(Z)-1,2-Bis(3-bromo­phen­yl)diazene 1-oxide

The title compound C₁₂H₈Br₂N₂O, lies on an inversion centre in the space group P2₁/n. Doubts are cast on the report of a polymorph of this structure in the non-centrosymmetric space group P2₁ [Zhu, R.-T., Liu, J.-C., Jin, S., Liu, B. & Guo J.-P. (2006). Hecheng Huaxue (Chin. J. Synth. Chem.) 14, 591] as ADDSYM alerts point strongly to a centrosymmetric structure. In the crystal, C—H...O and C—H...Br hydrogen bonds together with offset π–π inter­actions stack the mol­ecules along the a-axis direction.

Key indicators

• Single-crystal X-ray study
• T = 90 K
• Mean [sigma](C-C) = 0.007 Å
• Disorder in main residue
• R factor = 0.049
• wR factor = 0.137
• Data-to-parameter ratio = 14.3

checkCIF/PLATON results

No syntax errors found



Datablock: I


Alert level C
PLAT341_ALERT_3_C Low Bond Precision on  C-C Bonds ...............    0.00733 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H4       ..BR3      .       3.11 Ang.
PLAT906_ALERT_3_C Large K Value in the Analysis of Variance ......      3.298 Check
PLAT911_ALERT_3_C Missing FCF Refl Between Thmin & STh/L=    0.600          7 Report

Alert level G
PLAT300_ALERT_4_G Atom Site Occupancy of O1         Constrained at        0.5 Check
PLAT301_ALERT_3_G Main Residue  Disorder ..............(Resd  1  )         6% Note
PLAT802_ALERT_4_G CIF Input Record(s) with more than 80 Characters          1 Info
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Theta(Min).          1 Note
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         24 Note
PLAT913_ALERT_3_G Missing # of Very Strong Reflections in FCF ....          3 Note
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......     Please Check
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          1 Info

   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
   8 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   6 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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Computing details

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b) and TITAN (Hunter & Simpson, 1999); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2018 (Sheldrick, 2015b), enCIFer (Allen et al., 2004), PLATON (Spek, 2009), publCIF (Westrip 2010) and WinGX (Farrugia, 2012).

(Z)-1,2-Bis(3-bromophenyl)diazene 1-oxide

Crystal data

C12H8Br2N2O	F(000) = 344
Mr = 356.02	Dx = 2.018 Mg m^−3
Monoclinic, P21/n	Cu Kα radiation, λ = 1.54184 Å
a = 3.8938 (2) Å	Cell parameters from 2305 reflections
b = 5.8223 (3) Å	θ = 7.6–74.4°
c = 25.8645 (16) Å	µ = 8.65 mm^−1
β = 92.044 (5)°	T = 90 K
V = 586.00 (6) Å^3	Plate, yellow
Z = 2	0.38 × 0.19 × 0.08 mm

Data collection

Agilent SuperNova, Dual, Cu at zero, Atlas diffractometer	1171 independent reflections
Radiation source: SuperNova (Cu) X-ray Source	1128 reflections with I > 2σ(I)
Detector resolution: 5.1725 pixels mm^-1	Rint = 0.036
ω scans	θmax = 74.9°, θmin = 6.9°
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014)	h = −4→4
Tmin = 0.334, Tmax = 1.000	k = −7→5
3440 measured reflections	l = −31→30

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.049	H-atom parameters constrained
wR(F^2) = 0.137	w = 1/[σ^2(Fo^2) + (0.0939P)^2 + 2.3574P] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
1171 reflections	Δρmax = 0.85 e Å^−3
82 parameters	Δρmin = −0.99 e Å^−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
O1	0.224 (2)	0.2546 (11)	0.4785 (2)	0.0334 (16)	0.5
N1	0.4136 (12)	0.4117 (7)	0.50608 (16)	0.0311 (9)
C1	0.3955 (13)	0.3550 (8)	0.56013 (19)	0.0275 (10)
C2	0.5144 (10)	0.4990 (6)	0.60040 (15)	0.0184 (8)
H2	0.618227	0.642861	0.593489	0.022*
C3	0.4750 (11)	0.4241 (7)	0.65016 (17)	0.0211 (8)
Br3	0.63666 (13)	0.61575 (9)	0.70533 (2)	0.0335 (3)
C4	0.3228 (12)	0.2162 (8)	0.6618 (2)	0.0321 (11)
H4	0.298842	0.170406	0.696715	0.038*
C5	0.2071 (14)	0.0774 (8)	0.6218 (3)	0.0407 (14)
H5	0.102440	−0.065852	0.629059	0.049*
C6	0.2435 (14)	0.1471 (8)	0.5705 (3)	0.0391 (14)
H6	0.163488	0.051244	0.542931	0.047*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.049 (4)	0.030 (3)	0.020 (3)	−0.021 (3)	−0.008 (3)	−0.003 (2)
N1	0.036 (2)	0.0327 (19)	0.024 (2)	0.0138 (16)	−0.0080 (17)	−0.0113 (15)
C1	0.025 (2)	0.028 (2)	0.029 (2)	0.0114 (18)	−0.0094 (18)	−0.0117 (17)
C2	0.020 (2)	0.0133 (17)	0.0217 (19)	0.0007 (14)	−0.0023 (15)	−0.0010 (14)
C3	0.018 (2)	0.0245 (19)	0.021 (2)	0.0052 (16)	0.0023 (15)	−0.0020 (15)
Br3	0.0287 (4)	0.0520 (4)	0.0192 (4)	0.0121 (2)	−0.0056 (2)	−0.01095 (18)
C4	0.026 (2)	0.024 (2)	0.047 (3)	0.0106 (18)	0.0119 (19)	0.019 (2)
C5	0.021 (3)	0.0147 (19)	0.087 (5)	−0.0004 (17)	0.008 (3)	0.006 (2)
C6	0.022 (2)	0.025 (2)	0.069 (4)	0.0057 (18)	−0.013 (2)	−0.022 (2)

Geometric parameters (Å, º)

O1—N1	1.360 (7)	C3—C4	1.385 (6)
N1—N1^i	1.274 (9)	C3—Br3	1.901 (4)
N1—C1	1.440 (7)	C4—C5	1.375 (9)
C1—C6	1.378 (8)	C4—H4	0.9500
C1—C2	1.403 (6)	C5—C6	1.399 (10)
C2—C3	1.373 (6)	C5—H5	0.9500
C2—H2	0.9500	C6—H6	0.9500
N1^i—N1—O1	134.0 (6)	C4—C3—Br3	118.9 (4)
N1^i—N1—C1	118.0 (5)	C5—C4—C3	118.8 (5)
O1—N1—C1	108.0 (5)	C5—C4—H4	120.6
C6—C1—C2	120.8 (5)	C3—C4—H4	120.6
C6—C1—N1	115.3 (4)	C4—C5—C6	120.0 (4)
C2—C1—N1	123.9 (4)	C4—C5—H5	120.0
C3—C2—C1	117.5 (4)	C6—C5—H5	120.0
C3—C2—H2	121.3	C1—C6—C5	119.9 (5)
C1—C2—H2	121.3	C1—C6—H6	120.0
C2—C3—C4	122.9 (4)	C5—C6—H6	120.0
C2—C3—Br3	118.2 (3)
N1^i—N1—C1—C6	−172.0 (5)	C1—C2—C3—Br3	179.7 (3)
O1—N1—C1—C6	9.0 (6)	C2—C3—C4—C5	0.3 (7)
N1^i—N1—C1—C2	9.4 (8)	Br3—C3—C4—C5	−179.8 (4)
O1—N1—C1—C2	−169.6 (5)	C3—C4—C5—C6	−0.1 (7)
C6—C1—C2—C3	0.4 (6)	C2—C1—C6—C5	−0.1 (7)
N1—C1—C2—C3	178.9 (4)	N1—C1—C6—C5	−178.8 (4)
C1—C2—C3—C4	−0.5 (6)	C4—C5—C6—C1	0.0 (7)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O1^i	0.95	2.07	2.722 (7)	124
C6—H6···O1^ii	0.95	2.39	3.199 (8)	143
C4—H4···Br3^iii	0.95	3.11	3.974 (5)	151

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