1,4-Bis(4-bromo-2,6-diisopropyl-phen-yl)-1,4-diaza-buta-1,3-diene.

The molecule of the title compound, C(26)H(34)Br(2)N(2), lies on a crystallographic inversion center and hence the two imine groups are s-trans. The dihedral angle between the central 1,4-diaza-buta-1,3-diene unit and the attached substituted phenyl ring is 88.4 (7)°. The structure features a C-H⋯N close contact. The crystal selected for this study proved to be a non-merohedral twin with a minor component of 21.8 (3)%.

Related literature

1,4-diaza-1,3-butadiene (DAB) ligands containing sterically demanding N-substituents have proved to be versatile platforms for stabilizing s- and p-block atoms in unusual oxidation states or coordination geometries, see: Baker et al. (2008 ▶); Hill et al. (2009 ▶); Liu et al. (2009 ▶); Martin et al. (2009 ▶); Segawa et al. (2008 ▶). The title compound was prepared as part of our continuing studies on the chemistry of N-heterocyclic silylenes and germylenes, see: Hill et al. (2005 ▶); Naka et al. (2004 ▶); Tomasik et al. (2009 ▶). For the use of DAB ligands in olefin polymerization catalysis, see: Ittel et al. (2000 ▶); Jung et al. (2007 ▶). For related structures, see: (2003); Müller et al. (2003 ▶); Schaub et al. (2006 ▶); Berger et al. (2001 ▶); Laine et al. (1999 ▶). For the preparation of 4-bromo-2,6-di-iso-propyl aniline, see: Liu et al. (2005 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

C26H34Br2N2

M = 534.37

Monoclinic,

a = 8.961 (3) Å

b = 17.848 (7) Å

c = 8.620 (3) Å

β = 104.260 (11)°

V = 1336.2 (8) Å3

Z = 2

Mo Kα radiation

μ = 3.05 mm−1

T = 300 K

0.43 × 0.35 × 0.29 mm

Data collection

Bruker SMART X2S diffractometer

Absorption correction: multi-scan (TWINABS; Bruker, 2007 ▶) T min = 0.103, T max = 0.428

2286 measured reflections

2286 independent reflections

1585 reflections with I > 2σ(I)

R int = 0.110

Refinement

R[F 2 > 2σ(F 2)] = 0.069

wR(F 2) = 0.199

S = 1.04

2286 reflections

142 parameters

H-atom parameters constrained

Δρmax = 0.53 e Å−3

Δρmin = −0.60 e Å−3

Data collection: GIS (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL and OLEX2 (Dolomanov et al., 2009 ▶); mol­ecular graphics: SHELXTL and OLEX2; software used to prepare material for publication: SHELXTL, OLEX2 (Dolomanov et al., 2009 ▶), publCIF (Westrip, 2009 ▶) and modiCIFer (Guzei, 2007 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809050843/bx2248sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809050843/bx2248Isup2.hkl

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

C26H34Br2N2	F(000) = 548
Mr = 534.37	Dx = 1.328 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 999 reflections
a = 8.961 (3) Å	θ = 2.3–24.8°
b = 17.848 (7) Å	µ = 3.05 mm−1
c = 8.620 (3) Å	T = 300 K
β = 104.260 (11)°	Block, yellow
V = 1336.2 (8) Å3	0.43 × 0.35 × 0.29 mm
Z = 2

Bruker SMART X2S diffractometer	2286 independent reflections
Radiation source: micro-focus sealed tube	1585 reflections with I > 2σ(I)
doubly curved silicon crystal	Rint = 0.110
ω scans	θmax = 24.8°, θmin = 2.3°
Absorption correction: multi-scan (TWINABS; Bruker, 2007)	h = 0→10
Tmin = 0.103, Tmax = 0.428	k = −21→0
2286 measured reflections	l = −10→9

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)] = 0.069	H-atom parameters constrained
wR(F2) = 0.199	w = 1/[σ2(Fo2) + (0.0949P)2 + 1.843P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max = 0.001
2286 reflections	Δρmax = 0.53 e Å−3
142 parameters	Δρmin = −0.60 e Å−3
0 restraints	Extinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.038 (5)

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	1.14981 (9)	0.69711 (6)	0.27272 (12)	0.0957 (6)
N1	0.6097 (6)	0.5812 (3)	0.5079 (7)	0.0523 (14)
C1	0.5657 (8)	0.5148 (3)	0.4744 (8)	0.0513 (17)
H1	0.6173	0.4847	0.4166	0.062*
C2	0.7381 (6)	0.6090 (3)	0.4544 (7)	0.0395 (14)
C3	0.7094 (7)	0.6469 (3)	0.3074 (7)	0.0409 (14)
C4	0.8336 (7)	0.6738 (3)	0.2564 (7)	0.0456 (15)
H4	0.8179	0.6992	0.1595	0.055*
C5	0.9804 (7)	0.6630 (4)	0.3489 (8)	0.0500 (16)
C6	1.0083 (7)	0.6289 (4)	0.4968 (8)	0.0529 (16)
H6	1.1086	0.6245	0.5591	0.063*
C7	0.8860 (8)	0.6012 (3)	0.5528 (8)	0.0485 (16)
C8	0.5477 (7)	0.6575 (4)	0.2044 (9)	0.0536 (16)
H8	0.4780	0.6500	0.2746	0.064*
C9	0.5079 (12)	0.5984 (6)	0.0770 (14)	0.119 (4)
H9C	0.5672	0.6062	−0.0004	0.179*
H9B	0.4002	0.6013	0.0251	0.179*
H9A	0.5309	0.5498	0.1247	0.179*
C10	0.5185 (9)	0.7356 (5)	0.1375 (14)	0.088 (3)
H10C	0.5496	0.7714	0.2224	0.132*
H10A	0.4108	0.7416	0.0883	0.132*
H10B	0.5766	0.7436	0.0590	0.132*
C11	0.9157 (9)	0.5652 (4)	0.7203 (8)	0.0626 (18)
H11	0.8533	0.5195	0.7090	0.075*
C12	0.8601 (13)	0.6152 (5)	0.8316 (10)	0.101 (3)
H12B	0.8573	0.5880	0.9269	0.151*
H12A	0.7586	0.6327	0.7808	0.151*
H12C	0.9285	0.6572	0.8591	0.151*
C13	1.0834 (11)	0.5415 (5)	0.7895 (10)	0.087 (3)
H13A	1.1158	0.5093	0.7148	0.131*
H13B	1.0915	0.5152	0.8884	0.131*
H13C	1.1478	0.5852	0.8086	0.131*

	U11	U22	U33	U12	U13	U23
Br1	0.0555 (5)	0.1428 (10)	0.0961 (8)	−0.0228 (5)	0.0324 (5)	0.0295 (6)
N1	0.067 (3)	0.034 (3)	0.065 (4)	−0.011 (2)	0.036 (3)	−0.001 (2)
C1	0.068 (4)	0.035 (3)	0.063 (4)	−0.014 (3)	0.040 (4)	−0.007 (3)
C2	0.053 (3)	0.027 (3)	0.046 (4)	−0.006 (2)	0.026 (3)	−0.004 (3)
C3	0.046 (3)	0.033 (3)	0.046 (4)	−0.005 (3)	0.015 (3)	−0.003 (3)
C4	0.053 (4)	0.046 (3)	0.039 (3)	−0.006 (3)	0.014 (3)	0.002 (3)
C5	0.046 (4)	0.059 (4)	0.050 (4)	−0.011 (3)	0.021 (3)	0.000 (3)
C6	0.052 (3)	0.057 (4)	0.050 (4)	−0.006 (3)	0.014 (3)	0.006 (3)
C7	0.064 (4)	0.042 (3)	0.043 (4)	−0.006 (3)	0.020 (3)	0.002 (3)
C8	0.046 (3)	0.052 (4)	0.063 (4)	−0.005 (3)	0.014 (3)	0.007 (3)
C9	0.093 (7)	0.119 (8)	0.117 (9)	−0.024 (6)	−0.030 (6)	−0.045 (7)
C10	0.063 (5)	0.080 (5)	0.115 (8)	0.008 (4)	0.013 (6)	0.039 (6)
C11	0.083 (5)	0.059 (4)	0.052 (4)	−0.003 (4)	0.027 (4)	0.014 (4)
C12	0.161 (10)	0.094 (6)	0.063 (6)	0.043 (6)	0.058 (6)	0.026 (5)
C13	0.109 (7)	0.081 (6)	0.072 (6)	0.025 (5)	0.025 (5)	0.019 (5)

Br1—C5	1.897 (6)	C8—H8	0.9800
N1—C1	1.260 (7)	C9—H9C	0.9600
N1—C2	1.429 (7)	C9—H9B	0.9600
C1—C1i	1.455 (11)	C9—H9A	0.9600
C1—H1	0.9300	C10—H10C	0.9600
C2—C7	1.393 (9)	C10—H10A	0.9600
C2—C3	1.403 (8)	C10—H10B	0.9600
C3—C4	1.380 (8)	C11—C12	1.483 (11)
C3—C8	1.513 (9)	C11—C13	1.533 (12)
C4—C5	1.374 (9)	C11—H11	0.9800
C4—H4	0.9300	C12—H12B	0.9600
C5—C6	1.379 (9)	C12—H12A	0.9600
C6—C7	1.393 (9)	C12—H12C	0.9600
C6—H6	0.9300	C13—H13A	0.9600
C7—C11	1.542 (9)	C13—H13B	0.9600
C8—C9	1.501 (12)	C13—H13C	0.9600
C8—C10	1.507 (10)
C1—N1—C2	118.9 (5)	C8—C9—H9B	109.5
N1—C1—C1i	120.3 (7)	H9C—C9—H9B	109.5
N1—C1—H1	119.9	C8—C9—H9A	109.5
C1i—C1—H1	119.9	H9C—C9—H9A	109.5
C7—C2—C3	122.3 (5)	H9B—C9—H9A	109.5
C7—C2—N1	119.3 (5)	C8—C10—H10C	109.5
C3—C2—N1	118.4 (5)	C8—C10—H10A	109.5
C4—C3—C2	118.2 (5)	H10C—C10—H10A	109.5
C4—C3—C8	120.0 (5)	C8—C10—H10B	109.5
C2—C3—C8	121.8 (5)	H10C—C10—H10B	109.5
C5—C4—C3	119.9 (6)	H10A—C10—H10B	109.5
C5—C4—H4	120.1	C12—C11—C13	111.5 (8)
C3—C4—H4	120.1	C12—C11—C7	110.3 (6)
C4—C5—C6	121.9 (6)	C13—C11—C7	114.0 (6)
C4—C5—Br1	119.2 (5)	C12—C11—H11	106.9
C6—C5—Br1	118.9 (5)	C13—C11—H11	106.9
C5—C6—C7	119.9 (6)	C7—C11—H11	106.9
C5—C6—H6	120.1	C11—C12—H12B	109.5
C7—C6—H6	120.1	C11—C12—H12A	109.5
C6—C7—C2	117.7 (6)	H12B—C12—H12A	109.5
C6—C7—C11	120.2 (6)	C11—C12—H12C	109.5
C2—C7—C11	122.1 (6)	H12B—C12—H12C	109.5
C9—C8—C10	112.5 (8)	H12A—C12—H12C	109.5
C9—C8—C3	111.2 (6)	C11—C13—H13A	109.5
C10—C8—C3	113.0 (5)	C11—C13—H13B	109.5
C9—C8—H8	106.5	H13A—C13—H13B	109.5
C10—C8—H8	106.5	C11—C13—H13C	109.5
C3—C8—H8	106.5	H13A—C13—H13C	109.5
C8—C9—H9C	109.5	H13B—C13—H13C	109.5
C2—N1—C1—C1i	−179.3 (8)	C5—C6—C7—C11	−178.1 (6)
C1—N1—C2—C7	−90.5 (7)	C3—C2—C7—C6	−3.5 (9)
C1—N1—C2—C3	92.9 (7)	N1—C2—C7—C6	−179.9 (6)
C7—C2—C3—C4	3.3 (8)	C3—C2—C7—C11	174.9 (5)
N1—C2—C3—C4	179.8 (5)	N1—C2—C7—C11	−1.6 (8)
C7—C2—C3—C8	−177.7 (5)	C4—C3—C8—C9	82.5 (8)
N1—C2—C3—C8	−1.2 (8)	C2—C3—C8—C9	−96.4 (8)
C2—C3—C4—C5	0.1 (9)	C4—C3—C8—C10	−45.1 (9)
C8—C3—C4—C5	−178.9 (6)	C2—C3—C8—C10	135.9 (7)
C3—C4—C5—C6	−3.3 (10)	C6—C7—C11—C12	108.2 (9)
C3—C4—C5—Br1	177.6 (5)	C2—C7—C11—C12	−70.1 (9)
C4—C5—C6—C7	3.1 (10)	C6—C7—C11—C13	−18.1 (10)
Br1—C5—C6—C7	−177.8 (5)	C2—C7—C11—C13	163.6 (7)
C5—C6—C7—C2	0.3 (9)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8···N1	0.98	2.40	2.880 (9)	109

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯N1	0.98	2.40	2.880 (9)	109