4,4′-Dimethyl-1,1′-[ethyl­enedioxy­bis(nitrilo­methyl­idyne)]dibenzene

Ding, Y.-J.; Xue, Z.-L.; Dong, W.-K.; Sun, Y.-X.; Wu, J.-C.

doi:10.1107/S1600536809015840

organic compounds

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ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page o1193

doi:10.1107/S1600536809015840

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4,4′-Dimethyl-1,1′-[ethylenedioxybis(nitrilomethylidyne)]dibenzene

Yu-Jie Ding,^a Zhu-Lian Xue,^b Wen-Kui Dong,^b ^* Yin-Xia Sun ^b and Jian-Chao Wu ^b

^aDepartment of Biochemical Engineering, Anhui University of Technology and Science, Wuhu 241000, People's Republic of China, and ^bSchool of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, People's Republic of China
^*Correspondence e-mail: dongwk@mail.lzjtu.cn

(Received 26 April 2009; accepted 28 April 2009; online 7 May 2009)

The Schiff base, C₁₈H₂₀N₂O₂, which lies about an inversion centre, adopts a linear conformation. The molecules are packed by C—H⋯π interactions, forming a two-dimensional supramolecular network.

Related literature

For background literature on Schiff base oximes, see: Akine et al. (2005 ); Dong et al. (2008, 2009a ,b ); Yamada (1999 ). For a related structure, see: Dong et al. (2008 ).

Experimental

Crystal data

C₁₈H₂₀N₂O₂
M_r = 296.36
Monoclinic, P 2₁ /c
a = 13.6946 (12) Å
b = 4.8196 (9) Å
c = 12.1644 (11) Å
β = 104.936 (1)°
V = 775.75 (17) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 298 K
0.43 × 0.20 × 0.10 mm

Data collection

Siemens SMART 1000 CCD area-detector diffractometer
Absorption correction: none
3790 measured reflections
1370 independent reflections
1012 reflections with I > 2σ(I)
R_int = 0.043

Refinement

R[F² > 2σ(F²)] = 0.051
wR(F²) = 0.158
S = 1.03
1370 reflections
100 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9A⋯Cg1	0.96	2.66	3.578 (2)	160
Cg1 is the centroid of the C3–C8 ring.

Data collection: SMART (Siemens, 1996 ); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; 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.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809015840/ng2575sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809015840/ng2575Isup2.hkl

checkCIF report

Comment top

Schiff bases and their bis-oxime analogues are a significant class of compounds which can be used in a variety of studies such as organic synthesis, catalyst, drug design and life science and so on (Yamada, 1999; Akine et al., 2005; Dong et al., 2009a). In order to extend our work (Dong et al., 2008) on structural characterization of bisoxime compounds, we report the synthesis and the X-ray structure of 4,4'-dimethyl-1,1'-[ethylenedioxybis(nitrilomethylidyne)]dibenzene in this paper (Fig. 1).

The molecule of the title compound is disposed about a crystallographic inversion centre (Symmetry codes: -x, -y,-z) and twofold screw axis (symmetry code: -x, 1/2 + y, 1/2 - z). The oxime, methyl groups and benzene rings have anti-conformation. The two benzene rings of the molecule are parallel, and the methyl and oxime (–CH₂—O—N=C–) functional groups are coplanar with the benzene ring in each half of the molecule.

The molecule adopts a linear-shaped configuration with respect to the oxime C=N bonds, which is different from our previous reported bisoxime of 3,3'-dibromo-1,1'-[ethylenedioxybis(nitrilomethylidyne)]dibenzene in which the molecule assumes an E configuration (Dong et al., 2008). The packing of the molecule is controlled by C—H···π(Ph) interactions linking molecules into infinite supramolecular structure along b axis (Fig. 2).

Related literature top

For background literature on Schiff base oximes, see: Akine et al. (2005); Dong et al. (2008, 2009a,b); Yamada (1999). For a related structure, see: Dong et al. (2008). Cg1 is the centroid of the C3–C8 ring.

Experimental top

4,4'-Dimethyl-1,1'-[ethylenedioxybis(nitrilomethylidyne)]dibenzene was synthesized according to an analogous method reported earlier (Dong et al., 2009b). To an ethanol solution (4 ml) of 4-methyl-2-hydroxybenzaldehyde (125.8 mg, 1.05 mmol) was added an ethanol solution (3 ml) of 1,2-bis(aminooxy)ethane (47.7 mg, 0.518 mmol). The reaction mixture was stirred at 328–333 K for 8 h. After cool to room temperature, no precipitate was formed, which was concentrated to about 1 ml under reduced pressure. The precipitate formed was separated by filtration, and washed several times with n-hexane. The product was dried under vacuum to yield 90.0 mg of the title compound. Yield, 58.6%. mp. 359–360 K. Anal. Calcd. for C₁₈H₂₀N₂O₂: C, 72.95; H, 6.80; N, 9.45. Found: C, 72.66; H, 6.87; N, 9.32.

Colorless needle-like single crystals suitable for X-ray diffraction studies were obtained after about four days by slow evaporation from an diethyl ether solution of the title compound.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (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

	Fig. 1. The molecular structure of the title compound with atom numbering scheme [Symmetry codes: -x + 2,-y,-z + 1]. Displacement ellipsoids for non-hydrogen atoms are drawn at the 30% probability level.
	Fig. 2. Part of the supramolecular structure of the title compound. C—H···π(Ph) interactions are shown as dashed lines.

4,4'-Dimethyl-1,1'-[ethylenedioxybis(nitrilomethylidyne)]dibenzene top

Crystal data top

C₁₈H₂₀N₂O₂	F(000) = 316
M_r = 296.36	D_x = 1.269 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1400 reflections
a = 13.6946 (12) Å	θ = 3.4–27.7°
b = 4.8196 (9) Å	µ = 0.08 mm⁻¹
c = 12.1644 (11) Å	T = 298 K
β = 104.936 (1)°	Column, colorless
V = 775.75 (17) Å³	0.43 × 0.20 × 0.10 mm
Z = 2

Data collection top

Siemens SMART 1000 CCD area-detector diffractometer	1012 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.043
Graphite monochromator	θ_max = 25.0°, θ_min = 1.5°
ϕ and ω scans	h = −16→15
3790 measured reflections	k = −5→5
1370 independent reflections	l = −14→13

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.158	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.1037P)²] where P = (F_o² + 2F_c²)/3
1370 reflections	(Δ/σ)_max = 0.001
100 parameters	Δρ_max = 0.23 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₁₈H₂₀N₂O₂	V = 775.75 (17) Å³
M_r = 296.36	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 13.6946 (12) Å	µ = 0.08 mm⁻¹
b = 4.8196 (9) Å	T = 298 K
c = 12.1644 (11) Å	0.43 × 0.20 × 0.10 mm
β = 104.936 (1)°

Data collection top

Siemens SMART 1000 CCD area-detector diffractometer	1012 reflections with I > 2σ(I)
3790 measured reflections	R_int = 0.043
1370 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.051	0 restraints
wR(F²) = 0.158	H-atom parameters constrained
S = 1.03	Δρ_max = 0.23 e Å⁻³
1370 reflections	Δρ_min = −0.21 e Å⁻³
100 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

	x	y	z	U_iso*/U_eq
N1	0.87170 (11)	0.4357 (3)	0.55939 (12)	0.0389 (4)
O1	0.95570 (9)	0.2523 (3)	0.58336 (10)	0.0424 (4)
C1	0.95420 (13)	0.0920 (4)	0.48465 (15)	0.0381 (5)
H1A	0.9568	0.2120	0.4214	0.046*
H1B	0.8931	−0.0187	0.4631	0.046*
C2	0.86877 (13)	0.5688 (4)	0.64775 (16)	0.0386 (5)
H2	0.9180	0.5342	0.7148	0.046*
C3	0.79062 (13)	0.7762 (4)	0.64868 (15)	0.0366 (5)
C4	0.71621 (13)	0.8512 (4)	0.55207 (15)	0.0417 (5)
H4	0.7148	0.7693	0.4825	0.050*
C5	0.64425 (14)	1.0474 (4)	0.55907 (16)	0.0439 (5)
H5	0.5956	1.0971	0.4934	0.053*
C6	0.64272 (13)	1.1717 (4)	0.66137 (17)	0.0434 (5)
C7	0.71769 (15)	1.0973 (4)	0.75725 (16)	0.0457 (5)
H7	0.7189	1.1784	0.8270	0.055*
C8	0.79055 (14)	0.9047 (4)	0.75058 (15)	0.0424 (5)
H8	0.8406	0.8602	0.8158	0.051*
C9	0.56330 (16)	1.3823 (4)	0.6689 (2)	0.0577 (6)
H9A	0.5911	1.5656	0.6709	0.086*
H9B	0.5417	1.3507	0.7369	0.086*
H9C	0.5065	1.3647	0.6038	0.086*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0315 (8)	0.0384 (9)	0.0465 (9)	0.0052 (7)	0.0093 (6)	0.0011 (7)
O1	0.0343 (8)	0.0455 (8)	0.0446 (8)	0.0100 (6)	0.0052 (6)	−0.0053 (6)
C1	0.0335 (10)	0.0397 (10)	0.0405 (10)	0.0010 (8)	0.0084 (8)	−0.0035 (8)
C2	0.0349 (10)	0.0398 (11)	0.0396 (10)	0.0016 (8)	0.0072 (8)	0.0006 (8)
C3	0.0324 (10)	0.0365 (10)	0.0414 (10)	−0.0013 (7)	0.0104 (8)	0.0016 (8)
C4	0.0393 (10)	0.0446 (11)	0.0415 (10)	−0.0007 (9)	0.0108 (8)	−0.0032 (8)
C5	0.0366 (10)	0.0462 (11)	0.0473 (11)	0.0040 (8)	0.0080 (8)	0.0058 (9)
C6	0.0398 (11)	0.0342 (10)	0.0604 (12)	0.0000 (9)	0.0204 (9)	0.0036 (9)
C7	0.0537 (12)	0.0417 (11)	0.0452 (11)	0.0029 (9)	0.0189 (9)	−0.0056 (9)
C8	0.0452 (11)	0.0419 (11)	0.0388 (10)	0.0018 (9)	0.0085 (8)	0.0006 (8)
C9	0.0510 (12)	0.0461 (12)	0.0816 (17)	0.0075 (10)	0.0276 (11)	0.0031 (12)

Geometric parameters (Å, º) top

N1—C2	1.261 (2)	C4—H4	0.9300
N1—O1	1.4203 (18)	C5—C6	1.386 (3)
O1—C1	1.424 (2)	C5—H5	0.9300
C1—C1ⁱ	1.503 (3)	C6—C7	1.388 (3)
C1—H1A	0.9700	C6—C9	1.508 (3)
C1—H1B	0.9700	C7—C8	1.380 (3)
C2—C3	1.466 (2)	C7—H7	0.9300
C2—H2	0.9300	C8—H8	0.9300
C3—C8	1.386 (2)	C9—H9A	0.9600
C3—C4	1.390 (3)	C9—H9B	0.9600
C4—C5	1.384 (2)	C9—H9C	0.9600

C2—N1—O1	110.10 (14)	C4—C5—H5	119.1
N1—O1—C1	109.26 (12)	C6—C5—H5	119.1
O1—C1—C1ⁱ	106.32 (17)	C5—C6—C7	117.62 (17)
O1—C1—H1A	110.5	C5—C6—C9	121.59 (19)
C1ⁱ—C1—H1A	110.5	C7—C6—C9	120.78 (19)
O1—C1—H1B	110.5	C8—C7—C6	120.92 (18)
C1ⁱ—C1—H1B	110.5	C8—C7—H7	119.5
H1A—C1—H1B	108.7	C6—C7—H7	119.5
N1—C2—C3	122.47 (17)	C7—C8—C3	121.35 (17)
N1—C2—H2	118.8	C7—C8—H8	119.3
C3—C2—H2	118.8	C3—C8—H8	119.3
C8—C3—C4	118.06 (17)	C6—C9—H9A	109.5
C8—C3—C2	118.70 (17)	C6—C9—H9B	109.5
C4—C3—C2	123.24 (17)	H9A—C9—H9B	109.5
C5—C4—C3	120.27 (17)	C6—C9—H9C	109.5
C5—C4—H4	119.9	H9A—C9—H9C	109.5
C3—C4—H4	119.9	H9B—C9—H9C	109.5
C4—C5—C6	121.76 (17)

C2—N1—O1—C1	176.47 (14)	C4—C5—C6—C7	1.4 (3)
N1—O1—C1—C1ⁱ	178.87 (16)	C4—C5—C6—C9	−179.11 (16)
O1—N1—C2—C3	179.41 (14)	C5—C6—C7—C8	−0.5 (3)
N1—C2—C3—C8	177.36 (16)	C9—C6—C7—C8	−179.96 (17)
N1—C2—C3—C4	−2.7 (3)	C6—C7—C8—C3	−0.9 (3)
C8—C3—C4—C5	−0.5 (3)	C4—C3—C8—C7	1.4 (3)
C2—C3—C4—C5	179.58 (16)	C2—C3—C8—C7	−178.65 (16)
C3—C4—C5—C6	−0.9 (3)

Symmetry code: (i) −x+2, −y, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9A···Cg1	0.96	2.66	3.578 (2)	160

Experimental details

Crystal data
Chemical formula	C₁₈H₂₀N₂O₂
M_r	296.36
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	13.6946 (12), 4.8196 (9), 12.1644 (11)
β (°)	104.936 (1)
V (Å³)	775.75 (17)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.43 × 0.20 × 0.10

Data collection
Diffractometer	Siemens SMART 1000 CCD area-detector diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	3790, 1370, 1012
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.051, 0.158, 1.03
No. of reflections	1370
No. of parameters	100
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.21

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···A	D—H	H···A	D···A	D—H···A
C9—H9A···Cg1	0.96	2.66	3.578 (2)	160.22

Acknowledgements

The authors acknowledge finanical support from the `Jing Lan' Talent Engineering Funds of Lanzhou Jiaotong University and the Natural Science Foundation of the Department of Education, An-Hui Province (No. KJ2009B110).

References

Akine, S., Taniguchi, T., Dong, W. K., Masubuchi, S. & Nabeshima, T. (2005). J. Org. Chem. 70, 1704–1711. Web of Science CSD CrossRef PubMed CAS Google Scholar
Dong, W.-K., Ding, Y.-J., Luo, Y.-L., Yan, H.-B. & Wang, L. (2008). Acta Cryst. E64, o1636. Web of Science CSD CrossRef IUCr Journals Google Scholar
Dong, W. K., Sun, Y. X., Zhang, Y. P., Li, L., He, X. N. & Tang, X. L. (2009a). Inorg. Chim. Acta, 362, 117–124. Web of Science CSD CrossRef CAS Google Scholar
Dong, W. K., Zhao, C. Y., Sun, Y. X., Tang, X. L. & He, X. N. (2009b). Inorg. Chem. Commun. 12, 234–236. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar
Yamada, S. (1999). Coord. Chem. Rev. 190, 537–555. CrossRef Google Scholar