organic compounds
Isopropylaminium 2-carboxy-4,5-dichlorobenzoate
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 1:1 proton-transfer compound of isopropylamine with 4,5-dichlorophthalic acid, C3H10N+·C8H3Cl2O4−, the three cation H-atom donors associate with three separate carboxyl O-atom anion acceptors, giving conjoint cyclic R44(12), R44(16) hydrogen-bonding cation–anion interactions in a one-dimensional ribbon structure. In the anions, the carboxyl groups lie slightly out of the plane of the benzene ring [maximum deviations = 0.439 (1) for a carboxylic acid O atom and 0.433 (1) Å for a carboxylate O atom]. However, the syn-related proton of the carboxylic acid group forms the common short intramolecular O—H⋯Ocarboxyl hydrogen bond.
Related literature
For the structures of other hydrogen 4,5-dichlorophthalate salts, see: Mattes & Dorau (1986); Mallinson et al. (2003); Bozkurt et al. (2006); Odabaşoğlu & Büyükgüngör (2007); Smith et al. (2007, 2008a,b, 2009a,b,c); Smith & Wermuth (2010). For graph-set analysis see: Etter et al. (1990).
Experimental
Crystal data
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Refinement
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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/S1600536809052672/sj2696sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809052672/sj2696Isup2.hkl
The title compound (I) was synthesized by heating together 1 mmol quantities of isopropylamine 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. 533 K).
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
at calculated positions [C–Haromatic = 0.93 Å; C–Haliphatic = 0.96–0.98 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).C3H10N+·C8H3Cl2O4− | F(000) = 608 |
Mr = 294.12 | Dx = 1.541 Mg m−3 |
Monoclinic, P21/n | Melting point: 533 K |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 5.8362 (7) Å | Cell parameters from 3787 reflections |
b = 21.040 (2) Å | θ = 3.5–28.9° |
c = 10.3641 (13) Å | µ = 0.52 mm−1 |
β = 95.064 (12)° | T = 200 K |
V = 1267.7 (3) Å3 | Prism, colourless |
Z = 4 | 0.40 × 0.20 × 0.18 mm |
Oxford Diffraction Gemini-S CCD detector diffractometer | 2484 independent reflections |
Radiation source: Enhance (Mo) X-ray source | 2103 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.020 |
ω scans | θmax = 26.0°, θmin = 3.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −7→7 |
Tmin = 0.942, Tmax = 0.982 | k = −25→25 |
8508 measured reflections | l = −11→12 |
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)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.070 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | w = 1/[σ2(Fo2) + (0.0418P)2] where P = (Fo2 + 2Fc2)/3 |
2484 reflections | (Δ/σ)max = 0.001 |
179 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
C3H10N+·C8H3Cl2O4− | V = 1267.7 (3) Å3 |
Mr = 294.12 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 5.8362 (7) Å | µ = 0.52 mm−1 |
b = 21.040 (2) Å | T = 200 K |
c = 10.3641 (13) Å | 0.40 × 0.20 × 0.18 mm |
β = 95.064 (12)° |
Oxford Diffraction Gemini-S CCD detector diffractometer | 2484 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2103 reflections with I > 2σ(I) |
Tmin = 0.942, Tmax = 0.982 | Rint = 0.020 |
8508 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.070 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | Δρmax = 0.24 e Å−3 |
2484 reflections | Δρmin = −0.22 e Å−3 |
179 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 | −0.02700 (6) | 0.21328 (2) | 0.79371 (4) | 0.0321 (1) | |
Cl5 | −0.07644 (7) | 0.22223 (2) | 0.48482 (4) | 0.0381 (1) | |
O11 | 0.51763 (18) | 0.06697 (6) | 0.34762 (10) | 0.0380 (4) | |
O12 | 0.79781 (18) | 0.04757 (5) | 0.49757 (11) | 0.0363 (4) | |
O21 | 0.85388 (16) | 0.04986 (5) | 0.73467 (10) | 0.0284 (3) | |
O22 | 0.61961 (18) | 0.05281 (5) | 0.89173 (10) | 0.0319 (3) | |
C1 | 0.4642 (2) | 0.10656 (6) | 0.55707 (13) | 0.0208 (4) | |
C2 | 0.4887 (2) | 0.10301 (6) | 0.69407 (13) | 0.0197 (4) | |
C3 | 0.3362 (2) | 0.13730 (6) | 0.76294 (14) | 0.0214 (4) | |
C4 | 0.1622 (2) | 0.17415 (6) | 0.70180 (14) | 0.0230 (4) | |
C5 | 0.1406 (2) | 0.17807 (6) | 0.56719 (14) | 0.0247 (4) | |
C6 | 0.2902 (2) | 0.14478 (6) | 0.49726 (14) | 0.0241 (4) | |
C11 | 0.5991 (2) | 0.07119 (6) | 0.46084 (14) | 0.0250 (4) | |
C21 | 0.6660 (2) | 0.06527 (6) | 0.78049 (14) | 0.0225 (4) | |
N1A | 0.8171 (2) | 0.04013 (6) | 0.15582 (13) | 0.0231 (4) | |
C1A | 0.9564 (2) | 0.10018 (7) | 0.17227 (15) | 0.0271 (4) | |
C2A | 0.7999 (3) | 0.15688 (8) | 0.14539 (19) | 0.0420 (6) | |
C3A | 1.1460 (3) | 0.09810 (8) | 0.08332 (17) | 0.0350 (5) | |
H3 | 0.35150 | 0.13540 | 0.85290 | 0.0260* | |
H6 | 0.27510 | 0.14780 | 0.40740 | 0.0290* | |
H12 | 0.821 (4) | 0.0490 (11) | 0.594 (3) | 0.087 (8)* | |
H1A | 1.02480 | 0.10260 | 0.26190 | 0.0330* | |
H11A | 0.694 (3) | 0.0418 (8) | 0.2138 (18) | 0.040 (5)* | |
H12A | 0.907 (3) | 0.0072 (9) | 0.1720 (17) | 0.036 (5)* | |
H13A | 0.751 (3) | 0.0384 (8) | 0.072 (2) | 0.037 (5)* | |
H21A | 0.68170 | 0.15660 | 0.20420 | 0.0500* | |
H22A | 0.73080 | 0.15470 | 0.05790 | 0.0500* | |
H23A | 0.88790 | 0.19530 | 0.15700 | 0.0500* | |
H31A | 1.24140 | 0.06160 | 0.10360 | 0.0420* | |
H32A | 1.23720 | 0.13600 | 0.09430 | 0.0420* | |
H33A | 1.08070 | 0.09530 | −0.00480 | 0.0420* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl4 | 0.0289 (2) | 0.0304 (2) | 0.0377 (2) | 0.0045 (1) | 0.0069 (2) | −0.0040 (2) |
Cl5 | 0.0363 (2) | 0.0352 (2) | 0.0399 (3) | 0.0086 (2) | −0.0133 (2) | 0.0045 (2) |
O11 | 0.0356 (6) | 0.0582 (7) | 0.0205 (6) | −0.0017 (5) | 0.0050 (5) | −0.0080 (5) |
O12 | 0.0341 (6) | 0.0470 (6) | 0.0286 (7) | 0.0119 (5) | 0.0069 (5) | 0.0007 (5) |
O21 | 0.0221 (5) | 0.0317 (6) | 0.0309 (6) | 0.0035 (4) | −0.0002 (4) | 0.0045 (4) |
O22 | 0.0368 (6) | 0.0395 (6) | 0.0187 (6) | 0.0064 (4) | −0.0014 (4) | 0.0048 (4) |
C1 | 0.0216 (7) | 0.0217 (7) | 0.0189 (7) | −0.0057 (5) | 0.0008 (5) | 0.0006 (5) |
C2 | 0.0196 (6) | 0.0194 (6) | 0.0196 (7) | −0.0048 (5) | −0.0010 (5) | 0.0012 (5) |
C3 | 0.0248 (7) | 0.0226 (7) | 0.0168 (7) | −0.0038 (5) | 0.0011 (5) | 0.0007 (5) |
C4 | 0.0223 (7) | 0.0200 (7) | 0.0268 (8) | −0.0029 (5) | 0.0024 (6) | −0.0014 (5) |
C5 | 0.0249 (7) | 0.0208 (7) | 0.0268 (8) | −0.0018 (5) | −0.0069 (6) | 0.0028 (5) |
C6 | 0.0275 (7) | 0.0265 (7) | 0.0174 (8) | −0.0055 (5) | −0.0033 (6) | 0.0021 (5) |
C11 | 0.0273 (7) | 0.0268 (7) | 0.0214 (8) | −0.0060 (6) | 0.0052 (6) | 0.0006 (6) |
C21 | 0.0246 (7) | 0.0208 (7) | 0.0212 (8) | −0.0029 (5) | −0.0030 (6) | −0.0004 (5) |
N1A | 0.0237 (6) | 0.0269 (6) | 0.0183 (7) | 0.0018 (5) | −0.0003 (5) | 0.0007 (5) |
C1A | 0.0315 (8) | 0.0281 (7) | 0.0208 (8) | −0.0026 (6) | −0.0031 (6) | −0.0018 (6) |
C2A | 0.0512 (10) | 0.0287 (8) | 0.0474 (11) | 0.0071 (7) | 0.0111 (8) | −0.0027 (7) |
C3A | 0.0291 (8) | 0.0354 (8) | 0.0408 (10) | −0.0019 (6) | 0.0041 (7) | 0.0071 (7) |
Cl4—C4 | 1.7292 (14) | C2—C3 | 1.3908 (18) |
Cl5—C5 | 1.7337 (14) | C3—C4 | 1.3858 (18) |
O11—C11 | 1.2298 (18) | C4—C5 | 1.392 (2) |
O12—C11 | 1.2880 (16) | C5—C6 | 1.3747 (18) |
O21—C21 | 1.2747 (16) | C3—H3 | 0.9300 |
O22—C21 | 1.2354 (18) | C6—H6 | 0.9300 |
O12—H12 | 1.00 (3) | C1A—C2A | 1.513 (2) |
N1A—C1A | 1.5039 (19) | C1A—C3A | 1.502 (2) |
N1A—H11A | 0.977 (18) | C1A—H1A | 0.9800 |
N1A—H13A | 0.92 (2) | C2A—H21A | 0.9600 |
N1A—H12A | 0.876 (19) | C2A—H22A | 0.9600 |
C1—C6 | 1.3968 (18) | C2A—H23A | 0.9600 |
C1—C11 | 1.5189 (18) | C3A—H31A | 0.9600 |
C1—C2 | 1.4164 (19) | C3A—H32A | 0.9600 |
C2—C21 | 1.5297 (18) | C3A—H33A | 0.9600 |
C11—O12—H12 | 108.9 (14) | O21—C21—C2 | 118.27 (12) |
H11A—N1A—H12A | 111.8 (15) | O22—C21—C2 | 117.64 (11) |
C1A—N1A—H13A | 108.5 (11) | C2—C3—H3 | 119.00 |
C1A—N1A—H11A | 108.6 (10) | C4—C3—H3 | 119.00 |
H11A—N1A—H13A | 108.2 (16) | C1—C6—H6 | 119.00 |
H12A—N1A—H13A | 110.1 (16) | C5—C6—H6 | 119.00 |
C1A—N1A—H12A | 109.5 (12) | C2A—C1A—C3A | 112.05 (14) |
C6—C1—C11 | 112.92 (12) | N1A—C1A—C2A | 109.27 (11) |
C2—C1—C6 | 118.71 (12) | N1A—C1A—C3A | 109.03 (12) |
C2—C1—C11 | 128.32 (11) | N1A—C1A—H1A | 109.00 |
C1—C2—C21 | 128.14 (11) | C2A—C1A—H1A | 109.00 |
C1—C2—C3 | 118.33 (12) | C3A—C1A—H1A | 109.00 |
C3—C2—C21 | 113.53 (12) | C1A—C2A—H21A | 110.00 |
C2—C3—C4 | 122.13 (13) | C1A—C2A—H22A | 109.00 |
Cl4—C4—C5 | 121.21 (10) | C1A—C2A—H23A | 109.00 |
C3—C4—C5 | 119.29 (12) | H21A—C2A—H22A | 109.00 |
Cl4—C4—C3 | 119.49 (11) | H21A—C2A—H23A | 109.00 |
Cl5—C5—C4 | 121.52 (10) | H22A—C2A—H23A | 110.00 |
C4—C5—C6 | 119.51 (12) | C1A—C3A—H31A | 109.00 |
Cl5—C5—C6 | 118.94 (11) | C1A—C3A—H32A | 110.00 |
C1—C6—C5 | 122.01 (13) | C1A—C3A—H33A | 109.00 |
O11—C11—O12 | 121.09 (13) | H31A—C3A—H32A | 109.00 |
O11—C11—C1 | 118.87 (11) | H31A—C3A—H33A | 109.00 |
O12—C11—C1 | 120.03 (12) | H32A—C3A—H33A | 109.00 |
O21—C21—O22 | 124.07 (12) | ||
C6—C1—C2—C3 | 0.72 (18) | C1—C2—C21—O21 | 22.83 (19) |
C6—C1—C2—C21 | −179.34 (12) | C1—C2—C21—O22 | −158.69 (13) |
C11—C1—C2—C3 | −176.37 (12) | C3—C2—C21—O21 | −157.23 (12) |
C11—C1—C2—C21 | 3.6 (2) | C3—C2—C21—O22 | 21.26 (17) |
C2—C1—C6—C5 | −1.04 (19) | C2—C3—C4—Cl4 | 177.78 (10) |
C11—C1—C6—C5 | 176.47 (11) | C2—C3—C4—C5 | −1.10 (19) |
C2—C1—C11—O11 | 161.01 (13) | Cl4—C4—C5—Cl5 | −0.02 (16) |
C2—C1—C11—O12 | −20.7 (2) | Cl4—C4—C5—C6 | −178.09 (10) |
C6—C1—C11—O11 | −16.22 (17) | C3—C4—C5—Cl5 | 178.86 (10) |
C6—C1—C11—O12 | 162.10 (12) | C3—C4—C5—C6 | 0.78 (18) |
C1—C2—C3—C4 | 0.34 (19) | Cl5—C5—C6—C1 | −177.84 (10) |
C21—C2—C3—C4 | −179.61 (11) | C4—C5—C6—C1 | 0.29 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12···O21 | 1.00 (3) | 1.45 (3) | 2.4507 (16) | 179 (3) |
N1A—H11A···O11 | 0.977 (18) | 1.875 (18) | 2.8175 (17) | 161.2 (15) |
N1A—H12A···O21i | 0.876 (19) | 2.021 (18) | 2.8593 (16) | 159.6 (16) |
N1A—H13A···O22ii | 0.92 (2) | 1.98 (2) | 2.8869 (17) | 168.8 (15) |
C3—H3···O22 | 0.93 | 2.35 | 2.6996 (17) | 102 |
C6—H6···O11 | 0.93 | 2.33 | 2.6853 (18) | 102 |
C3A—H31A···O22i | 0.96 | 2.54 | 3.458 (2) | 160 |
Symmetry codes: (i) −x+2, −y, −z+1; (ii) x, y, z−1. |
Experimental details
Crystal data | |
Chemical formula | C3H10N+·C8H3Cl2O4− |
Mr | 294.12 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 200 |
a, b, c (Å) | 5.8362 (7), 21.040 (2), 10.3641 (13) |
β (°) | 95.064 (12) |
V (Å3) | 1267.7 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.52 |
Crystal size (mm) | 0.40 × 0.20 × 0.18 |
Data collection | |
Diffractometer | Oxford Diffraction Gemini-S CCD detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.942, 0.982 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8508, 2484, 2103 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.070, 1.11 |
No. of reflections | 2484 |
No. of parameters | 179 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.24, −0.22 |
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 |
O12—H12···O21 | 1.00 (3) | 1.45 (3) | 2.4507 (16) | 179 (3) |
N1A—H11A···O11 | 0.977 (18) | 1.875 (18) | 2.8175 (17) | 161.2 (15) |
N1A—H12A···O21i | 0.876 (19) | 2.021 (18) | 2.8593 (16) | 159.6 (16) |
N1A—H13A···O22ii | 0.92 (2) | 1.98 (2) | 2.8869 (17) | 168.8 (15) |
C3—H3···O22 | 0.93 | 2.35 | 2.6996 (17) | 102 |
C6—H6···O11 | 0.93 | 2.33 | 2.6853 (18) | 102 |
Symmetry codes: (i) −x+2, −y, −z+1; (ii) x, y, z−1. |
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
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
Mallinson, P. R., Smith, G. T., Wilson, C. C., Grech, E. & Wozniak, K. (2003). J. Am. Chem. Soc. 125, 4259–4270. Web of Science CSD CrossRef PubMed CAS Google Scholar
Mattes, R. & Dorau, A. (1986). Z. Naturforsch. Teil B, 41, 808–814. Google Scholar
Odabaşoğlu, M. & Büyükgüngör, O. (2007). Acta Cryst. E63, o4374–o4375. Web of Science CSD CrossRef IUCr Journals Google Scholar
Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, 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. (2010). J. Chem. Crystallogr. In the press. Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2007). Acta Cryst. E63, o4276–o4277. Web of Science CSD CrossRef IUCr Journals Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2008a). Acta Cryst. C64, o180–o183. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2008b). Acta Cryst. C64, o532–o536. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2009a). Acta Cryst. C65, o103–o107. Web of Science CSD CrossRef IUCr Journals Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2009b). Acta Cryst. E65, o2111. Web of Science CSD CrossRef IUCr Journals Google Scholar
Smith, G., Wermuth, U. D. & White, J. M. (2009c). Acta Cryst. E65, o2333. 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
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The 1:1 proton-transfer compounds of 4,5-dichlorophthalic acid (DCPA) with a number of nitrogen Lewis bases commonly have low-dimensional hydrogen-bonded structures (Smith et al., 2007, 2008a,b, 2009a,b,c; Smith & Wermuth, 2010). In the majority of these structures, the DCPA anions are essentially planar with short intramolecular carboxylic acid O–H···Ocarboxyl hydrogen bonds. These features were therefore expected and found in the 1:1 proton-transfer compound of DCPA with isopropylamine, the title compound C3H10N+ C8H3Cl2O4- (I), reported here.
In (I), the aminium group of the cation forms N+–H···Ocarboxyl hydrogen bonds with O acceptors of three separate DCPA anions (Figs. 1, 2). These associations (Table 1) give one-dimensional ribbon structures which extend across the c cell direction in the unit cell (Fig. 2) and feature conjoint cyclic R44(12) and R44(16) cation–anion hydrogen-bonding interactions (Etter et al., 1990). Within the DCPA anion [torsion angles C2–C1–C11–O11, -161.01 (13)° and C1–C2–C21–O22, -156.69 (13)°] indicate greater distortion from planarity than has been found in the common `planar' DCPA anion examples. The short intramolecular O–H···Ocarboxyl hydrogen bond is also slightly longer [2.4507 (16) Å] (cf. 1.4054 (19) Å (Smith et al., 2009c). Associated with this bond is a significant distortion of the exo-C1 and C2 bond angles [C1–C2–C21, 128.14 (11) ° and C2–C1–C11, 128.32 (11) °]. This and a lengthening of the C1–C11 and C2–C21 bonds [1.5189 (18) and 1.5297 (18) Å], as well as short intramolecular aromatic ring C–H···Ocarboxyl interactions [2.6853 (18), 2.6996 (17) Å], are features of the `planar' hydrogen DCPA anions which have been noted previously (Smith et al., 2009c).