trans-Bis(2-amino­phen­yl)diazene

The title compound, C₁₂H₁₂N₄, is a trans-azobenzene which crystallizes with an inversion center at the midpoint of the N=N bond.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.034
• wR factor = 0.098
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT420_ALERT_2_C D-H Without Acceptor       N2     -   H2B    ...          ?

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

   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
   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 (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Siemens, 1996); software used to prepare material for publication: SHELXTL.

2,2'-diaminoazobenzene

Crystal data

C12H12N4	F(000) = 448
Mr = 212.26	Dx = 1.362 Mg m^−3 Dm = 1.32 Mg m^−3 Dm measured by flotation in ????
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 157 reflections
a = 22.278 (6) Å	θ = 2.3–28.1°
b = 5.8647 (16) Å	µ = 0.09 mm^−1
c = 8.254 (2) Å	T = 100 K
β = 106.357 (3)°	Block, orange–red
V = 1034.8 (5) Å^3	0.20 × 0.10 × 0.07 mm
Z = 4

Data collection

Siemens SMART CCD diffractometer	1003 independent reflections
Radiation source: fine-focus sealed tube	929 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
ω scans	θmax = 25.9°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Siemens, 1996)	h = −27→27
Tmin = 0.983, Tmax = 0.990	k = −7→7
3927 measured reflections	l = −9→10

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)] = 0.034	Hydrogen site location: difference Fourier map
wR(F^2) = 0.098	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0584P)^2 + 0.6927P] where P = (Fo^2 + 2Fc^2)/3
1003 reflections	(Δ/σ)max < 0.001
81 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

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

	x	y	z	Uiso*/Ueq
N1	0.01100 (4)	0.09432 (15)	0.48469 (11)	0.0164 (3)
N2	0.06365 (5)	0.48594 (16)	0.41750 (12)	0.0196 (3)
C1	0.07248 (5)	0.14153 (18)	0.58466 (12)	0.0154 (3)
C2	0.09767 (5)	0.34962 (18)	0.54716 (12)	0.0158 (3)
C3	0.15849 (5)	0.40897 (19)	0.64058 (14)	0.0186 (3)
H3A	0.1760	0.5444	0.6170	0.022*
C4	0.19264 (5)	0.26818 (19)	0.76747 (14)	0.0206 (3)
H4A	0.2329	0.3104	0.8287	0.025*
C5	0.16749 (5)	0.0628 (2)	0.80508 (13)	0.0204 (3)
H5A	0.1907	−0.0307	0.8910	0.024*
C6	0.10796 (5)	0.00022 (18)	0.71356 (13)	0.0178 (3)
H6A	0.0912	−0.1367	0.7374	0.021*
H2B	0.0770 (7)	0.627 (3)	0.4141 (17)	0.030 (4)*
H2A	0.0230 (8)	0.458 (3)	0.3846 (18)	0.033 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0181 (5)	0.0164 (5)	0.0159 (5)	−0.0006 (3)	0.0066 (4)	−0.0012 (3)
N2	0.0197 (5)	0.0170 (5)	0.0215 (5)	−0.0013 (4)	0.0048 (4)	0.0022 (4)
C1	0.0162 (5)	0.0174 (5)	0.0140 (5)	0.0002 (4)	0.0064 (4)	−0.0031 (4)
C2	0.0188 (5)	0.0160 (5)	0.0146 (5)	0.0020 (4)	0.0079 (4)	−0.0021 (4)
C3	0.0191 (6)	0.0170 (6)	0.0217 (6)	−0.0031 (4)	0.0089 (4)	−0.0022 (4)
C4	0.0155 (5)	0.0249 (6)	0.0205 (6)	−0.0010 (4)	0.0037 (4)	−0.0038 (4)
C5	0.0200 (6)	0.0227 (6)	0.0172 (5)	0.0031 (4)	0.0033 (4)	0.0015 (4)
C6	0.0210 (6)	0.0166 (5)	0.0171 (5)	−0.0003 (4)	0.0077 (4)	0.0000 (4)

Geometric parameters (Å, º)

N1—N1^i	1.2641 (18)	C3—C4	1.3816 (16)
N1—C1	1.4131 (14)	C3—H3A	0.9300
N2—C2	1.3792 (14)	C4—C5	1.3999 (16)
N2—H2B	0.884 (16)	C4—H4A	0.9300
N2—H2A	0.884 (16)	C5—C6	1.3783 (16)
C1—C6	1.4036 (15)	C5—H5A	0.9300
C1—C2	1.4135 (15)	C6—H6A	0.9300
C2—C3	1.4011 (15)
N1^i—N1—C1	114.92 (11)	C4—C3—H3A	119.7
C2—N2—H2B	116.9 (9)	C2—C3—H3A	119.7
C2—N2—H2A	115.0 (10)	C3—C4—C5	120.86 (10)
H2B—N2—H2A	119.2 (13)	C3—C4—H4A	119.6
C6—C1—N1	124.98 (10)	C5—C4—H4A	119.6
C6—C1—C2	120.15 (10)	C6—C5—C4	119.41 (10)
N1—C1—C2	114.87 (9)	C6—C5—H5A	120.3
N2—C2—C3	121.20 (10)	C4—C5—H5A	120.3
N2—C2—C1	120.34 (10)	C5—C6—C1	120.52 (10)
C3—C2—C1	118.43 (10)	C5—C6—H6A	119.7
C4—C3—C2	120.63 (10)	C1—C6—H6A	119.7
N1^i—N1—C1—C6	−2.03 (17)	C1—C2—C3—C4	−0.68 (16)
N1^i—N1—C1—C2	178.34 (10)	C2—C3—C4—C5	0.33 (16)
C6—C1—C2—N2	178.18 (9)	C3—C4—C5—C6	0.29 (16)
N1—C1—C2—N2	−2.17 (14)	C4—C5—C6—C1	−0.55 (16)
C6—C1—C2—C3	0.42 (15)	N1—C1—C6—C5	−179.42 (9)
N1—C1—C2—C3	−179.93 (8)	C2—C1—C6—C5	0.19 (16)
N2—C2—C3—C4	−178.42 (9)

Symmetry code: (i) −x, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···N1	0.884 (18)	2.330 (17)	2.7064 (15)	105.7 (13)