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ISSN: 2056-9890

tert-Butyl­aminium 2-carb­­oxy-4,5-di­chloro­benzoate

aFaculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia
*Correspondence e-mail: g.smith@qut.edu.au

(Received 18 August 2011; accepted 20 August 2011; online 27 August 2011)

In the structure of the title anhydrous salt, C4H12N+·C8H3Cl2O4, the 4,5-dichloro­phthalate monoanions have the common `planar' conformation with the carboxyl groups close to coplanar with the benzene ring and with a short intra­molecular carb­oxy­lic acid O—H⋯O hydrogen bond. In the crystal, a two-dimensional sheet structure is formed through aminium N—H⋯Ocarbox­yl hydrogen-bonding associations.

Related literature

For structures of 1:1 salts of 4,5-dichloro­phthalic acid with acyclic aliphatic amines, see: Mattes & Dorau (1986[Mattes, R. & Dorau, A. (1986). Z. Naturforsch. B, 41, 808-814.]); Bozkurt et al. (2006[Bozkurt, E., Kartal, I., Odabaşoğlu, M. & Büyükgüngör, O. (2006). Acta Cryst. E62, o4258-o4260.]); Smith & Wermuth (2010a[Smith, G. & Wermuth, U. D. (2010a). Acta Cryst. E66, o133.],b[Smith, G. & Wermuth, U. D. (2010b). J. Chem. Crystallogr. 40, 207-212.],c[Smith, G. & Wermuth, U. D. (2010c). Acta Cryst. C66, o374-o380.]).

[Scheme 1]

Experimental

Crystal data
  • C4H12N+·C8H3Cl2O4

  • Mr = 308.15

  • Monoclinic, P 21 /n

  • a = 6.1778 (2) Å

  • b = 12.7158 (4) Å

  • c = 17.7125 (7) Å

  • β = 96.784 (4)°

  • V = 1381.68 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.48 mm−1

  • T = 200 K

  • 0.45 × 0.26 × 0.18 mm

Data collection
  • Oxford Diffraction Gemini-S CCD-detector diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]) Tmin = 0.977, Tmax = 0.990

  • 8677 measured reflections

  • 2719 independent reflections

  • 2307 reflections with I > 2σ(I)

  • Rint = 0.027

Refinement
  • R[F2 > 2σ(F2)] = 0.033

  • wR(F2) = 0.094

  • S = 0.90

  • 2719 reflections

  • 188 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1A—H11A⋯O21 0.89 (2) 2.02 (2) 2.883 (2) 164 (2)
N1A—H12A⋯O11i 0.91 (2) 1.88 (2) 2.784 (2) 174 (2)
N1A—H13A⋯O12ii 0.89 (2) 1.99 (2) 2.861 (2) 167 (2)
O21—H21⋯O12 0.94 (4) 1.47 (4) 2.4021 (19) 173 (4)
Symmetry codes: (i) -x+1, -y+1, -z+2; (ii) x-1, y, z.

Data collection: CrysAlis PRO (Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1994[Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) within WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]); molecular graphics: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: PLATON.

Supporting information


Comment top

4,5-Dichlorophthalic acid (DCPA) commonly forms 1:1 salts with the acyclic aliphatic amine analogues and with these, low-dimensional hydrogen-bonded structures are usually found, featuring the 'planar' hydrogen phthalate anion e.g with isopropylamine (Smith & Wermuth, 2010a), diisopropylamine (Smith & Wermuth, 2010b), diethylamine, triethylamine and n-butylamine (Smith & Wermuth, 2010c), the ammonium and tetra(nbutyl)ammonium salts (Mattes & Dorau, 1986) and the tetramethylammonium salt (Bozkurt et al., 2006). Our 1:1 stoichiometric reaction of DCPA with t-butylamine also gave a 1:1 salt C4H12N+ C8H3Cl2O4-, the title compound and the structure is reported here.

In this structure the common 'planar' DCPA anion is found (Fig. 1) and has the previously described (Smith & Wermuth, 2010c) short intramolecular carboxylic acid OH···Ocarboxy hydrogen bond (Table 1) (torsion angles C1–C2–C21–O22 and C2–C1–C11–O11: 176.59 (18) and 175.26 (17) Å respectively). Other structural features common to this 'planar' monoanion are a lengthening of the C1—C11 and C2—C21 bond lengths [1.522 (2) and 1.528 (3) Å] and distortion of the external bond angles at C1 and C2 [C1—C2—C21, 129.57 (15)° and C2—C1—C11, 128.84 (15)°].

Intermolecular aminium NH···O(carboxyl) hydrogen bonds (Table 1) link the DCPA monoanions across b as well as down the a axis, forming a two-dimensional sheet structure (Fig. 2).

Related literature top

For structures of 1:1 salts of 4,5-dichlorophthalic acid with acyclic aliphatic amines, see: Mattes & Dorau (1986); Bozkurt et al. (2006); Smith & Wermuth (2010a,b,c).

Experimental top

The title compound was synthesized by heating together for 10 min under reflux, 1 mmol quantities of 4,5-dichlorophthalic acid and t-butylamine in 50 ml of 50% ethanol–water. Partial evaporation of the solvent gave colourless crystalline plates from which a specimen was cleaved for the X-ray analysis..

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 at calculated positions [C—H (aromatic) = 0.93 Å or C—H (methyl) = 0.97 Å] and treated as riding, with Uiso(H) = 1.2UeqC(aromatic) or 1.5Ueq C(methyl).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); 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).

Figures top
[Figure 1] Fig. 1. Molecular conformation and atom-numbering scheme for the title salt, with the hydrogen bonds shown as a dashed lines. Non-H atoms are shown as 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. A perspective view the two-dimensional sheet structure looking down the sheet, showing hydrogen-bonding associations as dashed lines.
tert-Butylaminium 2-carboxy-4,5-dichlorobenzoate top
Crystal data top
C4H12N+·C8H3Cl2O4F(000) = 640
Mr = 308.15Dx = 1.481 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 4272 reflections
a = 6.1778 (2) Åθ = 3.3–28.8°
b = 12.7158 (4) ŵ = 0.48 mm1
c = 17.7125 (7) ÅT = 200 K
β = 96.784 (4)°Plate, colourless
V = 1381.68 (8) Å30.45 × 0.26 × 0.18 mm
Z = 4
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer
2719 independent reflections
Radiation source: Enhance (Mo) X-ray source2307 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.027
Detector resolution: 16.077 pixels mm-1θmax = 26.0°, θmin = 3.4°
ω scansh = 77
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2010)
k = 1515
Tmin = 0.977, Tmax = 0.990l = 2121
8677 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.033Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.094H atoms treated by a mixture of independent and constrained refinement
S = 0.90 w = 1/[σ2(Fo2) + (0.0608P)2 + 0.4558P]
where P = (Fo2 + 2Fc2)/3
2719 reflections(Δ/σ)max = 0.001
188 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.21 e Å3
Crystal data top
C4H12N+·C8H3Cl2O4V = 1381.68 (8) Å3
Mr = 308.15Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1778 (2) ŵ = 0.48 mm1
b = 12.7158 (4) ÅT = 200 K
c = 17.7125 (7) Å0.45 × 0.26 × 0.18 mm
β = 96.784 (4)°
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer
2719 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2010)
2307 reflections with I > 2σ(I)
Tmin = 0.977, Tmax = 0.990Rint = 0.027
8677 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0330 restraints
wR(F2) = 0.094H atoms treated by a mixture of independent and constrained refinement
S = 0.90Δρmax = 0.25 e Å3
2719 reflectionsΔρmin = 0.21 e Å3
188 parameters
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
Cl10.77566 (7)0.08494 (3)0.92701 (3)0.0313 (1)
Cl20.29591 (7)0.09103 (3)0.84148 (3)0.0370 (2)
O110.8896 (2)0.29012 (10)1.01297 (8)0.0394 (4)
O120.6289 (2)0.40012 (9)0.97033 (8)0.0353 (4)
O210.2615 (2)0.39679 (10)0.90835 (10)0.0452 (5)
O220.0363 (2)0.28642 (11)0.84456 (9)0.0475 (5)
C10.5836 (3)0.21454 (12)0.93969 (9)0.0218 (5)
C20.3705 (3)0.21275 (13)0.90024 (9)0.0230 (5)
C30.2876 (3)0.11656 (13)0.87218 (10)0.0239 (5)
C40.4066 (3)0.02459 (12)0.87963 (9)0.0233 (5)
C50.6169 (3)0.02693 (12)0.91703 (9)0.0221 (5)
C60.7012 (3)0.12081 (13)0.94635 (9)0.0236 (5)
C110.7102 (3)0.30722 (13)0.97701 (9)0.0268 (5)
C210.2089 (3)0.30285 (14)0.88234 (11)0.0311 (6)
N1A0.0938 (3)0.54459 (13)0.90362 (9)0.0257 (5)
C1A0.2152 (3)0.58740 (13)0.83097 (10)0.0255 (5)
C2A0.0614 (3)0.66054 (18)0.79557 (12)0.0450 (7)
C3A0.2819 (3)0.49408 (16)0.77986 (11)0.0380 (6)
C4A0.4120 (3)0.64663 (15)0.85216 (12)0.0373 (6)
H30.146300.114300.847400.0290*
H60.842000.121600.971600.0280*
H210.400 (6)0.399 (3)0.936 (2)0.109 (12)*
H11A0.016 (3)0.5023 (18)0.8953 (12)0.039 (6)*
H12A0.036 (4)0.5995 (18)0.9325 (13)0.044 (6)*
H13A0.185 (4)0.5080 (18)0.9289 (13)0.042 (6)*
H21A0.061200.621200.782200.0670*
H22A0.011400.714500.831400.0670*
H23A0.136600.692200.750700.0670*
H31A0.379400.449800.803900.0570*
H32A0.154600.454600.771200.0570*
H33A0.353800.518800.732200.0570*
H41A0.507200.598800.874100.0560*
H42A0.488300.678100.807400.0560*
H43A0.365100.700600.888400.0560*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0293 (2)0.0232 (2)0.0394 (3)0.0066 (2)0.0041 (2)0.0007 (2)
Cl20.0298 (3)0.0252 (2)0.0534 (3)0.0039 (2)0.0061 (2)0.0113 (2)
O110.0394 (8)0.0314 (7)0.0433 (8)0.0070 (6)0.0116 (6)0.0082 (6)
O120.0367 (7)0.0208 (6)0.0486 (8)0.0044 (5)0.0059 (6)0.0061 (5)
O210.0321 (8)0.0228 (7)0.0798 (11)0.0057 (6)0.0025 (8)0.0041 (7)
O220.0377 (8)0.0409 (8)0.0591 (10)0.0146 (6)0.0148 (7)0.0028 (7)
C10.0250 (8)0.0205 (8)0.0198 (8)0.0024 (6)0.0028 (7)0.0010 (6)
C20.0228 (8)0.0233 (8)0.0231 (8)0.0017 (6)0.0031 (7)0.0010 (6)
C30.0180 (8)0.0274 (8)0.0257 (8)0.0004 (7)0.0004 (7)0.0007 (7)
C40.0231 (8)0.0216 (8)0.0249 (8)0.0033 (6)0.0012 (7)0.0026 (7)
C50.0223 (8)0.0213 (8)0.0225 (8)0.0018 (6)0.0018 (6)0.0016 (6)
C60.0204 (8)0.0265 (8)0.0228 (8)0.0016 (6)0.0020 (7)0.0007 (7)
C110.0311 (9)0.0247 (9)0.0251 (9)0.0068 (7)0.0049 (8)0.0032 (7)
C210.0316 (10)0.0258 (9)0.0361 (10)0.0067 (7)0.0053 (8)0.0027 (8)
N1A0.0236 (8)0.0251 (8)0.0268 (8)0.0001 (7)0.0037 (7)0.0033 (6)
C1A0.0245 (9)0.0262 (9)0.0246 (9)0.0016 (7)0.0021 (7)0.0001 (7)
C2A0.0437 (12)0.0542 (13)0.0374 (11)0.0117 (10)0.0066 (9)0.0081 (10)
C3A0.0385 (11)0.0404 (11)0.0315 (10)0.0050 (9)0.0108 (8)0.0097 (8)
C4A0.0328 (10)0.0329 (10)0.0451 (11)0.0079 (8)0.0004 (9)0.0001 (9)
Geometric parameters (Å, º) top
Cl1—C51.7251 (17)C4—C51.387 (3)
Cl2—C41.7253 (16)C5—C61.379 (2)
O11—C111.231 (2)C3—H30.9300
O12—C111.284 (2)C6—H60.9300
O21—C211.307 (2)C1A—C2A1.517 (3)
O22—C211.208 (2)C1A—C3A1.520 (3)
O21—H210.94 (4)C1A—C4A1.515 (3)
N1A—C1A1.512 (2)C2A—H21A0.9600
N1A—H11A0.89 (2)C2A—H22A0.9600
N1A—H13A0.89 (2)C2A—H23A0.9600
N1A—H12A0.91 (2)C3A—H31A0.9600
C1—C111.522 (2)C3A—H32A0.9600
C1—C61.394 (2)C3A—H33A0.9600
C1—C21.416 (3)C4A—H41A0.9600
C2—C31.395 (2)C4A—H42A0.9600
C2—C211.528 (3)C4A—H43A0.9600
C3—C41.379 (2)
Cl1···Cl23.1661 (7)O11···C21v3.217 (2)
Cl1···O11i3.4197 (14)O11···Cl1i3.4197 (14)
Cl1···C3ii3.6461 (18)O11···N1Avi2.784 (2)
Cl2···Cl13.1661 (7)O12···C213.120 (2)
Cl1···H43Aiii2.9200O12···O12vi3.2387 (17)
Cl1···H6i2.8300O12···O212.4021 (19)
Cl2···H22Aiv3.1100O12···N1Av2.861 (2)
O11···O22v3.219 (2)O21···C113.109 (2)
C21—O21—H21113 (2)C4—C3—H3119.00
C1A—N1A—H11A112.8 (14)C1—C6—H6119.00
C1A—N1A—H12A108.9 (14)C5—C6—H6119.00
H11A—N1A—H12A107 (2)C3A—C1A—C4A111.52 (15)
H11A—N1A—H13A108 (2)N1A—C1A—C2A107.49 (15)
C1A—N1A—H13A109.6 (15)N1A—C1A—C3A107.35 (14)
H12A—N1A—H13A110 (2)N1A—C1A—C4A107.46 (15)
C2—C1—C11128.84 (15)C2A—C1A—C3A111.81 (16)
C6—C1—C11112.93 (15)C2A—C1A—C4A110.97 (15)
C2—C1—C6118.24 (15)C1A—C2A—H21A109.00
C1—C2—C21129.57 (15)C1A—C2A—H22A109.00
C1—C2—C3118.09 (15)C1A—C2A—H23A109.00
C3—C2—C21112.35 (16)H21A—C2A—H22A109.00
C2—C3—C4122.71 (17)H21A—C2A—H23A109.00
Cl2—C4—C5120.72 (12)H22A—C2A—H23A109.00
Cl2—C4—C3120.19 (14)C1A—C3A—H31A110.00
C3—C4—C5119.08 (15)C1A—C3A—H32A109.00
Cl1—C5—C4121.35 (12)C1A—C3A—H33A109.00
Cl1—C5—C6119.36 (14)H31A—C3A—H32A109.00
C4—C5—C6119.28 (15)H31A—C3A—H33A109.00
C1—C6—C5122.58 (17)H32A—C3A—H33A109.00
O11—C11—C1118.25 (15)C1A—C4A—H41A109.00
O11—C11—O12121.94 (16)C1A—C4A—H42A109.00
O12—C11—C1119.82 (15)C1A—C4A—H43A109.00
O21—C21—C2118.87 (16)H41A—C4A—H42A110.00
O21—C21—O22121.30 (17)H41A—C4A—H43A109.00
O22—C21—C2119.83 (16)H42A—C4A—H43A109.00
C2—C3—H3119.00
C6—C1—C2—C31.9 (2)C1—C2—C21—O213.2 (3)
C6—C1—C2—C21177.99 (17)C1—C2—C21—O22176.59 (18)
C11—C1—C2—C3178.68 (16)C3—C2—C21—O21176.90 (17)
C11—C1—C2—C211.4 (3)C3—C2—C21—O223.3 (2)
C2—C1—C6—C50.9 (2)C2—C3—C4—Cl2178.43 (14)
C11—C1—C6—C5179.57 (15)C2—C3—C4—C50.5 (3)
C2—C1—C11—O11175.26 (17)Cl2—C4—C5—Cl10.1 (2)
C2—C1—C11—O124.8 (3)Cl2—C4—C5—C6179.48 (13)
C6—C1—C11—O115.3 (2)C3—C4—C5—Cl1179.02 (13)
C6—C1—C11—O12174.65 (15)C3—C4—C5—C60.5 (2)
C1—C2—C3—C41.8 (3)Cl1—C5—C6—C1179.23 (13)
C21—C2—C3—C4178.14 (16)C4—C5—C6—C10.3 (3)
Symmetry codes: (i) x+2, y, z+2; (ii) x+1, y, z+2; (iii) x+1, y1, z; (iv) x, y1, z; (v) x+1, y, z; (vi) x+1, y+1, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H11A···O210.89 (2)2.02 (2)2.883 (2)164 (2)
N1A—H12A···O11vi0.91 (2)1.88 (2)2.784 (2)174 (2)
N1A—H13A···O12vii0.89 (2)1.99 (2)2.861 (2)167 (2)
O21—H21···O120.94 (4)1.47 (4)2.4021 (19)173 (4)
C3—H3···O220.932.292.671 (2)104
C6—H6···O110.932.272.657 (2)104
Symmetry codes: (vi) x+1, y+1, z+2; (vii) x1, y, z.

Experimental details

Crystal data
Chemical formulaC4H12N+·C8H3Cl2O4
Mr308.15
Crystal system, space groupMonoclinic, P21/n
Temperature (K)200
a, b, c (Å)6.1778 (2), 12.7158 (4), 17.7125 (7)
β (°) 96.784 (4)
V3)1381.68 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.48
Crystal size (mm)0.45 × 0.26 × 0.18
Data collection
DiffractometerOxford Diffraction Gemini-S CCD-detector
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Oxford Diffraction, 2010)
Tmin, Tmax0.977, 0.990
No. of measured, independent and
observed [I > 2σ(I)] reflections
8677, 2719, 2307
Rint0.027
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.033, 0.094, 0.90
No. of reflections2719
No. of parameters188
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.25, 0.21

Computer programs: CrysAlis PRO (Oxford Diffraction, 2010), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H11A···O210.89 (2)2.02 (2)2.883 (2)164 (2)
N1A—H12A···O11i0.91 (2)1.88 (2)2.784 (2)174 (2)
N1A—H13A···O12ii0.89 (2)1.99 (2)2.861 (2)167 (2)
O21—H21···O120.94 (4)1.47 (4)2.4021 (19)173 (4)
Symmetry codes: (i) x+1, y+1, z+2; (ii) x1, y, z.
 

Acknowledgements

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

References

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