supplementary materials


sj5350 scheme

Acta Cryst. (2013). E69, o1546    [ doi:10.1107/S1600536813025014 ]

4-Methoxyanilinium 2-carboxy-4,5-dichlorobenzoate

G. Smith and U. D. Wermuth

Abstract top

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 [pi]-[pi] ring interactions [minimum ring centroid separation = 3.734 (3) Å] give rise to a sheet structure lying parallel to (001).

Comment top

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 ππ 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).

Related literature top

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 top

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..

Refinement top

The aminium and carboxylic acid hydrogen atoms were located by difference methods but in the final refinement 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 parameter (Flack, 1983) was determined as 0.03 (13) for 1569 Friedel pairs. The TwinRotMat check [PLATON (Spek, 2009)] indicated no applicable twin law.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: 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).

Figures top
[Figure 1] 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.
[Figure 2] 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.
4-Methoxyanilinium 2-carboxy-4,5-dichlorobenzoate top
Crystal data top
C7H10NO+·C8H3Cl2O4Dx = 1.511 Mg m3
Mr = 358.16Melting point: 473 K
Orthorhombic, C2221Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c 2Cell parameters from 2436 reflections
a = 7.5319 (8) Åθ = 3.7–28.1°
b = 12.9302 (14) ŵ = 0.44 mm1
c = 32.3268 (18) ÅT = 200 K
V = 3148.3 (5) Å3Plate, colourless
Z = 80.35 × 0.30 × 0.15 mm
F(000) = 1472
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer
2730 independent reflections
Radiation source: Enhance (Mo) X-ray source2620 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.036
Detector resolution: 16.077 pixels mm-1θmax = 25.0°, θmin = 3.1°
ω scansh = 88
Absorption correction: multi-scan
(CrysAlis PRO, Agilent, 2012)
k = 1516
Tmin = 0.759, Tmax = 0.980l = 3838
6518 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.067H-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 reflectionsΔρmax = 0.32 e Å3
208 parametersΔρmin = 0.33 e Å3
0 restraintsAbsolute structure: Flack (1983), 1569 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.03 (13)
Crystal data top
C7H10NO+·C8H3Cl2O4V = 3148.3 (5) Å3
Mr = 358.16Z = 8
Orthorhombic, C2221Mo Kα radiation
a = 7.5319 (8) ŵ = 0.44 mm1
b = 12.9302 (14) ÅT = 200 K
c = 32.3268 (18) Å0.35 × 0.30 × 0.15 mm
Data collection top
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 = 0.980Rint = 0.036
6518 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.067H-atom parameters constrained
wR(F2) = 0.117 w = 1/[σ2(Fo2) + (0.0003P)2 + 10.2538P]
where P = (Fo2 + 2Fc2)/3
S = 1.42Δρmax = 0.32 e Å3
2730 reflectionsΔρmin = 0.33 e Å3
208 parametersAbsolute structure: Flack (1983), 1569 Friedel pairs
0 restraintsAbsolute structure parameter: 0.03 (13)
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl41.0614 (2)0.04524 (14)0.69649 (4)0.0504 (5)
Cl50.6536 (2)0.09989 (13)0.70946 (4)0.0482 (5)
O110.5402 (5)0.1011 (3)0.53015 (10)0.0269 (11)
O120.5633 (4)0.2669 (2)0.54919 (9)0.0213 (10)
O210.9047 (5)0.1895 (3)0.51574 (10)0.0281 (11)
O221.1354 (5)0.0921 (3)0.53458 (11)0.0380 (12)
C10.7212 (6)0.1407 (3)0.58796 (14)0.0170 (14)
C20.9001 (5)0.1197 (3)0.58236 (14)0.0147 (12)
C31.0023 (7)0.0889 (4)0.61632 (14)0.0240 (16)
C40.9274 (7)0.0827 (4)0.65531 (15)0.0270 (17)
C50.7505 (8)0.1047 (4)0.66078 (13)0.0263 (16)
C60.6454 (7)0.1346 (4)0.62745 (13)0.0233 (16)
C110.6000 (6)0.1710 (4)0.55224 (14)0.0163 (12)
C210.9909 (6)0.1314 (3)0.54121 (15)0.0200 (16)
O4A1.2905 (6)0.3233 (4)0.67922 (14)0.0607 (19)
N1A0.8469 (5)0.4080 (3)0.54416 (11)0.0233 (11)
C1A0.9599 (6)0.3876 (3)0.58068 (14)0.0203 (14)
C2A1.1396 (7)0.3733 (4)0.57540 (15)0.0270 (17)
C3A1.2440 (8)0.3499 (4)0.60887 (18)0.0350 (17)
C4A1.1695 (8)0.3463 (4)0.64817 (18)0.0333 (19)
C5A0.9921 (8)0.3605 (5)0.65369 (16)0.037 (2)
C6A0.8838 (7)0.3818 (4)0.61917 (15)0.0270 (17)
C41A1.2233 (11)0.3165 (6)0.71999 (19)0.072 (3)
H31.124100.072200.612600.0290*
H60.523600.150700.631400.0280*
H210.966200.206400.491000.0420*
H2A1.191100.379600.548700.0320*
H3A1.366900.336300.605200.0420*
H5A0.941600.356100.680600.0450*
H6A0.759700.392000.622500.0330*
H11A0.803500.465200.544700.0280*
H12A0.894100.400300.519800.0280*
H13A0.754600.355800.549900.0280*
H41A1.320100.299600.739100.1080*
H42A1.132500.262300.721300.1080*
H43A1.170600.382900.727900.1080*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl40.0580 (10)0.0630 (11)0.0301 (7)0.0060 (9)0.0209 (7)0.0088 (7)
Cl50.0724 (11)0.0539 (10)0.0182 (6)0.0038 (9)0.0077 (7)0.0036 (7)
O110.031 (2)0.0218 (18)0.0280 (17)0.0087 (16)0.0101 (16)0.0035 (16)
O120.0197 (18)0.0207 (18)0.0236 (16)0.0035 (15)0.0036 (15)0.0038 (14)
O210.027 (2)0.036 (2)0.0213 (17)0.0074 (17)0.0072 (15)0.0107 (15)
O220.030 (2)0.044 (2)0.040 (2)0.017 (2)0.0067 (18)0.0123 (19)
C10.026 (3)0.005 (2)0.020 (2)0.0021 (19)0.003 (2)0.0001 (19)
C20.010 (2)0.006 (2)0.028 (2)0.0044 (18)0.0030 (19)0.0034 (18)
C30.028 (3)0.014 (2)0.030 (3)0.006 (2)0.008 (2)0.001 (2)
C40.038 (3)0.014 (3)0.029 (3)0.006 (2)0.016 (3)0.003 (2)
C50.041 (3)0.022 (3)0.016 (2)0.000 (3)0.002 (2)0.002 (2)
C60.024 (3)0.022 (3)0.024 (2)0.000 (2)0.001 (2)0.000 (2)
C110.007 (2)0.019 (2)0.023 (2)0.0040 (19)0.0051 (18)0.005 (2)
C210.016 (3)0.011 (2)0.033 (3)0.003 (2)0.002 (2)0.006 (2)
O4A0.061 (3)0.075 (4)0.046 (3)0.013 (3)0.024 (2)0.010 (2)
N1A0.027 (2)0.020 (2)0.0228 (19)0.0015 (19)0.0007 (18)0.0026 (18)
C1A0.028 (3)0.007 (2)0.026 (2)0.006 (2)0.003 (2)0.001 (2)
C2A0.022 (3)0.026 (3)0.033 (3)0.001 (2)0.003 (2)0.002 (2)
C3A0.030 (3)0.027 (3)0.048 (3)0.001 (3)0.004 (3)0.000 (3)
C4A0.039 (4)0.019 (3)0.042 (3)0.003 (3)0.018 (3)0.004 (2)
C5A0.054 (4)0.038 (4)0.020 (3)0.004 (3)0.002 (2)0.002 (2)
C6A0.033 (3)0.016 (3)0.032 (3)0.003 (2)0.004 (2)0.002 (2)
C41A0.108 (7)0.065 (5)0.043 (4)0.007 (5)0.030 (4)0.016 (4)
Geometric parameters (Å, º) top
Cl4—C41.739 (5)C3—C41.383 (7)
Cl5—C51.736 (5)C4—C51.374 (8)
O11—C111.237 (6)C5—C61.392 (7)
O12—C111.274 (6)C3—H30.9500
O21—C211.290 (6)C6—H60.9500
O22—C211.220 (6)C1A—C6A1.372 (7)
O21—H210.9500C1A—C2A1.377 (7)
O4A—C41A1.415 (8)C2A—C3A1.371 (8)
O4A—C4A1.388 (7)C3A—C4A1.390 (8)
N1A—C1A1.479 (6)C4A—C5A1.361 (9)
N1A—H13A0.9900C5A—C6A1.409 (7)
N1A—H11A0.8100C2A—H2A0.9500
N1A—H12A0.8700C3A—H3A0.9500
C1—C111.523 (6)C5A—H5A0.9500
C1—C61.401 (6)C6A—H6A0.9500
C1—C21.386 (6)C41A—H41A0.9800
C2—C31.399 (6)C41A—H42A0.9800
C2—C211.503 (6)C41A—H43A0.9800
C21—O21—H21115.00C2—C3—H3120.00
C4A—O4A—C41A116.9 (5)C4—C3—H3120.00
H11A—N1A—H12A107.00C1—C6—H6120.00
C1A—N1A—H13A98.00C5—C6—H6120.00
H12A—N1A—H13A112.00C2A—C1A—C6A121.1 (4)
H11A—N1A—H13A110.00N1A—C1A—C6A119.6 (4)
C1A—N1A—H12A118.00N1A—C1A—C2A119.4 (4)
C1A—N1A—H11A112.00C1A—C2A—C3A119.7 (5)
C2—C1—C11122.3 (4)C2A—C3A—C4A119.8 (5)
C6—C1—C11117.5 (4)O4A—C4A—C3A113.8 (5)
C2—C1—C6120.3 (4)O4A—C4A—C5A125.4 (5)
C1—C2—C21122.5 (4)C3A—C4A—C5A120.8 (5)
C1—C2—C3119.2 (4)C4A—C5A—C6A119.4 (5)
C3—C2—C21118.2 (4)C1A—C6A—C5A119.1 (5)
C2—C3—C4120.5 (5)C1A—C2A—H2A120.00
C3—C4—C5120.1 (5)C3A—C2A—H2A120.00
Cl4—C4—C3118.5 (4)C2A—C3A—H3A120.00
Cl4—C4—C5121.5 (4)C4A—C3A—H3A120.00
Cl5—C5—C6118.2 (4)C4A—C5A—H5A120.00
C4—C5—C6120.6 (4)C6A—C5A—H5A120.00
Cl5—C5—C4121.1 (4)C1A—C6A—H6A120.00
C1—C6—C5119.3 (5)C5A—C6A—H6A120.00
O11—C11—O12126.0 (4)O4A—C41A—H41A110.00
O11—C11—C1117.9 (4)O4A—C41A—H42A110.00
O12—C11—C1116.0 (4)O4A—C41A—H43A109.00
O21—C21—O22125.4 (5)H41A—C41A—H42A109.00
O21—C21—C2113.2 (4)H41A—C41A—H43A109.00
O22—C21—C2121.3 (4)H42A—C41A—H43A109.00
C41A—O4A—C4A—C5A1.5 (9)C2—C3—C4—Cl4179.4 (4)
C41A—O4A—C4A—C3A178.9 (5)C2—C3—C4—C51.4 (8)
C6—C1—C2—C21176.1 (4)Cl4—C4—C5—C6180.0 (4)
C6—C1—C2—C32.2 (6)C3—C4—C5—Cl5178.8 (4)
C2—C1—C6—C51.6 (7)Cl4—C4—C5—Cl52.0 (7)
C11—C1—C6—C5178.4 (4)C3—C4—C5—C60.8 (8)
C2—C1—C11—O1181.2 (6)C4—C5—C6—C10.9 (8)
C2—C1—C11—O12101.9 (5)Cl5—C5—C6—C1179.0 (4)
C6—C1—C11—O1198.9 (5)N1A—C1A—C2A—C3A177.2 (4)
C11—C1—C2—C3177.8 (4)C6A—C1A—C2A—C3A1.9 (7)
C11—C1—C2—C213.8 (6)N1A—C1A—C6A—C5A178.9 (5)
C6—C1—C11—O1278.0 (5)C2A—C1A—C6A—C5A0.2 (7)
C1—C2—C21—O2119.1 (6)C1A—C2A—C3A—C4A3.5 (8)
C1—C2—C21—O22163.9 (4)C2A—C3A—C4A—O4A179.1 (5)
C21—C2—C3—C4176.3 (4)C2A—C3A—C4A—C5A3.4 (8)
C3—C2—C21—O2217.8 (6)O4A—C4A—C5A—C6A178.9 (5)
C3—C2—C21—O21159.3 (4)C3A—C4A—C5A—C6A1.7 (9)
C1—C2—C3—C42.1 (7)C4A—C5A—C6A—C1A0.1 (8)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H11A···O11i0.812.552.926 (5)110
N1A—H11A···O22ii0.812.102.881 (5)163
N1A—H12A···O11iii0.871.952.811 (5)168
N1A—H13A···O120.991.842.814 (5)167
O21—H21···O12iii0.951.532.480 (4)179
C3A—H3A···O12iv0.952.503.265 (7)137
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x1/2, y+1/2, z; (iii) x+1/2, y+1/2, z+1; (iv) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H11A···O22i0.812.102.881 (5)163
N1A—H12A···O11ii0.871.952.811 (5)168
N1A—H13A···O120.991.842.814 (5)167
O21—H21···O12ii0.951.532.480 (4)179
C3A—H3A···O12iii0.952.503.265 (7)137
Symmetry codes: (i) x1/2, y+1/2, z; (ii) x+1/2, y+1/2, z+1; (iii) x+1, y, z.
Acknowledgements top

The authors acknowledge financial support from the Australian Reseach Council, the Science and Engineering Faculty and the University Library, Queensland University of Technology.

references
References top

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