1,4-Bis(2-phenyl­ethoxy)­benzene

The title compound, C₂₂H₂₂O₂, crystallizes in the space group P2₁/c, with one half mol­ecule in the asymmetric unit and Z = 2.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.045
• wR factor = 0.131
• Data-to-parameter ratio = 20.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

The title compound, (I), is a new compound, synthesized as a precursor of substituted phenylene–vinylene oligomers, which are novel compounds for use as semiconductors in an electronic nose (Vanneste et al., 1998; De Wit et al., 1998). The structure of (I) is, apart from the outer phenyl rings, planar, with a maximum deviation in the torsion angles of −176.74 (13)° for C1—O1—C4—C5. The angle between the least-squares planes through the phenyl rings is 79.38 (9)°. The particular arrangement of the rings allows an intermolecular interaction between the π-system of the outer rings and one of the H atoms of the central ring [Cg1···H2¹ 2.71 Å; Cg1 is the centroid of ring C6–C11; symmetry code: (i) 1 − x, 1/2 − y, 1/2 + z]. Other than that, the structure contains no surprises.

S2. Experimental

The synthesis of (I) was carried out under a nitrogen atmosphere. Sodium (13.8 g, 0.60 mol) in ethanol (100 ml) was added dropwise to a stirred solution of hydroquinone (33.0 g, 0.30 mol) in ethanol (100 ml). 2-Bromoethylbenzene (84.6 ml, 0.62 mol) was added dropwise to the reaction mixture, which was stirred overnight at room temperature. The temperature was subsequently raised to 318 K for a duration of 7 h, and finally to 353 K overnight. The solvent was evaporated on a rotary evaporator and the resulting oil dissolved in 50 ml of diethyl ether. The ether fraction was washed three times with 50 ml of a 10% NaOH solution and three times with 30 ml of water. After the solution was dried on MgSO₄, the solvent was distilled off. After cooling, the resulting oil solidified. Recrystallization from ethanol yielded 11.6 g of 1,4-bis(2-phenylethoxy)benzene, which crystallized as white needles. The final yield was 13%. M.p. 335 K; ¹H NMR (400 MHz, CDCl₃, TMS): δ 7.32–7.18 (10H, m, H7, H11, H9, H8, H10), 6.80 (4H, s, H2, H3), 4.10 (2H, t, J = 7.17 Hz, H41, H42), 3.05 (2H, t, J = 7.10 Hz, H51, H52); ¹³C NMR (100 MHz, CDCl₃, TMS): δ 153.10 (C1), 138.38 (C6), 128.94 (C7, C11), 128.43 (C8, C10), 126.39 (C9), 115.63 (C2), 69.42 (C4), 35.93 (C5).

Computing details

Data collection: CAD-4 EXPRESS (Enraf Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme.

(I)

Crystal data

C22H22O2	Dx = 1.202 Mg m^−3
Mr = 318.40	Melting point: 62° K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.9286 (17) Å	Cell parameters from 25 reflections
b = 11.3470 (11) Å	θ = 5–16°
c = 8.925 (2) Å	µ = 0.08 mm^−1
β = 103.311 (16)°	T = 293 K
V = 879.9 (3) Å^3	Needle, colourless
Z = 2	0.3 × 0.3 × 0.2 mm
F(000) = 340

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.083
Radiation source: fine-focus sealed tube	θmax = 32.0°, θmin = 2.3°
Graphite monochromator	h = −13→12
non–profiled ω/2θ scans	k = −16→16
6278 measured reflections	l = 0→13
3053 independent reflections	3 standard reflections every 3600 min
1318 reflections with I > 2σ(I)	intensity decay: −1%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.131	All H-atom parameters refined
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0591P)^2] where P = (Fo^2 + 2Fc^2)/3
3053 reflections	(Δ/σ)max = 0.003
153 parameters	Δρmax = 0.14 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.17490 (12)	0.31145 (8)	−0.05794 (11)	0.0485 (3)
C2	0.07109 (17)	0.49919 (12)	−0.12096 (15)	0.0405 (3)
H2	0.1192 (18)	0.4974 (14)	−0.2046 (19)	0.056 (4)*
C1	0.08722 (15)	0.40293 (11)	−0.02389 (15)	0.0359 (3)
C3	0.01473 (17)	0.40407 (12)	0.09822 (16)	0.0396 (3)
H3	0.0248 (15)	0.3394 (13)	0.1655 (16)	0.041 (4)*
C4	0.19920 (19)	0.21175 (12)	0.04228 (18)	0.0433 (3)
H41	0.0989 (18)	0.1743 (14)	0.0394 (18)	0.055 (5)*
H42	0.2464 (18)	0.2379 (14)	0.149 (2)	0.057 (5)*
C5	0.30540 (19)	0.12785 (13)	−0.01402 (18)	0.0448 (3)
H51	0.2603 (17)	0.1093 (13)	−0.120 (2)	0.051 (4)*
H52	0.4042 (18)	0.1690 (14)	−0.0138 (19)	0.063 (5)*
C6	0.32979 (15)	0.01729 (11)	0.08147 (15)	0.0380 (3)
C7	0.2447 (2)	−0.08291 (14)	0.0338 (2)	0.0517 (4)
H7	0.171 (2)	−0.0792 (14)	−0.064 (2)	0.065 (5)*
C8	0.2610 (2)	−0.18284 (14)	0.1243 (2)	0.0607 (5)
H8	0.200 (2)	−0.2513 (18)	0.094 (2)	0.082 (6)*
C9	0.3636 (2)	−0.18409 (13)	0.2643 (2)	0.0584 (5)
H9	0.372 (2)	−0.2528 (16)	0.326 (2)	0.071 (5)*
C10	0.4519 (2)	−0.08611 (14)	0.3135 (2)	0.0542 (4)
H10	0.530 (2)	−0.0850 (15)	0.414 (2)	0.075 (6)*
C11	0.43395 (18)	0.01403 (14)	0.22327 (18)	0.0475 (4)
H11	0.492 (2)	0.0800 (15)	0.254 (2)	0.063 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0647 (7)	0.0396 (5)	0.0473 (6)	0.0162 (5)	0.0257 (5)	0.0092 (4)
C2	0.0474 (7)	0.0398 (7)	0.0384 (7)	0.0022 (6)	0.0179 (6)	0.0034 (6)
C1	0.0388 (7)	0.0323 (6)	0.0378 (7)	0.0022 (5)	0.0114 (6)	0.0003 (5)
C3	0.0488 (8)	0.0334 (7)	0.0388 (7)	0.0031 (6)	0.0143 (6)	0.0067 (6)
C4	0.0510 (9)	0.0367 (7)	0.0457 (8)	0.0095 (6)	0.0182 (7)	0.0080 (6)
C5	0.0509 (9)	0.0415 (7)	0.0441 (8)	0.0091 (7)	0.0157 (7)	0.0032 (7)
C6	0.0422 (7)	0.0342 (6)	0.0406 (7)	0.0084 (6)	0.0153 (6)	−0.0013 (6)
C7	0.0540 (9)	0.0463 (8)	0.0526 (9)	0.0017 (7)	0.0075 (8)	−0.0085 (7)
C8	0.0727 (11)	0.0359 (8)	0.0756 (12)	−0.0054 (8)	0.0213 (10)	−0.0071 (8)
C9	0.0780 (12)	0.0372 (8)	0.0664 (11)	0.0145 (8)	0.0299 (10)	0.0097 (8)
C10	0.0610 (10)	0.0533 (9)	0.0472 (9)	0.0150 (8)	0.0100 (8)	0.0070 (8)
C11	0.0481 (8)	0.0429 (8)	0.0503 (8)	0.0010 (7)	0.0089 (7)	0.0003 (7)

Geometric parameters (Å, º)

O1—C1	1.3756 (15)	C5—H52	0.998 (16)
O1—C4	1.4275 (16)	C6—C7	1.379 (2)
C2—C3^i	1.3801 (19)	C6—C11	1.388 (2)
C2—C1	1.3809 (18)	C7—C8	1.380 (2)
C2—H2	0.943 (17)	C7—H7	0.968 (18)
C1—C3	1.3899 (19)	C8—C9	1.369 (3)
C3—C2^i	1.3801 (19)	C8—H8	0.95 (2)
C3—H3	0.940 (15)	C9—C10	1.375 (2)
C4—C5	1.509 (2)	C9—H9	0.947 (18)
C4—H41	0.986 (15)	C10—C11	1.380 (2)
C4—H42	0.992 (18)	C10—H10	1.01 (2)
C5—C6	1.5040 (19)	C11—H11	0.917 (17)
C5—H51	0.966 (17)
C1—O1—C4	118.15 (10)	C4—C5—H52	109.1 (9)
C3^i—C2—C1	121.20 (12)	H51—C5—H52	105.8 (13)
C3^i—C2—H2	120.2 (10)	C7—C6—C11	117.71 (14)
C1—C2—H2	118.6 (10)	C7—C6—C5	121.03 (14)
O1—C1—C2	116.15 (12)	C11—C6—C5	121.21 (13)
O1—C1—C3	124.87 (11)	C6—C7—C8	121.40 (16)
C2—C1—C3	118.98 (12)	C6—C7—H7	117.0 (10)
C2^i—C3—C1	119.82 (12)	C8—C7—H7	121.6 (10)
C2^i—C3—H3	120.1 (8)	C9—C8—C7	120.04 (16)
C1—C3—H3	120.1 (8)	C9—C8—H8	118.1 (12)
O1—C4—C5	107.93 (12)	C7—C8—H8	121.8 (12)
O1—C4—H41	108.6 (9)	C8—C9—C10	119.79 (16)
C5—C4—H41	110.8 (9)	C8—C9—H9	119.2 (11)
O1—C4—H42	109.5 (10)	C10—C9—H9	121.1 (11)
C5—C4—H42	110.3 (9)	C9—C10—C11	119.91 (17)
H41—C4—H42	109.7 (14)	C9—C10—H10	121.7 (10)
C6—C5—C4	110.95 (12)	C11—C10—H10	118.4 (10)
C6—C5—H51	110.4 (9)	C10—C11—C6	121.15 (16)
C4—C5—H51	108.2 (9)	C10—C11—H11	121.2 (11)
C6—C5—H52	112.1 (9)	C6—C11—H11	117.7 (11)
C4—O1—C1—C2	177.88 (13)	C4—C5—C6—C11	−80.52 (18)
C4—O1—C1—C3	−2.65 (19)	C11—C6—C7—C8	0.7 (2)
C3^i—C2—C1—O1	179.78 (13)	C5—C6—C7—C8	−176.75 (15)
C3^i—C2—C1—C3	0.3 (2)	C6—C7—C8—C9	−0.2 (3)
O1—C1—C3—C2^i	−179.73 (13)	C7—C8—C9—C10	−0.9 (3)
C2—C1—C3—C2^i	−0.3 (2)	C8—C9—C10—C11	1.6 (3)
C1—O1—C4—C5	−176.74 (13)	C9—C10—C11—C6	−1.2 (2)
O1—C4—C5—C6	−177.03 (12)	C7—C6—C11—C10	0.1 (2)
C4—C5—C6—C7	96.80 (17)	C5—C6—C11—C10	177.47 (14)

Symmetry code: (i) −x, −y+1, −z.