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

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ISSN: 2056-9890
Volume 64| Part 8| August 2008| Pages o1600-o1601

6,6′-Dihydr­­oxy-2,2′-[(pentane-1,5-diyl­di­oxy)bis­­(nitrilo­methyl­­idyne)]diphenol

aSchool of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, People's Republic of China
*Correspondence e-mail: dongwk@mail.lzjtu.cn

(Received 18 July 2008; accepted 22 July 2008; online 26 July 2008)

The mol­ecule of the title compound, C19H22N2O6, assumes a W-shaped configuration with the dihedral angle between the two halves of the mol­ecule being 82.48 (5)°. There is one half-mol­ecule in the asymmetric unit with a crystallographic twofold rotation axis passing through the central C atom of the five methylene groups in the [—CH=N—O—(CH2)5—O—N=CH—] bridge. The dihedral angle formed by the two benzene rings in each mol­ecule of the title compound is 84.18 (4)°. There are strong intra­molecular O—H⋯N and O—H⋯O hydrogen bonds and weak inter­molecular ππ stacking inter­actions between neighbouring benzene rings, and the inter­molecular plane-to-plane distances are 3.488 (2) and 3.841 (3) Å along the b and c axes, respectively. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link each mol­ecule to two others, forming an infinite three-dimensional supra­molecular structure.

Related literature

For related literature, see: Akine et al. (2001[Akine, S., Taniguchi, T. & Nabeshima, T. (2001). Chem. Lett. 30, 682-683.], 2005[Akine, S., Takanori, T., Dong, W. K. & Nabeshima, T. (2005). J. Org. Chem. 70, 1704-1711.], 2006[Akine, S., Dong, W. K. & Nabeshima, T. (2006). Inorg. Chem. 45, 4677-4684.]); Atwood (1997[Atwood, D. A. (1997). Coord. Chem. Rev. 165, 267-296.]); Dong & Feng (2006[Dong, W.-K. & Feng, J.-H. (2006). Acta Cryst. E62, o3577-o3578.]); Dong, Zhao et al. (2008[Dong, W.-K., Zhao, C.-Y., Zhong, J.-K., Tang, X.-L. & Yu, T.-Z. (2008). Acta Cryst. E64, o1323.]); Dong, He et al. (2008[Dong, W.-K., He, X.-N., Li, L., Lv, Z.-W. & Tong, J.-F. (2008). Acta Cryst. E64, o1405.]); Duan et al. (2007[Duan, J.-G., Dong, C.-M., Shi, J.-Y., Wu, L. & Dong, W.-K. (2007). Acta Cryst. E63, o2704-o2705.]); Venkataramanan et al. (2005[Venkataramanan, N. S., Kuppuraj, G. & Rajagopal, S. (2005). Coord. Chem. Rev. 249, 1249-1268.]); Yu et al. (2008[Yu, T. Z., Zhang, K., Zhao, Y. L., Yang, C. H., Zhang, H., Qian, L., Fan, D. W., Dong, W. K., Chen, L. L. & Qiu, Y. Q. (2008). Inorg. Chim. Acta, 361, 233-240.]).

[Scheme 1]

Experimental

Crystal data
  • C19H22N2O6

  • Mr = 374.39

  • Monoclinic, C 2/c

  • a = 28.439 (3) Å

  • b = 4.6997 (6) Å

  • c = 14.0843 (17) Å

  • β = 100.354 (2)°

  • V = 1851.8 (4) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 298 (2) K

  • 0.46 × 0.27 × 0.25 mm

Data collection
  • Siemens SMART 1000 CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.955, Tmax = 0.975

  • 4246 measured reflections

  • 1621 independent reflections

  • 837 reflections with I > 2σ(I)

  • Rint = 0.062

Refinement
  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.135

  • S = 1.00

  • 1621 reflections

  • 123 parameters

  • H-atom parameters constrained

  • Δρmax = 0.24 e Å−3

  • Δρmin = −0.24 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H2⋯N1 0.82 1.92 2.630 (3) 144
O3—H3⋯O2 0.82 2.24 2.689 (3) 115
O3—H3⋯O1i 0.82 2.29 2.958 (3) 139
Symmetry code: (i) [x, -y, z-{\script{1\over 2}}].

Data collection: SMART (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: SMART; data reduction: SAINT (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Salen-type compounds are one of most versatile mixed-donor ligands in the field of coordination chemistry. There has been growing interest in salen-type ligands, mainly because of their wide application in the field of synthesis, biochemistry, photochemistry and catalysis (Akine et al., 2006; Atwood, 1997; Yu et al., 2008; Venkataramanan et al., 2005). Many salen-type complexes have been structurally characterized (Akine et al., 2006; Yu et al., 2008), but only a relatively small number of free salen-type compounds have been characterized (Akine et al., 2001). As an extension of our work (Dong & Feng, 2006; Duan et al., 2007; Dong, Zhao et al., 2008; Akine et al., 2005) on the structural characterization of salen-type bisoxime compounds, the title compound, (Fig. 1), is reported here.

The molecule assumes a W shape with the dihedral angle between the two halves of the molecule 82.48 (5)°. There is 1/2 molecule per asymmetric unit with a crystallographic twofold rotation axis passing through the central carbon (symmetry code: -x, y, 1/2 - z) of the five carbon atoms in the (—CH=N—O—(CH2)5—O—NCH—) bridge. This structure is similar to what was observed in our previously reported salen-type bisoxime compound (Duan et al., 2007). The dihedral angle formed by the two benzene rings in each molecule of the title compound is 84.18 (4)°. There are strong intramolecular O—H···N and O—H···O hydrogen bonds and weak intermolecular ππ stacking interactions between the neighbouring benzene rings, and the inter-molecular plane-to-plane distances are 3.488 (2) and 3.841 (3) Å along b and c axis, respectively. In the crystal structure, intermolecular O—H···O hydrogen bonds link each molecule to 2 others into infinite three-dimensional supramolecular structure, which is the crystal structure firstly reported of salen-type bisoxime compounds containing pentamethene bridge.

Related literature top

For related literature, see: Akine et al. (2001, 2005, 2006); Atwood (1997); Dong & Feng (2006); Dong, Zhao et al. (2008); Dong, He et al. (2008); Duan et al. (2007); Venkataramanan et al. (2005); Yu et al. (2008).

Experimental top

6,6'-Dihydroxy-2,2'-[(pentane-1,5-diyldioxy)bis(nitrilomethylidyne)]diphenol was synthesized according to an analogous method reported earlier (Dong & Feng, 2006; Dong, He et al., 2008). To an ethanol solution (3 ml) of 2,3-dihydroxybenzaldehyde (138.4 mg, 1.0 mmol) was added an ethanol solution (2 ml) of 1,5-bis(aminooxy)pentane (67.4 mg, 0.5 mmol). The reaction mixture was stirred at 328 K for 8 h. After cooling to room temperature, the formed precipitate was separated by filtration, and washed successively with ethanol and ethanol–hexane (1:4), respectively. The product was dried under vacuum to yield 109.3 mg of the title compound. Yield, 58.4%. mp. 408.5–409.5 K. Anal. Calc. for C19H22N2O6: C, 60.95; H, 5.92; N, 7.48. Found: C, 60.75; H, 5.99; N, 7.42.

Pale-brown needle-like single crystals suitable for X-ray diffraction studies were obtained after two weeks by slow evaporation from a ethanol–chloroform mixed solution of the title compound.

Refinement top

Non-H atoms were refined anisotropically. H atoms were treated as riding atoms with distances C—H = 0.97 (CH2), or 0.93 Å (CH), O—H = 0.82 Å, and Uiso(H) = 1.2Ueq(C) and 1.5Ueq(O).

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SMART (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with atom numbering scheme [Symmetry codes: -x + 1, y, -z + 3/2]. Displacement ellipsoids for non-hydrogen atoms are drawn at the 30% probability level.
[Figure 2] Fig. 2. The W shape configuration of the title compound.
[Figure 3] Fig. 3. Part of the supramolecular structure of the title compound along b axis. Intra- and intermolecular hydrogen bonds are shown as dashed lines.
6,6'-Dihydroxy-2,2'-[(pentane-1,5-diyldioxy)bis(nitrilomethylidyne)]diphenol top
Crystal data top
C19H22N2O6F(000) = 792
Mr = 374.39Dx = 1.343 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 875 reflections
a = 28.439 (3) Åθ = 2.9–22.4°
b = 4.6997 (6) ŵ = 0.10 mm1
c = 14.0843 (17) ÅT = 298 K
β = 100.354 (2)°Needle-like, pale-brown
V = 1851.8 (4) Å30.46 × 0.27 × 0.25 mm
Z = 4
Data collection top
Siemens SMART 1000 CCD area-detector
diffractometer
1621 independent reflections
Radiation source: fine-focus sealed tube837 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.062
ϕ and ω scansθmax = 25.0°, θmin = 1.5°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 3330
Tmin = 0.955, Tmax = 0.975k = 55
4246 measured reflectionsl = 1616
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.135H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0407P)2 + 1.5785P]
where P = (Fo2 + 2Fc2)/3
1621 reflections(Δ/σ)max < 0.001
123 parametersΔρmax = 0.24 e Å3
0 restraintsΔρmin = 0.24 e Å3
Crystal data top
C19H22N2O6V = 1851.8 (4) Å3
Mr = 374.39Z = 4
Monoclinic, C2/cMo Kα radiation
a = 28.439 (3) ŵ = 0.10 mm1
b = 4.6997 (6) ÅT = 298 K
c = 14.0843 (17) Å0.46 × 0.27 × 0.25 mm
β = 100.354 (2)°
Data collection top
Siemens SMART 1000 CCD area-detector
diffractometer
1621 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
837 reflections with I > 2σ(I)
Tmin = 0.955, Tmax = 0.975Rint = 0.062
4246 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.135H-atom parameters constrained
S = 1.00Δρmax = 0.24 e Å3
1621 reflectionsΔρmin = 0.24 e Å3
123 parameters
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
xyzUiso*/UeqOcc. (<1)
N10.40208 (8)0.0702 (5)0.51037 (15)0.0479 (7)
O10.41975 (7)0.2344 (4)0.59236 (12)0.0542 (6)
O20.39611 (7)0.1384 (5)0.33535 (13)0.0637 (7)
H20.40760.03850.38150.095*
O30.34987 (8)0.4908 (5)0.19941 (14)0.0782 (8)
H30.37300.38700.19910.117*
C10.46067 (10)0.3889 (7)0.57460 (19)0.0535 (9)
H1A0.48490.25760.56100.064*
H1B0.45180.51260.51920.064*
C20.47987 (11)0.5624 (7)0.66243 (18)0.0543 (9)
H2A0.50480.68680.64780.065*
H2B0.45440.68140.67800.065*
C30.50000.3833 (9)0.75000.0500 (11)
H3A0.47490.26170.76570.060*0.50
H3B0.52510.26170.73430.060*0.50
C40.36573 (10)0.0763 (7)0.52087 (19)0.0470 (8)
H40.35400.06440.57830.056*
C50.34239 (9)0.2611 (6)0.44479 (18)0.0418 (7)
C60.35833 (10)0.2865 (6)0.35701 (19)0.0439 (7)
C70.33496 (11)0.4666 (7)0.28589 (19)0.0509 (8)
C80.29684 (11)0.6252 (7)0.3023 (2)0.0573 (9)
H80.28190.74980.25500.069*
C90.28046 (11)0.6018 (7)0.3883 (2)0.0590 (9)
H90.25420.70750.39850.071*
C100.30300 (10)0.4222 (7)0.4586 (2)0.0538 (9)
H100.29180.40750.51650.065*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0471 (15)0.0517 (18)0.0431 (13)0.0017 (13)0.0029 (11)0.0029 (12)
O10.0510 (13)0.0670 (16)0.0443 (11)0.0114 (12)0.0076 (9)0.0072 (10)
O20.0557 (14)0.0800 (17)0.0593 (13)0.0191 (13)0.0211 (10)0.0113 (11)
O30.0804 (16)0.099 (2)0.0575 (13)0.0188 (15)0.0195 (12)0.0206 (13)
C10.0520 (19)0.056 (2)0.0516 (17)0.0052 (17)0.0074 (15)0.0072 (15)
C20.058 (2)0.049 (2)0.0529 (17)0.0074 (17)0.0018 (15)0.0022 (15)
C30.044 (2)0.049 (3)0.055 (2)0.0000.0043 (19)0.000
C40.0450 (18)0.056 (2)0.0408 (15)0.0017 (16)0.0093 (13)0.0038 (15)
C50.0342 (16)0.045 (2)0.0447 (15)0.0038 (15)0.0033 (13)0.0061 (13)
C60.0365 (16)0.046 (2)0.0498 (16)0.0021 (15)0.0093 (13)0.0063 (14)
C70.053 (2)0.055 (2)0.0440 (16)0.0018 (17)0.0059 (14)0.0002 (15)
C80.054 (2)0.055 (2)0.0579 (19)0.0044 (18)0.0037 (16)0.0007 (16)
C90.0465 (19)0.063 (2)0.066 (2)0.0112 (17)0.0040 (16)0.0084 (18)
C100.0471 (19)0.062 (2)0.0521 (17)0.0012 (17)0.0099 (14)0.0109 (16)
Geometric parameters (Å, º) top
N1—C41.273 (3)C3—H3A0.9700
N1—O11.405 (3)C3—H3B0.9700
O1—C11.431 (3)C4—C51.444 (4)
O2—C61.360 (3)C4—H40.9300
O2—H20.8200C5—C101.394 (4)
O3—C71.364 (3)C5—C61.396 (3)
O3—H30.8200C6—C71.386 (4)
C1—C21.500 (4)C7—C81.369 (4)
C1—H1A0.9700C8—C91.378 (4)
C1—H1B0.9700C8—H80.9300
C2—C31.518 (4)C9—C101.370 (4)
C2—H2A0.9700C9—H90.9300
C2—H2B0.9700C10—H100.9300
C3—C2i1.518 (4)
C4—N1—O1112.3 (2)N1—C4—C5120.9 (3)
N1—O1—C1108.47 (19)N1—C4—H4119.5
C6—O2—H2109.5C5—C4—H4119.5
C7—O3—H3109.5C10—C5—C6118.3 (3)
O1—C1—C2108.6 (2)C10—C5—C4119.8 (3)
O1—C1—H1A110.0C6—C5—C4122.0 (3)
C2—C1—H1A110.0O2—C6—C7116.5 (3)
O1—C1—H1B110.0O2—C6—C5123.4 (3)
C2—C1—H1B110.0C7—C6—C5120.2 (3)
H1A—C1—H1B108.4O3—C7—C8119.2 (3)
C1—C2—C3113.4 (3)O3—C7—C6120.7 (3)
C1—C2—H2A108.9C8—C7—C6120.1 (3)
C3—C2—H2A108.9C7—C8—C9120.5 (3)
C1—C2—H2B108.9C7—C8—H8119.8
C3—C2—H2B108.9C9—C8—H8119.8
H2A—C2—H2B107.7C10—C9—C8119.8 (3)
C2—C3—C2i112.6 (4)C10—C9—H9120.1
C2—C3—H3A109.1C8—C9—H9120.1
C2i—C3—H3A109.1C9—C10—C5121.2 (3)
C2—C3—H3B109.1C9—C10—H10119.4
C2i—C3—H3B109.1C5—C10—H10119.4
H3A—C3—H3B107.8
C4—N1—O1—C1179.4 (2)O2—C6—C7—O30.2 (4)
N1—O1—C1—C2179.5 (2)C5—C6—C7—O3179.2 (3)
O1—C1—C2—C366.3 (3)O2—C6—C7—C8179.4 (3)
C1—C2—C3—C2i178.9 (3)C5—C6—C7—C81.5 (4)
O1—N1—C4—C5179.6 (2)O3—C7—C8—C9178.9 (3)
N1—C4—C5—C10179.2 (3)C6—C7—C8—C91.9 (5)
N1—C4—C5—C60.2 (4)C7—C8—C9—C101.2 (5)
C10—C5—C6—O2179.5 (2)C8—C9—C10—C50.1 (5)
C4—C5—C6—O21.1 (4)C6—C5—C10—C90.2 (4)
C10—C5—C6—C70.5 (4)C4—C5—C10—C9179.2 (3)
C4—C5—C6—C7179.9 (3)
Symmetry code: (i) x+1, y, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···N10.821.922.630 (3)144
O3—H3···O20.822.242.689 (3)115
O3—H3···O1ii0.822.292.958 (3)139
Symmetry code: (ii) x, y, z1/2.

Experimental details

Crystal data
Chemical formulaC19H22N2O6
Mr374.39
Crystal system, space groupMonoclinic, C2/c
Temperature (K)298
a, b, c (Å)28.439 (3), 4.6997 (6), 14.0843 (17)
β (°) 100.354 (2)
V3)1851.8 (4)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.46 × 0.27 × 0.25
Data collection
DiffractometerSiemens SMART 1000 CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.955, 0.975
No. of measured, independent and
observed [I > 2σ(I)] reflections
4246, 1621, 837
Rint0.062
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.135, 1.00
No. of reflections1621
No. of parameters123
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.24, 0.24

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···N10.821.922.630 (3)144.4
O3—H3···O20.822.242.689 (3)114.7
O3—H3···O1i0.822.292.958 (3)138.5
Symmetry code: (i) x, y, z1/2.
 

Acknowledgements

This work was supported by the Foundation of the Education Department of Gansu Province (grant No. 0604-01) and the `Qing Lan' Talent Engineering Funds of Lanzhou Jiaotong University (grant No. QL-03-01A), which are gratefully acknowledged.

References

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ISSN: 2056-9890
Volume 64| Part 8| August 2008| Pages o1600-o1601
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