(2E,6E)-2,6-Bis(4-ethoxy­benzyl­idene)cyclo­hexa­none

Shi, X.; Li, S.; Liu, Z.

doi:10.1107/S1600536808034272

organic compounds

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Volume 64| Part 11| November 2008| Page o2199

doi:10.1107/S1600536808034272

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(2E,6E)-2,6-Bis(4-ethoxybenzylidene)cyclohexanone

Xiaopeng Shi,^a ^* Shuqin Li ^a and Zhenzhen Liu ^a

^aDepartment of Chemistry and Biology, Xiangfan University, Xiangfan 441053, People's Republic of China
^*Correspondence e-mail: chemch@163.com

(Received 6 September 2008; accepted 20 October 2008; online 25 October 2008)

The title compound, C₂₄H₂₆O₃, was prepared by the condensation reaction of 4-ethoxybenzaldehyde with cyclohexanone. The molecule has crystallographic mirror symmetry and exhibits a butterfly-shaped geometry, with a dihedral angle of 5.46 (1)° between the two benzene rings. Weak intermolecular C—H⋯π interactions help stabilize the crystal structure.

Related literature

For related structures, see: Du et al. (2007 ); Liang et al. (2007 ); Sun et al. (2007 ); Zhou et al. (2007 ). For background information, see: Guilford et al. (1999 ); Ompraba et al. (2003 ); Yu et al. (2000 ).

Experimental

Crystal data

C₂₄H₂₆O₃
M_r = 362.45
Orthorhombic, C m c 2₁
a = 24.2516 (6) Å
b = 10.8459 (3) Å
c = 7.5270 (2) Å
V = 1979.83 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 298 (2) K
0.20 × 0.10 × 0.10 mm

Data collection

Bruker SMART 4K CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1997 ) T_min = 0.974, T_max = 0.992
6002 measured reflections
1026 independent reflections
879 reflections with I > 2σ(I)
R_int = 0.121

Refinement

R[F² > 2σ(F²)] = 0.048
wR(F²) = 0.115
S = 1.05
1026 reflections
129 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯Cg1ⁱ	0.93	2.92	3.601 (2)	132
Symmetry code: (i) $[x, -y, z+{\script{1\over 2}}]$ . Cg1 is the centroid of atoms C6–C11.

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 1999 ); 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 I, global. DOI: 10.1107/S1600536808034272/bg2205sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808034272/bg2205Isup2.hkl

checkCIF report

Comment top

The development of highly efficient nonlinear optical crystals is extremely important for laser spectroscopy and laser processing. Bis(arylmethylidene) cycloalkanones are reported to exhibit promising nonlinear optical properties (Yu et al., 2000). In addiiton, these compounds are widely used as building blocks for the synthesis of biologically active heterocycles (Guilford et al., 1999) The title compound C₂₄H₂₆O₃ (I) was prepared by the condensation reaction of 4-ethoxybenzaldehyde with cyclohexanone. The molecular structure of (I) is shown in Fig. 1. It has crystallographic mirror symmetry and exhibits a butterfly-shaped geometry. Similar structures have been observed in the related substituted cyclohexanone analogues reported by Ompraba et al. (2003) and Sun et al. (2007). A dihedral angle of 5.46 (1)° is found between the mean planes of the two benzene rings. Molecules are mainly connected by intermolecular weak C—H···π interactions (Table 1).

Related literature top

For related structures, see: Du et al. (2007); Liang et al. (2007); Sun et al. (2007); Zhou et al. (2007). For background information, see: Guilford et al. (1999); Ompraba et al. (2003); Yu et al. (2000). Cg1 is the centroid of atoms C6–C11.

Experimental top

The title compound was synthesized as previously described (Sun et al., 2007). 4-Ethoxybenzaldehyde (15.0 g, 0.1 mol) and cyclohexanone (4.9 g, 0.05 mol) were dissolved in 80 ml of ethanol. To this solution, a 10% NaOH aqueous solution (20 ml) was added dropwise with stirring at room temperature. The reaction mixture was stirred for a further 8 h and then poured into a mixture of 100 ml water and diluted hydrochloric acid. The precipitate was filtered and washed thoroughly with water and finally with ethanol. The product was dried at room temperature and crystallized from ethanol to give the title compound as pale yellow solid (12.7 g, yield 70%). Crystals of (I) suitable for X-ray data collection were obtained by slow evaporation of a CH₂Cl₂ and MeOH solution in a ratio of 3:2 at 293 K.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT (Bruker, 1999); 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. View of the molecule of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. Symmetry code "a" represents the operation 1-x, y, z

(2E,6E)-2,6-Bis(4-ethoxybenzylidene)cyclohexanone top

Crystal data top

C₂₄H₂₆O₃	F(000) = 776
M_r = 362.45	D_x = 1.216 Mg m⁻³
Orthorhombic, Cmc2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C2c-2	Cell parameters from 1880 reflections
a = 24.2516 (6) Å	θ = 2.7–21.4°
b = 10.8459 (3) Å	µ = 0.08 mm⁻¹
c = 7.5270 (2) Å	T = 298 K
V = 1979.83 (9) Å³	Block, colourless
Z = 4	0.20 × 0.10 × 0.10 mm

Data collection top

Bruker SMART 4K CCD area-detector diffractometer	1026 independent reflections
Radiation source: fine-focus sealed tube	879 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.121
ϕ and ω scans	θ_max = 25.5°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −24→29
T_min = 0.974, T_max = 0.992	k = −12→13
6002 measured reflections	l = −9→9

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.115	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0642P)²] where P = (F_o² + 2F_c²)/3
1026 reflections	(Δ/σ)_max < 0.001
129 parameters	Δρ_max = 0.20 e Å⁻³
1 restraint	Δρ_min = −0.14 e Å⁻³

Crystal data top

C₂₄H₂₆O₃	V = 1979.83 (9) Å³
M_r = 362.45	Z = 4
Orthorhombic, Cmc2₁	Mo Kα radiation
a = 24.2516 (6) Å	µ = 0.08 mm⁻¹
b = 10.8459 (3) Å	T = 298 K
c = 7.5270 (2) Å	0.20 × 0.10 × 0.10 mm

Data collection top

Bruker SMART 4K CCD area-detector diffractometer	1026 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	879 reflections with I > 2σ(I)
T_min = 0.974, T_max = 0.992	R_int = 0.121
6002 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.048	1 restraint
wR(F²) = 0.115	H-atom parameters constrained
S = 1.05	Δρ_max = 0.20 e Å⁻³
1026 reflections	Δρ_min = −0.14 e Å⁻³
129 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. The authors have merged Friedel pairs before the final refinement. In the absence of anomalous scatterers, no attempt was made to establish the absolute configuration of the title compound.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.5000	0.2069 (4)	0.1013 (7)	0.0752 (13)
C2	0.44694 (11)	0.1650 (2)	0.1831 (4)	0.0599 (7)
C3	0.44890 (11)	0.0930 (3)	0.3532 (4)	0.0641 (8)
H3A	0.4486	0.0056	0.3262	0.077*
H3B	0.4163	0.1114	0.4231	0.077*
C4	0.5000	0.1232 (4)	0.4615 (5)	0.0713 (11)
H4A	0.5000	0.2100	0.4926	0.086*
H4B	0.5000	0.0755	0.5705	0.086*
C5	0.40084 (12)	0.1962 (2)	0.0943 (4)	0.0604 (8)
H5	0.4067	0.2472	−0.0033	0.072*
C6	0.34301 (12)	0.1637 (2)	0.1252 (3)	0.0534 (7)
C7	0.32483 (12)	0.0581 (2)	0.2149 (4)	0.0568 (8)
H7	0.3507	0.0059	0.2663	0.068*
C8	0.26987 (12)	0.0298 (2)	0.2288 (3)	0.0561 (7)
H8	0.2590	−0.0412	0.2885	0.067*
C9	0.23052 (12)	0.1066 (2)	0.1543 (4)	0.0535 (7)
C10	0.24723 (12)	0.2127 (2)	0.0674 (4)	0.0585 (7)
H10	0.2212	0.2658	0.0188	0.070*
C11	0.30222 (11)	0.2389 (2)	0.0536 (4)	0.0572 (7)
H11	0.3128	0.3101	−0.0062	0.069*
C12	0.13522 (12)	0.1324 (3)	0.0784 (6)	0.0798 (10)
H12A	0.1433	0.1310	−0.0477	0.096*
H12B	0.1331	0.2177	0.1168	0.096*
C13	0.08165 (14)	0.0681 (4)	0.1142 (7)	0.1005 (14)
H13A	0.0865	−0.0193	0.1008	0.151*
H13B	0.0543	0.0965	0.0316	0.151*
H13C	0.0698	0.0858	0.2332	0.151*
O1	0.5000	0.2707 (5)	−0.0304 (6)	0.1303 (19)
O2	0.17725 (8)	0.06933 (16)	0.1745 (3)	0.0673 (6)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.074 (3)	0.070 (2)	0.082 (3)	0.000	0.000	0.028 (2)
C2	0.0684 (18)	0.0474 (13)	0.0640 (18)	0.0046 (12)	0.0043 (15)	0.0077 (13)
C3	0.0661 (18)	0.0647 (19)	0.0614 (17)	0.0063 (13)	0.0094 (15)	0.0044 (15)
C4	0.085 (3)	0.077 (3)	0.052 (2)	0.000	0.000	0.000 (2)
C5	0.073 (2)	0.0483 (14)	0.0598 (17)	0.0014 (11)	0.0048 (14)	0.0111 (12)
C6	0.0702 (17)	0.0420 (13)	0.0481 (14)	0.0040 (11)	−0.0010 (13)	0.0023 (11)
C7	0.071 (2)	0.0422 (13)	0.0567 (17)	0.0091 (12)	0.0011 (14)	0.0086 (12)
C8	0.0723 (18)	0.0427 (14)	0.0532 (15)	0.0006 (12)	0.0008 (14)	0.0082 (12)
C9	0.0663 (17)	0.0460 (14)	0.0482 (14)	−0.0013 (11)	0.0004 (13)	−0.0063 (12)
C10	0.0701 (19)	0.0449 (14)	0.0605 (16)	0.0083 (12)	−0.0071 (14)	0.0016 (13)
C11	0.0731 (17)	0.0403 (14)	0.0583 (15)	−0.0021 (11)	−0.0034 (15)	0.0083 (11)
C12	0.072 (2)	0.075 (2)	0.092 (3)	0.0082 (16)	−0.008 (2)	0.0095 (19)
C13	0.065 (2)	0.099 (2)	0.138 (4)	0.0051 (17)	−0.004 (2)	0.008 (3)
O1	0.076 (2)	0.170 (4)	0.145 (4)	0.000	0.000	0.110 (4)
O2	0.0661 (13)	0.0624 (10)	0.0733 (14)	−0.0012 (9)	−0.0051 (12)	0.0077 (11)

Geometric parameters (Å, º) top

C1—O1	1.209 (6)	C7—H7	0.9300
C1—C2ⁱ	1.497 (4)	C8—C9	1.385 (4)
C1—C2	1.497 (4)	C8—H8	0.9300
C2—C5	1.346 (4)	C9—O2	1.362 (3)
C2—C3	1.500 (4)	C9—C10	1.384 (4)
C3—C4	1.519 (4)	C10—C11	1.367 (4)
C3—H3A	0.9700	C10—H10	0.9300
C3—H3B	0.9700	C11—H11	0.9300
C4—C3ⁱ	1.519 (4)	C12—O2	1.425 (4)
C4—H4A	0.9700	C12—C13	1.499 (5)
C4—H4B	0.9700	C12—H12A	0.9700
C5—C6	1.465 (4)	C12—H12B	0.9700
C5—H5	0.9300	C13—H13A	0.9600
C6—C11	1.391 (4)	C13—H13B	0.9600
C6—C7	1.400 (4)	C13—H13C	0.9600
C7—C8	1.372 (4)

O1—C1—C2ⁱ	120.73 (18)	C6—C7—H7	119.1
O1—C1—C2	120.73 (18)	C7—C8—C9	120.3 (2)
C2ⁱ—C1—C2	118.5 (4)	C7—C8—H8	119.9
C5—C2—C1	115.7 (3)	C9—C8—H8	119.9
C5—C2—C3	125.5 (3)	O2—C9—C10	125.3 (2)
C1—C2—C3	118.8 (3)	O2—C9—C8	115.4 (2)
C2—C3—C4	111.8 (3)	C10—C9—C8	119.3 (3)
C2—C3—H3A	109.3	C11—C10—C9	119.6 (3)
C4—C3—H3A	109.3	C11—C10—H10	120.2
C2—C3—H3B	109.3	C9—C10—H10	120.2
C4—C3—H3B	109.3	C10—C11—C6	122.8 (3)
H3A—C3—H3B	107.9	C10—C11—H11	118.6
C3ⁱ—C4—C3	109.3 (3)	C6—C11—H11	118.6
C3ⁱ—C4—H4A	109.8	O2—C12—C13	107.8 (3)
C3—C4—H4A	109.8	O2—C12—H12A	110.2
C3ⁱ—C4—H4B	109.8	C13—C12—H12A	110.2
C3—C4—H4B	109.8	O2—C12—H12B	110.2
H4A—C4—H4B	108.3	C13—C12—H12B	110.2
C2—C5—C6	131.0 (3)	H12A—C12—H12B	108.5
C2—C5—H5	114.5	C12—C13—H13A	109.5
C6—C5—H5	114.5	C12—C13—H13B	109.5
C11—C6—C7	116.3 (3)	H13A—C13—H13B	109.5
C11—C6—C5	118.6 (2)	C12—C13—H13C	109.5
C7—C6—C5	125.1 (3)	H13A—C13—H13C	109.5
C8—C7—C6	121.7 (2)	H13B—C13—H13C	109.5
C8—C7—H7	119.1	C9—O2—C12	118.6 (2)

O1—C1—C2—C5	4.1 (7)	C5—C6—C7—C8	−175.8 (3)
C2ⁱ—C1—C2—C5	−174.1 (3)	C6—C7—C8—C9	−0.4 (4)
O1—C1—C2—C3	−176.0 (5)	C7—C8—C9—O2	179.5 (3)
C2ⁱ—C1—C2—C3	5.7 (6)	C7—C8—C9—C10	−0.7 (4)
C5—C2—C3—C4	−153.2 (3)	O2—C9—C10—C11	−179.0 (3)
C1—C2—C3—C4	27.0 (4)	C8—C9—C10—C11	1.2 (4)
C2—C3—C4—C3ⁱ	−59.6 (4)	C9—C10—C11—C6	−0.7 (5)
C1—C2—C5—C6	174.4 (3)	C7—C6—C11—C10	−0.4 (4)
C3—C2—C5—C6	−5.4 (5)	C5—C6—C11—C10	176.5 (3)
C2—C5—C6—C11	158.6 (3)	C10—C9—O2—C12	9.9 (4)
C2—C5—C6—C7	−24.8 (5)	C8—C9—O2—C12	−170.3 (3)
C11—C6—C7—C8	1.0 (4)	C13—C12—O2—C9	176.1 (3)

Symmetry code: (i) −x+1, y, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8···Cg1ⁱⁱ	0.93	2.92	3.601 (2)	132

Symmetry code: (ii) x, −y, z+1/2.

Experimental details

Crystal data
Chemical formula	C₂₄H₂₆O₃
M_r	362.45
Crystal system, space group	Orthorhombic, Cmc2₁
Temperature (K)	298
a, b, c (Å)	24.2516 (6), 10.8459 (3), 7.5270 (2)
V (Å³)	1979.83 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.20 × 0.10 × 0.10

Data collection
Diffractometer	Bruker SMART 4K CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1997)
T_min, T_max	0.974, 0.992
No. of measured, independent and observed [I > 2σ(I)] reflections	6002, 1026, 879
R_int	0.121
(sin θ/λ)_max (Å⁻¹)	0.605

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.048, 0.115, 1.05
No. of reflections	1026
No. of parameters	129
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.20, −0.14

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 1999), 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
C8—H8···Cg1ⁱ	0.93	2.92	3.601 (2)	132

Symmetry code: (i) x, −y, z+1/2.

Acknowledgements

The authors are grateful to Xiangfan University for financial support.

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