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Acta Crystallogr Sect E Struct Rep Online. 2009 November 1; 65(Pt 11): o2643.
Published online 2009 October 3. doi:  10.1107/S1600536809039671
PMCID: PMC2971247

(R,R)-4,4′-Dibromo-2,2′-[cyclo­hexane-1,2-diylbis(nitrilo­methyl­idyne)]diphenol

Abstract

The mol­ecule of the title compound, C20H20Br2N2O2, lies on a twofold axis. It contains two stereogenic C atoms with R chirality and thus it is the enatiomerically pure R,R-diastereomer. There is an intra­molecular O—H(...)N hydrogen bond.

Related literature

For the structure of 1,2-cyclo­hexa­nediamine, see: Yang et al., (2004 [triangle], 2007 [triangle]). For background to the use of chiral Salen compounds containing the 1,2-cyclo­hexa­nediamine motif in asymmetric catalytic synthesis, see: Canail & Sherrington (1999 [triangle]); Jacobsen (2000 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-o2643-scheme1.jpg

Experimental

Crystal data

  • C20H20Br2N2O2
  • M r = 480.20
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-65-o2643-efi1.jpg
  • a = 5.9323 (16) Å
  • b = 19.079 (5) Å
  • c = 9.009 (2) Å
  • V = 1019.7 (4) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 3.99 mm−1
  • T = 298 K
  • 0.28 × 0.21 × 0.15 mm

Data collection

  • Bruker APEXII area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.401, T max = 0.586
  • 5912 measured reflections
  • 1727 independent reflections
  • 1449 reflections with I > 2σ(I)
  • R int = 0.024

Refinement

  • R[F 2 > 2σ(F 2)] = 0.032
  • wR(F 2) = 0.089
  • S = 1.06
  • 1727 reflections
  • 119 parameters
  • H-atom parameters constrained
  • Δρmax = 0.34 e Å−3
  • Δρmin = −0.39 e Å−3
  • Absolute structure: Flack (1983 [triangle]), 681 Friedel pairs
  • Flack parameter: 0.018 (18)

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 [triangle]) and ORTEP-3 for Windows (Farrugia, 1997 [triangle]); software used to prepare material for publication: SHELXL97.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809039671/dn2493sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809039671/dn2493Isup2.hkl

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

Acknowledgments

The authors are grateful for funding from the Northern University of China.

supplementary crystallographic information

Comment

Chiral Salen compounds containing 1,2-cyclohexanediamine motif are widely used in the asymmetric catalytic synthesis (Canail & Sherrington, 1999; Jacobsen et al., 2000). Until now, only few single-crystal structures of chiral Salen compounds were reported. Some interesting compounds with 1,2-cyclohexanediamine have however been reported (Yang et al., 2004; 2007). In an attempt to form a Cd(II) complex with the (R,R)-4,4'-bromo-2,2'-[cyclohexane-1,2-diylbis (nitrilomethylidyne)]diphenol, we unexpectedly obtained the title compound (I) whose crystal structure is reported herein.

The molecular structure of (I) is built from two halves related through a two fold axix passing through the middle of the C8-C8i and C10-C10i bonds [(i)= 1-x, 2-y, z)] (Fig. 1). The stereogenic carbon C8 has the R chirality and so the molecule is the enantiomerically pure R,R diastereomer which confirms the synthetic patway used. This molecule is closely related to the (R,R)-N,N'-Bis(5-chlorosalicylidene)- 1,2-cyclohexanediamine compound (Yang et al., 2004).

Intramolecular O-H···N hydrogen bonds also exist in this molecule and thus stabilize the structure (Table 1).

Experimental

The title compound was synthesized according to the literature (Yang et al., 2004) using the reaction of (R,R)-1,2-cyclohexanediamine, Na2SO4, and 5-bromon–2-hydroxybenzaldehyde under mild condition. (R,R)-4,4'-Bromo-2,2'-[cyclohexane-1,2-diylbis (nitrilomethylidyne)]diphenol (0.52 g, 1 mmol) was added to a solution of Cd(AC)2 .4H2O(0.26g, 1mmol) in methanol(20mL). The mixture was heated for 20 hs under reflux with stirring. It was then filtered to give a clear solution, into which diethyl ether vapour was allowed to condense in a closed vessel. After being allowed to stand for a two weeks at room temperature, colorless single crystals were used to measure X-ray diffraction analysis.

Refinement

The absolute configuration has been deduced from the X-ray structural analyses and confirms the predicted configuration expected from the synthetic pathway.

All H atoms attached to C atoms and O atom were fixed geometrically and treated as riding with C—H = 0.93 Å (aromatic), 0.97 Å (methylene) or 0.98Å (methine) and O—H = 0.82 Å with Uiso(H) = 1.2Ueq(C) or Uiso(H) = 1.5Ueq(O).

Figures

Fig. 1.
Molecular view of (I) with the atom-labeling scheme. Ellipsoids are drawn at the the 30% probability level. H atoms are represented as small spheres of arbitrary radii. [Symmetric code: (i): -x+1, -y+2, z]

Crystal data

C20H20Br2N2O2F(000) = 480
Mr = 480.20Dx = 1.564 Mg m3
Orthorhombic, P21212Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2 2abCell parameters from 1727 reflections
a = 5.9323 (16) Åθ = 2.1–24.9°
b = 19.079 (5) ŵ = 3.99 mm1
c = 9.009 (2) ÅT = 298 K
V = 1019.7 (4) Å3Block, colorless
Z = 20.28 × 0.21 × 0.15 mm

Data collection

Bruker APEXII area-detector diffractometer1727 independent reflections
Radiation source: fine-focus sealed tube1449 reflections with I > 2σ(I)
graphiteRint = 0.024
[var phi] and ω scansθmax = 24.7°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −6→0
Tmin = 0.401, Tmax = 0.586k = −22→22
5912 measured reflectionsl = −10→0

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.089w = 1/[σ2(Fo2) + (0.0509P)2 + 0.1466P] where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max = 0.001
1727 reflectionsΔρmax = 0.34 e Å3
119 parametersΔρmin = −0.39 e Å3
0 restraintsAbsolute structure: Flack (1983), 681 Friedel pairs
Primary atom site location: structure-invariant direct methodsFlack parameter: 0.018 (18)

Special details

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 > 2sigma(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)

xyzUiso*/Ueq
Br10.48940 (8)0.71173 (2)0.82889 (4)0.0863 (2)
N10.6206 (5)0.93317 (14)0.2921 (3)0.0608 (8)
O10.9786 (5)0.92461 (14)0.4597 (4)0.0835 (8)
H10.89270.94460.40230.125*
C10.6427 (6)0.77902 (19)0.7105 (4)0.0572 (9)
C20.8549 (7)0.7999 (2)0.7508 (4)0.0635 (10)
H20.92420.78100.83420.076*
C30.9636 (6)0.8492 (2)0.6663 (4)0.0677 (10)
H31.10760.86370.69330.081*
C40.8627 (6)0.87805 (17)0.5409 (5)0.0590 (9)
C50.6450 (6)0.85674 (15)0.5008 (4)0.0505 (8)
C60.5368 (6)0.80627 (17)0.5877 (3)0.0533 (8)
H60.39290.79110.56230.064*
C70.5283 (6)0.88710 (17)0.3743 (4)0.0533 (8)
H70.38230.87250.35290.064*
C80.4952 (8)0.95999 (17)0.1642 (3)0.0648 (9)
H80.33760.94500.17160.078*
C90.5975 (9)0.9300 (2)0.0232 (5)0.0878 (15)
H9A0.75800.93970.02220.105*
H9B0.57790.87960.02280.105*
C100.4915 (13)0.9604 (2)−0.1149 (5)0.1066 (17)
H10A0.33420.9467−0.11970.128*
H10B0.56700.9418−0.20200.128*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Br10.1059 (4)0.0925 (3)0.0605 (3)−0.0117 (3)0.0117 (3)0.01235 (19)
N10.0651 (18)0.0461 (16)0.071 (2)0.0081 (14)−0.0010 (17)0.0035 (15)
O10.0581 (16)0.0651 (15)0.127 (2)−0.0141 (15)0.001 (2)0.0131 (15)
C10.069 (2)0.057 (2)0.0452 (18)0.0034 (18)0.0052 (17)−0.0075 (15)
C20.070 (2)0.069 (2)0.0509 (19)0.011 (2)−0.0112 (19)−0.0097 (19)
C30.051 (2)0.071 (2)0.081 (2)0.0040 (18)−0.011 (3)−0.025 (2)
C40.054 (2)0.0445 (18)0.078 (2)0.0002 (16)0.001 (2)−0.0103 (18)
C50.051 (2)0.0417 (16)0.058 (2)0.0042 (14)0.0024 (18)−0.0087 (15)
C60.050 (2)0.0580 (18)0.0516 (17)−0.0006 (16)0.0032 (17)−0.0140 (15)
C70.0488 (19)0.0507 (18)0.0604 (17)0.0064 (17)−0.0017 (18)−0.0102 (14)
C80.074 (2)0.0500 (17)0.071 (2)0.014 (2)−0.003 (3)0.0000 (16)
C90.126 (4)0.061 (2)0.076 (3)0.030 (3)−0.004 (3)−0.007 (2)
C100.160 (5)0.093 (3)0.067 (2)0.042 (4)−0.003 (4)−0.010 (2)

Geometric parameters (Å, °)

Br1—C11.901 (4)C5—C71.454 (5)
N1—C71.273 (5)C6—H60.9300
N1—C81.464 (4)C7—H70.9300
O1—C41.341 (4)C8—C91.519 (5)
O1—H10.8200C8—C8i1.528 (7)
C1—C21.369 (6)C8—H80.9800
C1—C61.375 (5)C9—C101.510 (6)
C2—C31.371 (5)C9—H9A0.9700
C2—H20.9300C9—H9B0.9700
C3—C41.392 (5)C10—C10i1.515 (10)
C3—H30.9300C10—H10A0.9700
C4—C51.401 (5)C10—H10B0.9700
C5—C61.397 (5)
C7—N1—C8118.7 (4)N1—C7—H7119.1
C4—O1—H1109.5C5—C7—H7119.1
C2—C1—C6121.5 (4)N1—C8—C9108.9 (3)
C2—C1—Br1119.2 (3)N1—C8—C8i109.3 (3)
C6—C1—Br1119.2 (3)C9—C8—C8i111.2 (3)
C1—C2—C3119.0 (4)N1—C8—H8109.2
C1—C2—H2120.5C9—C8—H8109.2
C3—C2—H2120.5C8i—C8—H8109.2
C2—C3—C4121.3 (4)C10—C9—C8112.2 (4)
C2—C3—H3119.4C10—C9—H9A109.2
C4—C3—H3119.4C8—C9—H9A109.2
O1—C4—C3119.0 (4)C10—C9—H9B109.2
O1—C4—C5121.6 (4)C8—C9—H9B109.2
C3—C4—C5119.4 (4)H9A—C9—H9B107.9
C6—C5—C4118.6 (3)C9—C10—C10i110.8 (5)
C6—C5—C7119.6 (3)C9—C10—H10A109.5
C4—C5—C7121.7 (3)C10i—C10—H10A109.5
C1—C6—C5120.1 (3)C9—C10—H10B109.5
C1—C6—H6119.9C10i—C10—H10B109.5
C5—C6—H6119.9H10A—C10—H10B108.1
N1—C7—C5121.8 (4)

Symmetry codes: (i) −x+1, −y+2, z.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O1—H1···N10.821.912.611 (4)143

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2493).

References

  • Bruker (2005). APEX2, SAINT and SADABS Bruker AXS Inc, Madison, Wisconsin, USA.
  • Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.
  • Canail, L. & Sherrington, D. C. (1999). Chem. Soc. Rev.28, 85–93.
  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
  • Flack, H. D. (1983). Acta Cryst. A39, 876–881.
  • Jacobsen, E. N. (2000). Acc. Chem. Res.33, 421–431. [PubMed]
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Yang, M.-H., Li, Y.-Z., Zhu, C.-J., Pan, Y. & Liu, S.-H. (2004). Acta Cryst. E60, o2397–o2398.
  • Yang, M.-H., Zheng, Y.-F. & Yan, G.-B. (2007). Acta Cryst. E63, o982–o983.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography