4-Meth­oxy-2-nitro­aniline

The title mol­ecule, C₇H₈N₂O₃, lies on a mirror plane with two of the methyl H atoms related by mirror symmetry. The crystal structure is stabilized by inter­molecular N—H...O and C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.001 Å
• R factor = 0.033
• wR factor = 0.104
• Data-to-parameter ratio = 13.6

checkCIF/PLATON results

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Alert level C
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          2

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 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: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).

4-Methoxy-2-nitroaniline

Crystal data

C7H8N2O3	F(000) = 352
Mr = 168.15	Dx = 1.533 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 6881 reflections
a = 16.0264 (4) Å	θ = 3.1–31.5°
b = 6.3621 (1) Å	µ = 0.12 mm^−1
c = 7.1476 (1) Å	T = 100 K
V = 728.78 (2) Å^3	Block, orange
Z = 4	0.34 × 0.25 × 0.20 mm

Data collection

Bruker SMART APEX2 CCD area-detector diffractometer	1309 independent reflections
Radiation source: fine-focus sealed tube	1180 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
Detector resolution: 8.33 pixels mm^-1	θmax = 31.5°, θmin = 2.5°
ω scans	h = −23→19
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −9→9
Tmin = 0.873, Tmax = 0.976	l = −10→10
13427 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.033	All H-atom parameters refined
wR(F^2) = 0.104	w = 1/[σ^2(Fo^2) + (0.0635P)^2 + 0.1408P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.001
1309 reflections	Δρmax = 0.48 e Å^−3
96 parameters	Δρmin = −0.32 e Å^−3
0 restraints	Extinction correction: SHELXTL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.007 (2)

Special details

Experimental. The data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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	0.22454 (5)	0.2500	0.04740 (10)	0.0189 (2)
O2	−0.14739 (5)	0.2500	0.04473 (10)	0.01630 (19)
O3	−0.06370 (5)	0.2500	−0.19445 (10)	0.0167 (2)
N1	−0.08706 (6)	0.2500	0.38846 (13)	0.0185 (2)
N2	−0.07577 (6)	0.2500	−0.02280 (12)	0.01222 (19)
C1	0.07425 (6)	0.2500	0.01093 (14)	0.0127 (2)
C2	0.14517 (6)	0.2500	0.11742 (14)	0.0138 (2)
C3	0.13835 (7)	0.2500	0.31515 (14)	0.0162 (2)
C4	0.06169 (7)	0.2500	0.39880 (14)	0.0155 (2)
C5	−0.01407 (7)	0.2500	0.29468 (13)	0.0129 (2)
C6	−0.00489 (6)	0.2500	0.09861 (13)	0.0115 (2)
C7	0.23146 (7)	0.2500	−0.15234 (16)	0.0198 (2)
H1	0.0768 (11)	0.2500	−0.127 (3)	0.028 (4)*
H3	0.1884 (12)	0.2500	0.394 (3)	0.027 (4)*
H4	0.0587 (12)	0.2500	0.539 (3)	0.028 (5)*
H7A	0.2857 (13)	0.2500	−0.174 (2)	0.030 (5)*
H7B	0.2050 (8)	0.3748 (19)	−0.2047 (15)	0.027 (3)*
H1N1	−0.1341 (13)	0.2500	0.331 (3)	0.031 (5)*
H1N2	−0.0833 (12)	0.2500	0.501 (3)	0.031 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0095 (4)	0.0330 (4)	0.0140 (4)	0.000	0.0012 (3)	0.000
O2	0.0085 (4)	0.0242 (4)	0.0162 (4)	0.000	0.0013 (3)	0.000
O3	0.0155 (4)	0.0260 (4)	0.0086 (3)	0.000	−0.0010 (3)	0.000
N1	0.0127 (4)	0.0324 (5)	0.0103 (4)	0.000	0.0016 (3)	0.000
N2	0.0114 (4)	0.0147 (4)	0.0106 (4)	0.000	−0.0002 (3)	0.000
C1	0.0111 (5)	0.0167 (4)	0.0103 (4)	0.000	0.0001 (3)	0.000
C2	0.0094 (4)	0.0186 (4)	0.0134 (4)	0.000	0.0010 (3)	0.000
C3	0.0136 (5)	0.0224 (5)	0.0127 (4)	0.000	−0.0029 (3)	0.000
C4	0.0143 (5)	0.0223 (5)	0.0099 (4)	0.000	−0.0014 (3)	0.000
C5	0.0125 (5)	0.0160 (4)	0.0103 (4)	0.000	0.0008 (3)	0.000
C6	0.0095 (4)	0.0149 (4)	0.0100 (4)	0.000	−0.0017 (3)	0.000
C7	0.0127 (5)	0.0320 (6)	0.0147 (5)	0.000	0.0029 (4)	0.000

Geometric parameters (Å, º)

O1—C2	1.3669 (13)	C1—H1	0.98 (2)
O1—C7	1.4320 (13)	C2—C3	1.4175 (14)
O2—N2	1.2451 (12)	C3—C4	1.3664 (15)
O3—N2	1.2420 (11)	C3—H3	0.980 (19)
N1—C5	1.3483 (13)	C4—C5	1.4240 (15)
N1—H1N1	0.86 (2)	C4—H4	1.007 (19)
N1—H1N2	0.81 (2)	C5—C6	1.4091 (13)
N2—C6	1.4295 (13)	C7—H7A	0.88 (2)
C1—C2	1.3678 (14)	C7—H7B	0.975 (12)
C1—C6	1.4147 (14)
C2—O1—C7	115.92 (8)	C4—C3—H3	118.9 (10)
C5—N1—H1N1	121.7 (13)	C2—C3—H3	120.7 (10)
C5—N1—H1N2	115.5 (13)	C3—C4—C5	122.54 (9)
H1N1—N1—H1N2	122.8 (19)	C3—C4—H4	118.7 (11)
O3—N2—O2	121.77 (9)	C5—C4—H4	118.7 (11)
O3—N2—C6	118.42 (9)	N1—C5—C6	125.81 (10)
O2—N2—C6	119.82 (8)	N1—C5—C4	118.68 (9)
C2—C1—C6	119.90 (9)	C6—C5—C4	115.52 (9)
C2—C1—H1	121.4 (10)	C5—C6—C1	122.29 (9)
C6—C1—H1	118.7 (10)	C5—C6—N2	121.38 (9)
O1—C2—C1	124.71 (9)	C1—C6—N2	116.33 (9)
O1—C2—C3	115.90 (9)	O1—C7—H7A	104.6 (11)
C1—C2—C3	119.39 (10)	O1—C7—H7B	110.4 (7)
C4—C3—C2	120.37 (10)	H7A—C7—H7B	111.1 (9)
C7—O1—C2—C1	0.0	C4—C5—C6—C1	0.0
C7—O1—C2—C3	180.0	N1—C5—C6—N2	0.0
C6—C1—C2—O1	180.0	C4—C5—C6—N2	180.0
C6—C1—C2—C3	0.0	C2—C1—C6—C5	0.0
O1—C2—C3—C4	180.0	C2—C1—C6—N2	180.0
C1—C2—C3—C4	0.0	O3—N2—C6—C5	180.0
C2—C3—C4—C5	0.0	O2—N2—C6—C5	0.0
C3—C4—C5—N1	180.0	O3—N2—C6—C1	0.0
C3—C4—C5—C6	0.0	O2—N2—C6—C1	180.0
N1—C5—C6—C1	180.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O2	0.86 (2)	2.06 (2)	2.640 (1)	125 (2)
N1—H1N1···O1^i	0.86 (2)	2.43 (2)	3.054 (1)	130 (2)
N1—H1N2···O3^ii	0.81 (2)	2.20 (2)	3.005 (1)	176 (2)
C7—H7A···O3^iii	0.88 (2)	2.59 (2)	3.461 (1)	169 (1)

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