organic compounds
4-Methoxyanilinium 2-carboxy-4,5-dichlorobenzoate
aScience and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia
*Correspondence e-mail: g.smith@qut.edu.au
In the title salt C7H10NO+·C8H3Cl2O4− the benzene rings of the cation and anion are essentially parallel [inter-ring dihedral angle 4.8 (2)°]. In the anion the carboxylic acid and carboxylate groups make dihedral angles of 19.0 (2) and 79.5 (2)°, respectively, with the benzene ring. Aminium N—H⋯O, carboxylic acid O—H⋯O and weak aromatic C—H⋯O hydrogen-bonding associations with carboxyl O-atom acceptors together with cation–anion π–π ring interactions [minimum ring centroid separation = 3.734 (3) Å] give rise to a sheet structure lying parallel to (001).
CCDC reference: 960147
Related literature
For background to 4,5-dichlorophthalate salts, see: Mattes & Dorau (1986); Smith et al. (2008a). For structures of some 1:1 anilinium salts of 4,5-dichlorophthalic acid, see: Odabaşoğlu & Büyükgüngör (2007); Smith et al. (2008b); Smith et al. (2009). For the structure of a dianionic 4,5-dichlorophthalate salt, see: Smith & Wermuth (2012).
Experimental
Crystal data
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Data collection: CrysAlis PRO (Agilent, 2012); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within ORTEP-3 for Windows (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON.
Supporting information
CCDC reference: 960147
10.1107/S1600536813025014/sj5350sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813025014/sj5350Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813025014/sj5350Isup3.cml
The title compound was synthesized by heating together for 10 min under reflux, 1 mmol quantities of 4,5-dichlorophthalic acid and 4-methoxyaniline (p-anisidine) in 50 ml of methanol. Partial evaporation of the solvent gave large colourless crystalline plates of the title compound (m.p. 473 K) from which a specimen was cleaved for the X-ray analysis..
The aminium and carboxylic acid hydrogen atoms were located by difference methods but in the final
cycles these were allowed to ride on the parent atom, with Uiso(H) = 1.2Ueq(N) or 1.5Ueq(O)]. Other H atoms were included at calculated positions [C—H (aromatic) = 0.95 Å or C—H (methyl) = 0.98 Å] and allowed to ride, with Uiso(H) = 1.2 or 1.5Ueq(C), respectively. Although not of great importance in this achiral molecule, the (Flack, 1983) was determined as 0.03 (13) for 1569 Friedel pairs. The TwinRotMat check [PLATON (Spek, 2009)] indicated no applicable twin law.Data collection: CrysAlis PRO (Agilent, 2012); cell
CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within ORTEP-3 for Windows (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).Fig. 1. Molecular conformation and atom-numbering scheme for the cation and anion in the title salt, with the inter-species hydrogen bond shown as a dashed line. Non-H atoms are shown with 40% probability displacement ellipsoids. | |
Fig. 2. The two-dimensional structure in the unit cell viewed down the polymer layer, showing hydrogen-bonding associations as dashed lines. Non-associative H-atoms are omitted. |
C7H10NO+·C8H3Cl2O4− | Dx = 1.511 Mg m−3 |
Mr = 358.16 | Melting point: 473 K |
Orthorhombic, C2221 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: C 2c 2 | Cell parameters from 2436 reflections |
a = 7.5319 (8) Å | θ = 3.7–28.1° |
b = 12.9302 (14) Å | µ = 0.44 mm−1 |
c = 32.3268 (18) Å | T = 200 K |
V = 3148.3 (5) Å3 | Plate, colourless |
Z = 8 | 0.35 × 0.30 × 0.15 mm |
F(000) = 1472 |
Oxford Diffraction Gemini-S CCD-detector diffractometer | 2730 independent reflections |
Radiation source: Enhance (Mo) X-ray source | 2620 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
Detector resolution: 16.077 pixels mm-1 | θmax = 25.0°, θmin = 3.1° |
ω scans | h = −8→8 |
Absorption correction: multi-scan (CrysAlis PRO, Agilent, 2012) | k = −15→16 |
Tmin = 0.759, Tmax = 0.980 | l = −38→38 |
6518 measured 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)] = 0.067 | H-atom parameters constrained |
wR(F2) = 0.117 | w = 1/[σ2(Fo2) + (0.0003P)2 + 10.2538P] where P = (Fo2 + 2Fc2)/3 |
S = 1.42 | (Δ/σ)max = 0.001 |
2730 reflections | Δρmax = 0.32 e Å−3 |
208 parameters | Δρmin = −0.33 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 1569 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.03 (13) |
C7H10NO+·C8H3Cl2O4− | V = 3148.3 (5) Å3 |
Mr = 358.16 | Z = 8 |
Orthorhombic, C2221 | Mo Kα radiation |
a = 7.5319 (8) Å | µ = 0.44 mm−1 |
b = 12.9302 (14) Å | T = 200 K |
c = 32.3268 (18) Å | 0.35 × 0.30 × 0.15 mm |
Oxford Diffraction Gemini-S CCD-detector diffractometer | 2730 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO, Agilent, 2012) | 2620 reflections with I > 2σ(I) |
Tmin = 0.759, Tmax = 0.980 | Rint = 0.036 |
6518 measured reflections |
R[F2 > 2σ(F2)] = 0.067 | H-atom parameters constrained |
wR(F2) = 0.117 | w = 1/[σ2(Fo2) + (0.0003P)2 + 10.2538P] where P = (Fo2 + 2Fc2)/3 |
S = 1.42 | Δρmax = 0.32 e Å−3 |
2730 reflections | Δρmin = −0.33 e Å−3 |
208 parameters | Absolute structure: Flack (1983), 1569 Friedel pairs |
0 restraints | Absolute structure parameter: 0.03 (13) |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles |
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 | ||
Cl4 | 1.0614 (2) | 0.04524 (14) | 0.69649 (4) | 0.0504 (5) | |
Cl5 | 0.6536 (2) | 0.09989 (13) | 0.70946 (4) | 0.0482 (5) | |
O11 | 0.5402 (5) | 0.1011 (3) | 0.53015 (10) | 0.0269 (11) | |
O12 | 0.5633 (4) | 0.2669 (2) | 0.54919 (9) | 0.0213 (10) | |
O21 | 0.9047 (5) | 0.1895 (3) | 0.51574 (10) | 0.0281 (11) | |
O22 | 1.1354 (5) | 0.0921 (3) | 0.53458 (11) | 0.0380 (12) | |
C1 | 0.7212 (6) | 0.1407 (3) | 0.58796 (14) | 0.0170 (14) | |
C2 | 0.9001 (5) | 0.1197 (3) | 0.58236 (14) | 0.0147 (12) | |
C3 | 1.0023 (7) | 0.0889 (4) | 0.61632 (14) | 0.0240 (16) | |
C4 | 0.9274 (7) | 0.0827 (4) | 0.65531 (15) | 0.0270 (17) | |
C5 | 0.7505 (8) | 0.1047 (4) | 0.66078 (13) | 0.0263 (16) | |
C6 | 0.6454 (7) | 0.1346 (4) | 0.62745 (13) | 0.0233 (16) | |
C11 | 0.6000 (6) | 0.1710 (4) | 0.55224 (14) | 0.0163 (12) | |
C21 | 0.9909 (6) | 0.1314 (3) | 0.54121 (15) | 0.0200 (16) | |
O4A | 1.2905 (6) | 0.3233 (4) | 0.67922 (14) | 0.0607 (19) | |
N1A | 0.8469 (5) | 0.4080 (3) | 0.54416 (11) | 0.0233 (11) | |
C1A | 0.9599 (6) | 0.3876 (3) | 0.58068 (14) | 0.0203 (14) | |
C2A | 1.1396 (7) | 0.3733 (4) | 0.57540 (15) | 0.0270 (17) | |
C3A | 1.2440 (8) | 0.3499 (4) | 0.60887 (18) | 0.0350 (17) | |
C4A | 1.1695 (8) | 0.3463 (4) | 0.64817 (18) | 0.0333 (19) | |
C5A | 0.9921 (8) | 0.3605 (5) | 0.65369 (16) | 0.037 (2) | |
C6A | 0.8838 (7) | 0.3818 (4) | 0.61917 (15) | 0.0270 (17) | |
C41A | 1.2233 (11) | 0.3165 (6) | 0.71999 (19) | 0.072 (3) | |
H3 | 1.12410 | 0.07220 | 0.61260 | 0.0290* | |
H6 | 0.52360 | 0.15070 | 0.63140 | 0.0280* | |
H21 | 0.96620 | 0.20640 | 0.49100 | 0.0420* | |
H2A | 1.19110 | 0.37960 | 0.54870 | 0.0320* | |
H3A | 1.36690 | 0.33630 | 0.60520 | 0.0420* | |
H5A | 0.94160 | 0.35610 | 0.68060 | 0.0450* | |
H6A | 0.75970 | 0.39200 | 0.62250 | 0.0330* | |
H11A | 0.80350 | 0.46520 | 0.54470 | 0.0280* | |
H12A | 0.89410 | 0.40030 | 0.51980 | 0.0280* | |
H13A | 0.75460 | 0.35580 | 0.54990 | 0.0280* | |
H41A | 1.32010 | 0.29960 | 0.73910 | 0.1080* | |
H42A | 1.13250 | 0.26230 | 0.72130 | 0.1080* | |
H43A | 1.17060 | 0.38290 | 0.72790 | 0.1080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl4 | 0.0580 (10) | 0.0630 (11) | 0.0301 (7) | 0.0060 (9) | −0.0209 (7) | 0.0088 (7) |
Cl5 | 0.0724 (11) | 0.0539 (10) | 0.0182 (6) | 0.0038 (9) | 0.0077 (7) | 0.0036 (7) |
O11 | 0.031 (2) | 0.0218 (18) | 0.0280 (17) | −0.0087 (16) | −0.0101 (16) | 0.0035 (16) |
O12 | 0.0197 (18) | 0.0207 (18) | 0.0236 (16) | 0.0035 (15) | −0.0036 (15) | 0.0038 (14) |
O21 | 0.027 (2) | 0.036 (2) | 0.0213 (17) | 0.0074 (17) | 0.0072 (15) | 0.0107 (15) |
O22 | 0.030 (2) | 0.044 (2) | 0.040 (2) | 0.017 (2) | 0.0067 (18) | 0.0123 (19) |
C1 | 0.026 (3) | 0.005 (2) | 0.020 (2) | −0.0021 (19) | −0.003 (2) | 0.0001 (19) |
C2 | 0.010 (2) | 0.006 (2) | 0.028 (2) | 0.0044 (18) | 0.0030 (19) | 0.0034 (18) |
C3 | 0.028 (3) | 0.014 (2) | 0.030 (3) | −0.006 (2) | −0.008 (2) | 0.001 (2) |
C4 | 0.038 (3) | 0.014 (3) | 0.029 (3) | 0.006 (2) | −0.016 (3) | 0.003 (2) |
C5 | 0.041 (3) | 0.022 (3) | 0.016 (2) | 0.000 (3) | −0.002 (2) | 0.002 (2) |
C6 | 0.024 (3) | 0.022 (3) | 0.024 (2) | 0.000 (2) | −0.001 (2) | 0.000 (2) |
C11 | 0.007 (2) | 0.019 (2) | 0.023 (2) | −0.0040 (19) | 0.0051 (18) | 0.005 (2) |
C21 | 0.016 (3) | 0.011 (2) | 0.033 (3) | −0.003 (2) | 0.002 (2) | 0.006 (2) |
O4A | 0.061 (3) | 0.075 (4) | 0.046 (3) | 0.013 (3) | −0.024 (2) | 0.010 (2) |
N1A | 0.027 (2) | 0.020 (2) | 0.0228 (19) | −0.0015 (19) | 0.0007 (18) | 0.0026 (18) |
C1A | 0.028 (3) | 0.007 (2) | 0.026 (2) | −0.006 (2) | −0.003 (2) | −0.001 (2) |
C2A | 0.022 (3) | 0.026 (3) | 0.033 (3) | −0.001 (2) | 0.003 (2) | 0.002 (2) |
C3A | 0.030 (3) | 0.027 (3) | 0.048 (3) | −0.001 (3) | −0.004 (3) | 0.000 (3) |
C4A | 0.039 (4) | 0.019 (3) | 0.042 (3) | −0.003 (3) | −0.018 (3) | 0.004 (2) |
C5A | 0.054 (4) | 0.038 (4) | 0.020 (3) | −0.004 (3) | 0.002 (2) | 0.002 (2) |
C6A | 0.033 (3) | 0.016 (3) | 0.032 (3) | 0.003 (2) | 0.004 (2) | −0.002 (2) |
C41A | 0.108 (7) | 0.065 (5) | 0.043 (4) | −0.007 (5) | −0.030 (4) | 0.016 (4) |
Cl4—C4 | 1.739 (5) | C3—C4 | 1.383 (7) |
Cl5—C5 | 1.736 (5) | C4—C5 | 1.374 (8) |
O11—C11 | 1.237 (6) | C5—C6 | 1.392 (7) |
O12—C11 | 1.274 (6) | C3—H3 | 0.9500 |
O21—C21 | 1.290 (6) | C6—H6 | 0.9500 |
O22—C21 | 1.220 (6) | C1A—C6A | 1.372 (7) |
O21—H21 | 0.9500 | C1A—C2A | 1.377 (7) |
O4A—C41A | 1.415 (8) | C2A—C3A | 1.371 (8) |
O4A—C4A | 1.388 (7) | C3A—C4A | 1.390 (8) |
N1A—C1A | 1.479 (6) | C4A—C5A | 1.361 (9) |
N1A—H13A | 0.9900 | C5A—C6A | 1.409 (7) |
N1A—H11A | 0.8100 | C2A—H2A | 0.9500 |
N1A—H12A | 0.8700 | C3A—H3A | 0.9500 |
C1—C11 | 1.523 (6) | C5A—H5A | 0.9500 |
C1—C6 | 1.401 (6) | C6A—H6A | 0.9500 |
C1—C2 | 1.386 (6) | C41A—H41A | 0.9800 |
C2—C3 | 1.399 (6) | C41A—H42A | 0.9800 |
C2—C21 | 1.503 (6) | C41A—H43A | 0.9800 |
C21—O21—H21 | 115.00 | C2—C3—H3 | 120.00 |
C4A—O4A—C41A | 116.9 (5) | C4—C3—H3 | 120.00 |
H11A—N1A—H12A | 107.00 | C1—C6—H6 | 120.00 |
C1A—N1A—H13A | 98.00 | C5—C6—H6 | 120.00 |
H12A—N1A—H13A | 112.00 | C2A—C1A—C6A | 121.1 (4) |
H11A—N1A—H13A | 110.00 | N1A—C1A—C6A | 119.6 (4) |
C1A—N1A—H12A | 118.00 | N1A—C1A—C2A | 119.4 (4) |
C1A—N1A—H11A | 112.00 | C1A—C2A—C3A | 119.7 (5) |
C2—C1—C11 | 122.3 (4) | C2A—C3A—C4A | 119.8 (5) |
C6—C1—C11 | 117.5 (4) | O4A—C4A—C3A | 113.8 (5) |
C2—C1—C6 | 120.3 (4) | O4A—C4A—C5A | 125.4 (5) |
C1—C2—C21 | 122.5 (4) | C3A—C4A—C5A | 120.8 (5) |
C1—C2—C3 | 119.2 (4) | C4A—C5A—C6A | 119.4 (5) |
C3—C2—C21 | 118.2 (4) | C1A—C6A—C5A | 119.1 (5) |
C2—C3—C4 | 120.5 (5) | C1A—C2A—H2A | 120.00 |
C3—C4—C5 | 120.1 (5) | C3A—C2A—H2A | 120.00 |
Cl4—C4—C3 | 118.5 (4) | C2A—C3A—H3A | 120.00 |
Cl4—C4—C5 | 121.5 (4) | C4A—C3A—H3A | 120.00 |
Cl5—C5—C6 | 118.2 (4) | C4A—C5A—H5A | 120.00 |
C4—C5—C6 | 120.6 (4) | C6A—C5A—H5A | 120.00 |
Cl5—C5—C4 | 121.1 (4) | C1A—C6A—H6A | 120.00 |
C1—C6—C5 | 119.3 (5) | C5A—C6A—H6A | 120.00 |
O11—C11—O12 | 126.0 (4) | O4A—C41A—H41A | 110.00 |
O11—C11—C1 | 117.9 (4) | O4A—C41A—H42A | 110.00 |
O12—C11—C1 | 116.0 (4) | O4A—C41A—H43A | 109.00 |
O21—C21—O22 | 125.4 (5) | H41A—C41A—H42A | 109.00 |
O21—C21—C2 | 113.2 (4) | H41A—C41A—H43A | 109.00 |
O22—C21—C2 | 121.3 (4) | H42A—C41A—H43A | 109.00 |
C41A—O4A—C4A—C5A | −1.5 (9) | C2—C3—C4—Cl4 | −179.4 (4) |
C41A—O4A—C4A—C3A | −178.9 (5) | C2—C3—C4—C5 | 1.4 (8) |
C6—C1—C2—C21 | −176.1 (4) | Cl4—C4—C5—C6 | 180.0 (4) |
C6—C1—C2—C3 | 2.2 (6) | C3—C4—C5—Cl5 | −178.8 (4) |
C2—C1—C6—C5 | −1.6 (7) | Cl4—C4—C5—Cl5 | 2.0 (7) |
C11—C1—C6—C5 | 178.4 (4) | C3—C4—C5—C6 | −0.8 (8) |
C2—C1—C11—O11 | 81.2 (6) | C4—C5—C6—C1 | 0.9 (8) |
C2—C1—C11—O12 | −101.9 (5) | Cl5—C5—C6—C1 | 179.0 (4) |
C6—C1—C11—O11 | −98.9 (5) | N1A—C1A—C2A—C3A | −177.2 (4) |
C11—C1—C2—C3 | −177.8 (4) | C6A—C1A—C2A—C3A | 1.9 (7) |
C11—C1—C2—C21 | 3.8 (6) | N1A—C1A—C6A—C5A | 178.9 (5) |
C6—C1—C11—O12 | 78.0 (5) | C2A—C1A—C6A—C5A | −0.2 (7) |
C1—C2—C21—O21 | 19.1 (6) | C1A—C2A—C3A—C4A | −3.5 (8) |
C1—C2—C21—O22 | −163.9 (4) | C2A—C3A—C4A—O4A | −179.1 (5) |
C21—C2—C3—C4 | 176.3 (4) | C2A—C3A—C4A—C5A | 3.4 (8) |
C3—C2—C21—O22 | 17.8 (6) | O4A—C4A—C5A—C6A | −178.9 (5) |
C3—C2—C21—O21 | −159.3 (4) | C3A—C4A—C5A—C6A | −1.7 (9) |
C1—C2—C3—C4 | −2.1 (7) | C4A—C5A—C6A—C1A | 0.1 (8) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H11A···O11i | 0.81 | 2.55 | 2.926 (5) | 110 |
N1A—H11A···O22ii | 0.81 | 2.10 | 2.881 (5) | 163 |
N1A—H12A···O11iii | 0.87 | 1.95 | 2.811 (5) | 168 |
N1A—H13A···O12 | 0.99 | 1.84 | 2.814 (5) | 167 |
O21—H21···O12iii | 0.95 | 1.53 | 2.480 (4) | 179 |
C3A—H3A···O12iv | 0.95 | 2.50 | 3.265 (7) | 137 |
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x−1/2, y+1/2, z; (iii) x+1/2, −y+1/2, −z+1; (iv) x+1, y, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H11A···O22i | 0.81 | 2.10 | 2.881 (5) | 163 |
N1A—H12A···O11ii | 0.87 | 1.95 | 2.811 (5) | 168 |
N1A—H13A···O12 | 0.99 | 1.84 | 2.814 (5) | 167 |
O21—H21···O12ii | 0.95 | 1.53 | 2.480 (4) | 179 |
C3A—H3A···O12iii | 0.95 | 2.50 | 3.265 (7) | 137 |
Symmetry codes: (i) x−1/2, y+1/2, z; (ii) x+1/2, −y+1/2, −z+1; (iii) x+1, y, z. |
Acknowledgements
The authors acknowledge financial support from the Australian Reseach Council, the Science and Engineering Faculty and the University Library, Queensland University of Technology.
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4,5-Dichlorophthalic acid (DCPA) most commonly forms 1:1 salts with organic Lewis bases, often giving low-dimensional hydrogen-bonded structures (Mattes & Dorau, 1986; Smith et al., 2008a). The 1:2 DCPA salts are uncommon, as is the presence of water molecules of solvation, an example being the benzylamine salt (a monohydrate) (Smith & Wermuth, 2012). The salts with the aniline analogues are also not common, e.g. with 3-(trifluoromethyl)aniline (Odabaşoğlu & Büyükgüngör, 2007), the three isomeric carboxylanilines (Smith et al., 2008b and 2-chloroaniline (Smith et al., 2009). Our 1:1 stoichiometric reaction of DCPA with 4-methoxyaniline (p-anisidine) gave the anhydrous 1:1 salt C7H10NO+ C8H3Cl2O4-, the title compound, and the structure is reported herein.
In this structure (Fig. 1), the DCPA anion does not have the 'planar' conformation which is found in a large number of the 1:1 structures, but has the carboxylic acid and carboxylate groups rotated out of the benzene plane forming dihedral angles of 19.0 (2)° and 79.5 (2)°, respectively, with it. These correspond to torsion angles C1—C2—C21—O21 and C2—C1—C11—O11 of 19.1 (6) and 81.2 (5)°. In the crystal the cation and anion rings are close to parallel [inter-ring dihedral angle = 4.8 (2)°], giving layering along b. Weak π–π interactions are present between the benzene rings of the cations and anions [minimum ring centroid separation Cg···Cgiv = 3.734 (3) Å] [for symmetry code (iv): x + 1/2, y + 1/2, z]. Aminium N—H···O, water O—H···O and weak aromatic C—H···O hydrogen-bonding associations with carboxyl O-atom acceptors (Table 1) give a two-dimensional sheet structure which lies parallel to (001) (Fig. 2).