
H14A0.0065390.7325590.8541590.131*
H14B0.0011030.8599200.8294600.131*
H14C0.0907090.7975670.9350510.131*
N10.16822 (17)0.7284 (2)0.5012 (2)0.0500 (6)
H10.198 (2)0.718 (3)0.433 (3)0.077 (11)*
N20.1394 (2)0.5422 (2)0.5105 (3)0.0607 (7)
H2A0.123 (3)0.488 (2)0.558 (3)0.075 (11)*
H2B0.156 (3)0.533 (3)0.430 (2)0.071 (10)*
O10.26234 (15)0.70839 (18)0.2845 (2)0.0614 (6)
O20.1790 (2)0.5517 (2)0.2445 (3)0.0845 (8)
O30.37349 (16)0.5352 (2)0.2798 (2)0.0663 (6)
O40.0223 (2)0.4061 (2)0.1497 (3)0.0846 (8)
H4A0.068 (2)0.452 (3)0.171 (5)0.127*
H4B0.0250 (18)0.439 (4)0.0997 (15)0.127*
O50.43049 (16)0.84316 (18)0.3669 (2)0.0596 (5)
H5A0.383 (2)0.799 (3)0.340 (4)0.089*
H5B0.465 (3)0.859 (4)0.312 (4)0.089*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0507 (14)0.0501 (16)0.0493 (14)0.0098 (12)0.0220 (12)0.0039 (13)
C20.0419 (12)0.0418 (13)0.0395 (13)0.0052 (10)0.0138 (10)0.0023 (10)
C30.0596 (14)0.0461 (16)0.0529 (15)0.0147 (12)0.0249 (12)0.0041 (12)
C40.0670 (17)0.0479 (15)0.0502 (15)0.0094 (13)0.0224 (13)0.0117 (12)
C50.0434 (13)0.0543 (16)0.0413 (13)0.0038 (11)0.0143 (11)0.0042 (12)
C60.0540 (15)0.0504 (16)0.0438 (14)0.0099 (12)0.0199 (11)0.0006 (11)
C70.0513 (14)0.0414 (14)0.0480 (15)0.0094 (11)0.0186 (11)0.0062 (11)
C80.082 (2)0.099 (3)0.0652 (19)0.016 (2)0.0454 (18)0.006 (2)
C90.0411 (12)0.0630 (17)0.0408 (13)0.0006 (12)0.0099 (10)0.0049 (13)
C100.0478 (14)0.075 (2)0.0431 (14)0.0046 (14)0.0139 (11)0.0086 (13)
C110.0492 (15)0.083 (2)0.0456 (15)0.0021 (15)0.0165 (12)0.0088 (15)
C120.075 (2)0.066 (2)0.0635 (19)0.0022 (16)0.0252 (16)0.0126 (17)
C130.0670 (19)0.0617 (19)0.0565 (17)0.0098 (15)0.0226 (14)0.0036 (15)
C140.086 (2)0.125 (3)0.063 (2)0.005 (2)0.0386 (19)0.021 (2)
N10.0518 (12)0.0579 (14)0.0446 (13)0.0047 (10)0.0201 (10)0.0010 (11)
N20.0752 (17)0.0586 (16)0.0549 (15)0.0007 (13)0.0289 (13)0.0080 (13)
O10.0736 (13)0.0623 (12)0.0597 (12)0.0203 (10)0.0380 (10)0.0208 (10)
O20.1166 (19)0.0796 (16)0.0798 (16)0.0489 (15)0.0659 (15)0.0271 (14)
O30.0743 (13)0.0787 (14)0.0568 (11)0.0145 (11)0.0365 (10)0.0150 (11)
O40.0782 (16)0.0847 (18)0.0918 (18)0.0235 (14)0.0238 (13)0.0047 (15)
O50.0634 (13)0.0619 (13)0.0570 (12)0.0125 (10)0.0220 (10)0.0108 (10)
Geometric parameters (Å, º) top
C1—O21.247 (3)C9—C101.401 (4)
C1—O11.257 (3)C10—C111.357 (5)
C1—C21.491 (3)C10—H100.9300
C2—C71.380 (3)C11—C121.407 (5)
C2—C31.391 (4)C11—C141.508 (4)
C3—C41.372 (4)C12—C131.352 (4)
C3—H30.9300C12—H120.9300
C4—C51.382 (4)C13—N11.352 (4)
C4—H40.9300C13—H130.9300
C5—O31.376 (3)C14—H14A0.9600
C5—C61.381 (4)C14—H14B0.9600
C6—C71.387 (3)C14—H14C0.9600
C6—H60.9300N1—H10.870 (13)
C7—H70.9300N2—H2A0.864 (14)
C8—O31.422 (4)N2—H2B0.868 (13)
C8—H8A0.9600O4—H4A0.823 (14)
C8—H8B0.9600O4—H4B0.805 (14)
C8—H8C0.9600O5—H5A0.830 (14)
C9—N21.330 (4)O5—H5B0.822 (14)
C9—N11.342 (4)
O2—C1—O1122.4 (2)N1—C9—C10118.3 (3)
O2—C1—C2118.2 (2)C11—C10—C9120.6 (3)
O1—C1—C2119.4 (2)C11—C10—H10119.7
C7—C2—C3117.9 (2)C9—C10—H10119.7
C7—C2—C1121.6 (2)C10—C11—C12119.0 (3)
C3—C2—C1120.5 (2)C10—C11—C14120.2 (3)
C4—C3—C2121.4 (2)C12—C11—C14120.8 (3)
C4—C3—H3119.3C13—C12—C11119.4 (3)
C2—C3—H3119.3C13—C12—H12120.3
C3—C4—C5119.4 (2)C11—C12—H12120.3
C3—C4—H4120.3C12—C13—N1120.4 (3)
C5—C4—H4120.3C12—C13—H13119.8
O3—C5—C6123.8 (2)N1—C13—H13119.8
O3—C5—C4115.4 (2)C11—C14—H14A109.5
C6—C5—C4120.8 (2)C11—C14—H14B109.5
C5—C6—C7118.6 (2)H14A—C14—H14B109.5
C5—C6—H6120.7C11—C14—H14C109.5
C7—C6—H6120.7H14A—C14—H14C109.5
C2—C7—C6121.8 (2)H14B—C14—H14C109.5
C2—C7—H7119.1C9—N1—C13122.2 (2)
C6—C7—H7119.1C9—N1—H1121 (3)
O3—C8—H8A109.5C13—N1—H1117 (3)
O3—C8—H8B109.5C9—N2—H2A117 (2)
H8A—C8—H8B109.5C9—N2—H2B121 (3)
O3—C8—H8C109.5H2A—N2—H2B122 (4)
H8A—C8—H8C109.5C5—O3—C8117.3 (3)
H8B—C8—H8C109.5H4A—O4—H4B105 (2)
N2—C9—N1118.3 (2)H5A—O5—H5B119 (4)
N2—C9—C10123.4 (3)
O2—C1—C2—C7174.3 (3)C5—C6—C7—C20.6 (4)
O1—C1—C2—C77.1 (4)N2—C9—C10—C11177.7 (3)
O2—C1—C2—C36.6 (4)N1—C9—C10—C111.3 (4)
O1—C1—C2—C3172.0 (3)C9—C10—C11—C121.1 (4)
C7—C2—C3—C41.3 (4)C9—C10—C11—C14178.8 (3)
C1—C2—C3—C4177.9 (3)C10—C11—C12—C130.2 (5)
C2—C3—C4—C50.6 (5)C14—C11—C12—C13179.7 (3)
C3—C4—C5—O3180.0 (3)C11—C12—C13—N10.4 (5)
C3—C4—C5—C60.8 (4)N2—C9—N1—C13178.4 (3)
O3—C5—C6—C7179.5 (3)C10—C9—N1—C130.7 (4)
C4—C5—C6—C71.3 (4)C12—C13—N1—C90.1 (5)
C3—C2—C7—C60.7 (4)C6—C5—O3—C80.4 (4)
C1—C2—C7—C6178.5 (2)C4—C5—O3—C8178.8 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O10.87 (1)1.87 (1)2.737 (3)175 (4)
N2—H2B···O20.87 (1)1.91 (2)2.758 (3)165 (4)
N2—H2A···O5i0.86 (1)2.10 (2)2.951 (3)169 (3)
O4—H4A···O20.82 (1)1.92 (2)2.743 (3)173 (5)
O4—H4B···O4ii0.81 (1)2.45 (2)2.788 (6)107 (1)
O5—H5A···O10.83 (1)1.94 (2)2.764 (3)173 (4)
O5—H5B···O4iii0.82 (1)2.01 (2)2.814 (3)168 (4)
C6—H6···O4iv0.932.573.455 (4)160
Symmetry codes: (i) x+1/2, y1/2, 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.

References

First citationBruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSivakumar, P., Sudhahar, S., Gunasekaran, B., Israel, S. & Chakkaravarthi, G. (2016b). IUCrData, 1, x160817.  Google Scholar
First citationSivakumar, P., Sudhahar, S., Israel, S. & Chakkaravarthi, G. (2016a). IUCrData, 1, x160747.  Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS 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.

Journal logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds