4,4'-Dibromo-2,2'-{ethane-1,2-diylbis[(methyl-imino)-methyl-ene]}diphenol.

The asymmetric unit of the title compound, C(18)H(22)Br(2)N(2)O(2), contains one half-mol-ecule that is related to the other half by a center of inversion located at the mid-point of the central C-C bond. The hy-droxy (phenolic) groups are linked to the N atoms by O-H⋯N hydrogen bonds, which generate S(6) rings.

Related literature

For the synthesis, see: Rivera et al. (2010 ▶). For the uses of tetra­hydro­salens in coordination chemistry, see: Atwood (1997 ▶). For a related structure, see: Naza­renko et al. (2000 ▶). For reference bond lenghts, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C18H22Br2N2O2

M = 458.2

Orthorhombic,

a = 15.9282 (3) Å

b = 6.1123 (2) Å

c = 18.3315 (4) Å

V = 1784.72 (8) Å3

Z = 4

Cu Kα radiation

μ = 5.87 mm−1

T = 120 K

0.36 × 0.06 × 0.05 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector

Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T min = 0.611, T max = 1

24526 measured reflections

1591 independent reflections

1482 reflections with I > 3σ(I)

R int = 0.028

Refinement

R[F 2 > 2σ(F 2)] = 0.021

wR(F 2) = 0.075

S = 1.52

1591 reflections

112 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.20 e Å−3

Δρmin = −0.32 e Å−3

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2003 ▶); program(s) used to refine structure: JANA2006 (Petříček et al., 2006 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: JANA2006.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811017193/hb5874sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811017193/hb5874Isup2.hkl

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

C18H22Br2N2O2	F(000) = 920
Mr = 458.2	Dx = 1.705 Mg m−3
Orthorhombic, Pbca	Cu Kα radiation, λ = 1.5418 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 16599 reflections
a = 15.9282 (3) Å	θ = 2.8–66.9°
b = 6.1123 (2) Å	µ = 5.87 mm−1
c = 18.3315 (4) Å	T = 120 K
V = 1784.72 (8) Å3	Needle, colourless
Z = 4	0.36 × 0.06 × 0.05 mm

Oxford Diffraction Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector	1591 independent reflections
Radiation source: Enhance Ultra (Cu) X-ray Source	1482 reflections with I > 3σ(I)
mirror	Rint = 0.028
Detector resolution: 10.3784 pixels mm-1	θmax = 67.1°, θmin = 4.8°
Rotation method data acquisition using ω scans	h = −18→18
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −7→7
Tmin = 0.611, Tmax = 1	l = −21→21
24526 measured reflections

Refinement on F2	41 constraints
R[F2 > 2σ(F2)] = 0.021	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.075	Weighting scheme based on measured s.u.'s w = 1/[σ2(I) + 0.0016I2]
S = 1.52	(Δ/σ)max = 0.008
1591 reflections	Δρmax = 0.20 e Å−3
112 parameters	Δρmin = −0.32 e Å−3
0 restraints

Experimental. CrysAlisPro, Oxford Diffraction (2009), Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F2 for refinement carried out on F and F2, respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement.The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.

	x	y	z	Uiso*/Ueq
Br1	0.640851 (13)	0.05571 (4)	0.580303 (11)	0.03125 (11)
O4	0.61560 (9)	0.4268 (2)	0.88393 (7)	0.0270 (4)
N2	0.58909 (9)	0.0319 (2)	0.93218 (8)	0.0195 (4)
C1	0.59115 (9)	0.1285 (3)	0.80150 (9)	0.0202 (4)
C2	0.62193 (10)	0.3384 (3)	0.81629 (9)	0.0214 (5)
C3	0.66038 (12)	0.4593 (3)	0.76131 (11)	0.0242 (5)
C4	0.66647 (10)	0.3757 (3)	0.69103 (9)	0.0251 (5)
C5	0.63443 (9)	0.1714 (3)	0.67664 (10)	0.0227 (5)
C6	0.59736 (10)	0.0460 (3)	0.73124 (10)	0.0217 (5)
C7	0.54916 (10)	−0.0057 (3)	0.86063 (9)	0.0216 (4)
C8	0.53980 (10)	−0.0646 (3)	0.99219 (9)	0.0218 (5)
C9	0.67487 (11)	−0.0584 (3)	0.93342 (10)	0.0241 (5)
H3	0.682855	0.601479	0.77203	0.0291*
H4	0.692687	0.459508	0.65304	0.0301*
H6	0.576136	−0.09726	0.720273	0.026*
H7a	0.490778	0.032417	0.863354	0.0259*
H7b	0.552676	−0.158184	0.848428	0.0259*
H8a	0.573654	−0.070797	1.035465	0.0262*
H8b	0.525375	−0.212723	0.980158	0.0262*
H9a	0.701148	−0.023134	0.97905	0.0289*
H9b	0.672436	−0.214496	0.927867	0.0289*
H9c	0.706892	0.003417	0.894138	0.0289*
H4o	0.6031 (15)	0.326 (4)	0.9104 (12)	0.0323*

	U11	U22	U33	U12	U13	U23
Br1	0.03214 (19)	0.0431 (2)	0.01850 (19)	0.00457 (7)	−0.00120 (6)	−0.00091 (7)
O4	0.0343 (7)	0.0206 (6)	0.0260 (7)	−0.0033 (5)	0.0042 (5)	−0.0036 (5)
N2	0.0153 (7)	0.0236 (8)	0.0195 (7)	−0.0017 (5)	0.0009 (5)	0.0002 (5)
C1	0.0144 (7)	0.0228 (8)	0.0235 (8)	0.0010 (6)	−0.0004 (6)	0.0020 (7)
C2	0.0172 (7)	0.0228 (8)	0.0243 (8)	0.0015 (6)	−0.0011 (6)	0.0006 (7)
C3	0.0210 (8)	0.0226 (9)	0.0291 (10)	−0.0022 (6)	−0.0008 (7)	0.0037 (6)
C4	0.0180 (8)	0.0298 (9)	0.0276 (9)	−0.0002 (7)	−0.0002 (6)	0.0075 (7)
C5	0.0181 (8)	0.0314 (10)	0.0185 (8)	0.0044 (6)	−0.0013 (5)	0.0004 (7)
C6	0.0190 (8)	0.0228 (9)	0.0232 (9)	0.0018 (6)	−0.0032 (6)	0.0008 (6)
C7	0.0194 (8)	0.0244 (8)	0.0210 (8)	−0.0042 (7)	−0.0012 (6)	0.0005 (7)
C8	0.0189 (8)	0.0251 (9)	0.0214 (8)	−0.0012 (6)	0.0012 (6)	0.0036 (6)
C9	0.0163 (9)	0.0289 (10)	0.0271 (8)	0.0019 (6)	0.0000 (7)	0.0004 (6)

Br1—C5	1.9051 (18)	C4—H4	0.96
O4—H4o	0.81 (2)	C5—C6	1.392 (2)
N2—C7	1.476 (2)	C6—H6	0.96
N2—C8	1.475 (2)	C7—H7a	0.96
N2—C9	1.474 (2)	C7—H7b	0.96
C1—C2	1.400 (2)	C8—C8i	1.521 (2)
C1—C6	1.387 (2)	C8—H8a	0.96
C1—C7	1.515 (2)	C8—H8b	0.96
C2—C3	1.392 (3)	C9—H9a	0.96
C3—C4	1.389 (3)	C9—H9b	0.96
C3—H3	0.96	C9—H9c	0.96
C4—C5	1.375 (3)
C7—N2—C8	111.79 (13)	N2—C7—C1	111.17 (13)
C7—N2—C9	110.78 (13)	N2—C7—H7a	109.4713
C8—N2—C9	109.40 (13)	N2—C7—H7b	109.4711
C2—C1—C6	119.21 (15)	C1—C7—H7a	109.4712
C2—C1—C7	120.83 (14)	C1—C7—H7b	109.4709
C6—C1—C7	119.93 (15)	H7a—C7—H7b	107.7191
C1—C2—C3	120.04 (16)	N2—C8—C8i	112.14 (13)
C2—C3—C4	120.46 (16)	N2—C8—H8a	109.4713
C2—C3—H3	119.771	N2—C8—H8b	109.4716
C4—C3—H3	119.7725	C8i—C8—H8a	109.4716
C3—C4—C5	119.09 (16)	C8i—C8—H8b	109.4707
C3—C4—H4	120.4567	H8a—C8—H8b	106.6664
C5—C4—H4	120.4562	N2—C9—H9a	109.4705
Br1—C5—C4	119.68 (13)	N2—C9—H9b	109.471
Br1—C5—C6	119.00 (14)	N2—C9—H9c	109.4718
C4—C5—C6	121.31 (16)	H9a—C9—H9b	109.4713
C1—C6—C5	119.85 (16)	H9a—C9—H9c	109.4714
C1—C6—H6	120.0729	H9b—C9—H9c	109.4713
C5—C6—H6	120.073
N2—C8—C8i—N2i	180

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4o···N2	0.81 (2)	1.86 (2)	2.6051 (19)	154 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4o⋯N2	0.81 (2)	1.86 (2)	2.6051 (19)	154 (2)