organic compounds
Ethane-1,2-diaminium 4,5-dichlorophthalate
aSchool of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia, and bSchool of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland 4111, Australia
*Correspondence e-mail: g.smith@qut.edu.au
In the structure of the title compound, C2H10N22+·C8H2Cl2O42−, the dications and dianions form hydrogen-bonded ribbon substructures which enclose conjoint cyclic R21(7), R12(7) and R42(8) associations and extend down the c-axis direction. These ribbons inter-associate down b, giving a two-dimensional sheet structure. In the dianions, one of the carboxylate groups is essentially coplanar with the benzene ring, while the other is normal to it [C—C—C—O torsion angles = 177.67 (12) and 81.94 (17)°, respectively].
Related literature
For structures of 4,5-dichlorophthalates, see: Mattes & Dorau (1986); Bozkurt et al. (2006); Smith & Wermuth (2010a,b); Smith et al. (2009). For the structure of a dianionic 4,5-dichlorophthalate, see: Büyükgüngör & Odabaşoğlu (2007). For ring associations, see: Etter et al. (1990).
Experimental
Crystal data
|
Refinement
|
Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON.
Supporting information
10.1107/S1600536809054427/pv2246sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809054427/pv2246Isup2.hkl
The title compound (I) was synthesized by heating together 1 mmol quantities of ethylenediamine and 4,5-dichlorophthalic acid in 50 ml of methanol for 10 min under reflux. After concentration to ca. 30 ml, total room-temperature evaporation of the hot-filtered solution gave a white non-crystalline solid which was redissolved in water, finally providing colourless flat prisms (m.p. 529 K).
Hydrogen atoms of the aminium groups were located from a difference Fourier map and their positional and isotropic displacement parameters were refined. Other H atoms were included in the
at calculated positions [C–Haromatic = 0.93 Å; C–Haliphatic = 0.97 Å] and treated as riding models with Uiso(H) = 1.2Ueq (C).Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell
CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).Fig. 1. Molecular structure and atom numbering scheme for the ethylenediaminium cation and the 4,5-dichlorophthalate dianion in (I). Non-H atoms are shown as 50% probability displacement ellipsoids. The inter-species hydrogen bond is shown as a dashed line. | |
Fig. 2. The one-dimensional hydrogen-bonded ribbon substructures of (I) extending along the c axial direction in the unit cell. Hydrogen bonds are shown as dashed lines and non-interactive H atoms are omitted. For symmetry codes see Table 1. | |
Fig. 3. The inter-ribbon hydrogen-bonding in the two-dimensional structure of (I) extending down b axis in the unit cell. |
C2H10N22+·C8H2Cl2O42− | F(000) = 608 |
Mr = 295.12 | Dx = 1.577 Mg m−3 |
Monoclinic, P21/c | Melting point: 529 K |
Hall symbol: -P 2yc | Mo Kα radiation, λ = 0.71073 Å |
a = 12.892 (1) Å | Cell parameters from 7149 reflections |
b = 8.3881 (5) Å | θ = 3.2–28.8° |
c = 11.8873 (8) Å | µ = 0.53 mm−1 |
β = 104.761 (7)° | T = 200 K |
V = 1243.06 (15) Å3 | Block, colourless |
Z = 4 | 0.35 × 0.30 × 0.28 mm |
Oxford Diffraction Gemini-S CCD detector diffractometer | 2442 independent reflections |
Radiation source: Enhance (Mo) X-ray source | 2174 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
ω scans | θmax = 26.0°, θmin = 3.2° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −15→15 |
Tmin = 0.955, Tmax = 0.980 | k = −10→10 |
15108 measured reflections | l = −14→14 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.026 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.071 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0401P)2 + 0.2917P] where P = (Fo2 + 2Fc2)/3 |
2442 reflections | (Δ/σ)max = 0.001 |
187 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C2H10N22+·C8H2Cl2O42− | V = 1243.06 (15) Å3 |
Mr = 295.12 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.892 (1) Å | µ = 0.53 mm−1 |
b = 8.3881 (5) Å | T = 200 K |
c = 11.8873 (8) Å | 0.35 × 0.30 × 0.28 mm |
β = 104.761 (7)° |
Oxford Diffraction Gemini-S CCD detector diffractometer | 2442 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2174 reflections with I > 2σ(I) |
Tmin = 0.955, Tmax = 0.980 | Rint = 0.025 |
15108 measured reflections |
R[F2 > 2σ(F2)] = 0.026 | 0 restraints |
wR(F2) = 0.071 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | Δρmax = 0.28 e Å−3 |
2442 reflections | Δρmin = −0.24 e Å−3 |
187 parameters |
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 | 1.04287 (3) | 0.27191 (5) | 0.51216 (3) | 0.0296 (1) | |
Cl5 | 1.08544 (3) | 0.02709 (6) | 0.72577 (4) | 0.0387 (2) | |
O11 | 0.70606 (8) | −0.03906 (13) | 0.79920 (9) | 0.0278 (3) | |
O12 | 0.59071 (7) | 0.12464 (13) | 0.68133 (9) | 0.0241 (3) | |
O21 | 0.58818 (8) | 0.28845 (12) | 0.44570 (8) | 0.0219 (3) | |
O22 | 0.63839 (8) | 0.45072 (12) | 0.59914 (8) | 0.0212 (3) | |
C1 | 0.77314 (10) | 0.12670 (16) | 0.67229 (11) | 0.0161 (4) | |
C2 | 0.75625 (11) | 0.24125 (16) | 0.58269 (11) | 0.0157 (3) | |
C3 | 0.83974 (11) | 0.28193 (16) | 0.53312 (12) | 0.0179 (4) | |
C4 | 0.94056 (11) | 0.21453 (17) | 0.57457 (12) | 0.0199 (4) | |
C5 | 0.95892 (11) | 0.10573 (18) | 0.66647 (13) | 0.0218 (4) | |
C6 | 0.87486 (11) | 0.06009 (17) | 0.71298 (12) | 0.0209 (4) | |
C11 | 0.68289 (10) | 0.06677 (16) | 0.72250 (11) | 0.0164 (4) | |
C21 | 0.65154 (11) | 0.33073 (16) | 0.53918 (11) | 0.0160 (4) | |
N1A | 0.60404 (10) | 1.02002 (15) | 0.31902 (11) | 0.0207 (4) | |
N2A | 0.58594 (10) | 0.68181 (14) | 0.42855 (11) | 0.0180 (3) | |
C1A | 0.69095 (11) | 0.91156 (17) | 0.38430 (13) | 0.0209 (4) | |
C2A | 0.65833 (11) | 0.81624 (17) | 0.47846 (12) | 0.0212 (4) | |
H3 | 0.82780 | 0.35450 | 0.47200 | 0.0220* | |
H6 | 0.88660 | −0.01580 | 0.77190 | 0.0250* | |
H11A | 0.6007 (14) | 1.117 (2) | 0.3654 (15) | 0.034 (5)* | |
H12A | 0.6168 (15) | 1.044 (2) | 0.2495 (18) | 0.040 (5)* | |
H13A | 0.5379 (16) | 0.975 (2) | 0.3039 (16) | 0.033 (5)* | |
H14A | 0.75380 | 0.97470 | 0.41970 | 0.0250* | |
H15A | 0.71040 | 0.83840 | 0.32990 | 0.0250* | |
H21A | 0.5195 (15) | 0.718 (2) | 0.3925 (15) | 0.029 (5)* | |
H22A | 0.6153 (15) | 0.623 (2) | 0.3789 (16) | 0.036 (5)* | |
H23A | 0.5786 (15) | 0.610 (2) | 0.4847 (17) | 0.038 (5)* | |
H24A | 0.72210 | 0.77460 | 0.53250 | 0.0250* | |
H25A | 0.62220 | 0.88600 | 0.52140 | 0.0250* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl4 | 0.0202 (2) | 0.0375 (2) | 0.0362 (2) | −0.0003 (2) | 0.0163 (2) | 0.0087 (2) |
Cl5 | 0.0177 (2) | 0.0531 (3) | 0.0476 (3) | 0.0126 (2) | 0.0126 (2) | 0.0243 (2) |
O11 | 0.0252 (5) | 0.0276 (6) | 0.0354 (6) | 0.0057 (4) | 0.0163 (5) | 0.0159 (5) |
O12 | 0.0151 (5) | 0.0308 (6) | 0.0275 (5) | 0.0017 (4) | 0.0073 (4) | 0.0096 (4) |
O21 | 0.0203 (5) | 0.0256 (6) | 0.0190 (5) | 0.0050 (4) | 0.0038 (4) | −0.0004 (4) |
O22 | 0.0263 (5) | 0.0179 (5) | 0.0222 (5) | 0.0040 (4) | 0.0113 (4) | 0.0004 (4) |
C1 | 0.0164 (6) | 0.0151 (6) | 0.0183 (7) | −0.0008 (5) | 0.0070 (5) | −0.0009 (5) |
C2 | 0.0169 (6) | 0.0146 (6) | 0.0162 (6) | −0.0008 (5) | 0.0054 (5) | −0.0021 (5) |
C3 | 0.0199 (7) | 0.0177 (7) | 0.0173 (7) | −0.0013 (5) | 0.0067 (5) | 0.0017 (5) |
C4 | 0.0178 (7) | 0.0212 (7) | 0.0235 (7) | −0.0028 (5) | 0.0106 (6) | −0.0009 (6) |
C5 | 0.0151 (7) | 0.0243 (8) | 0.0267 (7) | 0.0040 (6) | 0.0067 (6) | 0.0035 (6) |
C6 | 0.0202 (7) | 0.0211 (7) | 0.0220 (7) | 0.0021 (6) | 0.0067 (6) | 0.0066 (6) |
C11 | 0.0178 (7) | 0.0149 (6) | 0.0180 (7) | −0.0013 (5) | 0.0073 (5) | −0.0012 (5) |
C21 | 0.0180 (7) | 0.0156 (7) | 0.0172 (7) | 0.0008 (5) | 0.0098 (5) | 0.0040 (5) |
N1A | 0.0227 (7) | 0.0195 (6) | 0.0224 (6) | −0.0010 (5) | 0.0105 (5) | 0.0022 (5) |
N2A | 0.0183 (6) | 0.0159 (6) | 0.0220 (6) | 0.0010 (5) | 0.0092 (5) | 0.0003 (5) |
C1A | 0.0181 (7) | 0.0183 (7) | 0.0283 (7) | −0.0013 (5) | 0.0095 (6) | −0.0008 (6) |
C2A | 0.0220 (7) | 0.0207 (7) | 0.0202 (7) | −0.0012 (6) | 0.0041 (6) | −0.0020 (6) |
Cl4—C4 | 1.7379 (15) | C1—C11 | 1.5220 (19) |
Cl5—C5 | 1.7340 (15) | C1—C6 | 1.394 (2) |
O11—C11 | 1.2529 (17) | C2—C21 | 1.516 (2) |
O12—C11 | 1.2614 (16) | C2—C3 | 1.395 (2) |
O21—C21 | 1.2511 (16) | C3—C4 | 1.388 (2) |
O22—C21 | 1.2694 (17) | C4—C5 | 1.397 (2) |
N1A—C1A | 1.497 (2) | C5—C6 | 1.390 (2) |
N2A—C2A | 1.4874 (19) | C3—H3 | 0.9300 |
N1A—H13A | 0.91 (2) | C6—H6 | 0.9300 |
N1A—H12A | 0.91 (2) | C1A—C2A | 1.520 (2) |
N1A—H11A | 0.990 (17) | C1A—H14A | 0.9700 |
N2A—H22A | 0.921 (18) | C1A—H15A | 0.9700 |
N2A—H21A | 0.907 (19) | C2A—H24A | 0.9700 |
N2A—H23A | 0.922 (18) | C2A—H25A | 0.9700 |
C1—C2 | 1.4096 (18) | ||
H12A—N1A—H13A | 107.0 (17) | C4—C5—C6 | 119.81 (13) |
H11A—N1A—H13A | 106.3 (16) | C1—C6—C5 | 120.77 (13) |
C1A—N1A—H12A | 108.8 (12) | O11—C11—C1 | 117.07 (12) |
C1A—N1A—H13A | 113.0 (11) | O12—C11—C1 | 117.36 (11) |
C1A—N1A—H11A | 110.1 (10) | O11—C11—O12 | 125.55 (13) |
H11A—N1A—H12A | 111.7 (15) | O21—C21—O22 | 124.97 (13) |
C2A—N2A—H22A | 110.1 (12) | O21—C21—C2 | 119.07 (12) |
C2A—N2A—H23A | 112.1 (12) | O22—C21—C2 | 115.84 (11) |
C2A—N2A—H21A | 110.8 (11) | C2—C3—H3 | 120.00 |
H21A—N2A—H23A | 107.6 (17) | C4—C3—H3 | 120.00 |
H22A—N2A—H23A | 104.4 (16) | C1—C6—H6 | 120.00 |
H21A—N2A—H22A | 111.7 (16) | C5—C6—H6 | 120.00 |
C2—C1—C6 | 119.08 (13) | N1A—C1A—C2A | 112.98 (12) |
C2—C1—C11 | 122.35 (12) | N2A—C2A—C1A | 111.62 (11) |
C6—C1—C11 | 118.50 (12) | N1A—C1A—H14A | 109.00 |
C3—C2—C12 | 116.79 (12) | N1A—C1A—H15A | 109.00 |
C1—C2—C3 | 119.92 (13) | C2A—C1A—H14A | 109.00 |
C1—C2—C12 | 123.24 (12) | C2A—C1A—H15A | 109.00 |
C2—C3—C4 | 120.28 (13) | H14A—C1A—H15A | 108.00 |
C3—C4—C5 | 120.05 (13) | N2A—C2A—H24A | 109.00 |
Cl4—C4—C5 | 121.27 (11) | N2A—C2A—H25A | 109.00 |
Cl4—C4—C3 | 118.67 (11) | C1A—C2A—H24A | 109.00 |
Cl5—C5—C4 | 121.40 (11) | C1A—C2A—H25A | 109.00 |
Cl5—C5—C6 | 118.78 (11) | H24A—C2A—H25A | 108.00 |
C6—C1—C2—C3 | 2.4 (2) | C1—C2—C21—O22 | 81.94 (17) |
C6—C1—C2—C12 | −174.79 (12) | C3—C2—C21—O21 | 80.75 (17) |
C11—C1—C2—C3 | −174.55 (12) | C3—C2—C21—O22 | −95.33 (15) |
C11—C1—C2—C12 | 8.3 (2) | C2—C3—C4—Cl4 | −178.67 (11) |
C2—C1—C6—C5 | 0.2 (2) | C2—C3—C4—C5 | −0.2 (2) |
C11—C1—C6—C5 | 177.24 (13) | Cl4—C4—C5—Cl5 | 1.97 (18) |
C2—C1—C11—O11 | 177.67 (12) | Cl4—C4—C5—C6 | −178.80 (11) |
C2—C1—C11—O12 | −0.51 (19) | C3—C4—C5—Cl5 | −176.52 (11) |
C6—C1—C11—O11 | 0.70 (18) | C3—C4—C5—C6 | 2.7 (2) |
C6—C1—C11—O12 | −177.48 (12) | Cl5—C5—C6—C1 | 176.53 (11) |
C1—C2—C3—C4 | −2.4 (2) | C4—C5—C6—C1 | −2.7 (2) |
C12—C2—C3—C4 | 174.95 (12) | N1A—C1A—C2A—N2A | 76.45 (15) |
C1—C2—C21—O21 | −101.99 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H11A···O21i | 0.990 (17) | 1.756 (17) | 2.7452 (16) | 177.3 (18) |
N1A—H12A···O22ii | 0.91 (2) | 1.88 (2) | 2.7709 (16) | 168.3 (16) |
N1A—H13A···O12iii | 0.91 (2) | 1.90 (2) | 2.7876 (17) | 163.8 (17) |
N2A—H21A···O12iii | 0.907 (19) | 1.974 (18) | 2.8306 (16) | 157.0 (16) |
N2A—H21A···O22iii | 0.907 (19) | 2.502 (19) | 3.0370 (17) | 118.2 (13) |
N2A—H22A···O11iv | 0.921 (18) | 1.824 (19) | 2.7221 (17) | 164.2 (17) |
N2A—H23A···O22 | 0.922 (18) | 1.922 (18) | 2.7619 (16) | 150.5 (18) |
C6—H6···O11 | 0.93 | 2.44 | 2.7594 (18) | 100 |
C1A—H15A···O11iv | 0.97 | 2.54 | 3.3052 (18) | 136 |
Symmetry codes: (i) x, y+1, z; (ii) x, −y+3/2, z−1/2; (iii) −x+1, −y+1, −z+1; (iv) x, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C2H10N22+·C8H2Cl2O42− |
Mr | 295.12 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 200 |
a, b, c (Å) | 12.892 (1), 8.3881 (5), 11.8873 (8) |
β (°) | 104.761 (7) |
V (Å3) | 1243.06 (15) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.53 |
Crystal size (mm) | 0.35 × 0.30 × 0.28 |
Data collection | |
Diffractometer | Oxford Diffraction Gemini-S CCD detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.955, 0.980 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15108, 2442, 2174 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.026, 0.071, 1.09 |
No. of reflections | 2442 |
No. of parameters | 187 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.28, −0.24 |
Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999), PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H11A···O21i | 0.990 (17) | 1.756 (17) | 2.7452 (16) | 177.3 (18) |
N1A—H12A···O22ii | 0.91 (2) | 1.88 (2) | 2.7709 (16) | 168.3 (16) |
N1A—H13A···O12iii | 0.91 (2) | 1.90 (2) | 2.7876 (17) | 163.8 (17) |
N2A—H21A···O12iii | 0.907 (19) | 1.974 (18) | 2.8306 (16) | 157.0 (16) |
N2A—H21A···O22iii | 0.907 (19) | 2.502 (19) | 3.0370 (17) | 118.2 (13) |
N2A—H22A···O11iv | 0.921 (18) | 1.824 (19) | 2.7221 (17) | 164.2 (17) |
N2A—H23A···O22 | 0.922 (18) | 1.922 (18) | 2.7619 (16) | 150.5 (18) |
Symmetry codes: (i) x, y+1, z; (ii) x, −y+3/2, z−1/2; (iii) −x+1, −y+1, −z+1; (iv) x, −y+1/2, z−1/2. |
Acknowledgements
The authors acknowledge financial support from the Australian Research Council, the School of Physical and Chemical Sciences, Queensland University of Technology, and the School of Biomolecular and Physical Sciences, Griffith University.
References
Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435. CrossRef Web of Science IUCr Journals Google Scholar
Bozkurt, E., Kartal, I., Odabaşoğlu, M. & Büyükgüngör, O. (2006). Acta Cryst. E62, o4258–o4260. Web of Science CSD CrossRef IUCr Journals Google Scholar
Büyükgüngör, O. & Odabaşoğlu, M. (2007). Acta Cryst. E63, o4376–o4377. Web of Science CSD CrossRef IUCr Journals Google Scholar
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. CrossRef CAS Web of Science IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Mattes, R. & Dorau, A. (1986). Z. Naturforsch. Teil B, 41, 808–814. Google Scholar
Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England. Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Smith, G. & Wermuth, U. D. (2010a). Acta Cryst. E66, o133. Web of Science CSD CrossRef IUCr Journals Google Scholar
Smith, G. & Wermuth, U. D. (2010b). J. Chem. Crystallogr. In the press. Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2009). Acta Cryst. C65, o103–o107. Web of Science CSD CrossRef IUCr Journals Google Scholar
Spek, 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.
The structures of proton-transfer compounds of 4,5-dichlorophthalic acid (DCPA) with the aliphatic nitrogen Lewis bases are not common. The 1:1 ammonium and the tetra(n-butyl)ammonium salts (Mattes & Dorau, 1986), the tetramethylammonium salt (Bozkurt et al., 2006) and the salts with the aliphatic amines isopropylamine (Smith & Wermuth, 2010a), diisopropylamine and hexamethylenediamine (a monohydrate) (Smith & Wermuth, 2010b) constitute the only reported examples. With one exception, the ammonium salt (a monohydrate) (Mattes & Dorau, 1986), one-dimensional hydrogen-bonded chain structures are found. In these, the DCPA anions are essentially planar with a short intramolecular carboxylic acid O–H···Ocarboxyl hydrogen bond. These 'planar' anions are also found in the majority of the hydrogen DCPA salts of the aromatic Lewis bases (Smith et al., 2009). The structures of dianionic 4,5-dichlorophthalate salts with any Lewis base are also uncommon, the only known example being the bis(4-ethylanilinium) salt (Büyükgüngör & Odabaşoğlu, 2007). As expected in the structure of the salt reported here, C2H10N22+ C8H3Cl2O42- (I), the DCPA dianions are nonplanar.
The title compound (I) was the product obtained from the 1:1 stoichiometric reaction of DCPA with ethylenediamine in methanol but suitable crystals were obtained only after recrystallization from water. In (I) (Fig. 1), the ethylenediaminium dications and the DCPA dianions form head-to-tail N+–H···Ocarboxyl hydrogen-bonding interactions (Table 1), forming crosslinked duplex chains which extend along the c cell direction (Fig. 2). These ribbon structures enclose conjoint R21(7), R12(7) and R42(8) associations (Etter et al., 1990). These ribbons associate down the b axial direction, giving a two-dimensional network structure (Fig. 3).
Within the DCPA dianions one of the carboxylate groups is essentially coplanar with the benzene ring [torsion angle C2–C1–C11–O11, 177.67 (12)°] while the other is normal to the plane [torsion angle C1–C2–C21–O22, 81.94 (17)°]. The coplanar carboxyl group is stabilized by a short intramolecular aromatic ring C–H···Ocarboxyl interaction [2.7594 (18) Å].