1,4-Bis(hex­yloxy)benzene

Abstract

The asymmetric unit of the title compound, C₁₈H₃₀O₂, contains one half-mol­ecule situated on an inversion center. The alkyl chain adopts a fully extended all-trans conformation. The C atoms of the alkyl chain are almost coplanar, with a maximum deviation of 0.042 (6) Å from the mean plane,which is inclined to the central benzene ring by 6.80 (9)°. The crystal packing exhibits no short inter­molecular contacts.

Related literature  

For the synthesis and applications of the title compound, see: Ramesh & Thomas (2010 ▶); Mayor & Didschies (2003 ▶); Choi et al. (2006 ▶). For the crystal structures of related compounds, see: Li et al. (2008 ▶); Thevenet et al. (2010 ▶).

Experimental  

Crystal data  

• C₁₈H₃₀O₂

• M _r = 278.42

• Monoclinic,

• a = 18.853 (12) Å

• b = 7.512 (5) Å

• c = 6.364 (4) Å

• β = 95.674 (10)°

• V = 896.9 (11) ų

• Z = 2

• Mo Kα radiation

• μ = 0.07 mm⁻¹

• T = 298 K

• 0.06 × 0.05 × 0.04 mm

Data collection  

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.996, T _max = 0.997

• 6024 measured reflections

• 1552 independent reflections

• 760 reflections with I > 2σ(I)

• R _int = 0.099

Refinement  

• R[F ² > 2σ(F ²)] = 0.067

• wR(F ²) = 0.238

• S = 0.99

• 1552 reflections

• 92 parameters

• H-atom parameters constrained

• Δρ_max = 0.17 e Å⁻³

• Δρ_min = −0.15 e Å⁻³

Data collection: APEX2 (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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.

Supplementary Material

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

supplementary crystallographic information

1. Comment

The title compound is an important intermediate in the synthesis of conjugated polymers (Mayor & Didschies, 2003; Choi et al., 2006) and supramolecular networks (Ramesh & Thomas, 2010). Herein we report its crystal structure.

In the molecule (Fig. 1), the alkyl chain adopts a fully extended all-trans conformation. The C-atoms of the alkyl chain are almost coplanar with the maximum deviation of 0.042 (6) Å from the mean plane, and this mean plane is inclined to the central benzene ring by 6.80 (9)°. The crystal packing exhibits no short intermolecular contacts.

2. Experimental

The title compound was synthesized according to the known method (Ramesh & Thomas, 2010). Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation of the solution in hexane-MeOH (5:1).

3. Refinement

All H atoms were positioned geometrically (C—H = 0.93–0.97 Å) and refined as riding, allowing for free rotation of the methyl groups. The constraint U_iso(H) = 1.2 U_eq(C) or 1.5 U_eq(C) (methyl C) was applied.

Figures

Fig. 1.

The title molecule with the atom-numbering scheme and 50% probability displacement ellipsoids [symmetry code: (a) -x, 1 -y, 2 -z].

Crystal data

C18H30O2	F(000) = 308
Mr = 278.42	Dx = 1.031 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 885 reflections
a = 18.853 (12) Å	θ = 2.2–21.8°
b = 7.512 (5) Å	µ = 0.07 mm−1
c = 6.364 (4) Å	T = 298 K
β = 95.674 (10)°	Block, colourless
V = 896.9 (11) Å3	0.06 × 0.05 × 0.04 mm
Z = 2

Data collection

Bruker APEXII CCD diffractometer	1552 independent reflections
Radiation source: fine-focus sealed tube	760 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.099
φ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −22→21
Tmin = 0.996, Tmax = 0.997	k = −8→8
6024 measured reflections	l = −7→7

Refinement

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)] = 0.067	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.238	H-atom parameters constrained
S = 0.99	w = 1/[σ2(Fo2) + (0.1237P)2] where P = (Fo2 + 2Fc2)/3
1552 reflections	(Δ/σ)max < 0.001
92 parameters	Δρmax = 0.17 e Å−3
0 restraints	Δρmin = −0.15 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
C1	0.01445 (17)	0.4133 (3)	0.8176 (4)	0.0693 (9)
H1	0.0241	0.3542	0.6952	0.083*
C2	0.06718 (16)	0.5102 (3)	0.9318 (4)	0.0664 (8)
C3	0.05200 (17)	0.5954 (4)	1.1147 (4)	0.0700 (8)
H3	0.0876	0.6597	1.1928	0.084*
C4	0.15191 (16)	0.4640 (4)	0.6777 (4)	0.0795 (9)
H4A	0.1171	0.5055	0.5661	0.095*
H4B	0.1514	0.3348	0.6782	0.095*
C5	0.22423 (18)	0.5306 (5)	0.6427 (5)	0.0905 (10)
H5A	0.2228	0.6595	0.6360	0.109*
H5B	0.2571	0.4978	0.7634	0.109*
C6	0.25233 (18)	0.4623 (5)	0.4483 (5)	0.0959 (11)
H6A	0.2207	0.4996	0.3269	0.115*
H6B	0.2520	0.3332	0.4520	0.115*
C7	0.3266 (2)	0.5246 (5)	0.4201 (6)	0.1107 (13)
H7A	0.3262	0.6535	0.4098	0.133*
H7B	0.3576	0.4929	0.5452	0.133*
C8	0.3570 (3)	0.4521 (8)	0.2347 (7)	0.1542 (19)
H8A	0.3263	0.4849	0.1095	0.185*
H8B	0.3569	0.3232	0.2443	0.185*
C9	0.4300 (3)	0.5113 (10)	0.2076 (9)	0.202 (3)
H9A	0.4313	0.6389	0.2018	0.303*
H9B	0.4444	0.4631	0.0787	0.303*
H9C	0.4619	0.4704	0.3245	0.303*
O1	0.13529 (11)	0.5307 (3)	0.8769 (3)	0.0818 (8)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.106 (2)	0.0549 (16)	0.0456 (15)	−0.0004 (15)	0.0022 (15)	−0.0034 (12)
C2	0.089 (2)	0.0570 (17)	0.0516 (15)	−0.0033 (13)	−0.0020 (13)	0.0104 (13)
C3	0.103 (2)	0.0531 (16)	0.0516 (15)	−0.0086 (14)	−0.0060 (13)	0.0021 (12)
C4	0.099 (2)	0.0787 (19)	0.0600 (18)	0.0063 (16)	0.0020 (14)	−0.0041 (15)
C5	0.105 (2)	0.085 (2)	0.081 (2)	0.0025 (18)	0.0044 (16)	−0.0080 (17)
C6	0.100 (3)	0.102 (3)	0.086 (2)	0.0084 (19)	0.0097 (17)	−0.0030 (19)
C7	0.108 (3)	0.116 (3)	0.108 (3)	0.002 (2)	0.013 (2)	−0.002 (2)
C8	0.140 (4)	0.200 (5)	0.127 (4)	0.002 (4)	0.041 (3)	−0.017 (4)
C9	0.140 (4)	0.272 (9)	0.205 (6)	−0.003 (4)	0.070 (4)	−0.004 (5)
O1	0.0997 (16)	0.0855 (15)	0.0591 (12)	−0.0089 (11)	0.0017 (10)	−0.0092 (10)

Geometric parameters (Å, º)

C1—C3i	1.366 (4)	C5—H5B	0.9700
C1—C2	1.380 (4)	C6—C7	1.505 (5)
C1—H1	0.9300	C6—H6A	0.9700
C2—O1	1.372 (3)	C6—H6B	0.9700
C2—C3	1.383 (4)	C7—C8	1.467 (5)
C3—C1i	1.366 (4)	C7—H7A	0.9700
C3—H3	0.9300	C7—H7B	0.9700
C4—O1	1.427 (3)	C8—C9	1.472 (6)
C4—C5	1.490 (4)	C8—H8A	0.9700
C4—H4A	0.9700	C8—H8B	0.9700
C4—H4B	0.9700	C9—H9A	0.9600
C5—C6	1.484 (4)	C9—H9B	0.9600
C5—H5A	0.9700	C9—H9C	0.9600
C3i—C1—C2	119.7 (3)	C7—C6—H6A	108.8
C3i—C1—H1	120.2	C5—C6—H6B	108.8
C2—C1—H1	120.2	C7—C6—H6B	108.8
O1—C2—C1	124.7 (3)	H6A—C6—H6B	107.7
O1—C2—C3	116.0 (2)	C8—C7—C6	115.0 (4)
C1—C2—C3	119.3 (3)	C8—C7—H7A	108.5
C1i—C3—C2	121.1 (2)	C6—C7—H7A	108.5
C1i—C3—H3	119.5	C8—C7—H7B	108.5
C2—C3—H3	119.5	C6—C7—H7B	108.5
O1—C4—C5	107.4 (3)	H7A—C7—H7B	107.5
O1—C4—H4A	110.2	C7—C8—C9	115.2 (5)
C5—C4—H4A	110.2	C7—C8—H8A	108.5
O1—C4—H4B	110.2	C9—C8—H8A	108.5
C5—C4—H4B	110.2	C7—C8—H8B	108.5
H4A—C4—H4B	108.5	C9—C8—H8B	108.5
C6—C5—C4	114.6 (3)	H8A—C8—H8B	107.5
C6—C5—H5A	108.6	C8—C9—H9A	109.5
C4—C5—H5A	108.6	C8—C9—H9B	109.5
C6—C5—H5B	108.6	H9A—C9—H9B	109.5
C4—C5—H5B	108.6	C8—C9—H9C	109.5
H5A—C5—H5B	107.6	H9A—C9—H9C	109.5
C5—C6—C7	113.9 (3)	H9B—C9—H9C	109.5
C5—C6—H6A	108.8	C2—O1—C4	118.7 (2)
C3i—C1—C2—O1	−178.8 (2)	C5—C6—C7—C8	177.1 (4)
C3i—C1—C2—C3	0.7 (4)	C6—C7—C8—C9	−179.4 (4)
O1—C2—C3—C1i	178.9 (2)	C1—C2—O1—C4	6.9 (4)
C1—C2—C3—C1i	−0.7 (4)	C3—C2—O1—C4	−172.7 (2)
O1—C4—C5—C6	175.7 (2)	C5—C4—O1—C2	170.4 (2)
C4—C5—C6—C7	−177.6 (3)

Symmetry code: (i) −x, −y+1, −z+2.