A monoclinic polymorph of (R,R)-4,4′-dibromo-2,2′-[cyclo­hexane-1,2-diylbis(nitrilo­methanylyl­idene)]diphenol

Ha, K.

doi:10.1107/S1600536812016376

organic compounds

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Volume 68| Part 5| May 2012| Page o1449

doi:10.1107/S1600536812016376

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A monoclinic polymorph of (R,R)-4,4′-dibromo-2,2′-[cyclohexane-1,2-diylbis(nitrilomethanylylidene)]diphenol

Kwang Ha ^a ^*

^aSchool of Applied Chemical Engineering, The Research Institute of Catalysis, Chonnam National University, Gwangju 500-757, Republic of Korea
^*Correspondence e-mail: hakwang@chonnam.ac.kr

(Received 9 April 2012; accepted 15 April 2012; online 21 April 2012)

The title compound, C₂₀H₂₀Br₂N₂O₂, a tetradentate Schiff base, is the enantiomerically pure R,R-diastereomer of four possible stereoisomers. The molecular structure reveals two strong intramolecular O—H⋯N hydrogen bonds between the hydroxy O atom and the imino N atom, which each generate S(6) rings. In the crystal, molecules are stacked in columns along the a axis; when viewed down the b axis, successive columns are stacked in the opposite direction. The structure reported herein is the monoclinic polymorph of the previously reported orthorhombic form [Yi & Hu (2009 ). Acta Cryst. E65, o2643], in which the complete molecule is generated by a crystallographic twofold axis.

Related literature

For the orthorhombic polymorph, see: Yi & Hu (2009).

Experimental

Crystal data

C₂₀H₂₀Br₂N₂O₂
M_r = 480.20
Monoclinic, P 2₁
a = 5.9082 (5) Å
b = 18.8626 (15) Å
c = 9.0088 (7) Å
β = 91.867 (2)°
V = 1003.44 (14) Å³
Z = 2
Mo Kα radiation
μ = 4.06 mm⁻¹
T = 200 K
0.31 × 0.17 × 0.16 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ) T_min = 0.786, T_max = 1.000
7343 measured reflections
3868 independent reflections
2484 reflections with I > 2σ(I)
R_int = 0.031

Refinement

R[F² > 2σ(F²)] = 0.039
wR(F²) = 0.108
S = 1.03
3868 reflections
235 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.88 e Å⁻³
Δρ_min = −0.47 e Å⁻³
Absolute structure: Flack (1983 ), 1331 Friedel pairs
Flack parameter: −0.010 (16)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O⋯N1	0.84	1.82	2.581 (7)	150
O2—H2O⋯N2	0.84	1.87	2.626 (7)	149

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: ORTEP-3 (Farrugia, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812016376/hb6734sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812016376/hb6734Isup2.hkl

checkCIF report

Comment top

The crystal structure of the title compound, C₂₀H₂₀Br₂N₂O₂, was previously reported in the orthorhombic space group P2₁2₁2 (Yi & Hu, 2009). The structure presented herein is essentially the same as the published structure and represents a monoclinic polymorph.

The title compound is a tetradentate Schiff base (Fig. 1), which can act as a dibasic ligand, i.e. the N and O donor atoms can coordinate one metal ion. The compound has two chiral C centres and is one of four possible stereoisomers. Crystallographically, the absolute configuration has been established by anomalous dispersion effects, and the R configuration of the asymmetric C atoms (C1 and C6) could be assigned. The Schiff base reveals strong intramolecular O—H···N hydrogen bonds between the hydroxy O atom and the imino N atom, with O···N distances of 2.581 (7) and 2.626 (7) Å, forming nearly planar six-membered rings (Fig. 2, Table 1). In the crystal structure, the benzene rings are not parallel: the dihedral angle between the benzene rings is 67.20 (15)°. The N—C bond lengths and the C—N—C bond angles indicate that the imino N atoms are sp²-hybridized [N1═C7 = 1.274 (8) Å, N1—C1 = 1.461 (8) Å, <C7—N1—C1 = 118.7 (6)°; N2═C14 = 1.280 (8) Å, N2—C6 = 1.474 (8) Å, <C14—N2—C6 = 118.3 (6)°]. The molecules are stacked in columns along the a axis. When viewed down the b axis, the successive compounds are stacked in the opposite direction. In the columns, the shortest centroid-centroid distance between aromatic rings is 4.709 (3) Å.

Related literature top

For the orthorhombic polymorph, see: Yi & Hu (2009).

Experimental top

1,2-Diaminocyclohexane (0.8007 g, 7.012 mmol) and 5-bromosalicylaldehyde (2.8204 g, 14.031 mmol) in EtOH (20 ml) were stirred for 1 h at room temperature. After addition of pentane (30 ml) to the reaction mixture, the formed precipitate was separated by filtration, washed with ether, and dried at 323 K, to give a yellow powder (1.7660 g). Yellow blocks were obtained by slow evaporation from a CH₃CN solution at room temperature. The previous polymorph (Yi & Hu, 2009) was crystallised from methanol.

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. A structure detail of the title compound, with atom numbering. Displacement ellipsoids are drawn at the 30% probability level for non-H atoms.
	Fig. 2. A view of the unit-cell contents of the title compound. Intramolecular O—H···N hydrogen-bond interactions are drawn with dashed lines.

(R,R)-4,4'-dibromo-2,2'- [cyclohexane-1,2-diylbis(nitrilomethanylylidene)]diphenol top

Crystal data top

C₂₀H₂₀Br₂N₂O₂	F(000) = 480
M_r = 480.20	D_x = 1.589 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 2758 reflections
a = 5.9082 (5) Å	θ = 2.5–25.8°
b = 18.8626 (15) Å	µ = 4.06 mm⁻¹
c = 9.0088 (7) Å	T = 200 K
β = 91.867 (2)°	Block, yellow
V = 1003.44 (14) Å³	0.31 × 0.17 × 0.16 mm
Z = 2

Data collection top

Bruker SMART 1000 CCD diffractometer	3868 independent reflections
Radiation source: fine-focus sealed tube	2484 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
ϕ and ω scans	θ_max = 28.3°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −7→7
T_min = 0.786, T_max = 1.000	k = −20→25
7343 measured reflections	l = −11→11

Refinement top

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)] = 0.039	H-atom parameters constrained
wR(F²) = 0.108	w = 1/[σ²(F_o²) + (0.0434P)²] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
3868 reflections	Δρ_max = 0.88 e Å⁻³
235 parameters	Δρ_min = −0.47 e Å⁻³
1 restraint	Absolute structure: Flack (1983), 1331 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.010 (16)

Crystal data top

C₂₀H₂₀Br₂N₂O₂	V = 1003.44 (14) Å³
M_r = 480.20	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 5.9082 (5) Å	µ = 4.06 mm⁻¹
b = 18.8626 (15) Å	T = 200 K
c = 9.0088 (7) Å	0.31 × 0.17 × 0.16 mm
β = 91.867 (2)°

Data collection top

Bruker SMART 1000 CCD diffractometer	3868 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2000)	2484 reflections with I > 2σ(I)
T_min = 0.786, T_max = 1.000	R_int = 0.031
7343 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	H-atom parameters constrained
wR(F²) = 0.108	Δρ_max = 0.88 e Å⁻³
S = 1.03	Δρ_min = −0.47 e Å⁻³
3868 reflections	Absolute structure: Flack (1983), 1331 Friedel pairs
235 parameters	Absolute structure parameter: −0.010 (16)
1 restraint

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Br1	0.25215 (12)	0.33723 (3)	−0.33161 (7)	0.0600 (3)
Br2	0.27364 (11)	−0.23777 (3)	−0.33104 (7)	0.0551 (2)
O1	0.7141 (7)	0.1204 (3)	0.0604 (6)	0.0539 (13)
H1O	0.6245	0.1070	0.1252	0.081*
O2	−0.2482 (8)	−0.0312 (3)	0.0322 (6)	0.0587 (14)
H2O	−0.1588	−0.0127	0.0955	0.088*
N1	0.3538 (9)	0.1159 (3)	0.2147 (5)	0.0428 (12)
N2	0.1109 (9)	−0.0185 (2)	0.2097 (5)	0.0427 (12)
C1	0.2247 (11)	0.0899 (5)	0.3390 (7)	0.0414 (18)
H1	0.0634	0.1054	0.3257	0.050*
C2	0.3242 (15)	0.1210 (4)	0.4830 (7)	0.0601 (19)
H2A	0.4888	0.1111	0.4893	0.072*
H2B	0.3038	0.1731	0.4816	0.072*
C3	0.2143 (15)	0.0908 (5)	0.6200 (10)	0.068 (2)
H3A	0.2893	0.1107	0.7106	0.081*
H3B	0.0525	0.1045	0.6194	0.081*
C4	0.2344 (16)	0.0103 (5)	0.6219 (10)	0.071 (3)
H4A	0.1588	−0.0089	0.7097	0.086*
H4B	0.3961	−0.0035	0.6288	0.086*
C5	0.1241 (15)	−0.0204 (4)	0.4802 (7)	0.061 (2)
H5A	0.1385	−0.0727	0.4818	0.073*
H5B	−0.0392	−0.0085	0.4763	0.073*
C6	0.2343 (11)	0.0086 (5)	0.3428 (8)	0.0452 (19)
H6	0.3957	−0.0073	0.3416	0.054*
C7	0.2650 (10)	0.1629 (4)	0.1295 (7)	0.0373 (15)
H7	0.1164	0.1795	0.1471	0.045*
C8	0.3885 (9)	0.1916 (3)	0.0051 (6)	0.0344 (12)
C9	0.6051 (10)	0.1676 (3)	−0.0268 (7)	0.0439 (14)
C10	0.7125 (11)	0.1940 (5)	−0.1518 (7)	0.0477 (19)
H10	0.8586	0.1771	−0.1751	0.057*
C11	0.6082 (11)	0.2443 (3)	−0.2412 (6)	0.0459 (15)
H11	0.6819	0.2623	−0.3255	0.055*
C12	0.3947 (9)	0.2685 (3)	−0.2071 (5)	0.0406 (12)
C13	0.2877 (10)	0.2432 (3)	−0.0852 (7)	0.0381 (16)
H13	0.1428	0.2612	−0.0622	0.046*
C14	0.2091 (10)	−0.0645 (4)	0.1293 (7)	0.0378 (15)
H14	0.3597	−0.0784	0.1555	0.045*
C15	0.0974 (10)	−0.0959 (3)	−0.0004 (6)	0.0366 (13)
C16	−0.1247 (10)	−0.0773 (3)	−0.0454 (6)	0.0387 (13)
C17	−0.2241 (12)	−0.1068 (4)	−0.1734 (7)	0.0443 (18)
H17	−0.3742	−0.0939	−0.2032	0.053*
C18	−0.1054 (10)	−0.1550 (3)	−0.2579 (6)	0.0443 (14)
H18	−0.1728	−0.1752	−0.3452	0.053*
C19	0.1098 (10)	−0.1725 (3)	−0.2129 (5)	0.0416 (13)
C20	0.2136 (9)	−0.1450 (3)	−0.0861 (6)	0.0333 (14)
H20	0.3628	−0.1592	−0.0572	0.040*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0820 (6)	0.0589 (6)	0.0384 (4)	0.0047 (4)	−0.0070 (3)	0.0073 (4)
Br2	0.0668 (5)	0.0587 (6)	0.0400 (4)	0.0071 (4)	0.0051 (3)	−0.0076 (4)
O1	0.042 (3)	0.041 (3)	0.080 (4)	0.010 (2)	0.004 (2)	0.005 (3)
O2	0.044 (3)	0.050 (3)	0.082 (4)	0.010 (2)	0.003 (3)	−0.012 (3)
N1	0.049 (3)	0.030 (3)	0.049 (3)	−0.004 (2)	0.000 (2)	0.002 (2)
N2	0.056 (3)	0.031 (3)	0.042 (3)	−0.007 (2)	0.003 (2)	0.000 (2)
C1	0.049 (4)	0.033 (4)	0.042 (5)	−0.007 (3)	0.004 (3)	0.000 (3)
C2	0.089 (6)	0.039 (4)	0.053 (4)	−0.013 (4)	0.007 (4)	−0.013 (3)
C3	0.100 (7)	0.058 (6)	0.046 (5)	−0.023 (5)	0.006 (4)	−0.014 (5)
C4	0.111 (7)	0.056 (6)	0.046 (5)	−0.022 (5)	−0.001 (4)	0.003 (5)
C5	0.086 (6)	0.047 (4)	0.049 (4)	−0.026 (4)	0.003 (4)	−0.004 (3)
C6	0.060 (5)	0.035 (5)	0.041 (5)	−0.012 (3)	−0.001 (4)	−0.002 (3)
C7	0.036 (3)	0.030 (4)	0.045 (4)	−0.001 (3)	−0.002 (3)	−0.007 (3)
C8	0.031 (3)	0.030 (3)	0.041 (3)	0.000 (2)	−0.002 (2)	−0.003 (2)
C9	0.041 (3)	0.035 (3)	0.056 (4)	0.004 (3)	0.000 (3)	−0.004 (3)
C10	0.038 (3)	0.048 (5)	0.058 (4)	−0.008 (3)	0.011 (3)	−0.018 (3)
C11	0.051 (4)	0.047 (4)	0.040 (3)	−0.011 (3)	0.007 (3)	−0.007 (3)
C12	0.054 (3)	0.036 (3)	0.031 (3)	0.000 (3)	−0.001 (2)	−0.006 (3)
C13	0.040 (3)	0.043 (4)	0.031 (3)	0.000 (3)	−0.001 (2)	−0.012 (3)
C14	0.038 (3)	0.038 (4)	0.038 (3)	−0.003 (3)	0.003 (3)	0.007 (3)
C15	0.042 (3)	0.029 (3)	0.038 (3)	−0.006 (2)	0.001 (2)	0.009 (2)
C16	0.039 (3)	0.029 (3)	0.049 (3)	0.004 (2)	0.006 (3)	0.004 (3)
C17	0.044 (4)	0.044 (4)	0.044 (4)	−0.003 (3)	−0.003 (3)	0.012 (3)
C18	0.056 (4)	0.044 (4)	0.032 (3)	−0.007 (3)	−0.005 (2)	0.007 (3)
C19	0.047 (3)	0.047 (4)	0.031 (3)	−0.002 (3)	0.002 (2)	0.000 (3)
C20	0.029 (3)	0.037 (4)	0.033 (3)	0.002 (2)	0.001 (2)	0.003 (3)

Geometric parameters (Å, º) top

Br1—C12	1.894 (6)	C5—H5B	0.9900
Br2—C19	1.912 (6)	C6—H6	1.0000
O1—C9	1.337 (7)	C7—C8	1.461 (8)
O1—H1O	0.8400	C7—H7	0.9500
O2—C16	1.345 (7)	C8—C13	1.391 (8)
O2—H2O	0.8400	C8—C9	1.396 (8)
N1—C7	1.274 (8)	C9—C10	1.403 (9)
N1—C1	1.461 (8)	C10—C11	1.377 (10)
N2—C14	1.280 (8)	C10—H10	0.9500
N2—C6	1.474 (8)	C11—C12	1.385 (8)
C1—C2	1.524 (10)	C11—H11	0.9500
C1—C6	1.534 (7)	C12—C13	1.370 (8)
C1—H1	1.0000	C13—H13	0.9500
C2—C3	1.523 (10)	C14—C15	1.451 (9)
C2—H2A	0.9900	C14—H14	0.9500
C2—H2B	0.9900	C15—C20	1.398 (8)
C3—C4	1.522 (8)	C15—C16	1.405 (8)
C3—H3A	0.9900	C16—C17	1.393 (9)
C3—H3B	0.9900	C17—C18	1.390 (9)
C4—C5	1.528 (11)	C17—H17	0.9500
C4—H4A	0.9900	C18—C19	1.363 (8)
C4—H4B	0.9900	C18—H18	0.9500
C5—C6	1.520 (10)	C19—C20	1.380 (8)
C5—H5A	0.9900	C20—H20	0.9500

C9—O1—H1O	107.9	N1—C7—H7	119.6
C16—O2—H2O	106.3	C8—C7—H7	119.6
C7—N1—C1	118.7 (6)	C13—C8—C9	119.0 (5)
C14—N2—C6	118.3 (6)	C13—C8—C7	119.6 (5)
N1—C1—C2	109.1 (6)	C9—C8—C7	121.5 (5)
N1—C1—C6	109.5 (7)	O1—C9—C8	121.4 (5)
C2—C1—C6	110.6 (7)	O1—C9—C10	119.1 (6)
N1—C1—H1	109.2	C8—C9—C10	119.4 (6)
C2—C1—H1	109.2	C11—C10—C9	120.6 (6)
C6—C1—H1	109.2	C11—C10—H10	119.7
C3—C2—C1	112.5 (7)	C9—C10—H10	119.7
C3—C2—H2A	109.1	C10—C11—C12	119.4 (6)
C1—C2—H2A	109.1	C10—C11—H11	120.3
C3—C2—H2B	109.1	C12—C11—H11	120.3
C1—C2—H2B	109.1	C13—C12—C11	120.7 (5)
H2A—C2—H2B	107.8	C13—C12—Br1	120.3 (4)
C4—C3—C2	110.3 (8)	C11—C12—Br1	119.0 (4)
C4—C3—H3A	109.6	C12—C13—C8	120.9 (5)
C2—C3—H3A	109.6	C12—C13—H13	119.6
C4—C3—H3B	109.6	C8—C13—H13	119.6
C2—C3—H3B	109.6	N2—C14—C15	122.0 (6)
H3A—C3—H3B	108.1	N2—C14—H14	119.0
C3—C4—C5	109.8 (9)	C15—C14—H14	119.0
C3—C4—H4A	109.7	C20—C15—C16	118.5 (5)
C5—C4—H4A	109.7	C20—C15—C14	119.8 (5)
C3—C4—H4B	109.7	C16—C15—C14	121.7 (5)
C5—C4—H4B	109.7	O2—C16—C17	117.8 (6)
H4A—C4—H4B	108.2	O2—C16—C15	122.0 (5)
C6—C5—C4	111.2 (6)	C17—C16—C15	120.2 (6)
C6—C5—H5A	109.4	C18—C17—C16	120.5 (6)
C4—C5—H5A	109.4	C18—C17—H17	119.7
C6—C5—H5B	109.4	C16—C17—H17	119.7
C4—C5—H5B	109.4	C19—C18—C17	118.5 (6)
H5A—C5—H5B	108.0	C19—C18—H18	120.7
N2—C6—C5	108.9 (6)	C17—C18—H18	120.7
N2—C6—C1	108.2 (7)	C18—C19—C20	122.7 (5)
C5—C6—C1	111.2 (7)	C18—C19—Br2	118.3 (4)
N2—C6—H6	109.5	C20—C19—Br2	119.0 (4)
C5—C6—H6	109.5	C19—C20—C15	119.5 (5)
C1—C6—H6	109.5	C19—C20—H20	120.2
N1—C7—C8	120.9 (6)	C15—C20—H20	120.2

C7—N1—C1—C2	−106.0 (7)	C9—C10—C11—C12	−0.3 (10)
C7—N1—C1—C6	132.8 (6)	C10—C11—C12—C13	0.4 (9)
N1—C1—C2—C3	−174.3 (7)	C10—C11—C12—Br1	−179.6 (5)
C6—C1—C2—C3	−53.9 (9)	C11—C12—C13—C8	−1.4 (9)
C1—C2—C3—C4	56.4 (11)	Br1—C12—C13—C8	178.5 (4)
C2—C3—C4—C5	−57.8 (10)	C9—C8—C13—C12	2.4 (9)
C3—C4—C5—C6	58.7 (10)	C7—C8—C13—C12	−176.7 (5)
C14—N2—C6—C5	−109.5 (7)	C6—N2—C14—C15	177.7 (6)
C14—N2—C6—C1	129.6 (7)	N2—C14—C15—C20	178.8 (6)
C4—C5—C6—N2	−175.8 (7)	N2—C14—C15—C16	0.4 (9)
C4—C5—C6—C1	−56.7 (9)	C20—C15—C16—O2	179.1 (5)
N1—C1—C6—N2	−66.8 (7)	C14—C15—C16—O2	−2.4 (8)
C2—C1—C6—N2	173.0 (5)	C20—C15—C16—C17	−0.6 (9)
N1—C1—C6—C5	173.7 (5)	C14—C15—C16—C17	177.9 (6)
C2—C1—C6—C5	53.5 (8)	O2—C16—C17—C18	−179.7 (6)
C1—N1—C7—C8	178.9 (6)	C15—C16—C17—C18	0.1 (10)
N1—C7—C8—C13	−179.5 (6)	C16—C17—C18—C19	−0.1 (10)
N1—C7—C8—C9	1.5 (9)	C17—C18—C19—C20	0.7 (9)
C13—C8—C9—O1	176.9 (5)	C17—C18—C19—Br2	−179.2 (5)
C7—C8—C9—O1	−4.1 (9)	C18—C19—C20—C15	−1.3 (9)
C13—C8—C9—C10	−2.3 (9)	Br2—C19—C20—C15	178.6 (4)
C7—C8—C9—C10	176.7 (5)	C16—C15—C20—C19	1.2 (8)
O1—C9—C10—C11	−177.9 (6)	C14—C15—C20—C19	−177.3 (5)
C8—C9—C10—C11	1.3 (10)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···N1	0.84	1.82	2.581 (7)	150
O2—H2O···N2	0.84	1.87	2.626 (7)	149

Experimental details

Crystal data
Chemical formula	C₂₀H₂₀Br₂N₂O₂
M_r	480.20
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	200
a, b, c (Å)	5.9082 (5), 18.8626 (15), 9.0088 (7)
β (°)	91.867 (2)
V (Å³)	1003.44 (14)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	4.06
Crystal size (mm)	0.31 × 0.17 × 0.16

Data collection
Diffractometer	Bruker SMART 1000 CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2000)
T_min, T_max	0.786, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	7343, 3868, 2484
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.108, 1.03
No. of reflections	3868
No. of parameters	235
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.88, −0.47
Absolute structure	Flack (1983), 1331 Friedel pairs
Absolute structure parameter	−0.010 (16)

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···N1	0.84	1.82	2.581 (7)	150
O2—H2O···N2	0.84	1.87	2.626 (7)	149

Acknowledgements

This work was supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2011–0030747).

References

Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yi, J. & Hu, S. (2009). Acta Cryst. E65, o2643. Web of Science CSD CrossRef IUCr Journals Google Scholar

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Volume 68| Part 5| May 2012| Page o1449

doi:10.1107/S1600536812016376

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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

A monoclinic polymorph of (R,R)-4,4′-di­bromo-2,2′-[cyclo­hexane-1,2-diylbis(nitrilo­methanylyl­­idene)]diphenol

Related literature

Experimental

Crystal data

Data collection

Refinement

Supporting information

Acknowledgements

References

organic compounds

A monoclinic polymorph of (R,R)-4,4′-dibromo-2,2′-[cyclohexane-1,2-diylbis(nitrilomethanylylidene)]diphenol