4-Nitro­aniline: a redetermination

The occurrence of N—H...O and C—H...O hydrogen bonds in the title compound, C₆H₆N₂O₂, results in the formation of two-dimensional sheets parallel to the (101) plane.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.033
• wR factor = 0.095
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O2     -   N1      ..       6.95 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    N1     -   C1      ..       6.75 su

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 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
   0 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, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL.

4-nitroaniline

Crystal data

C6H6N2O2	F(000) = 288
Mr = 138.13	Dx = 1.430 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1869 reflections
a = 8.601 (1) Å	θ = 2.7–28.1°
b = 6.043 (1) Å	µ = 0.11 mm^−1
c = 12.352 (2) Å	T = 298 K
β = 91.43 (3)°	Block, colorless
V = 641.81 (17) Å^3	0.30 × 0.23 × 0.18 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	1334 independent reflections
Radiation source: fine-focus sealed tube	1010 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
ω scans	θmax = 26.5°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
Tmin = 0.968, Tmax = 0.980	k = −7→7
4953 measured reflections	l = −15→14

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.095	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.041P)^2 + 0.0481P] where P = (Fo^2 + 2Fc^2)/3
1334 reflections	(Δ/σ)max = 0.001
91 parameters	Δρmax = 0.14 e Å^−3
0 restraints	Δρmin = −0.12 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	0.13518 (12)	0.12030 (18)	1.07067 (8)	0.0798 (3)
O2	0.27899 (12)	0.40842 (16)	1.05394 (8)	0.0771 (4)
N1	0.24026 (11)	0.21968 (18)	1.02619 (8)	0.0546 (3)
N2	0.54929 (14)	−0.1791 (2)	0.68754 (9)	0.0763 (4)
H2A	0.5222	−0.3085	0.6650	0.092*
H2B	0.6239	−0.1100	0.6571	0.092*
C1	0.32067 (12)	0.11439 (18)	0.93955 (9)	0.0442 (3)
C2	0.27604 (14)	−0.09554 (18)	0.90513 (10)	0.0497 (3)
H2	0.1950	−0.1690	0.9383	0.060*
C3	0.35252 (13)	−0.19298 (19)	0.82193 (10)	0.0524 (3)
H3	0.3231	−0.3337	0.7989	0.063*
C4	0.47456 (13)	−0.0844 (2)	0.77078 (10)	0.0512 (3)
C5	0.51814 (14)	0.1269 (2)	0.80791 (10)	0.0521 (3)
H5	0.5995	0.2011	0.7754	0.062*
C6	0.44237 (13)	0.22455 (19)	0.89115 (9)	0.0477 (3)
H6	0.4722	0.3644	0.9154	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0764 (6)	0.0864 (7)	0.0780 (7)	−0.0224 (5)	0.0336 (5)	−0.0069 (5)
O2	0.0841 (7)	0.0619 (6)	0.0864 (7)	−0.0141 (5)	0.0241 (5)	−0.0223 (5)
N1	0.0529 (6)	0.0585 (7)	0.0527 (6)	−0.0050 (5)	0.0062 (5)	0.0015 (5)
N2	0.0780 (8)	0.0774 (8)	0.0744 (8)	−0.0006 (6)	0.0196 (6)	−0.0184 (6)
C1	0.0439 (6)	0.0453 (6)	0.0434 (6)	−0.0013 (5)	0.0004 (5)	0.0035 (5)
C2	0.0491 (6)	0.0469 (6)	0.0530 (7)	−0.0087 (5)	0.0001 (5)	0.0083 (5)
C3	0.0586 (7)	0.0411 (6)	0.0573 (7)	−0.0031 (5)	−0.0049 (6)	−0.0003 (5)
C4	0.0490 (7)	0.0543 (7)	0.0501 (7)	0.0059 (5)	−0.0020 (5)	−0.0003 (5)
C5	0.0455 (6)	0.0576 (7)	0.0533 (7)	−0.0073 (5)	0.0052 (5)	0.0044 (5)
C6	0.0489 (6)	0.0438 (6)	0.0502 (7)	−0.0075 (5)	−0.0016 (5)	0.0025 (5)

Geometric parameters (Å, º)

O1—N1	1.2265 (13)	C2—C3	1.3672 (17)
O2—N1	1.2343 (13)	C2—H2	0.9300
N1—C1	1.4371 (15)	C3—C4	1.4017 (17)
N2—C4	1.3531 (16)	C3—H3	0.9300
N2—H2A	0.8600	C4—C5	1.4047 (17)
N2—H2B	0.8600	C5—C6	1.3651 (17)
C1—C6	1.3884 (16)	C5—H5	0.9300
C1—C2	1.3890 (16)	C6—H6	0.9300
O1—N1—O2	121.65 (11)	C2—C3—C4	121.13 (11)
O1—N1—C1	119.37 (11)	C2—C3—H3	119.4
O2—N1—C1	118.97 (10)	C4—C3—H3	119.4
C4—N2—H2A	120.0	N2—C4—C3	121.32 (12)
C4—N2—H2B	120.0	N2—C4—C5	120.31 (12)
H2A—N2—H2B	120.0	C3—C4—C5	118.37 (11)
C6—C1—C2	120.78 (11)	C6—C5—C4	120.69 (11)
C6—C1—N1	119.36 (10)	C6—C5—H5	119.7
C2—C1—N1	119.86 (10)	C4—C5—H5	119.7
C3—C2—C1	119.27 (11)	C5—C6—C1	119.76 (11)
C3—C2—H2	120.4	C5—C6—H6	120.1
C1—C2—H2	120.4	C1—C6—H6	120.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O1^i	0.86	2.43	3.1290 (17)	139
N2—H2B···O2^ii	0.86	2.23	3.0765 (17)	168
C6—H6···O2^iii	0.93	2.56	3.3229 (17)	139
C3—H3···Cg1^iv	0.93	2.81	3.5103 (15)	133

Symmetry codes: (i) x+1/2, −y−1/2, z−1/2; (ii) x+1/2, −y+1/2, z−1/2; (iii) −x+1, −y+1, −z+2; (iv) −x+1/2, y−1/2, −z+3/2.