Acta Cryst. (2008). E64, o847 [ doi:10.1107/S1600536808009690 ]
In the title compound, C18H20, the five-membered ring of the indane fragment adopts an envelope conformation, with the flap atom deviating by 0.399 (3) Å from the plane of the remaining four atoms. The dihedral angle between the phenyl ring and the indane benzene ring is 79.58 (7)°.
α-Methylstyrene (32.0 g, 0.30 mol) was added to a 500 ml flask equipped with a condenser and a mechanical stirrer, followed by slow addition of a previously prepared mixture of H2SO4 (68 ml) and H2O (130 ml). The reaction mixture was refluxed for 20 h. After it was cooled to room temperature, the lower acid phase was drawn off and discarded. The organic phase containing the phenylindane was washed with water several times. The product was recrystallized from methanol that afforded white crystals (24 g, yield 68%, m.p. 323–324 K).
H atoms were positioned geometrically (C—H = 0.93–0.97 Å) and refined using a riding model, with Uiso(H) = 1.2Ueq (aromatic, methylene) or Uiso(H) = 1.5Ueq(methyl).
Data collection: DIFRAC (Gabe & White, 1993); cell refinement: DIFRAC (Gabe & White, 1993); data reduction: NRCVAX (Gabe et al., 1989); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
![[Figure 1]](./gk2139fig1thm.gif)
| Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level. |
| C18H20 | Z = 2 |
| Mr = 236.34 | F000 = 256 |
| Triclinic, P1 | Dx = 1.120 Mg m−3 |
| Hall symbol: -P 1 | Mo Kα radiation λ = 0.71073 Å |
| a = 8.192 (2) Å | Cell parameters from 28 reflections |
| b = 8.426 (3) Å | θ = 4.4–7.7º |
| c = 11.113 (4) Å | µ = 0.06 mm−1 |
| α = 69.30 (3)º | T = 291 (2) K |
| β = 79.44 (5)º | Block, colourless |
| γ = 80.37 (2)º | 0.46 × 0.44 × 0.42 mm |
| V = 701.0 (7) Å3 |
| Enraf–Nonius CAD-4 diffractometer | Rint = 0.007 |
| Radiation source: fine-focus sealed tube | θmax = 25.5º |
| Monochromator: graphite | θmin = 2.6º |
| T = 291(2) K | h = −9→9 |
| ω/2τ scans | k = −3→10 |
| Absorption correction: none | l = −12→13 |
| 3682 measured reflections | 3 standard reflections |
| 2582 independent reflections | every 200 reflections |
| 1770 reflections with I > 2σ(I) | intensity decay: 0.7% |
| Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
| Least-squares matrix: full | H-atom parameters constrained |
| R[F2 > 2σ(F2)] = 0.040 | w = 1/[σ2(Fo2) + (0.0549P)2 + 0.0915P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.117 | (Δ/σ)max < 0.001 |
| S = 1.06 | Δρmax = 0.17 e Å−3 |
| 2582 reflections | Δρmin = −0.14 e Å−3 |
| 170 parameters | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.154 (10) |
| Secondary atom site location: difference Fourier map |
| C18H20 | γ = 80.37 (2)º |
| Mr = 236.34 | V = 701.0 (7) Å3 |
| Triclinic, P1 | Z = 2 |
| a = 8.192 (2) Å | Mo Kα |
| b = 8.426 (3) Å | µ = 0.06 mm−1 |
| c = 11.113 (4) Å | T = 291 (2) K |
| α = 69.30 (3)º | 0.46 × 0.44 × 0.42 mm |
| β = 79.44 (5)º |
| Enraf–Nonius CAD-4 diffractometer | Rint = 0.007 |
| Absorption correction: none | 3 standard reflections |
| 3682 measured reflections | every 200 reflections |
| 2582 independent reflections | intensity decay: 0.7% |
| 1770 reflections with I > 2σ(I) |
| R[F2 > 2σ(F2)] = 0.040 | 170 parameters |
| wR(F2) = 0.117 | H-atom parameters constrained |
| S = 1.06 | Δρmax = 0.17 e Å−3 |
| 2582 reflections | Δρmin = −0.14 e Å−3 |
Experimental. 1H NMR (400 MHz, CDCl3): δ = 1.03, 1.35, 1.69 (s, 3H, –CH3), 2.21 and 2.40 (d, 2H, –CH2–), 7.11–7.29 (m, 9H, Ar—H). |
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 > 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. |
| x | y | z | Uiso*/Ueq | ||
| C18 | 0.39195 (18) | 0.00422 (18) | 0.21135 (14) | 0.0428 (4) | |
| C6 | 0.20481 (17) | 0.27044 (18) | 0.22736 (14) | 0.0436 (4) | |
| C14 | 0.6116 (2) | −0.1842 (2) | 0.32179 (15) | 0.0527 (4) | |
| H14 | 0.7136 | −0.2011 | 0.3526 | 0.063* | |
| C13 | 0.54458 (18) | −0.02135 (18) | 0.25548 (14) | 0.0421 (4) | |
| C7 | 0.34020 (18) | 0.19224 (19) | 0.14280 (14) | 0.0453 (4) | |
| C17 | 0.3069 (2) | −0.1345 (2) | 0.23220 (17) | 0.0567 (4) | |
| H17 | 0.2043 | −0.1181 | 0.2025 | 0.068* | |
| C10 | 0.61857 (19) | 0.14541 (19) | 0.22095 (15) | 0.0478 (4) | |
| C1 | 0.1330 (2) | 0.4375 (2) | 0.17672 (18) | 0.0595 (5) | |
| H1 | 0.1670 | 0.5006 | 0.0908 | 0.071* | |
| C5 | 0.1502 (2) | 0.1821 (2) | 0.35573 (16) | 0.0542 (4) | |
| H5 | 0.1951 | 0.0697 | 0.3928 | 0.065* | |
| C3 | −0.0391 (2) | 0.4221 (3) | 0.3779 (2) | 0.0665 (5) | |
| H3 | −0.1201 | 0.4724 | 0.4279 | 0.080* | |
| C15 | 0.5266 (2) | −0.3214 (2) | 0.34208 (17) | 0.0606 (5) | |
| H15 | 0.5716 | −0.4313 | 0.3863 | 0.073* | |
| C2 | 0.0126 (2) | 0.5121 (2) | 0.2504 (2) | 0.0696 (5) | |
| H2 | −0.0339 | 0.6240 | 0.2137 | 0.083* | |
| C4 | 0.0303 (2) | 0.2575 (3) | 0.43009 (18) | 0.0653 (5) | |
| H4 | −0.0034 | 0.1957 | 0.5164 | 0.078* | |
| C9 | 0.5091 (2) | 0.2673 (2) | 0.11982 (16) | 0.0543 (4) | |
| H9A | 0.5650 | 0.2782 | 0.0329 | 0.065* | |
| H9B | 0.4892 | 0.3795 | 0.1289 | 0.065* | |
| C16 | 0.3754 (2) | −0.2966 (2) | 0.29712 (18) | 0.0640 (5) | |
| H16 | 0.3192 | −0.3899 | 0.3107 | 0.077* | |
| C8 | 0.2796 (2) | 0.2204 (2) | 0.01297 (16) | 0.0664 (5) | |
| H8A | 0.3617 | 0.1654 | −0.0374 | 0.100* | |
| H8B | 0.2635 | 0.3405 | −0.0340 | 0.100* | |
| H8C | 0.1759 | 0.1728 | 0.0293 | 0.100* | |
| C11 | 0.5994 (3) | 0.1997 (2) | 0.34135 (19) | 0.0690 (5) | |
| H11A | 0.4832 | 0.2128 | 0.3749 | 0.104* | |
| H11B | 0.6446 | 0.3062 | 0.3180 | 0.104* | |
| H11C | 0.6585 | 0.1139 | 0.4065 | 0.104* | |
| C12 | 0.8028 (2) | 0.1333 (3) | 0.1630 (2) | 0.0723 (6) | |
| H12A | 0.8426 | 0.2429 | 0.1377 | 0.109* | |
| H12B | 0.8146 | 0.0980 | 0.0883 | 0.109* | |
| H12C | 0.8669 | 0.0513 | 0.2266 | 0.109* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C18 | 0.0409 (8) | 0.0477 (9) | 0.0410 (8) | −0.0052 (7) | −0.0006 (6) | −0.0185 (7) |
| C6 | 0.0386 (8) | 0.0477 (9) | 0.0461 (9) | −0.0021 (7) | −0.0125 (7) | −0.0155 (7) |
| C14 | 0.0555 (10) | 0.0501 (10) | 0.0506 (9) | 0.0029 (8) | −0.0100 (8) | −0.0171 (8) |
| C13 | 0.0434 (8) | 0.0441 (8) | 0.0388 (8) | −0.0017 (6) | −0.0031 (6) | −0.0162 (7) |
| C7 | 0.0423 (8) | 0.0506 (9) | 0.0411 (8) | −0.0023 (7) | −0.0078 (6) | −0.0131 (7) |
| C17 | 0.0481 (9) | 0.0637 (11) | 0.0656 (11) | −0.0115 (8) | −0.0018 (8) | −0.0309 (9) |
| C10 | 0.0422 (8) | 0.0472 (9) | 0.0537 (9) | −0.0060 (7) | −0.0078 (7) | −0.0155 (7) |
| C1 | 0.0623 (11) | 0.0537 (10) | 0.0595 (11) | −0.0005 (8) | −0.0128 (9) | −0.0157 (8) |
| C5 | 0.0530 (10) | 0.0568 (10) | 0.0482 (9) | 0.0022 (8) | −0.0064 (8) | −0.0158 (8) |
| C3 | 0.0483 (10) | 0.0852 (14) | 0.0811 (14) | 0.0089 (9) | −0.0138 (9) | −0.0509 (12) |
| C15 | 0.0738 (12) | 0.0422 (9) | 0.0581 (10) | −0.0012 (8) | −0.0002 (9) | −0.0138 (8) |
| C2 | 0.0668 (12) | 0.0601 (11) | 0.0882 (15) | 0.0127 (9) | −0.0238 (11) | −0.0348 (11) |
| C4 | 0.0590 (11) | 0.0837 (14) | 0.0536 (10) | −0.0014 (10) | −0.0020 (9) | −0.0289 (10) |
| C9 | 0.0491 (9) | 0.0510 (9) | 0.0525 (10) | −0.0069 (7) | −0.0026 (7) | −0.0063 (8) |
| C16 | 0.0715 (12) | 0.0493 (10) | 0.0735 (12) | −0.0191 (9) | 0.0083 (10) | −0.0267 (9) |
| C8 | 0.0659 (12) | 0.0851 (13) | 0.0473 (10) | 0.0056 (10) | −0.0148 (9) | −0.0236 (9) |
| C11 | 0.0802 (13) | 0.0639 (11) | 0.0758 (13) | −0.0119 (9) | −0.0212 (10) | −0.0317 (10) |
| C12 | 0.0464 (10) | 0.0720 (12) | 0.0943 (15) | −0.0103 (9) | −0.0070 (10) | −0.0219 (11) |
| C18—C13 | 1.382 (2) | C5—H5 | 0.9300 |
| C18—C17 | 1.388 (2) | C3—C4 | 1.368 (3) |
| C18—C7 | 1.520 (2) | C3—C2 | 1.375 (3) |
| C6—C5 | 1.384 (3) | C3—H3 | 0.9300 |
| C6—C1 | 1.388 (2) | C15—C16 | 1.376 (3) |
| C6—C7 | 1.536 (2) | C15—H15 | 0.9300 |
| C14—C15 | 1.379 (2) | C2—H2 | 0.9300 |
| C14—C13 | 1.382 (2) | C4—H4 | 0.9300 |
| C14—H14 | 0.9300 | C9—H9A | 0.9700 |
| C13—C10 | 1.519 (2) | C9—H9B | 0.9700 |
| C7—C8 | 1.538 (2) | C16—H16 | 0.9300 |
| C7—C9 | 1.558 (2) | C8—H8A | 0.9600 |
| C17—C16 | 1.377 (3) | C8—H8B | 0.9600 |
| C17—H17 | 0.9300 | C8—H8C | 0.9600 |
| C10—C12 | 1.530 (2) | C11—H11A | 0.9600 |
| C10—C11 | 1.535 (3) | C11—H11B | 0.9600 |
| C10—C9 | 1.539 (2) | C11—H11C | 0.9600 |
| C1—C2 | 1.378 (3) | C12—H12A | 0.9600 |
| C1—H1 | 0.9300 | C12—H12B | 0.9600 |
| C5—C4 | 1.385 (2) | C12—H12C | 0.9600 |
| C13—C18—C17 | 119.85 (15) | C16—C15—C14 | 120.29 (16) |
| C13—C18—C7 | 111.75 (13) | C16—C15—H15 | 119.9 |
| C17—C18—C7 | 128.40 (14) | C14—C15—H15 | 119.9 |
| C5—C6—C1 | 116.91 (16) | C3—C2—C1 | 120.35 (18) |
| C5—C6—C7 | 122.83 (14) | C3—C2—H2 | 119.8 |
| C1—C6—C7 | 120.26 (15) | C1—C2—H2 | 119.8 |
| C15—C14—C13 | 119.63 (16) | C3—C4—C5 | 120.67 (18) |
| C15—C14—H14 | 120.2 | C3—C4—H4 | 119.7 |
| C13—C14—H14 | 120.2 | C5—C4—H4 | 119.7 |
| C14—C13—C18 | 120.23 (15) | C10—C9—C7 | 108.20 (13) |
| C14—C13—C10 | 128.01 (14) | C10—C9—H9A | 110.1 |
| C18—C13—C10 | 111.76 (14) | C7—C9—H9A | 110.1 |
| C18—C7—C6 | 112.36 (13) | C10—C9—H9B | 110.1 |
| C18—C7—C8 | 111.23 (14) | C7—C9—H9B | 110.1 |
| C6—C7—C8 | 109.72 (13) | H9A—C9—H9B | 108.4 |
| C18—C7—C9 | 100.82 (13) | C15—C16—C17 | 120.42 (16) |
| C6—C7—C9 | 111.63 (13) | C15—C16—H16 | 119.8 |
| C8—C7—C9 | 110.83 (14) | C17—C16—H16 | 119.8 |
| C16—C17—C18 | 119.56 (16) | C7—C8—H8A | 109.5 |
| C16—C17—H17 | 120.2 | C7—C8—H8B | 109.5 |
| C18—C17—H17 | 120.2 | H8A—C8—H8B | 109.5 |
| C13—C10—C12 | 112.22 (14) | C7—C8—H8C | 109.5 |
| C13—C10—C11 | 110.21 (14) | H8A—C8—H8C | 109.5 |
| C12—C10—C11 | 109.67 (15) | H8B—C8—H8C | 109.5 |
| C13—C10—C9 | 101.46 (13) | C10—C11—H11A | 109.5 |
| C12—C10—C9 | 111.39 (15) | C10—C11—H11B | 109.5 |
| C11—C10—C9 | 111.70 (15) | H11A—C11—H11B | 109.5 |
| C2—C1—C6 | 121.72 (18) | C10—C11—H11C | 109.5 |
| C2—C1—H1 | 119.1 | H11A—C11—H11C | 109.5 |
| C6—C1—H1 | 119.1 | H11B—C11—H11C | 109.5 |
| C6—C5—C4 | 121.37 (17) | C10—C12—H12A | 109.5 |
| C6—C5—H5 | 119.3 | C10—C12—H12B | 109.5 |
| C4—C5—H5 | 119.3 | H12A—C12—H12B | 109.5 |
| C4—C3—C2 | 118.96 (18) | C10—C12—H12C | 109.5 |
| C4—C3—H3 | 120.5 | H12A—C12—H12C | 109.5 |
| C2—C3—H3 | 120.5 | H12B—C12—H12C | 109.5 |
The authors are grateful to the National Undergraduates' Innovative Experiment Project of China for financial support, and thank Mr Zhi-Hua Mao of Sichuan University for the X-ray data collection.
Bateman, J. & Gordon, D. A. (1974). US Patent 3856752.
Bateman, J. & Gordon, D. A. (1976). US Patent 3983092.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Feger, C., Khohasteh, M. M. & McGrath, J. E. (1989). Editors. Polyimides: Chemistry, Materials and Characterization. Amsterdam: Elsevier.
Gabe, E. J., Le Page, Y., Charland, J.-P., Lee, F. L. & White, P. S. (1989). J. Appl. Cryst. 22, 384–387.
Gabe, E. J. & White, P. S. (1993). Am. Crystallogr. Assoc. Pittsburgh Meet. Abstract PA104.
Ghosh, M. K. & Mittal, K. L. (1996). Polyimides: Fundamentals and Applications. New York: Dekker.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Polyimides are well known for possessing excellent thermal and oxidative stability, as well as excellent mechanical properties (Ghosh & Mittal, 1996; Feger et al., 1989). Furthermore, polyimides with phenylindane diamines and/or dianhydrides incorporated into the polyimide backbone have been found to be soluble in high concentration in polar organic solvents (Bateman & Gordon, 1974). Phenylindane diamines are prepared by a process comprising acid-catalyzed dimerization of α-methylstyrene and subsequent nitration and reduction of the 1,1,3-trimethyl-3-phenyl-2,3-dihydro-1H-indene (Bateman & Gordon, 1976).
The molecule of the title compound is shown in Fig. 1. Rings A (C1–C6) and B (C13–C18) are planar and form dihedral angle of 79.58 (7)°. The B ring forms dihedral angle of 25.38 (14)° with the plane defined by the indane Csp3 atoms C7, C9 and C10.