organic compounds
4-Methylpyridinium 2-carboxy-6-nitrobenzoate
aDepartment of Physics, Presidency College, Chennai 600 005, India, bDepartment of Physics, Aksheyaa College of Engineering, Kancheepuram 603 314, India, and cDepartment of Physics, CPCL Polytechnic College, Chennai 600 068, India
*Correspondence e-mail: mohan66@hotmail.com, chakkaravarthi_2005@yahoo.com
In the title molecular salt, C6H8N+·C8H4NO6−, the anion is deprotonated at the carboxylic acid group adjacent to the nitro group. In the crystal, the anions are linked into an [001] chain by O—H⋯O hydrogen bonds. The cations are linked to these chains by N—H⋯O hydrogen bonds and weak C—H⋯O contacts, generating a three-dimensional network.
Keywords: molecular salt; crystal structure; hydrogen bonding..
CCDC reference: 1515803
Structure description
As part of our ongoing studies of molecular salts (Sivakumar et al., 2016), we now report the synthesis and the of the title compound (Fig. 1). Its geometric parameters are comparable with those of reported structures (Li & Chai, 2007)
The anion is deprotonated at the central carboxylic acid group (C8/O3/O4), but not the other (C7/O5/O6), hence a 1:1 stoichiometry salt arises. The dihedral angles between the C1–C6 benzene ring and the C7/O5/O6, C8/O3/O4 and N1/O1/O2 substituents are 27.09 (11), 71.59 (10) and 68.44 (11)°, respectively.
In the crystal, the N2—H2A⋯O4 hydrogen bond and C13—H13⋯O6 contact generate an R22(10) ring-set motif (Table 1, Fig. 2). The O6—H6⋯O3i hydrogen bond (Table 1) links adjacent anions into an infinite chain along [001]. The is consolidated by weak C—H⋯O contacts to form a three dimensional network (Table 1, Fig. 3).
Synthesis and crystallization
The title salt was synthesized from 4-methylpyridine (4.90 g) and 3-nitrophthalic acid (5.28 g) in a 2:1 ratio. These reactants were dissolved in water and continuously stirred about 5 h and kept at 35°C using a constant temperature bath. After 20 days, crystals suitable for X-ray diffraction were harvested.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1515803
https://doi.org/10.1107/S2414314616018034/hb4095sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616018034/hb4095Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314616018034/hb4095Isup3.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).C6H8N+·C8H4NO6− | F(000) = 632 |
Mr = 304.26 | Dx = 1.441 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 7.683 (5) Å | Cell parameters from 5621 reflections |
b = 17.309 (6) Å | θ = 2.3–31.0° |
c = 11.172 (5) Å | µ = 0.12 mm−1 |
β = 109.260 (5)° | T = 295 K |
V = 1402.6 (12) Å3 | Block, colourless |
Z = 4 | 0.28 × 0.26 × 0.22 mm |
Bruker axs kappa apex2 CCD diffractometer | 2572 reflections with I > 2σ(I) |
ω and φ scan | Rint = 0.054 |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | θmax = 30.8°, θmin = 2.3° |
Tmin = 0.504, Tmax = 0.746 | h = −10→9 |
18131 measured reflections | k = −24→24 |
4295 independent reflections | l = −14→16 |
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)] = 0.054 | w = 1/[σ2(Fo2) + (0.0595P)2 + 0.4448P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.153 | (Δ/σ)max < 0.001 |
S = 1.04 | Δρmax = 0.58 e Å−3 |
4295 reflections | Δρmin = −0.35 e Å−3 |
208 parameters | Extinction correction: SHELXL-2016/4 (Sheldrick 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.015 (3) |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.5227 (2) | 0.13436 (10) | 0.49500 (16) | 0.0344 (4) | |
C2 | 0.7063 (2) | 0.15506 (12) | 0.54221 (19) | 0.0455 (5) | |
H2 | 0.792007 | 0.132931 | 0.510103 | 0.055* | |
C3 | 0.7598 (3) | 0.20898 (13) | 0.6376 (2) | 0.0515 (5) | |
H3 | 0.883187 | 0.223208 | 0.670951 | 0.062* | |
C4 | 0.6323 (3) | 0.24217 (12) | 0.68415 (19) | 0.0455 (5) | |
H4 | 0.670037 | 0.278336 | 0.749197 | 0.055* | |
C5 | 0.4471 (2) | 0.22170 (10) | 0.63407 (16) | 0.0333 (4) | |
C6 | 0.3892 (2) | 0.16713 (9) | 0.53821 (15) | 0.0292 (3) | |
C7 | 0.3055 (2) | 0.26237 (10) | 0.67731 (17) | 0.0380 (4) | |
C8 | 0.1850 (2) | 0.14998 (9) | 0.48115 (15) | 0.0307 (3) | |
C9 | 0.1140 (3) | −0.02111 (13) | 0.75650 (18) | 0.0462 (5) | |
H9 | 0.057618 | −0.038361 | 0.673896 | 0.055* | |
C10 | 0.1235 (3) | −0.06817 (12) | 0.8561 (2) | 0.0490 (5) | |
H10 | 0.072761 | −0.117460 | 0.841181 | 0.059* | |
C11 | 0.2077 (3) | −0.04341 (12) | 0.97884 (19) | 0.0474 (5) | |
C12 | 0.2786 (4) | 0.03076 (14) | 0.9961 (2) | 0.0599 (6) | |
H12 | 0.335995 | 0.049530 | 1.077639 | 0.072* | |
C13 | 0.2645 (3) | 0.07629 (13) | 0.8942 (2) | 0.0594 (6) | |
H13 | 0.310476 | 0.126439 | 0.906422 | 0.071* | |
C14 | 0.2237 (4) | −0.09521 (17) | 1.0893 (2) | 0.0760 (8) | |
H14A | 0.110131 | −0.122777 | 1.074606 | 0.114* | |
H14B | 0.249051 | −0.064691 | 1.164917 | 0.114* | |
H14C | 0.322252 | −0.131367 | 1.099301 | 0.114* | |
N1 | 0.4690 (2) | 0.07633 (10) | 0.39439 (15) | 0.0455 (4) | |
N2 | 0.1856 (2) | 0.04959 (11) | 0.77753 (17) | 0.0471 (4) | |
O1 | 0.5633 (2) | 0.07038 (13) | 0.32559 (17) | 0.0863 (6) | |
O2 | 0.3329 (2) | 0.03729 (9) | 0.38272 (15) | 0.0610 (4) | |
O3 | 0.10343 (16) | 0.17716 (8) | 0.37237 (12) | 0.0429 (3) | |
O4 | 0.10975 (16) | 0.11345 (8) | 0.54551 (12) | 0.0433 (3) | |
O5 | 0.1921 (3) | 0.30446 (12) | 0.60735 (17) | 0.0875 (7) | |
O6 | 0.3113 (2) | 0.24557 (9) | 0.78951 (14) | 0.0574 (4) | |
H2A | 0.180 (3) | 0.0781 (15) | 0.713 (2) | 0.064 (7)* | |
H6 | 0.233 (3) | 0.2727 (16) | 0.808 (3) | 0.096* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0292 (8) | 0.0394 (9) | 0.0369 (9) | 0.0043 (7) | 0.0142 (7) | 0.0024 (7) |
C2 | 0.0279 (8) | 0.0576 (12) | 0.0550 (11) | 0.0066 (8) | 0.0191 (8) | 0.0051 (10) |
C3 | 0.0278 (8) | 0.0607 (13) | 0.0629 (13) | −0.0068 (8) | 0.0110 (9) | 0.0018 (11) |
C4 | 0.0393 (10) | 0.0460 (11) | 0.0470 (11) | −0.0085 (8) | 0.0084 (8) | −0.0049 (9) |
C5 | 0.0337 (8) | 0.0316 (8) | 0.0367 (9) | −0.0002 (6) | 0.0146 (7) | 0.0014 (7) |
C6 | 0.0245 (7) | 0.0322 (8) | 0.0333 (8) | 0.0008 (6) | 0.0126 (6) | 0.0036 (7) |
C7 | 0.0430 (10) | 0.0330 (9) | 0.0408 (10) | 0.0019 (7) | 0.0176 (8) | −0.0023 (8) |
C8 | 0.0264 (7) | 0.0337 (8) | 0.0351 (9) | 0.0005 (6) | 0.0143 (6) | −0.0013 (7) |
C9 | 0.0410 (10) | 0.0577 (13) | 0.0397 (10) | −0.0020 (9) | 0.0133 (8) | −0.0031 (9) |
C10 | 0.0513 (11) | 0.0430 (11) | 0.0528 (12) | −0.0065 (9) | 0.0173 (9) | −0.0006 (9) |
C11 | 0.0506 (11) | 0.0501 (12) | 0.0432 (11) | 0.0058 (9) | 0.0176 (9) | 0.0062 (9) |
C12 | 0.0750 (15) | 0.0550 (13) | 0.0436 (12) | −0.0034 (11) | 0.0113 (11) | −0.0079 (10) |
C13 | 0.0696 (14) | 0.0409 (11) | 0.0643 (15) | −0.0078 (10) | 0.0173 (11) | −0.0011 (10) |
C14 | 0.0891 (19) | 0.0815 (18) | 0.0584 (14) | 0.0061 (15) | 0.0256 (13) | 0.0259 (13) |
N1 | 0.0381 (8) | 0.0537 (10) | 0.0452 (9) | 0.0135 (7) | 0.0145 (7) | −0.0059 (8) |
N2 | 0.0437 (9) | 0.0529 (10) | 0.0486 (10) | 0.0029 (8) | 0.0204 (8) | 0.0125 (9) |
O1 | 0.0699 (11) | 0.1304 (18) | 0.0740 (12) | 0.0046 (11) | 0.0447 (9) | −0.0371 (11) |
O2 | 0.0559 (9) | 0.0570 (9) | 0.0707 (10) | −0.0050 (7) | 0.0215 (8) | −0.0227 (8) |
O3 | 0.0320 (6) | 0.0555 (8) | 0.0393 (7) | −0.0012 (5) | 0.0093 (5) | 0.0098 (6) |
O4 | 0.0311 (6) | 0.0563 (8) | 0.0458 (7) | −0.0048 (5) | 0.0170 (5) | 0.0100 (6) |
O5 | 0.1094 (15) | 0.0963 (14) | 0.0725 (11) | 0.0649 (12) | 0.0511 (11) | 0.0296 (10) |
O6 | 0.0695 (10) | 0.0642 (10) | 0.0476 (8) | 0.0214 (8) | 0.0315 (7) | 0.0034 (7) |
C1—C2 | 1.380 (2) | C9—C10 | 1.362 (3) |
C1—C6 | 1.391 (2) | C9—H9 | 0.9300 |
C1—N1 | 1.462 (2) | C10—C11 | 1.377 (3) |
C2—C3 | 1.373 (3) | C10—H10 | 0.9300 |
C2—H2 | 0.9300 | C11—C12 | 1.383 (3) |
C3—C4 | 1.377 (3) | C11—C14 | 1.497 (3) |
C3—H3 | 0.9300 | C12—C13 | 1.359 (3) |
C4—C5 | 1.392 (3) | C12—H12 | 0.9300 |
C4—H4 | 0.9300 | C13—N2 | 1.327 (3) |
C5—C6 | 1.387 (2) | C13—H13 | 0.9300 |
C5—C7 | 1.503 (2) | C14—H14A | 0.9600 |
C6—C8 | 1.515 (2) | C14—H14B | 0.9600 |
C7—O5 | 1.205 (2) | C14—H14C | 0.9600 |
C7—O6 | 1.273 (2) | N1—O2 | 1.216 (2) |
C8—O4 | 1.2350 (19) | N1—O1 | 1.222 (2) |
C8—O3 | 1.260 (2) | N2—H2A | 0.86 (3) |
C9—N2 | 1.330 (3) | O6—H6 | 0.842 (10) |
C2—C1—C6 | 122.63 (17) | C10—C9—H9 | 120.1 |
C2—C1—N1 | 117.77 (15) | C9—C10—C11 | 120.56 (19) |
C6—C1—N1 | 119.59 (15) | C9—C10—H10 | 119.7 |
C3—C2—C1 | 118.66 (16) | C11—C10—H10 | 119.7 |
C3—C2—H2 | 120.7 | C10—C11—C12 | 117.50 (19) |
C1—C2—H2 | 120.7 | C10—C11—C14 | 121.2 (2) |
C2—C3—C4 | 120.55 (17) | C12—C11—C14 | 121.3 (2) |
C2—C3—H3 | 119.7 | C13—C12—C11 | 120.2 (2) |
C4—C3—H3 | 119.7 | C13—C12—H12 | 119.9 |
C3—C4—C5 | 120.14 (18) | C11—C12—H12 | 119.9 |
C3—C4—H4 | 119.9 | N2—C13—C12 | 120.4 (2) |
C5—C4—H4 | 119.9 | N2—C13—H13 | 119.8 |
C6—C5—C4 | 120.57 (15) | C12—C13—H13 | 119.8 |
C6—C5—C7 | 119.04 (15) | C11—C14—H14A | 109.5 |
C4—C5—C7 | 120.26 (16) | C11—C14—H14B | 109.5 |
C5—C6—C1 | 117.42 (15) | H14A—C14—H14B | 109.5 |
C5—C6—C8 | 118.83 (13) | C11—C14—H14C | 109.5 |
C1—C6—C8 | 123.64 (15) | H14A—C14—H14C | 109.5 |
O5—C7—O6 | 124.05 (17) | H14B—C14—H14C | 109.5 |
O5—C7—C5 | 121.33 (17) | O2—N1—O1 | 123.59 (18) |
O6—C7—C5 | 114.54 (16) | O2—N1—C1 | 118.63 (15) |
O4—C8—O3 | 124.97 (15) | O1—N1—C1 | 117.77 (18) |
O4—C8—C6 | 118.29 (14) | C13—N2—C9 | 121.48 (19) |
O3—C8—C6 | 116.68 (13) | C13—N2—H2A | 120.1 (17) |
N2—C9—C10 | 119.90 (19) | C9—N2—H2A | 118.4 (17) |
N2—C9—H9 | 120.1 | C7—O6—H6 | 109 (2) |
C6—C1—C2—C3 | 1.4 (3) | C4—C5—C7—O6 | −71.7 (2) |
N1—C1—C2—C3 | −179.43 (17) | C5—C6—C8—O4 | −72.1 (2) |
C1—C2—C3—C4 | −0.6 (3) | C1—C6—C8—O4 | 111.72 (19) |
C2—C3—C4—C5 | −0.5 (3) | C5—C6—C8—O3 | 105.15 (18) |
C3—C4—C5—C6 | 0.9 (3) | C1—C6—C8—O3 | −71.0 (2) |
C3—C4—C5—C7 | −175.09 (18) | N2—C9—C10—C11 | −0.4 (3) |
C4—C5—C6—C1 | −0.1 (2) | C9—C10—C11—C12 | 1.0 (3) |
C7—C5—C6—C1 | 175.92 (15) | C9—C10—C11—C14 | −178.3 (2) |
C4—C5—C6—C8 | −176.47 (16) | C10—C11—C12—C13 | −0.2 (3) |
C7—C5—C6—C8 | −0.5 (2) | C14—C11—C12—C13 | 179.1 (2) |
C2—C1—C6—C5 | −1.1 (3) | C11—C12—C13—N2 | −1.1 (4) |
N1—C1—C6—C5 | 179.78 (15) | C2—C1—N1—O2 | 153.77 (18) |
C2—C1—C6—C8 | 175.13 (16) | C6—C1—N1—O2 | −27.0 (2) |
N1—C1—C6—C8 | −4.0 (2) | C2—C1—N1—O1 | −26.9 (3) |
C6—C5—C7—O5 | −64.6 (3) | C6—C1—N1—O1 | 152.23 (19) |
C4—C5—C7—O5 | 111.4 (2) | C12—C13—N2—C9 | 1.8 (3) |
C6—C5—C7—O6 | 112.27 (19) | C10—C9—N2—C13 | −1.0 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O4 | 0.86 (3) | 1.87 (3) | 2.699 (2) | 160 (2) |
O6—H6···O3i | 0.84 (1) | 1.65 (1) | 2.484 (2) | 170 (3) |
C13—H13···O6 | 0.93 | 2.44 | 3.219 (3) | 141 |
C2—H2···O4ii | 0.93 | 2.36 | 3.171 (3) | 145 |
C10—H10···O3iii | 0.93 | 2.54 | 3.191 (3) | 127 |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) x+1, y, z; (iii) −x, −y, −z+1. |
Acknowledgements
The authors acknowledge the SAIF, IIT, Madras, for the data collection.
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