N,N'-Bis(4-bromo-benzyl-idene)-2,2-dimethyl-propane-1,3-diamine.

The mol-ecule of the title compound, C(19)H(20)Br(2)N(2), is a potential bidentate Schiff base ligand. The two benzene rings are inclined at a dihedral angle of 30.85 (8)°. An inter-esting feature of the crystal structure is a weak inter-molecular Br⋯Br [3.4752 (4) Å] inter-action which is shorter than the sum of the van der Waals radii of the Br atoms and links neighbouring mol-ecules into chains along the c axis. The crystal structure is further stabilized by inter-molecular C-H⋯π inter-actions.

Related literature

For details of hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For related structure see, for example: Li et al. (2005 ▶); Bomfim et al. (2005 ▶); Glidewell et al. (2005 ▶, 2006 ▶); Sun et al. (2004 ▶); Fun et al. (2008 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C19H20Br2N2

M = 436.19

Orthorhombic,

a = 5.6687 (1) Å

b = 7.7919 (2) Å

c = 41.5932 (9) Å

V = 1837.17 (7) Å3

Z = 4

Mo Kα radiation

μ = 4.41 mm−1

T = 100 K

0.45 × 0.44 × 0.12 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (; Bruker, 2005 ▶) T min = 0.229, T max = 0.586

38732 measured reflections

9454 independent reflections

7585 reflections with I > 2σ(I)

R int = 0.049

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.079

S = 1.03

9454 reflections

208 parameters

H-atom parameters constrained

Δρmax = 1.04 e Å−3

Δρmin = −0.61 e Å−3

Absolute structure: Flack (1983 ▶), 3971 Friedel pairs

Flack parameter: 0.019 (6)

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809008113/at2737sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809008113/at2737Isup2.hkl

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

C19H20Br2N2	F(000) = 872
Mr = 436.19	Dx = 1.577 Mg m−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 9987 reflections
a = 5.6687 (1) Å	θ = 2.7–35.5°
b = 7.7919 (2) Å	µ = 4.41 mm−1
c = 41.5932 (9) Å	T = 100 K
V = 1837.17 (7) Å3	Block, colourless
Z = 4	0.45 × 0.44 × 0.12 mm

Bruker SMART APEXII CCD area-detector diffractometer	9454 independent reflections
Radiation source: fine-focus sealed tube	7585 reflections with I > 2σ(I)
graphite	Rint = 0.049
φ and ω scans	θmax = 37.5°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −9→9
Tmin = 0.229, Tmax = 0.586	k = −10→13
38732 measured reflections	l = −71→55

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)] = 0.037	H-atom parameters constrained
wR(F2) = 0.079	w = 1/[σ2(Fo2) + (0.0316P)2 + 0.2032P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max = 0.011
9454 reflections	Δρmax = 1.04 e Å−3
208 parameters	Δρmin = −0.60 e Å−3
0 restraints	Absolute structure: Flack (1983), 3971 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.019 (6)

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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	1.59060 (4)	0.70918 (3)	0.679860 (5)	0.03041 (5)
Br2	1.02132 (3)	0.35735 (2)	1.095005 (4)	0.02216 (4)
N1	0.9734 (3)	0.7039 (2)	0.82239 (4)	0.0214 (3)
N2	0.8180 (3)	0.6175 (2)	0.93830 (4)	0.0198 (3)
C1	1.0509 (3)	0.5599 (2)	0.74067 (5)	0.0203 (3)
H1A	0.9062	0.4991	0.7388	0.024*
C2	1.1894 (4)	0.5835 (3)	0.71353 (5)	0.0219 (3)
H2A	1.1410	0.5403	0.6932	0.026*
C3	1.4013 (3)	0.6720 (2)	0.71684 (4)	0.0212 (3)
C4	1.4767 (3)	0.7348 (2)	0.74652 (4)	0.0197 (3)
H4A	1.6230	0.7935	0.7484	0.024*
C5	1.3353 (3)	0.7104 (3)	0.77327 (4)	0.0184 (3)
H5A	1.3848	0.7528	0.7936	0.022*
C6	1.1191 (3)	0.6235 (2)	0.77059 (4)	0.0180 (3)
C7	0.9574 (3)	0.6067 (2)	0.79820 (5)	0.0198 (3)
H7A	0.8386	0.5208	0.7978	0.024*
C8	0.8001 (3)	0.6814 (3)	0.84805 (4)	0.0209 (3)
H8A	0.6996	0.5808	0.8432	0.025*
H8B	0.6972	0.7839	0.8491	0.025*
C9	0.9225 (3)	0.6548 (2)	0.88094 (4)	0.0179 (3)
C10	0.7242 (3)	0.6457 (2)	0.90606 (4)	0.0188 (3)
H10A	0.6333	0.7542	0.9057	0.023*
H10B	0.6152	0.5510	0.9005	0.023*
C11	0.6955 (3)	0.5293 (2)	0.95790 (4)	0.0178 (3)
H11A	0.5486	0.4841	0.9509	0.021*
C12	0.7732 (3)	0.4951 (2)	0.99097 (4)	0.0165 (3)
C13	0.6324 (3)	0.3938 (2)	1.01110 (5)	0.0184 (3)
H13A	0.4861	0.3514	1.0033	0.022*
C14	0.7025 (3)	0.3543 (3)	1.04224 (4)	0.0196 (3)
H14A	0.6050	0.2867	1.0558	0.024*
C15	0.9177 (3)	0.4158 (2)	1.05301 (4)	0.0184 (3)
C16	1.0606 (3)	0.5189 (2)	1.03375 (4)	0.0192 (3)
H16A	1.2063	0.5616	1.0417	0.023*
C17	0.9877 (3)	0.5583 (2)	1.00290 (4)	0.0193 (3)
H17A	1.0838	0.6289	0.9897	0.023*
C18	1.0856 (3)	0.8053 (3)	0.88844 (5)	0.0241 (4)
H18A	1.1615	0.7866	0.9093	0.036*
H18B	0.9935	0.9117	0.8891	0.036*
H18C	1.2065	0.8142	0.8717	0.036*
C19	1.0619 (4)	0.4868 (3)	0.88061 (5)	0.0244 (4)
H19A	1.1393	0.4706	0.9015	0.037*
H19B	1.1816	0.4913	0.8636	0.037*
H19C	0.9544	0.3908	0.8765	0.037*

	U11	U22	U33	U12	U13	U23
Br1	0.02919 (10)	0.04538 (12)	0.01667 (8)	0.00266 (9)	0.00467 (7)	0.00429 (9)
Br2	0.02804 (9)	0.02117 (7)	0.01728 (8)	−0.00042 (7)	−0.00430 (7)	0.00085 (7)
N1	0.0223 (6)	0.0248 (7)	0.0169 (6)	−0.0017 (6)	0.0014 (6)	0.0021 (6)
N2	0.0204 (7)	0.0234 (8)	0.0155 (7)	0.0001 (6)	0.0011 (5)	0.0003 (6)
C1	0.0215 (8)	0.0207 (8)	0.0189 (8)	0.0001 (6)	−0.0015 (6)	−0.0033 (6)
C2	0.0239 (8)	0.0251 (8)	0.0168 (8)	0.0028 (7)	−0.0041 (7)	−0.0041 (7)
C3	0.0228 (7)	0.0233 (9)	0.0176 (8)	0.0044 (6)	0.0029 (6)	0.0023 (6)
C4	0.0183 (7)	0.0218 (7)	0.0190 (7)	−0.0006 (6)	0.0004 (6)	0.0019 (6)
C5	0.0194 (7)	0.0208 (8)	0.0150 (7)	−0.0003 (7)	−0.0011 (6)	−0.0011 (7)
C6	0.0209 (7)	0.0170 (8)	0.0161 (7)	0.0012 (6)	0.0000 (6)	0.0006 (6)
C7	0.0178 (7)	0.0216 (8)	0.0199 (8)	−0.0008 (6)	−0.0005 (6)	0.0034 (6)
C8	0.0181 (7)	0.0277 (10)	0.0168 (8)	−0.0001 (6)	0.0012 (6)	0.0024 (7)
C9	0.0160 (7)	0.0201 (7)	0.0175 (7)	0.0003 (6)	0.0006 (5)	0.0009 (6)
C10	0.0186 (7)	0.0221 (7)	0.0157 (7)	−0.0007 (6)	−0.0008 (6)	0.0019 (8)
C11	0.0191 (7)	0.0186 (8)	0.0157 (7)	−0.0003 (6)	0.0002 (6)	−0.0017 (6)
C12	0.0181 (7)	0.0161 (7)	0.0152 (7)	0.0006 (6)	0.0006 (6)	−0.0013 (6)
C13	0.0166 (7)	0.0197 (8)	0.0189 (8)	−0.0009 (6)	0.0002 (6)	−0.0003 (6)
C14	0.0206 (7)	0.0205 (7)	0.0178 (8)	−0.0013 (7)	0.0020 (6)	0.0015 (7)
C15	0.0226 (8)	0.0186 (7)	0.0141 (7)	0.0027 (6)	−0.0013 (6)	−0.0020 (6)
C16	0.0176 (8)	0.0191 (7)	0.0208 (8)	−0.0016 (6)	0.0004 (6)	−0.0026 (6)
C17	0.0206 (7)	0.0192 (7)	0.0180 (7)	−0.0022 (7)	0.0004 (7)	−0.0009 (6)
C18	0.0212 (8)	0.0259 (9)	0.0251 (9)	−0.0045 (7)	0.0019 (7)	−0.0011 (8)
C19	0.0246 (9)	0.0235 (8)	0.0250 (9)	0.0057 (7)	0.0037 (7)	0.0021 (7)

Br1—C3	1.8978 (19)	C9—C19	1.529 (3)
Br2—C15	1.8983 (18)	C9—C10	1.536 (2)
N1—C7	1.263 (2)	C10—H10A	0.9900
N1—C8	1.462 (2)	C10—H10B	0.9900
N2—C11	1.272 (2)	C11—C12	1.469 (3)
N2—C10	1.459 (2)	C11—H11A	0.9500
C1—C2	1.387 (3)	C12—C13	1.400 (3)
C1—C6	1.394 (3)	C12—C17	1.402 (3)
C1—H1A	0.9500	C13—C14	1.389 (3)
C2—C3	1.392 (3)	C13—H13A	0.9500
C2—H2A	0.9500	C14—C15	1.385 (3)
C3—C4	1.395 (3)	C14—H14A	0.9500
C4—C5	1.384 (2)	C15—C16	1.394 (3)
C4—H4A	0.9500	C16—C17	1.383 (3)
C5—C6	1.404 (3)	C16—H16A	0.9500
C5—H5A	0.9500	C17—H17A	0.9500
C6—C7	1.475 (3)	C18—H18A	0.9800
C7—H7A	0.9500	C18—H18B	0.9800
C8—C9	1.548 (3)	C18—H18C	0.9800
C8—H8A	0.9900	C19—H19A	0.9800
C8—H8B	0.9900	C19—H19B	0.9800
C9—C18	1.525 (3)	C19—H19C	0.9800
C7—N1—C8	117.50 (17)	C9—C10—H10A	109.3
C11—N2—C10	118.11 (16)	N2—C10—H10B	109.3
C2—C1—C6	121.48 (17)	C9—C10—H10B	109.3
C2—C1—H1A	119.3	H10A—C10—H10B	108.0
C6—C1—H1A	119.3	N2—C11—C12	122.30 (17)
C1—C2—C3	118.26 (18)	N2—C11—H11A	118.9
C1—C2—H2A	120.9	C12—C11—H11A	118.9
C3—C2—H2A	120.9	C13—C12—C17	118.72 (17)
C2—C3—C4	121.73 (18)	C13—C12—C11	119.43 (16)
C2—C3—Br1	118.89 (15)	C17—C12—C11	121.84 (17)
C4—C3—Br1	119.37 (14)	C14—C13—C12	121.29 (17)
C5—C4—C3	119.03 (17)	C14—C13—H13A	119.4
C5—C4—H4A	120.5	C12—C13—H13A	119.4
C3—C4—H4A	120.5	C15—C14—C13	118.47 (17)
C4—C5—C6	120.53 (16)	C15—C14—H14A	120.8
C4—C5—H5A	119.7	C13—C14—H14A	120.8
C6—C5—H5A	119.7	C14—C15—C16	121.70 (17)
C1—C6—C5	118.96 (16)	C14—C15—Br2	119.15 (14)
C1—C6—C7	119.40 (17)	C16—C15—Br2	119.15 (14)
C5—C6—C7	121.56 (16)	C17—C16—C15	119.17 (17)
N1—C7—C6	121.50 (17)	C17—C16—H16A	120.4
N1—C7—H7A	119.3	C15—C16—H16A	120.4
C6—C7—H7A	119.3	C16—C17—C12	120.63 (17)
N1—C8—C9	111.10 (15)	C16—C17—H17A	119.7
N1—C8—H8A	109.4	C12—C17—H17A	119.7
C9—C8—H8A	109.4	C9—C18—H18A	109.5
N1—C8—H8B	109.4	C9—C18—H18B	109.5
C9—C8—H8B	109.4	H18A—C18—H18B	109.5
H8A—C8—H8B	108.0	C9—C18—H18C	109.5
C18—C9—C19	110.28 (15)	H18A—C18—H18C	109.5
C18—C9—C10	109.88 (15)	H18B—C18—H18C	109.5
C19—C9—C10	110.16 (15)	C9—C19—H19A	109.5
C18—C9—C8	110.46 (16)	C9—C19—H19B	109.5
C19—C9—C8	109.78 (16)	H19A—C19—H19B	109.5
C10—C9—C8	106.20 (14)	C9—C19—H19C	109.5
N2—C10—C9	111.43 (14)	H19A—C19—H19C	109.5
N2—C10—H10A	109.3	H19B—C19—H19C	109.5
C6—C1—C2—C3	0.4 (3)	C11—N2—C10—C9	−146.93 (17)
C1—C2—C3—C4	0.7 (3)	C18—C9—C10—N2	−61.5 (2)
C1—C2—C3—Br1	−178.88 (14)	C19—C9—C10—N2	60.2 (2)
C2—C3—C4—C5	−0.9 (3)	C8—C9—C10—N2	178.99 (16)
Br1—C3—C4—C5	178.64 (14)	C10—N2—C11—C12	−179.41 (16)
C3—C4—C5—C6	0.1 (3)	N2—C11—C12—C13	−178.58 (17)
C2—C1—C6—C5	−1.2 (3)	N2—C11—C12—C17	0.2 (3)
C2—C1—C6—C7	175.36 (17)	C17—C12—C13—C14	−0.6 (3)
C4—C5—C6—C1	0.9 (3)	C11—C12—C13—C14	178.16 (17)
C4—C5—C6—C7	−175.54 (17)	C12—C13—C14—C15	−0.8 (3)
C8—N1—C7—C6	177.89 (16)	C13—C14—C15—C16	1.7 (3)
C1—C6—C7—N1	−157.81 (18)	C13—C14—C15—Br2	−178.06 (14)
C5—C6—C7—N1	18.7 (3)	C14—C15—C16—C17	−1.2 (3)
C7—N1—C8—C9	126.29 (18)	Br2—C15—C16—C17	178.54 (14)
N1—C8—C9—C18	57.0 (2)	C15—C16—C17—C12	−0.2 (3)
N1—C8—C9—C19	−64.8 (2)	C13—C12—C17—C16	1.1 (3)
N1—C8—C9—C10	176.10 (15)	C11—C12—C17—C16	−177.63 (17)

D—H···A	D—H	H···A	D···A	D—H···A
C18—H18C···N1	0.98	2.59	2.929 (3)	101
C4—H4A···Cg1i	0.95	2.85	3.5630 (18)	132
C13—H13A···Cg2ii	0.95	2.74	3.4648 (18)	134

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4A⋯Cg1i	0.95	2.85	3.5630 (18)	132
C13—H13A⋯Cg2ii	0.95	2.74	3.4648 (18)	134

Symmetry codes: (i) ; (ii) . Cg1 and Cg2 are the centroids of the C1–C6 and C9–C17 benzene rings, respectively.