2,3-Bis(4-bromo-phen-yl)quinoxaline.

The title compound, C(20)H(12)Br(2)N(2), was prepared by the reaction of 1-(3-bromo-phen-yl)-2-(4-bromo-phen-yl)ethane-1,2-dione with o-phenyl-enediamine in refluxing ethanol. In the mol-ecule, all bond lengths and angles are within normal ranges. The dihedral angle between the two benzene rings is 34.89 (1)°. The dihedral angles between the benzene rings and the quinoxaline system are 57.23 (1) and 36.75 (1)°. The crystal packing is stabilized by van der Waals forces.

Related literature

For related literature, see: Brock et al. (1999 ▶); Dailey et al. (2001 ▶); Guillon et al. (1998 ▶); Kim et al. (1993 ▶); Patel et al. (2000 ▶); Rong et al. (2006 ▶).

Experimental

Crystal data

C20H12Br2N2

M = 440.14

Triclinic,

a = 6.0830 (12) Å

b = 12.018 (2) Å

c = 12.323 (3) Å

α = 105.47 (3)°

β = 91.89 (3)°

γ = 97.47 (3)°

V = 858.7 (3) Å3

Z = 2

Mo Kα radiation

μ = 4.72 mm−1

T = 293 (2) K

0.20 × 0.18 × 0.15 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

Absorption correction: ψ scan (North et al., 1968 ▶) T min = 0.404, T max = 0.492

3338 measured reflections

2888 independent reflections

1824 reflections with I > 2σ(I)

R int = 0.027

3 standard reflections every 100 reflections intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.046

wR(F 2) = 0.128

S = 1.06

2888 reflections

217 parameters

H-atom parameters constrained

Δρmax = 0.56 e Å−3

Δρmin = −0.74 e Å−3

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: NRCVAX (Gabe et al., 1989 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: SHELXTL/PC (Sheldrick, 1990 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680705516X/hg2324sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680705516X/hg2324Isup2.hkl

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

C20H12Br2N2	Z = 2
Mr = 440.14	F000 = 432
Triclinic, P1	Dx = 1.702 Mg m−3
Hall symbol: -P 1	Mo Kα radiation λ = 0.71073 Å
a = 6.0830 (12) Å	Cell parameters from 25 reflections
b = 12.018 (2) Å	θ = 4–14º
c = 12.323 (3) Å	µ = 4.72 mm−1
α = 105.47 (3)º	T = 293 (2) K
β = 91.89 (3)º	Block, yellow
γ = 97.47 (3)º	0.20 × 0.18 × 0.15 mm
V = 858.7 (3) Å3

Enraf–Nonius CAD-4 diffractometer	Rint = 0.027
Radiation source: fine-focus sealed tube	θmax = 25.0º
Monochromator: graphite	θmin = 1.7º
T = 293(2) K	h = 0→7
ω scans	k = −14→14
Absorption correction: ψ scan(North et al., 1968)	l = −14→14
Tmin = 0.404, Tmax = 0.492	3 standard reflections
3338 measured reflections	every 100 reflections
2888 independent reflections	intensity decay: none
1824 reflections with I > 2σ(I)

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.046	H-atom parameters constrained
wR(F2) = 0.128	w = 1/[σ2(Fo2) + (0.0589P)2 + 0.7939P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max < 0.001
2888 reflections	Δρmax = 0.56 e Å−3
217 parameters	Δρmin = −0.74 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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	0.47031 (12)	0.83130 (5)	0.45247 (6)	0.0741 (3)
Br2	−0.24223 (11)	0.30938 (6)	−0.14438 (6)	0.0753 (3)
N1	0.7857 (7)	0.2921 (4)	0.3229 (4)	0.0493 (11)
N2	0.4951 (8)	0.1176 (4)	0.1656 (4)	0.0542 (12)
C1	0.3718 (9)	0.4705 (5)	0.3533 (5)	0.0526 (14)
H1B	0.2564	0.4116	0.3532	0.063*
C2	0.3425 (9)	0.5854 (5)	0.3977 (5)	0.0529 (14)
H2B	0.2112	0.6041	0.4297	0.064*
C3	0.5130 (10)	0.6720 (5)	0.3936 (5)	0.0522 (14)
C4	0.7127 (10)	0.6469 (5)	0.3496 (5)	0.0589 (15)
H4A	0.8255	0.7065	0.3480	0.071*
C5	0.7412 (9)	0.5309 (5)	0.3078 (5)	0.0544 (14)
H5A	0.8755	0.5129	0.2789	0.065*
C6	0.5720 (9)	0.4407 (4)	0.3082 (4)	0.0461 (13)
C7	0.6106 (9)	0.3173 (4)	0.2700 (4)	0.0462 (13)
C8	0.8169 (9)	0.1783 (5)	0.2990 (5)	0.0493 (13)
C9	0.9999 (10)	0.1469 (6)	0.3534 (5)	0.0652 (17)
H9A	1.1007	0.2046	0.4025	0.078*
C10	1.0281 (12)	0.0335 (6)	0.3342 (6)	0.0709 (18)
H10A	1.1480	0.0130	0.3695	0.085*
C11	0.8729 (12)	−0.0534 (6)	0.2597 (6)	0.0735 (19)
H11A	0.8904	−0.1314	0.2479	0.088*
C12	0.7000 (11)	−0.0263 (5)	0.2052 (6)	0.0694 (18)
H12A	0.6031	−0.0852	0.1551	0.083*
C13	0.6657 (9)	0.0901 (5)	0.2238 (5)	0.0505 (13)
C14	0.4677 (8)	0.2285 (4)	0.1856 (5)	0.0472 (13)
C15	0.2918 (9)	0.2540 (5)	0.1121 (4)	0.0477 (13)
C16	0.3189 (10)	0.3520 (5)	0.0707 (5)	0.0584 (15)
H16A	0.4455	0.4071	0.0940	0.070*
C17	0.1619 (10)	0.3685 (5)	−0.0041 (5)	0.0611 (16)
H17A	0.1836	0.4330	−0.0326	0.073*
C18	−0.0301 (9)	0.2875 (5)	−0.0366 (5)	0.0545 (14)
C19	−0.0638 (10)	0.1897 (5)	0.0024 (5)	0.0576 (15)
H19A	−0.1927	0.1362	−0.0200	0.069*
C20	0.0981 (9)	0.1728 (5)	0.0755 (5)	0.0516 (14)
H20A	0.0783	0.1062	0.1010	0.062*

	U11	U22	U33	U12	U13	U23
Br1	0.0889 (5)	0.0564 (4)	0.0746 (5)	0.0182 (3)	0.0012 (4)	0.0107 (3)
Br2	0.0645 (4)	0.0854 (5)	0.0725 (5)	0.0068 (3)	−0.0241 (3)	0.0212 (4)
N1	0.044 (3)	0.053 (3)	0.049 (3)	0.009 (2)	−0.002 (2)	0.009 (2)
N2	0.048 (3)	0.056 (3)	0.057 (3)	−0.001 (2)	0.002 (2)	0.016 (2)
C1	0.040 (3)	0.056 (3)	0.057 (4)	0.001 (3)	−0.004 (3)	0.011 (3)
C2	0.039 (3)	0.065 (4)	0.052 (3)	0.011 (3)	−0.002 (3)	0.010 (3)
C3	0.059 (4)	0.051 (3)	0.045 (3)	0.010 (3)	−0.006 (3)	0.012 (3)
C4	0.050 (4)	0.056 (3)	0.066 (4)	−0.004 (3)	−0.001 (3)	0.014 (3)
C5	0.039 (3)	0.061 (3)	0.061 (4)	0.007 (3)	0.002 (3)	0.013 (3)
C6	0.041 (3)	0.053 (3)	0.041 (3)	0.004 (2)	−0.008 (2)	0.010 (2)
C7	0.041 (3)	0.053 (3)	0.044 (3)	0.004 (2)	0.001 (2)	0.013 (2)
C8	0.044 (3)	0.058 (3)	0.047 (3)	0.009 (3)	0.007 (3)	0.014 (3)
C9	0.059 (4)	0.073 (4)	0.064 (4)	0.022 (3)	−0.010 (3)	0.016 (3)
C10	0.076 (5)	0.075 (4)	0.072 (4)	0.033 (4)	0.001 (4)	0.027 (4)
C11	0.084 (5)	0.059 (4)	0.087 (5)	0.027 (4)	0.018 (4)	0.027 (4)
C12	0.065 (4)	0.054 (3)	0.087 (5)	0.003 (3)	0.000 (4)	0.019 (3)
C13	0.047 (3)	0.052 (3)	0.054 (3)	0.007 (3)	0.010 (3)	0.017 (3)
C14	0.037 (3)	0.051 (3)	0.050 (3)	0.000 (2)	0.004 (2)	0.011 (3)
C15	0.042 (3)	0.058 (3)	0.041 (3)	0.005 (2)	0.001 (2)	0.011 (3)
C16	0.051 (4)	0.061 (4)	0.057 (4)	−0.008 (3)	−0.010 (3)	0.015 (3)
C17	0.063 (4)	0.059 (3)	0.061 (4)	−0.002 (3)	−0.009 (3)	0.021 (3)
C18	0.043 (3)	0.071 (4)	0.045 (3)	0.008 (3)	−0.011 (3)	0.011 (3)
C19	0.049 (3)	0.070 (4)	0.048 (3)	−0.002 (3)	−0.004 (3)	0.013 (3)
C20	0.047 (3)	0.057 (3)	0.049 (3)	0.002 (3)	−0.002 (3)	0.014 (3)

Br1—C3	1.913 (5)	C9—C10	1.355 (8)
Br2—C18	1.913 (5)	C9—H9A	0.9300
N1—C7	1.339 (6)	C10—C11	1.414 (9)
N1—C8	1.360 (7)	C10—H10A	0.9300
N2—C14	1.322 (7)	C11—C12	1.350 (9)
N2—C13	1.367 (7)	C11—H11A	0.9300
C1—C2	1.380 (8)	C12—C13	1.400 (8)
C1—C6	1.404 (8)	C12—H12A	0.9300
C1—H1B	0.9300	C14—C15	1.493 (7)
C2—C3	1.383 (8)	C15—C16	1.397 (8)
C2—H2B	0.9300	C15—C20	1.405 (7)
C3—C4	1.383 (8)	C16—C17	1.374 (8)
C4—C5	1.388 (8)	C16—H16A	0.9300
C4—H4A	0.9300	C17—C18	1.392 (8)
C5—C6	1.395 (7)	C17—H17A	0.9300
C5—H5A	0.9300	C18—C19	1.378 (8)
C6—C7	1.484 (7)	C19—C20	1.384 (7)
C7—C14	1.443 (7)	C19—H19A	0.9300
C8—C13	1.412 (7)	C20—H20A	0.9300
C8—C9	1.424 (7)
C7—N1—C8	117.5 (4)	C11—C10—H10A	120.4
C14—N2—C13	118.5 (4)	C12—C11—C10	121.8 (6)
C2—C1—C6	121.4 (5)	C12—C11—H11A	119.1
C2—C1—H1B	119.3	C10—C11—H11A	119.1
C6—C1—H1B	119.3	C11—C12—C13	120.4 (6)
C1—C2—C3	118.5 (5)	C11—C12—H12A	119.8
C1—C2—H2B	120.8	C13—C12—H12A	119.8
C3—C2—H2B	120.8	N2—C13—C12	120.2 (5)
C2—C3—C4	122.1 (5)	N2—C13—C8	120.9 (5)
C2—C3—Br1	118.5 (4)	C12—C13—C8	118.8 (5)
C4—C3—Br1	119.3 (4)	N2—C14—C7	120.4 (5)
C3—C4—C5	118.6 (5)	N2—C14—C15	115.8 (4)
C3—C4—H4A	120.7	C7—C14—C15	123.7 (5)
C5—C4—H4A	120.7	C16—C15—C20	118.0 (5)
C4—C5—C6	121.2 (5)	C16—C15—C14	122.4 (5)
C4—C5—H5A	119.4	C20—C15—C14	119.4 (5)
C6—C5—H5A	119.4	C17—C16—C15	121.2 (5)
C5—C6—C1	118.1 (5)	C17—C16—H16A	119.4
C5—C6—C7	120.4 (5)	C15—C16—H16A	119.4
C1—C6—C7	121.3 (5)	C16—C17—C18	119.2 (5)
N1—C7—C14	121.5 (5)	C16—C17—H17A	120.4
N1—C7—C6	114.9 (4)	C18—C17—H17A	120.4
C14—C7—C6	123.5 (5)	C19—C18—C17	121.5 (5)
N1—C8—C13	120.9 (5)	C19—C18—Br2	119.8 (4)
N1—C8—C9	119.7 (5)	C17—C18—Br2	118.6 (5)
C13—C8—C9	119.4 (5)	C18—C19—C20	118.6 (5)
C10—C9—C8	120.4 (6)	C18—C19—H19A	120.7
C10—C9—H9A	119.8	C20—C19—H19A	120.7
C8—C9—H9A	119.8	C19—C20—C15	121.5 (5)
C9—C10—C11	119.1 (6)	C19—C20—H20A	119.3
C9—C10—H10A	120.4	C15—C20—H20A	119.3
C6—C1—C2—C3	2.2 (8)	C11—C12—C13—C8	1.0 (9)
C1—C2—C3—C4	−1.9 (8)	N1—C8—C13—N2	5.8 (8)
C1—C2—C3—Br1	178.8 (4)	C9—C8—C13—N2	−176.5 (5)
C2—C3—C4—C5	0.4 (9)	N1—C8—C13—C12	−177.5 (5)
Br1—C3—C4—C5	179.7 (4)	C9—C8—C13—C12	0.2 (8)
C3—C4—C5—C6	0.9 (9)	C13—N2—C14—C7	−2.2 (8)
C4—C5—C6—C1	−0.6 (8)	C13—N2—C14—C15	174.7 (5)
C4—C5—C6—C7	−176.0 (5)	N1—C7—C14—N2	6.1 (8)
C2—C1—C6—C5	−1.0 (8)	C6—C7—C14—N2	−171.5 (5)
C2—C1—C6—C7	174.4 (5)	N1—C7—C14—C15	−170.5 (5)
C8—N1—C7—C14	−3.8 (8)	C6—C7—C14—C15	11.9 (8)
C8—N1—C7—C6	174.0 (5)	N2—C14—C15—C16	−140.4 (6)
C5—C6—C7—N1	54.7 (7)	C7—C14—C15—C16	36.3 (8)
C1—C6—C7—N1	−120.5 (6)	N2—C14—C15—C20	34.6 (7)
C5—C6—C7—C14	−127.6 (6)	C7—C14—C15—C20	−148.6 (6)
C1—C6—C7—C14	57.2 (7)	C20—C15—C16—C17	−0.3 (9)
C7—N1—C8—C13	−1.9 (8)	C14—C15—C16—C17	174.8 (5)
C7—N1—C8—C9	−179.6 (5)	C15—C16—C17—C18	1.7 (9)
N1—C8—C9—C10	177.2 (6)	C16—C17—C18—C19	−1.6 (9)
C13—C8—C9—C10	−0.5 (9)	C16—C17—C18—Br2	−178.0 (5)
C8—C9—C10—C11	−0.3 (10)	C17—C18—C19—C20	0.1 (9)
C9—C10—C11—C12	1.5 (11)	Br2—C18—C19—C20	176.5 (4)
C10—C11—C12—C13	−1.9 (11)	C18—C19—C20—C15	1.3 (9)
C14—N2—C13—C12	179.9 (6)	C16—C15—C20—C19	−1.2 (8)
C14—N2—C13—C8	−3.5 (8)	C14—C15—C20—C19	−176.5 (5)
C11—C12—C13—N2	177.7 (6)