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

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ISSN: 2056-9890

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

aSchool of Material Science and Engineering, North University of China, Taiyuan 030051, People's Republic of China, and bSchool of Chemical Engineering and Environment, North University of China, Taiyuan 030051, People's Republic of China
*Correspondence e-mail: yijianhongnu@126.com

(Received 28 September 2009; accepted 29 September 2009; online 3 October 2009)

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[Yang, M.-H., Li, Y.-Z., Zhu, C.-J., Pan, Y. & Liu, S.-H. (2004). Acta Cryst. E60, o2397-o2398.], 2007[Yang, M.-H., Zheng, Y.-F. & Yan, G.-B. (2007). Acta Cryst. E63, o982-o983.]). For background to the use of chiral Salen compounds containing the 1,2-cyclo­hexa­nediamine motif in asymmetric catalytic synthesis, see: Canail & Sherrington (1999[Canail, L. & Sherrington, D. C. (1999). Chem. Soc. Rev. 28, 85-93.]); Jacobsen (2000[Jacobsen, E. N. (2000). Acc. Chem. Res. 33, 421-431.]).

[Scheme 1]

Experimental

Crystal data
  • C20H20Br2N2O2

  • Mr = 480.20

  • Orthorhombic, P 21 21 2

  • 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[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc, Madison, Wisconsin, USA.]) Tmin = 0.401, Tmax = 0.586

  • 5912 measured reflections

  • 1727 independent reflections

  • 1449 reflections with I > 2σ(I)

  • Rint = 0.024

Refinement
  • R[F2 > 2σ(F2)] = 0.032

  • wR(F2) = 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[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 681 Friedel pairs

  • Flack parameter: 0.018 (18)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯N1 0.82 1.91 2.611 (4) 143

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc, Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc, Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEPIII (Burnett & Johnson, 1996[Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.]) and ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

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).

Related literature top

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

Experimental top

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 top

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).

Structure description top

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).

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

Computing details top

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

Figures top
[Figure 1] 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]
(R,R)-4,4'-Dibromo-2,2'-[cyclohexane-1,2- diylbis(nitrilomethylidyne)]diphenol top
Crystal data top
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 top
Bruker APEXII area-detector
diffractometer
1727 independent reflections
Radiation source: fine-focus sealed tube1449 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
φ and ω scansθmax = 24.7°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 60
Tmin = 0.401, Tmax = 0.586k = 2222
5912 measured reflectionsl = 100
Refinement top
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) = 0.089 w = 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 methodsAbsolute structure parameter: 0.018 (18)
Crystal data top
C20H20Br2N2O2V = 1019.7 (4) Å3
Mr = 480.20Z = 2
Orthorhombic, P21212Mo Kα radiation
a = 5.9323 (16) ŵ = 3.99 mm1
b = 19.079 (5) ÅT = 298 K
c = 9.009 (2) Å0.28 × 0.21 × 0.15 mm
Data collection top
Bruker APEXII area-detector
diffractometer
1727 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
1449 reflections with I > 2σ(I)
Tmin = 0.401, Tmax = 0.586Rint = 0.024
5912 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.089Δρmax = 0.34 e Å3
S = 1.06Δρmin = 0.39 e Å3
1727 reflectionsAbsolute structure: Flack (1983), 681 Friedel pairs
119 parametersAbsolute structure parameter: 0.018 (18)
0 restraints
Special details top

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) top
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)
H10A0.33420.94670.11970.128*
H10B0.56700.94180.20200.128*
Atomic displacement parameters (Å2) top
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, º) top
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 code: (i) x+1, y+2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N10.821.912.611 (4)143

Experimental details

Crystal data
Chemical formulaC20H20Br2N2O2
Mr480.20
Crystal system, space groupOrthorhombic, P21212
Temperature (K)298
a, b, c (Å)5.9323 (16), 19.079 (5), 9.009 (2)
V3)1019.7 (4)
Z2
Radiation typeMo Kα
µ (mm1)3.99
Crystal size (mm)0.28 × 0.21 × 0.15
Data collection
DiffractometerBruker APEXII area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.401, 0.586
No. of measured, independent and
observed [I > 2σ(I)] reflections
5912, 1727, 1449
Rint0.024
(sin θ/λ)max1)0.587
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.032, 0.089, 1.06
No. of reflections1727
No. of parameters119
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.34, 0.39
Absolute structureFlack (1983), 681 Friedel pairs
Absolute structure parameter0.018 (18)

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPIII (Burnett & Johnson, 1996) and ORTEP-3 for Windows (Farrugia, 1997).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N10.821.912.611 (4)143.2
 

Acknowledgements

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

References

First citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc, Madison, Wisconsin, USA.  Google Scholar
First citationBurnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.  Google Scholar
First citationCanail, L. & Sherrington, D. C. (1999). Chem. Soc. Rev. 28, 85–93.  Web of Science CrossRef Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationJacobsen, E. N. (2000). Acc. Chem. Res. 33, 421–431.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYang, M.-H., Li, Y.-Z., Zhu, C.-J., Pan, Y. & Liu, S.-H. (2004). Acta Cryst. E60, o2397–o2398.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationYang, M.-H., Zheng, Y.-F. & Yan, G.-B. (2007). Acta Cryst. E63, o982–o983.  Web of Science CSD CrossRef IUCr Journals Google Scholar

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