supplementary materials


Acta Cryst. (2009). E65, o2111    [ doi:10.1107/S160053680903044X ]

4-Chloroanilinium 2-carboxy-4,5-dichlorobenzoate

G. Smith, U. D. Wermuth and J. M. White

Abstract top

The structure of the 1:1 proton-transfer compound of 4-chloroaniline with 4,5-dichlorophthalic acid (DCPA), viz. C6H7ClN+·C8H3Cl2O4-, has been determined at 130 K. The non-planar hydrogen phthalate anions and the 4-chloroanilinium cations form two-dimensional O-H...O and N-H...O hydrogen-bonded substructures which have no peripheral extension. Between the sheets there are weak [pi]-[pi] associations between alternating cation-anion aromatic ring systems [shortest centroid-centroid separation = 3.735 (4) Å].

Comment top

Among the known structures of the 1:1 aromatic Lewis base compounds of 4,5-dichlorophthalic acid (DCPA), a small number have similar hydrogen-bonded substructures in which the basic N+H···Ocarboxyl linked cation–anion unit is propagated in two dimensions (Smith et al., 2008b). In these the DCPA anions are non-planar with the carboxylic acid and carboxylate groups rotated out of the plane of the benzene ring. This contrasts with the majority of the compounds in which the DCPA anion is planar with a short intramolecular carboxylic acid OH···Ocarboxyl hydrogen bond (Smith et al., 2007, 2008a, 2009). Since the examples having the two-dimensional substructures were substituted anilines, the 4-chloro-analogue was reacted with DCPA, giving anhydrous 4-chloroanilinium 2-carboxy-4,5-dichlorobenzoate C6H7ClN+. C8H3Cl2O4- (I) and its structure is reported here.

In (I), as expected, the primary hydrogen-bonded cation–anion structural unit (Fig.1) provides the basis for formation of the previously described two-dimensional substructure which extends across the ab plane in the unit cell, having no lateral interactions (Fig. 2). The hydrogen bonding within the plane (Table 1) includes a cyclic R21(6) anilinium–H···O12,O21 interaction. The alternating cation–anion aromatic ring systems (C1–C6 and C1A–C6A) give weak ππ interactions [shortest centroid separation 3.735 (4) Å]. The hydrogen 4,5-dichlorophthalate anion is non-planar [torsion angles C2–C1–C11–O11, 163.7 (7)°: C1–C2–C21–O22, -83.3 (8)°].,

Related literature top

For the structures of other hydrogen DCPA salts with aromatic Lewis bases showing similar two-dimensional substructures, see: Smith et al. (2008b). This contrasts with the majority of the compounds in which the DCPA anion is planar with a short intramolecular carboxylic acid hydrogen bond, see: Smith et al. (2007, 2008a, 2009).

Experimental top

The title compound (I) was synthesized by heating together 1 mmol quantities of 4-chloroaniline and 4,5-dichlorophthalic acid in 50 ml of 50% aqueous methanol for 10 min under reflux. After concentration to ca. 30 ml, partial room-temperature evaporation of the hot-filtered solution gave small colourless plates [m.p. 492 K]).

Refinement top

Hydrogen atoms potentially involved in hydrogen-bonding interactions were located by difference methods and their positional and isotropic displacement parameters were refined. Other H atoms were included in the refinement at calculated positions [C–H, 0.93 Å] and treated as riding models with Uiso(H) = 1.2Ueq (C).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. Molecular configuration and atom numbering scheme for the 4-chloroanilinium cation and the hydrogen 4,5-dichlorophthalate anion in (I). Non-H atoms are shown as 50% probability displacement ellipsoids. Hydrogen bonds are shown as dashed lines.
[Figure 2] Fig. 2. The two-dimensional sheet structure in (I) viewed down the b axis in the unit cell. Non-interactive H atoms are omitted and hydrogen bonds are shown as dashed lines. (For symmetry codes, see Table 1).
4-Chloroanilinium 2-carboxy-4,5-dichlorobenzoate top
Crystal data top
C6H7ClN+·C8H3Cl2O4F(000) = 736
Mr = 362.58Dx = 1.634 Mg m3
Monoclinic, C2Melting point: 492 K
Hall symbol: C 2yCu Kα radiation, λ = 1.54184 Å
a = 12.8171 (8) ÅCell parameters from 1721 reflections
b = 7.5954 (3) Åθ = 2.9–71.8°
c = 16.0909 (6) ŵ = 5.80 mm1
β = 109.815 (5)°T = 130 K
V = 1473.72 (13) Å3Plate, colourless
Z = 40.34 × 0.27 × 0.05 mm
Data collection top
Oxford Diffraction Gemini Ultra CCD-detector
diffractometer
2288 independent reflections
Radiation source: Enhance Ultra (Cu) X-ray source1879 reflections with I > 2σ(I)
mirrorRint = 0.061
ω scansθmax = 72.1°, θmin = 2.9°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1514
Tmin = 0.201, Tmax = 0.748k = 98
3680 measured reflectionsl = 1519
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)] = 0.062H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.175 w = 1/[σ2(Fo2) + (0.135P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.00(Δ/σ)max < 0.001
2288 reflectionsΔρmax = 0.64 e Å3
215 parametersΔρmin = 0.56 e Å3
1 restraintAbsolute structure: Flack (1983), 723 Friedel pairs
Primary atom site location: structure-invariant direct methodsFlack parameter: 0.04 (3)
Crystal data top
C6H7ClN+·C8H3Cl2O4V = 1473.72 (13) Å3
Mr = 362.58Z = 4
Monoclinic, C2Cu Kα radiation
a = 12.8171 (8) ŵ = 5.80 mm1
b = 7.5954 (3) ÅT = 130 K
c = 16.0909 (6) Å0.34 × 0.27 × 0.05 mm
β = 109.815 (5)°
Data collection top
Oxford Diffraction Gemini Ultra CCD-detector
diffractometer
2288 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1879 reflections with I > 2σ(I)
Tmin = 0.201, Tmax = 0.748Rint = 0.061
3680 measured reflectionsθmax = 72.1°
Refinement top
R[F2 > 2σ(F2)] = 0.062H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.175Δρmax = 0.64 e Å3
S = 1.00Δρmin = 0.56 e Å3
2288 reflectionsAbsolute structure: Flack (1983), 723 Friedel pairs
215 parametersFlack parameter: 0.04 (3)
1 restraint
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
Cl40.39571 (14)0.8094 (3)0.55613 (9)0.0377 (5)
Cl50.37318 (14)0.3980 (3)0.58289 (9)0.0418 (5)
O110.5642 (4)0.3295 (7)0.9286 (3)0.0348 (14)
O120.6750 (3)0.5632 (6)0.9688 (2)0.0282 (11)
O210.7198 (3)0.9010 (6)0.8943 (2)0.0243 (10)
O220.5704 (3)0.9285 (6)0.9364 (2)0.0272 (13)
C10.5441 (5)0.5652 (8)0.8257 (4)0.0244 (16)
C20.5583 (5)0.7457 (8)0.8141 (3)0.0222 (16)
C30.5118 (5)0.8181 (9)0.7299 (4)0.0257 (16)
C40.4522 (5)0.7126 (9)0.6581 (4)0.0289 (18)
C50.4402 (5)0.5333 (9)0.6707 (4)0.0311 (18)
C60.4861 (5)0.4599 (9)0.7537 (4)0.0276 (17)
C110.5956 (5)0.4739 (9)0.9139 (4)0.0244 (17)
C210.6212 (4)0.8673 (7)0.8897 (3)0.0237 (16)
Cl4A0.13666 (14)0.6564 (2)0.60330 (9)0.0387 (5)
N1A0.3688 (4)1.1240 (7)0.9059 (3)0.0234 (14)
C1A0.3149 (5)1.0096 (8)0.8304 (3)0.0233 (16)
C2A0.2717 (5)1.0813 (9)0.7460 (4)0.0292 (17)
C3A0.2162 (5)0.9729 (9)0.6753 (4)0.0300 (18)
C4A0.2064 (5)0.7965 (9)0.6903 (4)0.0286 (17)
C5A0.2510 (5)0.7210 (9)0.7743 (4)0.0283 (17)
C6A0.3054 (5)0.8316 (9)0.8443 (3)0.0263 (18)
H30.520500.937600.721400.0310*
H60.478300.340000.761700.0340*
H120.700 (3)0.509 (4)1.015 (2)0.042 (11)*
H2A0.279901.200800.737100.0340*
H3A0.186101.019000.618600.0360*
H5A0.244500.601000.782900.0340*
H6A0.335600.785600.901000.0320*
H11A0.425 (3)1.179 (4)0.897 (3)0.035 (10)*
H12A0.393 (4)1.059 (3)0.954 (2)0.041 (11)*
H13A0.320 (4)1.202 (4)0.910 (3)0.038 (11)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl40.0444 (9)0.0546 (10)0.0141 (6)0.0005 (8)0.0035 (5)0.0056 (6)
Cl50.0482 (10)0.0479 (10)0.0206 (6)0.0014 (8)0.0002 (6)0.0120 (6)
O110.038 (2)0.035 (3)0.026 (2)0.011 (2)0.0037 (17)0.0002 (19)
O120.031 (2)0.034 (2)0.0147 (17)0.0000 (18)0.0015 (15)0.0039 (16)
O210.0266 (18)0.031 (2)0.0155 (15)0.0022 (18)0.0075 (14)0.0015 (15)
O220.026 (2)0.033 (3)0.0203 (17)0.0019 (17)0.0050 (15)0.0038 (16)
C10.028 (3)0.027 (3)0.017 (2)0.001 (2)0.006 (2)0.004 (2)
C20.023 (3)0.029 (3)0.015 (2)0.001 (2)0.007 (2)0.001 (2)
C30.028 (3)0.029 (3)0.020 (2)0.001 (3)0.008 (2)0.001 (2)
C40.029 (3)0.043 (4)0.011 (2)0.002 (3)0.002 (2)0.000 (2)
C50.030 (3)0.041 (4)0.017 (2)0.005 (3)0.001 (2)0.006 (3)
C60.030 (3)0.031 (3)0.024 (3)0.003 (3)0.012 (2)0.002 (2)
C110.022 (3)0.033 (3)0.019 (3)0.003 (2)0.008 (2)0.001 (2)
C210.023 (3)0.030 (3)0.018 (2)0.002 (2)0.007 (2)0.001 (2)
Cl4A0.0489 (9)0.0436 (10)0.0201 (6)0.0072 (8)0.0073 (6)0.0054 (6)
N1A0.023 (2)0.030 (3)0.016 (2)0.001 (2)0.0050 (16)0.0040 (19)
C1A0.024 (3)0.029 (3)0.017 (2)0.004 (2)0.007 (2)0.003 (2)
C2A0.036 (3)0.029 (3)0.020 (3)0.005 (3)0.006 (2)0.001 (2)
C3A0.034 (3)0.039 (4)0.016 (2)0.000 (3)0.007 (2)0.001 (2)
C4A0.035 (3)0.029 (3)0.022 (3)0.003 (3)0.010 (2)0.000 (2)
C5A0.032 (3)0.031 (3)0.021 (3)0.002 (3)0.008 (2)0.002 (2)
C6A0.029 (3)0.032 (4)0.018 (2)0.000 (3)0.008 (2)0.002 (2)
Geometric parameters (Å, °) top
Cl4—C41.718 (6)C2—C31.395 (8)
Cl5—C51.723 (7)C3—C41.401 (9)
Cl4A—C4A1.744 (7)C4—C51.393 (10)
O11—C111.219 (9)C5—C61.381 (9)
O12—C111.291 (8)C3—H30.9300
O21—C211.267 (7)C6—H60.9300
O22—C211.240 (6)C1A—C6A1.383 (9)
O12—H120.81 (3)C1A—C2A1.392 (8)
N1A—C1A1.463 (7)C2A—C3A1.389 (9)
N1A—H13A0.89 (4)C3A—C4A1.375 (10)
N1A—H12A0.88 (3)C4A—C5A1.400 (9)
N1A—H11A0.88 (4)C5A—C6A1.389 (8)
C1—C21.404 (9)C2A—H2A0.9300
C1—C111.515 (9)C3A—H3A0.9300
C1—C61.397 (9)C5A—H5A0.9300
C2—C211.523 (7)C6A—H6A0.9300
C11—O12—H12110 (2)O22—C21—C2117.9 (5)
H11A—N1A—H12A110 (4)O21—C21—C2114.6 (5)
H11A—N1A—H13A109 (4)C2—C3—H3120.00
C1A—N1A—H13A108 (3)C4—C3—H3120.00
C1A—N1A—H11A109 (3)C5—C6—H6120.00
H12A—N1A—H13A111 (4)C1—C6—H6120.00
C6—C1—C11117.1 (6)C2A—C1A—C6A120.9 (5)
C2—C1—C11122.5 (5)N1A—C1A—C6A119.3 (4)
C2—C1—C6120.4 (5)N1A—C1A—C2A119.8 (5)
C1—C2—C3118.8 (5)C1A—C2A—C3A119.4 (6)
C3—C2—C21118.2 (5)C2A—C3A—C4A119.1 (6)
C1—C2—C21122.9 (5)Cl4A—C4A—C3A120.4 (5)
C2—C3—C4120.6 (6)Cl4A—C4A—C5A117.1 (5)
C3—C4—C5119.7 (6)C3A—C4A—C5A122.5 (6)
Cl4—C4—C5121.7 (5)C4A—C5A—C6A117.6 (6)
Cl4—C4—C3118.6 (5)C1A—C6A—C5A120.5 (5)
Cl5—C5—C6118.9 (5)C1A—C2A—H2A120.00
C4—C5—C6120.2 (6)C3A—C2A—H2A120.00
Cl5—C5—C4120.9 (5)C2A—C3A—H3A120.00
C1—C6—C5120.2 (6)C4A—C3A—H3A120.00
O11—C11—C1121.7 (6)C4A—C5A—H5A121.00
O11—C11—O12125.1 (6)C6A—C5A—H5A121.00
O12—C11—C1113.1 (6)C1A—C6A—H6A120.00
O21—C21—O22127.4 (5)C5A—C6A—H6A120.00
C6—C1—C2—C31.2 (10)C2—C3—C4—C50.7 (10)
C6—C1—C2—C21179.6 (6)Cl4—C4—C5—Cl53.1 (9)
C11—C1—C2—C3177.4 (6)Cl4—C4—C5—C6179.6 (5)
C11—C1—C2—C213.4 (10)C3—C4—C5—Cl5176.9 (5)
C2—C1—C6—C51.4 (10)C3—C4—C5—C60.5 (10)
C11—C1—C6—C5177.8 (6)Cl5—C5—C6—C1177.9 (5)
C2—C1—C11—O11163.7 (7)C4—C5—C6—C10.5 (10)
C2—C1—C11—O1217.4 (9)N1A—C1A—C2A—C3A177.1 (6)
C6—C1—C11—O1120.0 (10)C6A—C1A—C2A—C3A1.5 (10)
C6—C1—C11—O12159.0 (6)N1A—C1A—C6A—C5A177.6 (6)
C1—C2—C3—C40.2 (10)C2A—C1A—C6A—C5A0.9 (10)
C21—C2—C3—C4179.4 (6)C1A—C2A—C3A—C4A0.8 (10)
C1—C2—C21—O21100.2 (7)C2A—C3A—C4A—Cl4A179.7 (5)
C1—C2—C21—O2283.3 (8)C2A—C3A—C4A—C5A0.5 (10)
C3—C2—C21—O2180.6 (7)Cl4A—C4A—C5A—C6A179.1 (5)
C3—C2—C21—O2295.9 (7)C3A—C4A—C5A—C6A1.0 (10)
C2—C3—C4—Cl4179.4 (5)C4A—C5A—C6A—C1A0.3 (10)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O12—H12···O21i0.81 (3)1.69 (3)2.485 (5)166 (4)
N1A—H11A···O11ii0.89 (4)2.03 (4)2.867 (8)157 (4)
N1A—H11A···O220.89 (4)2.59 (4)2.875 (7)100 (2)
N1A—H12A···O220.88 (3)2.58 (5)2.875 (7)100 (3)
N1A—H12A···O22iii0.88 (3)1.94 (3)2.813 (6)172 (5)
N1A—H13A···O12iv0.88 (4)2.58 (5)3.019 (7)112 (3)
N1A—H13A···O21iv0.88 (4)1.94 (4)2.805 (7)166 (4)
C5A—H5A···O21v0.932.453.212 (8)139
Symmetry codes: (i) −x+3/2, y−1/2, −z+2; (ii) x, y+1, z; (iii) −x+1, y, −z+2; (iv) x−1/2, y+1/2, z; (v) x−1/2, y−1/2, z.
Table 1
Hydrogen-bond geometry (Å, °)
top
D—H···AD—HH···AD···AD—H···A
O12—H12···O21i0.81 (3)1.69 (3)2.485 (5)166 (4)
N1A—H11A···O11ii0.89 (4)2.03 (4)2.867 (8)157 (4)
N1A—H11A···O220.89 (4)2.59 (4)2.875 (7)100 (2)
N1A—H12A···O220.88 (3)2.58 (5)2.875 (7)100 (3)
N1A—H12A···O22iii0.88 (3)1.94 (3)2.813 (6)172 (5)
N1A—H13A···O12iv0.88 (4)2.58 (5)3.019 (7)112 (3)
N1A—H13A···O21iv0.88 (4)1.94 (4)2.805 (7)166 (4)
Symmetry codes: (i) −x+3/2, y−1/2, −z+2; (ii) x, y+1, z; (iii) −x+1, y, −z+2; (iv) x−1/2, y+1/2, z.
Acknowledgements top

The authors acknowledge financial support from the School of Physical and Chemical Sciences (Queensland University of Technology) and the School of Chemistry, the University of Melbourne.

references
References top

Flack, H. D. (1983). Acta Cryst. A39, 876–881.

Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.

Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Smith, G., Wermuth, U. D. & White, J. M. (2007). Acta Cryst. E63, o4276–o4277.

Smith, G., Wermuth, U. D. & White, J. M. (2008a). Acta Cryst. C64, o180–o183.

Smith, G., Wermuth, U. D. & White, J. M. (2008b). Acta Cryst. C64, o532–o536.

Smith, G., Wermuth, U. D. & White, J. M. (2009). Acta Cryst. C65, o103–o107.

Spek, A. L. (2009). Acta Cryst. D65, 148–155.