supplementary materials


su2725 scheme

Acta Cryst. (2014). E70, o617    [ doi:10.1107/S1600536814009222 ]

1,6-Bis(p-tol­yloxy)hexa­ne

X. Q. Zhang, J. Xiao, W.-W. Xue, Q. Chen and K. Wang

CCDC reference: 999158

Abstract top

The title compound, C20H26O2, crystallized with one half-mol­ecule in the asymmetric unit. The whole mol­ecule is generated by inversion symmetry, with the center of inversion being situated at the mid-point of the central -CH2-CH2- bond of the bridging hexane chain. In the crystal, mol­ecules stack in columns along the b axis. C-H...[pi] inter­actions are present within the columns.

Comment top

The title compound is used as a sensitizer for thermal recording materials, polyester-resin monomers and fire-resistant materials (Saito et al., 1988).

The molecular structure of the title compound is shown in Fig. 1. The bond lengths (Allen et al. (1987) and angles are within normal ranges. It crystallized with half a molecule in the asymmetric unit. The whole molecule is generated by inversion symmetry with the center of inversion being situated at the center of the C10—C10i bond of the bridging hexane chain [symmetry code: (i) -x, -y, -z + 2].

In the crystal, there are no intermolecular hydrogen bonds present (Fig. 2). The molecules stack in columns along the b axis and within the columns there are C—H···π interactions present (Table 1).

Related literature top

For the properties and synthesis of the title compound, see: Saito et al. (1988). For bond-length data, see: Allen et al. (1987).

Experimental top

The title compound was prepared by the reported procedure (Saito et al., 1988). Anhydrous potassium carbonate (6.2 g, 45 mmol) was added to a solution of 1,6-dibromohexane (2.5 g, 10.25 mmol) and 4-methoxyphenol (3.18 g, 25.6 mmol) in acetonitrile (100 ml). The mixture was stirred overnight at 338 K, and then filtered and the filtrate evaporated under reduced pressure. The residue was subjected to flash chromatography on silica gel, eluting with (10:1/petroleum ether:ethyl acetate) to give the title compound (Yield 2.13 g). Colourless block-like crystals of the title compound were obtained by slow evaporation of a solution in ethanol (20 ml), after ca. 7 days.

Refinement top

All the H atoms were positioned geometrically and constrained to ride on their parent atoms: C—H = 0.93 - 0.97 Å with Uiso(H) = 1.5Ueq(C-methyl) and = 1.2Ueq(C) for other H atoms.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software (Enraf–Nonius, 1985); data reduction: XCAD4 (Harms & Wocadlo,1995); 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
[Figure 1] Fig. 1. The molecular structure of the title molecule, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. A view along the b axis of the crystal packing of the title compound.
1,6-Bis(p-tolyloxy)hexane top
Crystal data top
C20H26O2F(000) = 324
Mr = 298.41Dx = 1.125 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1071 reflections
a = 18.932 (12) Åθ = 2.2–23.2°
b = 7.327 (4) ŵ = 0.07 mm1
c = 6.352 (4) ÅT = 293 K
β = 91.000 (13)°Block, colourless
V = 881.0 (9) Å30.25 × 0.20 × 0.18 mm
Z = 2
Data collection top
Enraf–Nonius CAD-4
diffractometer
963 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.117
Graphite monochromatorθmax = 25.0°, θmin = 1.1°
ω/2θ scansh = 2221
Absorption correction: ψ scan
(North et al., 1968)
k = 58
Tmin = 0.983, Tmax = 0.987l = 77
4572 measured reflections3 standard reflections every 200 reflections
1544 independent reflections intensity decay: 1%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.077Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.316H-atom parameters constrained
S = 1.10 w = 1/[σ2(Fo2) + (0.2P)2]
where P = (Fo2 + 2Fc2)/3
1544 reflections(Δ/σ)max < 0.001
101 parametersΔρmax = 0.36 e Å3
0 restraintsΔρmin = 0.32 e Å3
Crystal data top
C20H26O2V = 881.0 (9) Å3
Mr = 298.41Z = 2
Monoclinic, P21/cMo Kα radiation
a = 18.932 (12) ŵ = 0.07 mm1
b = 7.327 (4) ÅT = 293 K
c = 6.352 (4) Å0.25 × 0.20 × 0.18 mm
β = 91.000 (13)°
Data collection top
Enraf–Nonius CAD-4
diffractometer
963 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.117
Tmin = 0.983, Tmax = 0.987θmax = 25.0°
4572 measured reflections3 standard reflections every 200 reflections
1544 independent reflections intensity decay: 1%
Refinement top
R[F2 > 2σ(F2)] = 0.077H-atom parameters constrained
wR(F2) = 0.316Δρmax = 0.36 e Å3
S = 1.10Δρmin = 0.32 e Å3
1544 reflectionsAbsolute structure: ?
101 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
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
xyzUiso*/Ueq
O10.15451 (11)0.0150 (4)0.5211 (3)0.0524 (8)
C10.4342 (2)0.0202 (7)0.2221 (7)0.0812 (15)
H1A0.45080.14390.23020.122*
H1B0.46440.05670.30670.122*
H1C0.43490.02030.07840.122*
C20.36013 (17)0.0103 (5)0.3018 (6)0.0535 (10)
C30.34523 (17)0.0740 (5)0.4910 (6)0.0555 (10)
H30.38190.12770.56820.067*
C40.27798 (16)0.0806 (5)0.5681 (5)0.0497 (10)
H40.26910.14090.69370.060*
C50.22302 (16)0.0041 (4)0.4560 (5)0.0400 (9)
C60.23675 (16)0.0871 (5)0.2660 (4)0.0439 (9)
H60.20020.14160.18920.053*
C70.30380 (17)0.0892 (5)0.1906 (5)0.0502 (10)
H70.31210.14480.06180.060*
C80.13751 (15)0.0427 (5)0.7259 (5)0.0456 (9)
H8A0.13780.17490.73360.055*
H8B0.17190.00420.82730.055*
C90.06519 (15)0.0294 (5)0.7732 (4)0.0449 (9)
H9A0.06690.16170.77450.054*
H9B0.03270.00740.66120.054*
C100.03691 (14)0.0366 (5)0.9817 (4)0.0403 (9)
H10A0.03580.16900.98260.048*
H10B0.06820.00321.09510.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0479 (16)0.0683 (18)0.0413 (14)0.0032 (10)0.0101 (10)0.0063 (11)
C10.064 (3)0.093 (4)0.088 (3)0.002 (2)0.034 (2)0.005 (3)
C20.053 (2)0.043 (2)0.065 (2)0.0025 (15)0.0202 (17)0.0055 (17)
C30.051 (2)0.051 (2)0.065 (2)0.0086 (16)0.0069 (16)0.0079 (18)
C40.055 (2)0.049 (2)0.0456 (18)0.0020 (15)0.0089 (15)0.0109 (16)
C50.0429 (18)0.0390 (19)0.0385 (18)0.0012 (13)0.0136 (13)0.0055 (13)
C60.0538 (19)0.043 (2)0.0346 (16)0.0022 (14)0.0030 (13)0.0022 (14)
C70.065 (2)0.043 (2)0.0433 (18)0.0040 (16)0.0137 (15)0.0009 (15)
C80.0469 (19)0.049 (2)0.0411 (18)0.0042 (14)0.0062 (14)0.0022 (14)
C90.0475 (19)0.053 (2)0.0341 (17)0.0005 (14)0.0093 (13)0.0078 (14)
C100.0457 (19)0.046 (2)0.0297 (16)0.0024 (13)0.0059 (13)0.0025 (12)
Geometric parameters (Å, º) top
O1—C51.371 (3)C6—C71.365 (4)
O1—C81.410 (4)C6—H60.9300
C1—C21.502 (4)C7—H70.9300
C1—H1A0.9600C8—C91.503 (4)
C1—H1B0.9600C8—H8A0.9700
C1—H1C0.9600C8—H8B0.9700
C2—C31.385 (5)C9—C101.516 (4)
C2—C71.394 (5)C9—H9A0.9700
C3—C41.373 (4)C9—H9B0.9700
C3—H30.9300C10—C10i1.519 (5)
C4—C51.396 (5)C10—H10A0.9700
C4—H40.9300C10—H10B0.9700
C5—C61.380 (4)
C5—O1—C8119.6 (2)C6—C7—C2121.7 (3)
C2—C1—H1A109.5C6—C7—H7119.2
C2—C1—H1B109.5C2—C7—H7119.2
H1A—C1—H1B109.5O1—C8—C9107.6 (3)
C2—C1—H1C109.5O1—C8—H8A110.2
H1A—C1—H1C109.5C9—C8—H8A110.2
H1B—C1—H1C109.5O1—C8—H8B110.2
C3—C2—C7117.3 (3)C9—C8—H8B110.2
C3—C2—C1121.3 (4)H8A—C8—H8B108.5
C7—C2—C1121.3 (3)C8—C9—C10113.5 (3)
C4—C3—C2122.0 (3)C8—C9—H9A108.9
C4—C3—H3119.0C10—C9—H9A108.9
C2—C3—H3119.0C8—C9—H9B108.9
C3—C4—C5119.3 (3)C10—C9—H9B108.9
C3—C4—H4120.3H9A—C9—H9B107.7
C5—C4—H4120.3C9—C10—C10i111.2 (3)
O1—C5—C6115.6 (3)C9—C10—H10A109.4
O1—C5—C4124.9 (3)C10i—C10—H10A109.4
C6—C5—C4119.5 (3)C9—C10—H10B109.4
C7—C6—C5120.2 (3)C10i—C10—H10B109.4
C7—C6—H6119.9H10A—C10—H10B108.0
C5—C6—H6119.9
C7—C2—C3—C40.0 (5)C4—C5—C6—C71.3 (5)
C1—C2—C3—C4178.6 (4)C5—C6—C7—C20.6 (5)
C2—C3—C4—C51.8 (5)C3—C2—C7—C61.2 (5)
C8—O1—C5—C6171.1 (3)C1—C2—C7—C6177.4 (4)
C8—O1—C5—C47.9 (5)C5—O1—C8—C9165.3 (3)
C3—C4—C5—O1176.6 (3)O1—C8—C9—C10174.7 (3)
C3—C4—C5—C62.4 (5)C8—C9—C10—C10i178.6 (3)
O1—C5—C6—C7177.8 (3)
Symmetry code: (i) x, y, z+2.
Hydrogen-bond geometry (Å, º) top
Cg is the centroid of the C2–C7 benzene ring.
D—H···AD—HH···AD···AD—H···A
C4—H4···Cgii0.932.953.696 (4)138
C7—H7···Cgiii0.932.843.572 (4)137
Symmetry codes: (ii) x, y+1/2, z+1/2; (iii) x, y1/2, z1/2.
Hydrogen-bond geometry (Å, º) top
Cg is the centroid of the C2–C7 benzene ring.
D—H···AD—HH···AD···AD—H···A
C4—H4···Cgi0.932.953.696 (4)138
C7—H7···Cgii0.932.843.572 (4)137
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x, y1/2, z1/2.
Acknowledgements top

The authors thank the Center of Testing and Analysis, Nanjing University, for the data collection.

references
References top

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.

Enraf–Nonius (1985). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands.

Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.

North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.

Saito, T., Kitani, M. & Ishibashi, T. (1988). Patent No. JP 63156731.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.