5-Bromo-1H-indole-2,3-dione

The title compound, C₈H₄BrNO₂, has a single, almost planar, planar mol­ecule in the asymmetric unit, with the non-H atoms having a mean deviation from planarity of 0.024 Å. In the crystal, N—H...O hydrogen bonds link the molecules into [001] C(4) chains. C—H...O inter­actions form [0-11] chains. These interactions combine to generate sheets along (100). No π–π inter­actions are observed in the structure.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.025
• wR factor = 0.054
• Data-to-parameter ratio = 11.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT090_ALERT_3_C Poor Data / Parameter Ratio (Zmax > 18) ........       6.66 Note
PLAT341_ALERT_3_C Low Bond Precision on  C-C Bonds ...............      0.008 Ang.
PLAT369_ALERT_2_C Long    C(sp2)-C(sp2) Bond  C1     -   C2     ..       1.56 Ang.
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          3 Report

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          2 Note
PLAT172_ALERT_4_G The CIF-Embedded .res File Contains DFIX Records          1 Report
PLAT432_ALERT_2_G Short Inter X...Y Contact  O1     ..  C2      ..       2.77 Ang.
PLAT860_ALERT_3_G Number of Least-Squares Restraints .............          2 Note
PLAT870_ALERT_4_G ALERTS Related to Twinning Effects Suppressed ..          ! Info
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Th(Min) ...          1 Report

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   4 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   6 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   5 ALERT type 3 Indicator that the structure quality may be low
   2 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, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009) and publCIF (Westrip, 2010).

5-Bromo-1H-indole-2,3-dione

Crystal data

C8H4BrNO2	F(000) = 440
Mr = 226.03	Dx = 2.036 Mg m^−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 5354 reflections
a = 25.1411 (18) Å	θ = 3.2–25.4°
b = 5.6851 (4) Å	µ = 5.52 mm^−1
c = 5.1593 (3) Å	T = 120 K
V = 737.42 (9) Å^3	Block, orange
Z = 4	0.2 × 0.12 × 0.1 mm

Data collection

Bruker D8 Venture CMOS diffractometer	1334 independent reflections
Radiation source: Mo	1232 reflections with I > 2σ(I)
TRIUMPH monochromator	Rint = 0.035
φ and ω scans	θmax = 25.4°, θmin = 3.2°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −30→30
Tmin = 0.109, Tmax = 0.148	k = −6→6
8877 measured reflections	l = −6→6

Refinement

Refinement on F^2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.025	w = 1/[σ^2(Fo^2) + 1.6735P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.054	(Δ/σ)max < 0.001
S = 1.12	Δρmax = 0.45 e Å^−3
1334 reflections	Δρmin = −0.79 e Å^−3
113 parameters	Absolute structure: Refined as an inversion twin
2 restraints	Absolute structure parameter: 0.02 (2)

Special details

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

Refinement. Refined as a 2-component inversion twin.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.26549 (2)	0.64837 (9)	0.99780 (18)	0.02277 (16)
O1	0.50004 (16)	0.2784 (7)	0.1243 (9)	0.0188 (9)
O2	0.42674 (16)	0.6864 (6)	0.1519 (8)	0.0185 (9)
N1	0.45090 (16)	0.1622 (7)	0.4830 (18)	0.0185 (10)
H1	0.4664 (18)	0.028 (5)	0.496 (19)	0.022*
C1	0.4649 (2)	0.3068 (9)	0.2839 (11)	0.0151 (12)
C2	0.4258 (2)	0.5187 (9)	0.2971 (12)	0.0144 (12)
C3	0.38981 (18)	0.4647 (8)	0.5154 (17)	0.0146 (11)
C4	0.3472 (2)	0.5867 (10)	0.6209 (12)	0.0156 (12)
H4	0.3359	0.7335	0.5523	0.019*
C5	0.3218 (2)	0.4844 (10)	0.8311 (11)	0.0148 (12)
C6	0.3381 (2)	0.2689 (10)	0.9336 (10)	0.0151 (14)
H6	0.3195	0.2040	1.0771	0.018*
C7	0.3812 (2)	0.1476 (11)	0.8286 (11)	0.0176 (13)
H7	0.3925	0.0011	0.8980	0.021*
C8	0.4068 (2)	0.2485 (10)	0.6199 (11)	0.0138 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0220 (3)	0.0254 (3)	0.0210 (3)	0.0056 (2)	0.0035 (5)	−0.0021 (5)
O1	0.021 (2)	0.016 (2)	0.020 (2)	0.0018 (17)	0.0033 (18)	−0.0030 (17)
O2	0.026 (2)	0.012 (2)	0.017 (2)	0.0028 (17)	−0.0013 (18)	0.0046 (18)
N1	0.020 (2)	0.0111 (19)	0.024 (3)	0.0047 (18)	−0.002 (4)	0.003 (3)
C1	0.018 (3)	0.009 (3)	0.018 (3)	0.002 (2)	−0.003 (3)	−0.002 (2)
C2	0.016 (3)	0.013 (3)	0.014 (3)	−0.001 (2)	−0.004 (2)	−0.003 (2)
C3	0.017 (2)	0.015 (2)	0.012 (3)	0.0009 (19)	−0.004 (4)	0.004 (4)
C4	0.018 (3)	0.013 (3)	0.016 (3)	0.002 (2)	−0.006 (2)	−0.001 (2)
C5	0.016 (3)	0.019 (3)	0.010 (3)	0.001 (2)	0.000 (2)	−0.004 (2)
C6	0.020 (3)	0.016 (3)	0.009 (4)	−0.005 (2)	−0.002 (2)	0.000 (2)
C7	0.021 (3)	0.014 (3)	0.018 (3)	−0.001 (3)	−0.004 (2)	0.004 (3)
C8	0.017 (3)	0.011 (3)	0.013 (3)	0.001 (2)	−0.004 (2)	−0.003 (3)

Geometric parameters (Å, º)

Br1—C5	1.901 (5)	C3—C8	1.409 (8)
O1—C1	1.219 (7)	C4—H4	0.9500
O2—C2	1.213 (7)	C4—C5	1.386 (8)
N1—H1	0.858 (14)	C5—C6	1.396 (8)
N1—C1	1.362 (9)	C6—H6	0.9500
N1—C8	1.403 (8)	C6—C7	1.394 (8)
C1—C2	1.555 (7)	C7—H7	0.9500
C2—C3	1.478 (9)	C7—C8	1.380 (8)
C3—C4	1.387 (8)
C1—N1—H1	119 (6)	C5—C4—H4	121.5
C1—N1—C8	111.9 (4)	C4—C5—Br1	119.4 (4)
C8—N1—H1	129 (5)	C4—C5—C6	122.0 (5)
O1—C1—N1	128.1 (5)	C6—C5—Br1	118.5 (4)
O1—C1—C2	126.2 (5)	C5—C6—H6	119.5
N1—C1—C2	105.8 (5)	C7—C6—C5	121.0 (5)
O2—C2—C1	124.7 (5)	C7—C6—H6	119.5
O2—C2—C3	130.2 (5)	C6—C7—H7	121.3
C3—C2—C1	105.0 (4)	C8—C7—C6	117.4 (5)
C4—C3—C2	132.0 (5)	C8—C7—H7	121.3
C4—C3—C8	121.3 (6)	N1—C8—C3	110.6 (5)
C8—C3—C2	106.7 (5)	C7—C8—N1	128.1 (5)
C3—C4—H4	121.5	C7—C8—C3	121.3 (5)
C5—C4—C3	116.9 (5)
Br1—C5—C6—C7	−176.2 (4)	C2—C3—C8—C7	−180.0 (5)
O1—C1—C2—O2	−2.1 (9)	C3—C4—C5—Br1	176.7 (5)
O1—C1—C2—C3	177.5 (6)	C3—C4—C5—C6	0.1 (8)
O2—C2—C3—C4	−0.6 (11)	C4—C3—C8—N1	−179.0 (6)
O2—C2—C3—C8	−179.4 (6)	C4—C3—C8—C7	1.1 (9)
N1—C1—C2—O2	178.7 (6)	C4—C5—C6—C7	0.4 (8)
N1—C1—C2—C3	−1.7 (6)	C5—C6—C7—C8	−0.2 (8)
C1—N1—C8—C3	−1.2 (7)	C6—C7—C8—N1	179.6 (6)
C1—N1—C8—C7	178.7 (6)	C6—C7—C8—C3	−0.6 (8)
C1—C2—C3—C4	179.9 (7)	C8—N1—C1—O1	−177.4 (6)
C1—C2—C3—C8	1.1 (6)	C8—N1—C1—C2	1.8 (7)
C2—C3—C4—C5	−179.5 (6)	C8—C3—C4—C5	−0.8 (9)
C2—C3—C8—N1	−0.1 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.86 (1)	2.05 (3)	2.886 (6)	166 (9)
C7—H7···O2^ii	0.95	2.38	3.312 (7)	167

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