1,5-Diamino-2,6-dibromo-9,10-anthraquinone.

In the title compound, C(14)H(8)Br(2)N(2)O(2), the mol-ecular structure features intra-molecular N-H⋯O [2.639 (2) Å and 130°] and N-H⋯Br [3.053 (2) Å and 114°] hydrogen bonding. Due to inversion symmetry, the asymmetric part of the unit cell consits of one half-mol-ecule. In the crystal, inversion dimers linked by pairs of N-H⋯O [2.955 (2) Å and 135°] hydrogen bonds occur. The structure also features C=O⋯π [3.228 (2) Å] and Br⋯Br [3.569 (1) Å] contacts.

Related literature

For background information on anthraquinones and their pharmacological potential, see: Thomson (1967 ▶); Bohacova et al. (1998 ▶). For the X-ray structure of anthraquinone at different temperatures, see: Fu & Brock (1998 ▶). For a description of the resonance assisted hydrogen bond (RAHB) model, see: Gilli et al. (1989 ▶); Sanz et al. (2008 ▶). For structures with typical intramolecular N—H⋯Br, N—H⋯O and C=O⋯π contacts, see: Brammer et al. (2001 ▶); Shimpi et al. (2007 ▶); Marten et al. (2007 ▶). For the synthetic procedure, see: Scholl & Krieger (1904 ▶).

Experimental

Crystal data

C14H8Br2N2O2

M = 396.04

Triclinic,

a = 4.4177 (1) Å

b = 6.2240 (2) Å

c = 11.8410 (3) Å

α = 94.455 (2)°

β = 99.970 (2)°

γ = 100.859 (2)°

V = 312.87 (2) Å3

Z = 1

Mo Kα radiation

μ = 6.48 mm−1

T = 153 K

0.58 × 0.22 × 0.05 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T min = 0.117, T max = 0.759

7769 measured reflections

2003 independent reflections

1844 reflections with I > 2σ(I)

R int = 0.029

Refinement

R[F 2 > 2σ(F 2)] = 0.026

wR(F 2) = 0.071

S = 0.96

2003 reflections

91 parameters

H-atom parameters constrained

Δρmax = 0.86 e Å−3

Δρmin = −0.63 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812004229/im2352sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812004229/im2352Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812004229/im2352Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C14H8Br2N2O2	Z = 1
Mr = 396.04	F(000) = 192
Triclinic, P1	Dx = 2.102 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.4177 (1) Å	Cell parameters from 5166 reflections
b = 6.2240 (2) Å	θ = 3.2–38.8°
c = 11.8410 (3) Å	µ = 6.48 mm−1
α = 94.455 (2)°	T = 153 K
β = 99.970 (2)°	Irregular, red
γ = 100.859 (2)°	0.58 × 0.22 × 0.05 mm
V = 312.87 (2) Å3

Bruker APEXII CCD area-detector diffractometer	2003 independent reflections
Radiation source: fine-focus sealed tube	1844 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
φ and ω scans	θmax = 31.1°, θmin = 3.4°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −6→6
Tmin = 0.117, Tmax = 0.759	k = −9→9
7769 measured reflections	l = −17→17

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.071	H-atom parameters constrained
S = 0.96	w = 1/[σ2(Fo2) + (0.0454P)2 + 0.2515P] where P = (Fo2 + 2Fc2)/3
2003 reflections	(Δ/σ)max < 0.001
91 parameters	Δρmax = 0.86 e Å−3
0 restraints	Δρmin = −0.63 e Å−3

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.

	x	y	z	Uiso*/Ueq
Br1	0.18844 (5)	0.30597 (3)	0.572710 (15)	0.02812 (8)
O1	0.1853 (3)	0.3189 (2)	1.04118 (13)	0.0228 (3)
N1	0.1114 (4)	0.3920 (3)	0.82251 (13)	0.0197 (3)
H1A	0.0439	0.4563	0.7622	0.024*
H1B	0.0777	0.4351	0.8910	0.024*
C1	0.3215 (4)	0.1566 (3)	0.69978 (14)	0.0184 (3)
C2	0.4697 (4)	−0.0157 (3)	0.68165 (15)	0.0205 (3)
H2	0.4972	−0.0606	0.6062	0.025*
C3	0.5785 (4)	−0.1235 (3)	0.77398 (15)	0.0188 (3)
H3	0.6811	−0.2421	0.7618	0.023*
C4	0.5371 (4)	−0.0574 (3)	0.88430 (14)	0.0152 (3)
C5	0.3340 (4)	0.1755 (3)	1.02023 (15)	0.0159 (3)
C6	0.3806 (4)	0.1154 (3)	0.90319 (14)	0.0145 (3)
C7	0.2662 (4)	0.2273 (3)	0.80995 (14)	0.0158 (3)

	U11	U22	U33	U12	U13	U23
Br1	0.04356 (14)	0.03062 (12)	0.01527 (11)	0.01733 (9)	0.00600 (8)	0.00918 (7)
O1	0.0304 (7)	0.0252 (7)	0.0177 (6)	0.0166 (5)	0.0062 (5)	0.0020 (5)
N1	0.0264 (7)	0.0191 (7)	0.0164 (7)	0.0110 (6)	0.0032 (5)	0.0048 (5)
C1	0.0223 (7)	0.0205 (8)	0.0132 (7)	0.0063 (6)	0.0027 (5)	0.0042 (6)
C2	0.0257 (8)	0.0246 (8)	0.0123 (7)	0.0074 (6)	0.0045 (6)	0.0019 (6)
C3	0.0249 (8)	0.0185 (7)	0.0152 (7)	0.0090 (6)	0.0050 (6)	0.0011 (6)
C4	0.0161 (7)	0.0162 (7)	0.0138 (7)	0.0044 (5)	0.0030 (5)	0.0012 (5)
C5	0.0167 (7)	0.0154 (7)	0.0156 (7)	0.0041 (5)	0.0027 (5)	0.0016 (6)
C6	0.0161 (7)	0.0150 (7)	0.0127 (7)	0.0038 (5)	0.0026 (5)	0.0011 (5)
C7	0.0173 (7)	0.0154 (7)	0.0150 (7)	0.0038 (5)	0.0027 (5)	0.0019 (5)

Br1—C1	1.8949 (18)	C2—H2	0.9500
O1—C5	1.238 (2)	C3—C4	1.392 (2)
N1—C7	1.348 (2)	C3—H3	0.9500
N1—H1A	0.8800	C4—C6	1.407 (2)
N1—H1B	0.8800	C5—C6	1.467 (2)
C1—C2	1.379 (3)	C5—C4i	1.485 (2)
C1—C7	1.420 (2)	C6—C7	1.421 (2)
C2—C3	1.389 (3)
C7—N1—H1A	120.0	C3—C4—C6	120.66 (16)
C7—N1—H1B	120.0	C3—C4—C5i	117.24 (15)
H1A—N1—H1B	120.0	C6—C4—C5i	122.10 (15)
C2—C1—C7	122.64 (16)	O1—C5—C6	121.83 (16)
C2—C1—Br1	118.66 (13)	O1—C5—C4i	119.18 (16)
C7—C1—Br1	118.69 (13)	C6—C5—C4i	118.98 (15)
C1—C2—C3	119.84 (16)	C4—C6—C7	120.42 (15)
C1—C2—H2	120.1	C4—C6—C5	118.89 (15)
C3—C2—H2	120.1	C7—C6—C5	120.69 (15)
C2—C3—C4	119.87 (16)	N1—C7—C1	120.38 (16)
C2—C3—H3	120.1	N1—C7—C6	123.08 (15)
C4—C3—H3	120.1	C1—C7—C6	116.54 (15)
Br1—Br1—C1—C2	0.00 (9)	O1—C5—C6—C4	−176.53 (16)
Br1—Br1—C1—C7	0.00 (10)	C4i—C5—C6—C4	2.1 (2)
C7—C1—C2—C3	−1.7 (3)	O1—C5—C6—C7	2.6 (2)
Br1—C1—C2—C3	177.95 (14)	C4i—C5—C6—C7	−178.77 (14)
C1—C2—C3—C4	0.1 (3)	C2—C1—C7—N1	−177.84 (17)
C2—C3—C4—C6	1.1 (3)	Br1—C1—C7—N1	2.5 (2)
C2—C3—C4—C5i	−178.47 (16)	C2—C1—C7—C6	1.9 (2)
O1—O1—C5—C6	0.0 (5)	Br1—C1—C7—C6	−177.76 (12)
O1—O1—C5—C4i	0.0 (6)	C4—C6—C7—N1	179.15 (16)
C3—C4—C6—C7	−0.9 (2)	C5—C6—C7—N1	0.0 (2)
C5i—C4—C6—C7	178.70 (15)	C4—C6—C7—C1	−0.6 (2)
C3—C4—C6—C5	178.25 (15)	C5—C6—C7—C1	−179.71 (15)
C5i—C4—C6—C5	−2.2 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···O1	0.88	1.99	2.639 (2)	130
N1—H1A···Br1	0.88	2.59	3.053 (2)	114
N1—H1B···O1ii	0.88	2.27	2.955 (2)	135

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1B⋯O1	0.88	1.99	2.639 (2)	130
N1—H1A⋯Br1	0.88	2.59	3.053 (2)	114
N1—H1B⋯O1i	0.88	2.27	2.955 (2)	135

Symmetry code: (i) .