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Acta Cryst. (2008). E64, o620    [ doi:10.1107/S1600536808003383 ]

1,4-Bis(benzyloxy)-2-tert-butylbenzene

G. Wang, W. Wu, L. Zhuang and J. Wang

Abstract top

The title compound, C24H26O2, was obtained unintentionally as the product of an attempted synthesis of a new chiral cobalt salen catalyst. There are no classical hydrogen bonds; intermolecular C-H...[pi] stacking interactions between aromatic rings help to establish the molecular conformation.

Comment top

Chiral Co(salen) complexes are widely used in the Hydrolytic Kinetic Resolution of terminal epoxides, such as epichlorohydrin (Annis & Jacobsen, 1999). Bis–phenols, such as 2–tert–butyl–hydroquinone, are useful as starting materials for the synthesis of salicylaldehyde (Ready & Jacobsen, 2001), especially in the synthesis of polymeric salen complexes (Kwon & Kim, 2003). We here report the molecular and crystal structure of the title compound (I).

The atom–numbering scheme of (I) is shown in Fig. 1. A l l bond lengths and angles are within normal ranges (Allen et al., 1987). The molecule contains three phenyl rings - ring 1 (C1–C6), ring 2 (C8–C13), ring 3 (C19—C24), which are planar. The dihedral angle between ring 1 and ring 2 is 48.5 (4)°. There are no typical hydrogen bonds, while intermolecular C—H···π stacking interactions between aromatic rings help to stabilize the molecular conformation of compound (I).

Related literature top

For related literature, see: Annis & Jacobsen (1999); Kwon & Kim (2003); Ready & Jacobsen (2001). For bond-length data, see: Allen et al. (1987).

Experimental top

Under N2 atmosphere, a mixture of 5.5 g (33 mmol) of 2–tert–butyl–hydroquinone, 2.25 g anhydrous potassium carbonate (16.0 mmol) in 75 ml dry acetonitrile were stirred for half an hour at room temperature. Subsequently 8.2 g (66 mmol) of benzyl chloride and 600 mg (3.6 mmol) of potassium iodide were added to the reaction mixture and was refluxed for 3 h in inert atmosphere. The mixture was cooled to room temperature and was filtrated and the solvent was removed under reduced pressure. The crude product was purified with n–hexane solution. Crystals of (I) suitable for X–ray diffraction were further recrystallized by slow evaporation of acetone. 1H NMR (CDCl3, δ, p.p.m.) 7.45 (q, 10H), 7.00 (s, 1H), 6.89 (d, 1H), 6.74 (d, 1H), 5.05 (s, 2H), 4.99 (S, 2H), 1.38 (s, 9H).

Refinement top

During the refinement, the phenyl rings were treated as rigid hexagons with C–C bond lengths of 1.39 Å. H atoms were positioned geometrically (C—H = 0.930, 0.970 and 0.960Å for aromatic, methylene and methyl H atoms respectively) and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C), where x = 1.5 for methyl and x = 1.2 for all other H atoms.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); 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. A view of the molecular structure of (I) with the atom numbering scheme. Displacement ellipsoids are drawn at 30% probability level. H atoms are presented as a small spheres of arbitrary radius.
[Figure 2] Fig. 2. A packing diagram of (I) showing the intermolecular C—H···π interactions (dashed lines). The H atoms not involved in H–bonds are omitted for clarity. Cg2 and Cg3 denote the centroids of the C8–C13 and C19–C24 phenyl rings respectively. [Symmetry codes: (i) -x, -y + 1, -z + 1; (ii) -x, -y + 1, -z; (iii) x - 1, y, z.]
1,4-Bis(benzyloxy)-2-tert-butylbenzene top
Crystal data top
C24H26O2F000 = 744
Mr = 346.45Dx = 1.144 Mg m−3
Monoclinic, P21/cMo Kα radiation
λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 25 reflections
a = 6.5570 (13) Åθ = 9–13º
b = 23.772 (5) ŵ = 0.07 mm−1
c = 12.924 (3) ÅT = 293 (2) K
β = 93.21 (3)ºBlock, colourless
V = 2011.3 (7) Å30.40 × 0.30 × 0.20 mm
Z = 4
Data collection top
Enraf–Nonius CAD-4
diffractometer		Rint = 0.027
Radiation source: fine–focus sealed tubeθmax = 26.0º
Monochromator: graphiteθmin = 1.7º
T = 293(2) Kh = 0→8
ω/2θ scansk = 0→29
Absorption correction: ψ scan
(North et al., 1968)		l = −15→15
Tmin = 0.969, Tmax = 0.9863 standard reflections
4285 measured reflections every 200 reflections
3935 independent reflections intensity decay: none
2336 reflections with I > 2σ(I)
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.072  w = 1/[σ2(Fo2) + (0.0054P)2 + 4.1075P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.162(Δ/σ)max < 0.001
S = 1.03Δρmax = 0.35 e Å−3
3935 reflectionsΔρmin = −0.33 e Å−3
188 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0384 (15)
Secondary atom site location: difference Fourier map
Crystal data top
C24H26O2V = 2011.3 (7) Å3
Mr = 346.45Z = 4
Monoclinic, P21/cMo Kα
a = 6.5570 (13) ŵ = 0.07 mm−1
b = 23.772 (5) ÅT = 293 (2) K
c = 12.924 (3) Å0.40 × 0.30 × 0.20 mm
β = 93.21 (3)º
Data collection top
Enraf–Nonius CAD-4
diffractometer		2336 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)		Rint = 0.027
Tmin = 0.969, Tmax = 0.9863 standard reflections
4285 measured reflections every 200 reflections
3935 independent reflections intensity decay: none
Refinement top
R[F2 > 2σ(F2)] = 0.072188 parameters
wR(F2) = 0.162H-atom parameters constrained
S = 1.03Δρmax = 0.35 e Å−3
3935 reflectionsΔρmin = −0.33 e Å−3
Special details top

Geometry. All s.u.'s (except the s.u.'s in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
C11.0565 (4)0.27733 (12)0.5023 (3)0.0843 (15)
H11.16450.25230.51330.101*
C21.0574 (4)0.31573 (15)0.4212 (3)0.0931 (17)
H21.16610.31640.37800.112*
C30.8960 (4)0.35314 (12)0.4048 (2)0.0765 (13)
H30.89660.37880.35050.092*
C40.7335 (4)0.35215 (11)0.4694 (2)0.0582 (11)
C50.7326 (4)0.31375 (13)0.55046 (19)0.0719 (13)
H50.62390.31310.59370.086*
C60.8941 (5)0.27634 (11)0.5669 (2)0.0777 (14)
H60.89340.25060.62120.093*
C70.5631 (7)0.3943 (2)0.4568 (3)0.0746 (14)
H7A0.45140.38310.49840.090*
H7B0.61120.43090.48060.090*
C80.3396 (3)0.43592 (8)0.32489 (12)0.0461 (9)
C90.2627 (2)0.43853 (6)0.22256 (11)0.0447 (8)
C100.1057 (2)0.47575 (8)0.19454 (11)0.0475 (9)
H100.05430.47750.12610.057*
C110.0255 (3)0.51035 (8)0.26886 (14)0.0486 (9)
C120.1024 (3)0.50774 (8)0.37119 (13)0.0530 (10)
H120.04870.53090.42090.064*
C130.2594 (3)0.47053 (9)0.39920 (10)0.0547 (10)
H130.31080.46880.46770.066*
C140.3591 (3)0.40301 (9)0.13571 (14)0.0655 (10)
C150.2469 (4)0.41208 (13)0.02966 (13)0.0934 (18)
H15A0.25070.45120.01180.140*
H15B0.10740.40020.03260.140*
H15C0.31230.3905−0.02180.140*
C160.3501 (8)0.34034 (19)0.1595 (4)0.0885 (16)
H16A0.42010.33310.22540.133*
H16B0.41450.31970.10650.133*
H16C0.21010.32880.16160.133*
C170.5827 (6)0.4212 (2)0.1272 (4)0.0834 (15)
H17A0.65650.41560.19270.125*
H17B0.58750.46020.10850.125*
H17C0.64390.39900.07510.125*
C18−0.2037 (6)0.58533 (19)0.3026 (3)0.0689 (13)
H18A−0.09480.60940.33070.083*
H18B−0.26100.56530.35960.083*
C19−0.3651 (2)0.61998 (7)0.24720 (11)0.0528 (10)
C20−0.3295 (3)0.67607 (6)0.2238 (2)0.0705 (12)
H20−0.20360.69230.24220.085*
C21−0.4821 (3)0.70793 (7)0.1730 (2)0.0846 (15)
H21−0.45830.74550.15740.102*
C22−0.6703 (3)0.68368 (9)0.14560 (14)0.0824 (15)
H22−0.77240.70500.11160.099*
C23−0.7060 (2)0.62759 (9)0.1690 (2)0.0797 (14)
H23−0.83190.61140.15060.096*
C24−0.5534 (2)0.59573 (8)0.21979 (18)0.0636 (11)
H24−0.57720.55820.23540.076*
O10.4937 (3)0.39766 (9)0.35168 (17)0.0581 (7)
O2−0.1255 (2)0.54656 (6)0.23203 (9)0.0577 (7)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.061 (3)0.083 (4)0.107 (4)0.019 (3)−0.014 (3)0.000 (3)
C20.056 (3)0.102 (4)0.123 (5)0.014 (3)0.013 (3)0.024 (4)
C30.061 (3)0.078 (3)0.089 (3)0.009 (2)0.002 (2)0.021 (3)
C40.058 (2)0.070 (2)0.055 (2)0.013 (2)−0.0180 (19)−0.015 (2)
C50.076 (3)0.084 (3)0.056 (3)0.013 (3)−0.001 (2)−0.003 (2)
C60.096 (4)0.070 (3)0.065 (3)0.014 (3)−0.014 (3)0.008 (2)
C70.081 (3)0.082 (3)0.058 (3)0.032 (3)−0.023 (2)−0.013 (2)
C80.0405 (19)0.051 (2)0.046 (2)−0.0003 (17)−0.0038 (15)−0.0029 (17)
C90.0414 (19)0.049 (2)0.0437 (19)−0.0036 (17)0.0049 (15)−0.0008 (16)
C100.0413 (19)0.061 (2)0.0397 (19)−0.0004 (18)−0.0004 (15)−0.0006 (17)
C110.0343 (18)0.058 (2)0.053 (2)−0.0001 (17)0.0006 (16)0.0002 (18)
C120.057 (2)0.057 (2)0.044 (2)0.0122 (19)0.0000 (17)−0.0064 (18)
C130.055 (2)0.066 (3)0.041 (2)0.015 (2)−0.0061 (17)−0.0015 (18)
C140.065 (2)0.075 (3)0.057 (2)0.002 (2)0.0035 (17)−0.0086 (19)
C150.100 (4)0.131 (5)0.049 (3)0.039 (3)−0.004 (2)−0.020 (3)
C160.114 (4)0.071 (3)0.081 (3)0.001 (3)0.009 (3)−0.021 (3)
C170.065 (3)0.112 (4)0.076 (3)0.001 (3)0.028 (2)−0.009 (3)
C180.066 (3)0.090 (3)0.051 (2)0.032 (2)−0.001 (2)−0.004 (2)
C190.051 (2)0.063 (3)0.045 (2)0.0094 (19)0.0053 (17)−0.0049 (18)
C200.069 (3)0.066 (3)0.076 (3)−0.012 (2)0.000 (2)−0.012 (2)
C210.109 (4)0.054 (3)0.091 (4)0.011 (3)0.005 (3)0.008 (3)
C220.077 (3)0.096 (4)0.073 (3)0.032 (3)0.000 (3)0.010 (3)
C230.050 (3)0.107 (4)0.082 (3)0.002 (3)0.003 (2)0.004 (3)
C240.054 (2)0.066 (3)0.072 (3)0.002 (2)0.008 (2)0.007 (2)
O10.0566 (16)0.0708 (18)0.0461 (14)0.0190 (14)−0.0045 (12)−0.0035 (13)
O20.0476 (15)0.0733 (18)0.0516 (15)0.0168 (13)−0.0015 (12)−0.0063 (13)
Geometric parameters (Å, °) top
C1—C21.3900C14—C161.523 (5)
C1—C61.3900C14—C151.5341
C1—H10.9300C14—C171.539 (5)
C2—C31.3900C15—H15A0.9600
C2—H20.9300C15—H15B0.9600
C3—C41.3900C15—H15C0.9600
C3—H30.9300C16—H16A0.9600
C4—C51.3900C16—H16B0.9600
C4—C71.503 (4)C16—H16C0.9600
C5—C61.3900C17—H17A0.9600
C5—H50.9300C17—H17B0.9600
C6—H60.9300C17—H17C0.9600
C7—O11.411 (4)C18—O21.413 (4)
C7—H7A0.9700C18—C191.492 (4)
C7—H7B0.9700C18—H18A0.9700
C8—O11.3888C18—H18B0.9700
C8—C91.3900C19—C201.3900
C8—C131.3900C19—C241.3900
C9—C101.3900C20—C211.3900
C9—C141.5657C20—H200.9300
C10—C111.3900C21—C221.3900
C10—H100.9300C21—H210.9300
C11—O21.3766C22—C231.3900
C11—C121.3900C22—H220.9300
C12—C131.3900C23—C241.3900
C12—H120.9300C23—H230.9300
C13—H130.9300C24—H240.9300
C2—C1—C6120.0C15—C14—C9111.8
C2—C1—H1120.0C17—C14—C9108.9 (2)
C6—C1—H1120.0C14—C15—H15A109.5
C1—C2—C3120.0C14—C15—H15B109.5
C1—C2—H2120.0H15A—C15—H15B109.5
C3—C2—H2120.0C14—C15—H15C109.5
C4—C3—C2120.0H15A—C15—H15C109.5
C4—C3—H3120.0H15B—C15—H15C109.5
C2—C3—H3120.0C14—C16—H16A109.5
C5—C4—C3120.0C14—C16—H16B109.5
C5—C4—C7119.0 (3)H16A—C16—H16B109.5
C3—C4—C7120.9 (3)C14—C16—H16C109.5
C4—C5—C6120.0H16A—C16—H16C109.5
C4—C5—H5120.0H16B—C16—H16C109.5
C6—C5—H5120.0C14—C17—H17A109.5
C5—C6—C1120.0C14—C17—H17B109.5
C5—C6—H6120.0H17A—C17—H17B109.5
C1—C6—H6120.0C14—C17—H17C109.5
O1—C7—C4109.9 (3)H17A—C17—H17C109.5
O1—C7—H7A109.7H17B—C17—H17C109.5
C4—C7—H7A109.7O2—C18—C19108.9 (3)
O1—C7—H7B109.7O2—C18—H18A109.9
C4—C7—H7B109.7C19—C18—H18A109.9
H7A—C7—H7B108.2O2—C18—H18B109.9
O1—C8—C9119.10C19—C18—H18B109.9
O1—C8—C13120.88H18A—C18—H18B108.3
C9—C8—C13120.0C20—C19—C24120.0
C10—C9—C8120.0C20—C19—C18120.7 (2)
C10—C9—C14118.6C24—C19—C18119.3 (2)
C8—C9—C14121.2C21—C20—C19120.0
C11—C10—C9120.0C21—C20—H20120.0
C11—C10—H10120.0C19—C20—H20120.0
C9—C10—H10120.0C20—C21—C22120.0
O2—C11—C10115.07C20—C21—H21120.0
O2—C11—C12124.91C22—C21—H21120.0
C10—C11—C12120.0C21—C22—C23120.0
C13—C12—C11120.0C21—C22—H22120.0
C13—C12—H12120.0C23—C22—H22120.0
C11—C12—H12120.0C24—C23—C22120.0
C12—C13—C8120.0C24—C23—H23120.0
C12—C13—H13120.0C22—C23—H23120.0
C8—C13—H13120.0C23—C24—C19120.0
C16—C14—C15107.2 (2)C23—C24—H24120.0
C16—C14—C17109.7 (3)C19—C24—H24120.0
C15—C14—C17108.0 (2)C8—O1—C7117.9 (2)
C16—C14—C9111.2 (2)C11—O2—C18117.68 (19)
C6—C1—C2—C30.0C10—C9—C14—C16−124.7 (3)
C1—C2—C3—C40.0C8—C9—C14—C1659.3 (3)
C2—C3—C4—C50.0C10—C9—C14—C15−4.9
C2—C3—C4—C7176.5 (3)C8—C9—C14—C15179.1
C3—C4—C5—C60.0C10—C9—C14—C17114.4 (2)
C7—C4—C5—C6−176.6 (3)C8—C9—C14—C17−61.6 (2)
C4—C5—C6—C10.0O2—C18—C19—C20−107.8 (3)
C2—C1—C6—C50.0O2—C18—C19—C2472.8 (3)
C5—C4—C7—O1−135.2 (3)C24—C19—C20—C210.0
C3—C4—C7—O148.2 (4)C18—C19—C20—C21−179.40 (18)
O1—C8—C9—C10178.7C19—C20—C21—C220.0
C13—C8—C9—C100.0C20—C21—C22—C230.0
O1—C8—C9—C14−5.3C21—C22—C23—C240.0
C13—C8—C9—C14176.0C22—C23—C24—C190.0
C8—C9—C10—C110.0C20—C19—C24—C230.0
C14—C9—C10—C11−176.1C18—C19—C24—C23179.41 (18)
C9—C10—C11—O2178.3C9—C8—O1—C7−177.5 (3)
C9—C10—C11—C120.0C13—C8—O1—C71.2 (4)
O2—C11—C12—C13−178.2C4—C7—O1—C8−178.2 (3)
C10—C11—C12—C130.0C10—C11—O2—C18−176.0 (2)
C11—C12—C13—C80.0C12—C11—O2—C182.3 (3)
O1—C8—C13—C12−178.7C19—C18—O2—C11−179.7 (2)
C9—C8—C13—C120.0
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C5—H5···Cg3i0.932.963.725141
C15—H15C···Cg3ii0.962.873.818168
C24—H24···Cg2iii0.932.713.560153
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, −y+1, −z; (iii) x−1, y, z.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C5—H5···Cg3i0.932.963.725141
C15—H15C···Cg3ii0.962.873.818168
C24—H24···Cg2iii0.932.713.560153
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, −y+1, −z; (iii) x−1, y, z.
Acknowledgements top

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

references
References top

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