2-(2-Methyl-3-nitro­phen­yl)acetic acid

In the crystal structure of the title compound, C₉H₉NO₄, inter­molecular O—H...O hydrogen bonds link the mol­ecules into centrosymmetric dimers.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.047
• wR factor = 0.117
• Data-to-parameter ratio = 13.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT030_ALERT_1_C _diffrn_reflns_number .LE.  _reflns_number_total          ?
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal (x 10000)        3000 Deg.
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         C1

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 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: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL.

2-(2-Methyl-3-nitrophenyl)acetic acid

Crystal data

C9H9NO4	Z = 2
Mr = 195.17	F(000) = 204
Triclinic, P1	Dx = 1.434 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2250 (14) Å	Cell parameters from 25 reflections
b = 8.2220 (16) Å	θ = 10–14°
c = 8.6470 (17) Å	µ = 0.11 mm^−1
α = 74.21 (3)°	T = 294 K
β = 75.65 (3)°	Block, colourless
γ = 67.96 (3)°	0.30 × 0.20 × 0.10 mm
V = 452.01 (19) Å^3

Data collection

Enraf–Nonius CAD-4 diffractometer	1263 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 26.0°, θmin = 2.5°
ω/2θ scans	h = −8→8
Absorption correction: ψ scan (North et al., 1968)	k = −9→10
Tmin = 0.944, Tmax = 0.987	l = 0→10
1767 measured reflections	3 standard reflections every 120 min
1767 independent reflections	intensity decay: none

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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.05P)^2 + 0.08P] where P = (Fo^2 + 2Fc^2)/3
1767 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.17 e Å^−3
0 restraints	Δρmin = −0.17 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
O1	0.5191 (3)	0.1679 (2)	0.2384 (2)	0.0769 (6)
O2	0.2996 (3)	0.0797 (2)	0.4254 (2)	0.0712 (5)
O3	0.2238 (2)	1.08223 (19)	0.04882 (19)	0.0569 (4)
H3A	0.3225	1.1099	−0.0037	0.085*
O4	0.4596 (2)	0.82312 (18)	0.12413 (16)	0.0461 (4)
N	0.3797 (3)	0.1920 (2)	0.3506 (2)	0.0510 (5)
C1	0.2225 (4)	0.5275 (3)	0.1222 (3)	0.0565 (6)
H1A	0.2695	0.4073	0.1042	0.085*
H1B	0.3031	0.5936	0.0460	0.085*
H1C	0.0836	0.5841	0.1074	0.085*
C2	0.2403 (3)	0.5234 (3)	0.2928 (2)	0.0388 (5)
C3	0.3051 (3)	0.3641 (3)	0.4046 (2)	0.0397 (5)
C4	0.3126 (3)	0.3528 (3)	0.5642 (2)	0.0439 (5)
H4A	0.3540	0.2422	0.6337	0.053*
C5	0.2575 (3)	0.5090 (3)	0.6185 (3)	0.0483 (5)
H5A	0.2629	0.5061	0.7256	0.058*
C6	0.1937 (3)	0.6708 (3)	0.5121 (3)	0.0475 (5)
H6A	0.1568	0.7765	0.5492	0.057*
C7	0.1831 (3)	0.6802 (3)	0.3524 (2)	0.0403 (5)
C8	0.1130 (3)	0.8621 (3)	0.2426 (3)	0.0491 (5)
H8A	0.0243	0.8595	0.1761	0.059*
H8B	0.0352	0.9506	0.3094	0.059*
C9	0.2843 (3)	0.9180 (2)	0.1332 (2)	0.0398 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0919 (14)	0.0610 (11)	0.0662 (12)	−0.0179 (10)	0.0073 (11)	−0.0227 (9)
O2	0.0813 (13)	0.0402 (9)	0.0970 (14)	−0.0300 (9)	−0.0180 (10)	−0.0045 (9)
O3	0.0517 (9)	0.0406 (8)	0.0665 (10)	−0.0135 (7)	−0.0144 (8)	0.0102 (7)
O4	0.0456 (9)	0.0372 (8)	0.0484 (9)	−0.0123 (7)	−0.0085 (7)	0.0014 (6)
N	0.0596 (12)	0.0392 (10)	0.0550 (12)	−0.0146 (9)	−0.0176 (10)	−0.0056 (9)
C1	0.0682 (16)	0.0533 (14)	0.0489 (14)	−0.0194 (12)	−0.0183 (12)	−0.0045 (10)
C2	0.0364 (11)	0.0387 (11)	0.0423 (11)	−0.0165 (8)	−0.0070 (8)	−0.0031 (9)
C3	0.0400 (11)	0.0365 (11)	0.0454 (12)	−0.0169 (9)	−0.0073 (9)	−0.0064 (9)
C4	0.0451 (12)	0.0444 (12)	0.0421 (12)	−0.0198 (9)	−0.0096 (9)	0.0010 (9)
C5	0.0477 (13)	0.0613 (14)	0.0395 (12)	−0.0229 (11)	−0.0045 (10)	−0.0112 (10)
C6	0.0423 (12)	0.0488 (13)	0.0556 (14)	−0.0196 (10)	0.0008 (10)	−0.0185 (11)
C7	0.0345 (11)	0.0376 (11)	0.0480 (12)	−0.0148 (8)	−0.0043 (9)	−0.0054 (9)
C8	0.0453 (12)	0.0352 (11)	0.0624 (14)	−0.0124 (9)	−0.0077 (10)	−0.0051 (10)
C9	0.0482 (13)	0.0305 (10)	0.0418 (11)	−0.0121 (9)	−0.0127 (9)	−0.0053 (8)

Geometric parameters (Å, º)

O1—N	1.210 (2)	C3—C4	1.371 (3)
O2—N	1.223 (2)	C4—C5	1.371 (3)
O3—C9	1.314 (2)	C4—H4A	0.9300
O3—H3A	0.8200	C5—C6	1.383 (3)
O4—C9	1.209 (2)	C5—H5A	0.9300
N—C3	1.474 (3)	C6—C7	1.382 (3)
C1—C2	1.503 (3)	C6—H6A	0.9300
C1—H1A	0.9600	C7—C8	1.514 (3)
C1—H1B	0.9600	C8—C9	1.499 (3)
C1—H1C	0.9600	C8—H8A	0.9700
C2—C3	1.394 (3)	C8—H8B	0.9700
C2—C7	1.398 (3)
C9—O3—H3A	109.5	C4—C5—C6	119.2 (2)
O1—N—O2	123.8 (2)	C4—C5—H5A	120.4
O1—N—C3	118.61 (19)	C6—C5—H5A	120.4
O2—N—C3	117.6 (2)	C7—C6—C5	122.0 (2)
C2—C1—H1A	109.5	C7—C6—H6A	119.0
C2—C1—H1B	109.5	C5—C6—H6A	119.0
H1A—C1—H1B	109.5	C6—C7—C2	120.16 (19)
C2—C1—H1C	109.5	C6—C7—C8	119.10 (19)
H1A—C1—H1C	109.5	C2—C7—C8	120.72 (19)
H1B—C1—H1C	109.5	C9—C8—C7	113.07 (17)
C3—C2—C7	115.49 (18)	C9—C8—H8A	109.0
C3—C2—C1	122.59 (18)	C7—C8—H8A	109.0
C7—C2—C1	121.85 (18)	C9—C8—H8B	109.0
C4—C3—C2	124.93 (19)	C7—C8—H8B	109.0
C4—C3—N	115.59 (18)	H8A—C8—H8B	107.8
C2—C3—N	119.43 (18)	O4—C9—O3	123.43 (19)
C5—C4—C3	118.18 (19)	O4—C9—C8	123.84 (18)
C5—C4—H4A	120.9	O3—C9—C8	112.72 (17)
C3—C4—H4A	120.9
C7—C2—C3—C4	1.0 (3)	C4—C5—C6—C7	0.2 (3)
C1—C2—C3—C4	−176.0 (2)	C5—C6—C7—C2	−0.8 (3)
C7—C2—C3—N	−176.45 (17)	C5—C6—C7—C8	−179.65 (19)
C1—C2—C3—N	6.6 (3)	C3—C2—C7—C6	0.2 (3)
O1—N—C3—C4	−121.1 (2)	C1—C2—C7—C6	177.27 (19)
O2—N—C3—C4	57.0 (3)	C3—C2—C7—C8	179.03 (18)
O1—N—C3—C2	56.6 (3)	C1—C2—C7—C8	−3.9 (3)
O2—N—C3—C2	−125.3 (2)	C6—C7—C8—C9	99.6 (2)
C2—C3—C4—C5	−1.7 (3)	C2—C7—C8—C9	−79.2 (2)
N—C3—C4—C5	175.88 (18)	C7—C8—C9—O4	5.2 (3)
C3—C4—C5—C6	1.0 (3)	C7—C8—C9—O3	−174.32 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···O4^i	0.82	1.84	2.661 (2)	179

Symmetry code: (i) −x+1, −y+2, −z.