4,4'-Dimethyl-1,1'-[ethyl-enedioxy-bis(nitrilo-methyl-idyne)]dibenzene.

The Schiff base, C(18)H(20)N(2)O(2), which lies about an inversion centre, adopts a linear conformation. The mol-ecules are packed by C-H⋯π inter-actions, forming a two-dimensional supra-molecular 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 = 296.36

Monoclinic,

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[F 2 > 2σ(F 2)] = 0.051

wR(F 2) = 0.158

S = 1.03

1370 reflections

100 parameters

H-atom parameters constrained

Δρmax = 0.23 e Å−3

Δρmin = −0.21 e Å−3

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.

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

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

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

C18H20N2O2	F(000) = 316
Mr = 296.36	Dx = 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

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

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(Fo2) + (0.1037P)2] where P = (Fo2 + 2Fc2)/3
1370 reflections	(Δ/σ)max = 0.001
100 parameters	Δρmax = 0.23 e Å−3
0 restraints	Δρmin = −0.21 e Å−3

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.

	x	y	z	Uiso*/Ueq
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*

	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)

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)

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

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.