4-Chloro-3,5-dinitro­benzoic acid

The title compound, C₇H₃ClN₂O₆, crystallizes with two independent mol­ecules in the asymmetric unit. Strong inter­molecular O—H...O hydrogen bonds link the mol­ecules into centrosymmetric dimers. The crystal packing is further stabilized by weak inter­molecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.034
• wR factor = 0.086
• Data-to-parameter ratio = 12.1

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    O7     -   N3      ..      12.31 su
PLAT230_ALERT_2_B Hirshfeld Test Diff for    O8     -   N3      ..      10.14 su
PLAT430_ALERT_2_B Short Inter D...A Contact  O2     ..  O7      ..       2.82 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact  O2     ..  O2      ..       2.84 Ang.

Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.97
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.62 Ratio
PLAT431_ALERT_2_C Short Inter HL..A Contact  Cl1    ..  O7      ..       3.04 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  O5     ..  C14     ..       2.99 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  O7     ..  C12     ..       2.96 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  O12    ..  C9      ..       2.98 Ang.

   0 ALERT level A = In general: serious problem
   4 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   8 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.

4-Chloro-3,5-dinitrobenzoic acid

Crystal data

C7H3ClN2O6	Z = 4
Mr = 246.56	F(000) = 496
Triclinic, P1	Dx = 1.817 Mg m^−3
a = 7.9200 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.1507 (10) Å	Cell parameters from 2505 reflections
c = 11.6802 (10) Å	θ = 0.0–0.0°
α = 111.335 (2)°	µ = 0.44 mm^−1
β = 100.217 (2)°	T = 100 K
γ = 102.314 (1)°	Irregular, colourless
V = 901.13 (14) Å^3	0.35 × 0.35 × 0.30 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2981 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.041
Graphite monochromator	θmax = 26.4°, θmin = 2.0°
φ and ω scans	h = −9→9
5255 measured reflections	k = −13→13
3592 independent reflections	l = −14→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.086	H atoms treated by a mixture of independent and constrained refinement
S = 0.97	w = 1/[σ^2(Fo^2) + (0.0435P)^2] where P = (Fo^2 + 2Fc^2)/3
3592 reflections	(Δ/σ)max = 0.001
297 parameters	Δρmax = 0.38 e Å^−3
2 restraints	Δρmin = −0.26 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	−0.34591 (7)	0.20724 (5)	0.76512 (5)	0.02119 (14)
O1	−0.1967 (2)	0.11834 (16)	0.54645 (14)	0.0304 (4)
O2	−0.14972 (18)	−0.07246 (13)	0.52392 (13)	0.0214 (3)
O3	0.38423 (19)	0.01195 (14)	0.85919 (13)	0.0189 (3)
H3O	0.464 (3)	−0.015 (2)	0.885 (2)	0.041 (8)*
O4	0.35018 (18)	0.07275 (13)	1.05763 (12)	0.0184 (3)
O5	−0.1417 (2)	0.40554 (15)	1.04710 (15)	0.0334 (4)
O6	−0.2076 (2)	0.24529 (15)	1.10879 (14)	0.0287 (4)
N1	−0.1490 (2)	0.04338 (17)	0.58900 (16)	0.0181 (4)
N2	−0.1498 (2)	0.29202 (16)	1.04021 (16)	0.0189 (4)
C1	−0.1544 (3)	0.16999 (18)	0.81383 (18)	0.0149 (4)
C2	−0.0753 (3)	0.09295 (18)	0.72857 (18)	0.0152 (4)
C3	0.0748 (3)	0.05976 (18)	0.76973 (18)	0.0143 (4)
H3	0.1282	0.0100	0.7095	0.017*
C4	0.1478 (3)	0.09951 (18)	0.89994 (18)	0.0144 (4)
C5	0.0690 (3)	0.17254 (18)	0.98711 (18)	0.0159 (4)
H5	0.1148	0.1972	1.0761	0.019*
C6	−0.0763 (3)	0.20864 (18)	0.94269 (18)	0.0167 (4)
C7	0.3052 (3)	0.05988 (18)	0.94688 (18)	0.0148 (4)
Cl2	0.18201 (6)	0.53034 (5)	0.33150 (4)	0.01805 (13)
O7	0.50481 (19)	0.74970 (14)	0.46865 (13)	0.0237 (3)
O8	0.5217 (2)	0.86599 (14)	0.66679 (14)	0.0264 (4)
O9	0.53968 (18)	0.60449 (13)	0.93008 (12)	0.0204 (3)
O10	0.3536 (2)	0.39179 (13)	0.83975 (14)	0.0195 (3)
H10O	0.388 (4)	0.396 (3)	0.9106 (18)	0.058 (10)*
O11	0.13328 (19)	0.23531 (13)	0.29766 (12)	0.0205 (3)
O12	−0.08309 (18)	0.25159 (13)	0.38819 (13)	0.0220 (3)
N3	0.47820 (19)	0.76366 (14)	0.57138 (13)	0.0084 (3)
N4	0.0701 (2)	0.29014 (15)	0.38429 (15)	0.0148 (3)
C8	0.2640 (3)	0.52637 (18)	0.47558 (17)	0.0132 (4)
C9	0.3894 (3)	0.63549 (18)	0.58137 (18)	0.0138 (4)
C10	0.4404 (2)	0.63020 (18)	0.69843 (17)	0.0137 (4)
H10	0.5253	0.7063	0.7690	0.016*
C11	0.3675 (3)	0.51344 (18)	0.71297 (17)	0.0132 (4)
C12	0.2418 (3)	0.40315 (18)	0.61020 (17)	0.0142 (4)
H12	0.1890	0.3235	0.6194	0.017*
C13	0.1951 (2)	0.41144 (18)	0.49483 (17)	0.0134 (4)
C14	0.4283 (3)	0.50795 (19)	0.83826 (18)	0.0160 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0183 (3)	0.0266 (3)	0.0273 (3)	0.0124 (2)	0.0078 (2)	0.0169 (2)
O1	0.0378 (10)	0.0426 (10)	0.0275 (9)	0.0269 (8)	0.0125 (7)	0.0232 (8)
O2	0.0206 (8)	0.0190 (8)	0.0185 (7)	0.0011 (6)	0.0043 (6)	0.0045 (6)
O3	0.0186 (8)	0.0248 (8)	0.0198 (8)	0.0131 (6)	0.0074 (6)	0.0118 (6)
O4	0.0196 (8)	0.0190 (7)	0.0152 (7)	0.0084 (6)	0.0020 (6)	0.0054 (6)
O5	0.0458 (11)	0.0194 (8)	0.0417 (10)	0.0170 (8)	0.0207 (8)	0.0125 (7)
O6	0.0370 (10)	0.0278 (8)	0.0280 (9)	0.0137 (7)	0.0193 (7)	0.0121 (7)
N1	0.0136 (9)	0.0237 (9)	0.0179 (9)	0.0048 (7)	0.0057 (7)	0.0095 (8)
N2	0.0183 (9)	0.0180 (9)	0.0185 (9)	0.0084 (7)	0.0035 (7)	0.0048 (7)
C1	0.0128 (10)	0.0133 (9)	0.0210 (10)	0.0042 (8)	0.0041 (8)	0.0100 (8)
C2	0.0152 (10)	0.0139 (10)	0.0164 (10)	0.0020 (8)	0.0032 (8)	0.0081 (8)
C3	0.0154 (10)	0.0109 (9)	0.0171 (10)	0.0035 (8)	0.0057 (8)	0.0062 (8)
C4	0.0135 (10)	0.0107 (9)	0.0174 (10)	0.0026 (8)	0.0039 (8)	0.0050 (8)
C5	0.0172 (10)	0.0135 (10)	0.0157 (10)	0.0038 (8)	0.0034 (8)	0.0056 (8)
C6	0.0192 (11)	0.0125 (10)	0.0200 (11)	0.0053 (8)	0.0088 (8)	0.0065 (8)
C7	0.0147 (10)	0.0098 (9)	0.0170 (10)	0.0017 (8)	0.0028 (8)	0.0043 (8)
Cl2	0.0216 (3)	0.0170 (2)	0.0145 (2)	0.0045 (2)	0.00070 (19)	0.0082 (2)
O7	0.0235 (8)	0.0254 (8)	0.0230 (8)	0.0056 (6)	0.0061 (6)	0.0122 (7)
O8	0.0310 (9)	0.0188 (8)	0.0252 (9)	0.0054 (7)	0.0047 (7)	0.0071 (7)
O9	0.0224 (8)	0.0176 (7)	0.0161 (7)	0.0005 (6)	−0.0014 (6)	0.0077 (6)
O10	0.0273 (8)	0.0148 (7)	0.0142 (8)	0.0039 (6)	0.0007 (6)	0.0074 (6)
O11	0.0270 (8)	0.0172 (7)	0.0154 (7)	0.0058 (6)	0.0075 (6)	0.0047 (6)
O12	0.0145 (8)	0.0201 (8)	0.0257 (8)	0.0029 (6)	0.0023 (6)	0.0061 (6)
N3	0.0062 (7)	0.0113 (8)	0.0070 (8)	0.0043 (6)	0.0008 (6)	0.0029 (7)
N4	0.0196 (9)	0.0106 (8)	0.0142 (9)	0.0046 (7)	0.0023 (7)	0.0062 (7)
C8	0.0141 (10)	0.0139 (9)	0.0127 (9)	0.0067 (8)	0.0037 (8)	0.0053 (8)
C9	0.0150 (10)	0.0125 (9)	0.0164 (10)	0.0078 (8)	0.0062 (8)	0.0058 (8)
C10	0.0128 (10)	0.0125 (9)	0.0135 (10)	0.0058 (8)	0.0032 (8)	0.0020 (8)
C11	0.0153 (10)	0.0149 (9)	0.0128 (9)	0.0087 (8)	0.0054 (8)	0.0065 (8)
C12	0.0145 (10)	0.0123 (9)	0.0178 (10)	0.0056 (8)	0.0061 (8)	0.0071 (8)
C13	0.0113 (10)	0.0125 (9)	0.0138 (10)	0.0040 (8)	0.0022 (7)	0.0030 (8)
C14	0.0178 (10)	0.0170 (10)	0.0157 (10)	0.0084 (8)	0.0050 (8)	0.0078 (9)

Geometric parameters (Å, º)

Cl1—C1	1.7124 (19)	Cl2—C8	1.7130 (19)
O1—N1	1.208 (2)	O7—N3	1.2151 (19)
O2—N1	1.236 (2)	O8—N3	1.1972 (19)
O3—C7	1.303 (2)	O9—C14	1.227 (2)
O3—H3O	0.811 (16)	O10—C14	1.312 (2)
O4—C7	1.225 (2)	O10—H10O	0.804 (17)
O5—N2	1.226 (2)	O11—N4	1.2278 (19)
O6—N2	1.206 (2)	O12—N4	1.213 (2)
N1—C2	1.474 (2)	N3—C9	1.508 (2)
N2—C6	1.482 (2)	N4—C13	1.477 (2)
C1—C6	1.385 (3)	C8—C13	1.395 (3)
C1—C2	1.396 (3)	C8—C9	1.396 (3)
C2—C3	1.377 (3)	C9—C10	1.382 (3)
C3—C4	1.390 (3)	C10—C11	1.390 (3)
C3—H3	0.9500	C10—H10	0.9500
C4—C5	1.388 (3)	C11—C12	1.387 (3)
C4—C7	1.489 (3)	C11—C14	1.485 (2)
C5—C6	1.376 (3)	C12—C13	1.375 (2)
C5—H5	0.9500	C12—H12	0.9500
C7—O3—H3O	111.2 (18)	C14—O10—H10O	109 (2)
O1—N1—O2	125.02 (17)	O8—N3—O7	127.68 (16)
O1—N1—C2	119.01 (17)	O8—N3—C9	116.45 (15)
O2—N1—C2	115.90 (15)	O7—N3—C9	115.77 (14)
O6—N2—O5	125.10 (17)	O12—N4—O11	125.87 (16)
O6—N2—C6	118.06 (16)	O12—N4—C13	117.74 (15)
O5—N2—C6	116.81 (16)	O11—N4—C13	116.36 (16)
C6—C1—C2	116.33 (17)	C13—C8—C9	116.00 (17)
C6—C1—Cl1	120.44 (15)	C13—C8—Cl2	119.55 (14)
C2—C1—Cl1	123.09 (15)	C9—C8—Cl2	124.30 (14)
C3—C2—C1	122.17 (18)	C10—C9—C8	121.87 (17)
C3—C2—N1	116.58 (16)	C10—C9—N3	117.13 (16)
C1—C2—N1	121.25 (17)	C8—C9—N3	120.98 (16)
C2—C3—C4	119.58 (17)	C9—C10—C11	119.99 (17)
C2—C3—H3	120.2	C9—C10—H10	120.0
C4—C3—H3	120.2	C11—C10—H10	120.0
C5—C4—C3	119.71 (17)	C12—C11—C10	119.82 (17)
C5—C4—C7	119.48 (17)	C12—C11—C14	120.92 (17)
C3—C4—C7	120.76 (17)	C10—C11—C14	119.26 (17)
C6—C5—C4	119.00 (18)	C13—C12—C11	118.68 (17)
C6—C5—H5	120.5	C13—C12—H12	120.7
C4—C5—H5	120.5	C11—C12—H12	120.7
C5—C6—C1	123.11 (18)	C12—C13—C8	123.62 (17)
C5—C6—N2	116.78 (17)	C12—C13—N4	117.99 (15)
C1—C6—N2	120.10 (17)	C8—C13—N4	118.35 (16)
O4—C7—O3	125.66 (18)	O9—C14—O10	124.39 (17)
O4—C7—C4	121.18 (17)	O9—C14—C11	121.76 (17)
O3—C7—C4	113.16 (16)	O10—C14—C11	113.84 (16)
C6—C1—C2—C3	−1.6 (3)	C13—C8—C9—C10	−0.7 (3)
Cl1—C1—C2—C3	−177.44 (14)	Cl2—C8—C9—C10	174.79 (14)
C6—C1—C2—N1	178.63 (16)	C13—C8—C9—N3	177.92 (16)
Cl1—C1—C2—N1	2.8 (3)	Cl2—C8—C9—N3	−6.6 (2)
O1—N1—C2—C3	−137.19 (18)	O8—N3—C9—C10	−30.9 (2)
O2—N1—C2—C3	39.9 (2)	O7—N3—C9—C10	145.66 (17)
O1—N1—C2—C1	42.6 (3)	O8—N3—C9—C8	150.37 (17)
O2—N1—C2—C1	−140.32 (18)	O7—N3—C9—C8	−33.0 (2)
C1—C2—C3—C4	2.3 (3)	C8—C9—C10—C11	0.6 (3)
N1—C2—C3—C4	−177.92 (16)	N3—C9—C10—C11	−178.12 (15)
C2—C3—C4—C5	−0.2 (3)	C9—C10—C11—C12	−0.9 (3)
C2—C3—C4—C7	177.28 (17)	C9—C10—C11—C14	178.02 (17)
C3—C4—C5—C6	−2.5 (3)	C10—C11—C12—C13	1.4 (3)
C7—C4—C5—C6	−179.99 (16)	C14—C11—C12—C13	−177.50 (17)
C4—C5—C6—C1	3.3 (3)	C11—C12—C13—C8	−1.6 (3)
C4—C5—C6—N2	−177.18 (17)	C11—C12—C13—N4	176.11 (16)
C2—C1—C6—C5	−1.2 (3)	C9—C8—C13—C12	1.3 (3)
Cl1—C1—C6—C5	174.73 (15)	Cl2—C8—C13—C12	−174.46 (14)
C2—C1—C6—N2	179.24 (17)	C9—C8—C13—N4	−176.45 (15)
Cl1—C1—C6—N2	−4.8 (2)	Cl2—C8—C13—N4	7.8 (2)
O6—N2—C6—C5	−61.1 (2)	O12—N4—C13—C12	66.2 (2)
O5—N2—C6—C5	116.8 (2)	O11—N4—C13—C12	−111.99 (19)
O6—N2—C6—C1	118.5 (2)	O12—N4—C13—C8	−115.96 (19)
O5—N2—C6—C1	−63.6 (2)	O11—N4—C13—C8	65.9 (2)
C5—C4—C7—O4	10.8 (3)	C12—C11—C14—O9	179.82 (17)
C3—C4—C7—O4	−166.67 (17)	C10—C11—C14—O9	0.9 (3)
C5—C4—C7—O3	−169.32 (17)	C12—C11—C14—O10	0.4 (3)
C3—C4—C7—O3	13.2 (2)	C10—C11—C14—O10	−178.44 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3O···O4^i	0.81 (2)	1.85 (2)	2.6553 (19)	178 (3)
O10—H10O···O9^ii	0.80 (2)	1.85 (2)	2.6537 (19)	176 (3)
C5—H5···O11^iii	0.95	2.44	3.354 (2)	162
C10—H10···O4^ii	0.95	2.40	3.310 (2)	160

Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+1, −y+1, −z+2; (iii) x, y, z+1.