Butane-2,3-dione bis-[(4-bromo-benzyl-idene)hydrazone].

The title compound, C(18)H(16)Br(2)N(4), is a linear double Schiff base compound having two parallel 4-bromo-phenyl groups connected across a crystallographic inversion centre by flexible C-C and C=N-N=C bonds and stabilized in the solid state by weak inter-molecular Br⋯Br inter-actions [3.7992 (11) Å], generating an infinite two-dimensional network structure.

Related literature

As a result of their geometry, including the zigzag conformation of the spacer moiety (C—C and C=N-N=C) between the two terminal groups, double Schiff base compounds have proved to be very versatile in their ability to form novel frameworks by self-assembly reactions with metal salts, see: He et al. (2008 ▶). For Br⋯Br inter­actions, see: Metrangolo et al. (2005 ▶).

Experimental

Crystal data

C18H16Br2N4

M = 448.17

Monoclinic,

a = 6.9139 (16) Å

b = 4.0931 (10) Å

c = 31.480 (7) Å

β = 95.186 (3)°

V = 887.2 (4) Å3

Z = 2

Mo Kα radiation

μ = 4.58 mm−1

T = 298 K

0.15 × 0.14 × 0.14 mm

Data collection

Bruker SMART CCD area-detector diffractometer

4238 measured reflections

1627 independent reflections

1308 reflections with I > 2σ(I)

R int = 0.035

Refinement

R[F 2 > 2σ(F 2)] = 0.034

wR(F 2) = 0.081

S = 1.04

1627 reflections

110 parameters

H-atom parameters constrained

Δρmax = 0.36 e Å−3

Δρmin = −0.37 e Å−3

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810014790/zs2037sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810014790/zs2037Isup2.hkl

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

C18H16Br2N4	F(000) = 444
Mr = 448.17	Dx = 1.678 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1433 reflections
a = 6.9139 (16) Å	θ = 2.6–25.1°
b = 4.0931 (10) Å	µ = 4.58 mm−1
c = 31.480 (7) Å	T = 298 K
β = 95.186 (3)°	Block, yellow
V = 887.2 (4) Å3	0.15 × 0.14 × 0.14 mm
Z = 2

Bruker SMART CCD area-detector diffractometer	1308 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
graphite	θmax = 25.5°, θmin = 2.6°
φ and ω scans	h = −8→8
4238 measured reflections	k = −4→4
1627 independent reflections	l = −22→38

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.081	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.0347P)2 + 0.331P] where P = (Fo2 + 2Fc2)/3
1627 reflections	(Δ/σ)max < 0.001
110 parameters	Δρmax = 0.36 e Å−3
0 restraints	Δρmin = −0.37 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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	1.09932 (5)	0.94173 (10)	0.208298 (11)	0.05710 (17)
C1	0.2315 (5)	0.7300 (10)	−0.01605 (10)	0.0558 (9)
H1A	0.2938	0.9047	0.0003	0.084*
H1B	0.1611	0.8175	−0.0412	0.084*
H1C	0.3279	0.5791	−0.0242	0.084*
C2	0.0949 (4)	0.5575 (8)	0.01014 (10)	0.0424 (8)
C3	0.3412 (5)	0.5400 (8)	0.10658 (10)	0.0459 (8)
H3	0.2486	0.4244	0.1201	0.055*
C4	0.5231 (4)	0.6363 (8)	0.13083 (9)	0.0384 (7)
C5	0.5589 (5)	0.5517 (8)	0.17327 (10)	0.0445 (8)
H5	0.4663	0.4334	0.1865	0.053*
C6	0.7302 (4)	0.6397 (8)	0.19646 (10)	0.0435 (8)
H6	0.7533	0.5825	0.2251	0.052*
C7	0.8655 (4)	0.8131 (8)	0.17650 (10)	0.0399 (7)
C8	0.8342 (5)	0.9003 (8)	0.13405 (10)	0.0470 (8)
H8	0.9278	1.0161	0.1208	0.056*
C9	0.6625 (4)	0.8128 (9)	0.11179 (10)	0.0467 (8)
H9	0.6392	0.8733	0.0833	0.056*
N1	0.1261 (4)	0.4971 (7)	0.05018 (9)	0.0492 (8)
N2	0.3081 (4)	0.6106 (8)	0.06790 (8)	0.0545 (8)

	U11	U22	U33	U12	U13	U23
Br1	0.0437 (2)	0.0655 (3)	0.0587 (3)	−0.00573 (17)	−0.01464 (16)	−0.00470 (18)
C1	0.0459 (18)	0.072 (3)	0.049 (2)	−0.0148 (19)	−0.0034 (16)	0.0041 (19)
C2	0.0395 (17)	0.047 (2)	0.0392 (18)	−0.0009 (14)	−0.0035 (14)	−0.0010 (15)
C3	0.0399 (17)	0.057 (2)	0.0395 (19)	−0.0073 (15)	−0.0008 (14)	0.0015 (15)
C4	0.0382 (16)	0.044 (2)	0.0314 (16)	−0.0019 (14)	−0.0034 (13)	−0.0031 (13)
C5	0.0443 (17)	0.052 (2)	0.0373 (18)	−0.0060 (15)	0.0032 (14)	0.0012 (15)
C6	0.0483 (18)	0.052 (2)	0.0289 (16)	−0.0012 (15)	−0.0048 (14)	0.0032 (14)
C7	0.0332 (15)	0.0444 (19)	0.0404 (18)	0.0015 (14)	−0.0072 (13)	−0.0091 (15)
C8	0.0446 (18)	0.057 (2)	0.0388 (19)	−0.0132 (16)	0.0029 (15)	0.0024 (16)
C9	0.0497 (18)	0.059 (2)	0.0300 (16)	−0.0081 (17)	−0.0019 (14)	0.0046 (15)
N1	0.0407 (15)	0.065 (2)	0.0397 (16)	−0.0119 (13)	−0.0084 (12)	0.0001 (13)
N2	0.0466 (16)	0.075 (2)	0.0387 (16)	−0.0154 (14)	−0.0105 (13)	0.0030 (14)

Br1—C7	1.898 (3)	C4—C9	1.384 (4)
C1—C2	1.487 (4)	C5—C6	1.382 (4)
C1—H1A	0.9600	C5—H5	0.9300
C1—H1B	0.9600	C6—C7	1.371 (4)
C1—H1C	0.9600	C6—H6	0.9300
C2—N1	1.283 (4)	C7—C8	1.381 (4)
C2—C2i	1.483 (6)	C8—C9	1.371 (4)
C3—N2	1.252 (4)	C8—H8	0.9300
C3—C4	1.465 (4)	C9—H9	0.9300
C3—H3	0.9300	N1—N2	1.408 (4)
C4—C5	1.381 (4)
C2—C1—H1A	109.5	C4—C5—H5	119.5
C2—C1—H1B	109.5	C6—C5—H5	119.5
H1A—C1—H1B	109.5	C7—C6—C5	118.7 (3)
C2—C1—H1C	109.5	C7—C6—H6	120.6
H1A—C1—H1C	109.5	C5—C6—H6	120.6
H1B—C1—H1C	109.5	C6—C7—C8	121.6 (3)
N1—C2—C2i	115.2 (4)	C6—C7—Br1	119.1 (2)
N1—C2—C1	125.2 (3)	C8—C7—Br1	119.3 (2)
C2i—C2—C1	119.6 (3)	C9—C8—C7	118.7 (3)
N2—C3—C4	121.2 (3)	C9—C8—H8	120.7
N2—C3—H3	119.4	C7—C8—H8	120.7
C4—C3—H3	119.4	C8—C9—C4	121.3 (3)
C5—C4—C9	118.6 (3)	C8—C9—H9	119.3
C5—C4—C3	120.5 (3)	C4—C9—H9	119.3
C9—C4—C3	120.9 (3)	C2—N1—N2	113.0 (3)
C4—C5—C6	121.1 (3)	C3—N2—N1	112.8 (3)
N2—C3—C4—C5	−178.8 (3)	Br1—C7—C8—C9	−178.4 (3)
N2—C3—C4—C9	1.0 (5)	C7—C8—C9—C4	−1.0 (5)
C9—C4—C5—C6	−0.1 (5)	C5—C4—C9—C8	0.7 (5)
C3—C4—C5—C6	179.7 (3)	C3—C4—C9—C8	−179.1 (3)
C4—C5—C6—C7	−0.2 (5)	C2i—C2—N1—N2	179.9 (3)
C5—C6—C7—C8	−0.1 (5)	C1—C2—N1—N2	−0.3 (5)
C5—C6—C7—Br1	178.9 (2)	C4—C3—N2—N1	179.9 (3)
C6—C7—C8—C9	0.7 (5)	C2—N1—N2—C3	−177.4 (3)