Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801011825/wn6034sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801011825/wn6034Isup2.hkl |
CCDC reference: 170912
A catalytic amount of tris(2,4-dibromophenyl)ammoniumyl hexachloroantimonate (A; 0.105 g, 0.10 mmol) was added rapidly to a stirred HFP (10 ml) solution of 1-o-tolyl-1-phenylethylene (0.194 g, 1 mmol) at room temperature. The reaction mixture, whose intensely green colour faded slowly, was monitored by TLC (petroleum ether/ethyl acetate, 20:1) and by GC—MS spectrometry, revealing the total disappearance of the starting material within 6 h, and the simultaneous formation of the main reaction product with molecular peak m/z = 388. The excess of aminium salt was destroyed by addition of 2 ml of ethyl ether, then the reaction mixture was poured into 10 ml of water and extracted with ethyl ether (10 ml × 2). The organic phase was separated, dried over sodium sulfate and the solvent removed in vacuo. Column chromatography (silica gel, petroleum ether/ethyl acetate, 20:1) of the residue gave a pale-yellow crystalline product (0.175 g, 90%). Recrystallization from methanol furnished colourless crystals of pure cis-1,3-diphenyl-1-o-tolyl-3,4-dimethylindan: m.p. 448–449 K with elemental analysis consistent with C30H28; calculated: C 92.73, H 7.26%; found: C 92.87, H 7.16%; IR (KBr) 3055, 3020, 2967, 1492, 1444, 770, 758, 744, 731, 697, 637 cm-1; 1H NMR (500 MHz, CDCl3): δH 7.36–6.63 (m, 17H), 3.53 (d, J = 13.8 Hz, 1H), 2.78 (d, J = 13.8 Hz, 1H), 1.91, (s, 3H), 1.53 (s, 3H), 1.42 (s, 3H) p.p.m.; 13C NMR (CDCl3): δC 150.7, 149.6, 149.3, 148.3, 147.9, 147.6, 136.6, 134.5, 132.2, 129.9, 128.9. 128.4, 128.1, 127.1, 126.3, 125.9, 125.6, 125.5, 125.0, 60.9, 51.67, 24.4, 22.2, 18.9 p.p.m.; MS m/z (relATIVE abundance): 388 (M+, 20), 373 (11), 297 (100), 282 (19), 265 (13).
The poor data/parameter ratio of 8.85 is a result of the weak diffracting power of the crystal. The position of the H atoms were calculated geometrically at a distance of 0.96 Å from the corresponding C atom, and a riding model was used during their refinament. The orientation of the methyl H atoms was not refined.
Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Coorporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Coorporation, 1985); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: CAOS (Camalli & Spagna, 1994); molecular graphics: CAOS; software used to prepare material for publication: CAOS.
Fig. 1. Drawing of the title compound with the atom-numbering scheme. Displacement ellipsoids are at the 50% probability level. | |
Fig. 2. The molecular packing in the unit cell. |
C30H28 | Z = 2 |
Mr = 388.55 | F(000) = 416 |
Triclinic, P1 | Dx = 1.163 Mg m−3 |
a = 8.577 (2) Å | Cu Kα radiation, λ = 1.54178 Å |
b = 10.997 (3) Å | Cell parameters from 25 reflections |
c = 12.327 (3) Å | θ = 29.2–38.9° |
α = 92.56 (2)° | µ = 0.49 mm−1 |
β = 93.38 (2)° | T = 293 K |
γ = 106.67 (2)° | Prism, colourless |
V = 1109.6 (5) Å3 | 0.35 × 0.20 × 0.15 mm |
Rigaku AFC-5 four-circle diffractometer | 2397 reflections with F > 6σ(F) |
Radiation source: rotating-anode X-ray tube | Rint = 0.029 |
Graphite monochromator | θmax = 62.0°, θmin = 3.6° |
θ/2θ scans | h = 0→9 |
Absorption correction: empirical (using intensity measurements) (North et al., 1968) | k = −12→12 |
Tmin = 0.931, Tmax = 1.000 | l = −14→14 |
3828 measured reflections | 3 standard reflections every 97 reflections |
3495 independent reflections | intensity decay: none |
Refinement on F | 271 parameters |
Least-squares matrix: Full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.045 | w = 1/(5.1485 + 0.0617*F + 0.0005*F2) |
wR(F2) = 0.057 | (Δ/σ)max < 0.001 |
S = 0.94 | Δρmax = 0.23 e Å−3 |
2397 reflections | Δρmin = −0.17 e Å−3 |
C30H28 | γ = 106.67 (2)° |
Mr = 388.55 | V = 1109.6 (5) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.577 (2) Å | Cu Kα radiation |
b = 10.997 (3) Å | µ = 0.49 mm−1 |
c = 12.327 (3) Å | T = 293 K |
α = 92.56 (2)° | 0.35 × 0.20 × 0.15 mm |
β = 93.38 (2)° |
Rigaku AFC-5 four-circle diffractometer | 2397 reflections with F > 6σ(F) |
Absorption correction: empirical (using intensity measurements) (North et al., 1968) | Rint = 0.029 |
Tmin = 0.931, Tmax = 1.000 | θmax = 62.0° |
3828 measured reflections | 3 standard reflections every 97 reflections |
3495 independent reflections | intensity decay: none |
R[F2 > 2σ(F2)] = 0.045 | 271 parameters |
wR(F2) = 0.057 | H-atom parameters constrained |
S = 0.94 | Δρmax = 0.23 e Å−3 |
2397 reflections | Δρmin = −0.17 e Å−3 |
x | y | z | Uiso*/Ueq | ||
C1 | 0.3398 (3) | 0.1115 (2) | 0.3017 (2) | 0.042 (1) | |
C2 | 0.3957 (3) | −0.0118 (2) | 0.3059 (2) | 0.049 (1) | |
C3 | 0.2968 (3) | −0.1083 (2) | 0.2122 (2) | 0.045 (1) | |
C4 | 0.0027 (3) | −0.1230 (2) | 0.1281 (2) | 0.046 (1) | |
C5 | −0.1153 (3) | −0.0591 (2) | 0.1181 (2) | 0.051 (1) | |
C6 | −0.0926 (3) | 0.0601 (3) | 0.1688 (2) | 0.054 (1) | |
C7 | 0.0508 (3) | 0.1199 (2) | 0.2311 (2) | 0.049 (1) | |
C8 | 0.1714 (3) | 0.0587 (2) | 0.2408 (2) | 0.040 (1) | |
C9 | 0.1477 (3) | −0.0616 (2) | 0.1912 (2) | 0.040 (1) | |
C10 | 0.3934 (3) | −0.0935 (3) | 0.1102 (2) | 0.063 (1) | |
C11 | −0.0300 (4) | −0.2536 (3) | 0.0718 (2) | 0.064 (1) | |
C12 | 0.4577 (3) | 0.2113 (2) | 0.2379 (2) | 0.045 (1) | |
C13 | 0.6231 (3) | 0.2637 (2) | 0.2730 (2) | 0.055 (1) | |
C14 | 0.7225 (3) | 0.3515 (3) | 0.2098 (3) | 0.070 (1) | |
C15 | 0.6645 (4) | 0.3885 (3) | 0.1137 (3) | 0.072 (1) | |
C16 | 0.5024 (4) | 0.3390 (3) | 0.0797 (2) | 0.062 (1) | |
C17 | 0.4021 (3) | 0.2516 (2) | 0.1412 (2) | 0.050 (1) | |
C18 | 0.7007 (3) | 0.2321 (3) | 0.3780 (2) | 0.073 (1) | |
C19 | 0.3183 (3) | 0.1667 (2) | 0.4157 (2) | 0.045 (1) | |
C20 | 0.3657 (3) | 0.2959 (2) | 0.4427 (2) | 0.058 (1) | |
C21 | 0.3393 (4) | 0.3435 (3) | 0.5443 (3) | 0.074 (1) | |
C22 | 0.2662 (4) | 0.2633 (3) | 0.6194 (2) | 0.074 (1) | |
C23 | 0.2136 (4) | 0.1354 (3) | 0.5928 (2) | 0.075 (1) | |
C24 | 0.2387 (4) | 0.0871 (3) | 0.4921 (2) | 0.064 (1) | |
C25 | 0.2535 (3) | −0.2425 (2) | 0.2519 (2) | 0.047 (1) | |
C26 | 0.1382 (3) | −0.2770 (2) | 0.3280 (2) | 0.055 (1) | |
C27 | 0.0935 (4) | −0.3976 (3) | 0.3659 (2) | 0.067 (1) | |
C28 | 0.1661 (4) | −0.4864 (3) | 0.3300 (3) | 0.079 (1) | |
C29 | 0.2807 (5) | −0.4545 (3) | 0.2559 (3) | 0.088 (2) | |
C30 | 0.3254 (4) | −0.3337 (3) | 0.2165 (3) | 0.071 (1) | |
H1 | 0.5103 | 0.0083 | 0.2960 | 0.049* | |
H2 | 0.3745 | −0.0479 | 0.3750 | 0.049* | |
H3 | −0.2153 | −0.0988 | 0.0748 | 0.052* | |
H4 | −0.1766 | 0.1016 | 0.1607 | 0.053* | |
H5 | 0.0665 | 0.2022 | 0.2671 | 0.049* | |
H6 | 0.3323 | −0.1529 | 0.0527 | 0.063* | |
H7 | 0.4123 | −0.0084 | 0.0874 | 0.063* | |
H8 | 0.4961 | −0.1097 | 0.1266 | 0.063* | |
H9 | −0.1359 | −0.2777 | 0.0333 | 0.065* | |
H10 | 0.0515 | −0.2521 | 0.0213 | 0.065* | |
H11 | −0.0260 | −0.3140 | 0.1250 | 0.065* | |
H12 | 0.8355 | 0.3879 | 0.2340 | 0.070* | |
H13 | 0.7365 | 0.4479 | 0.0712 | 0.072* | |
H14 | 0.4591 | 0.3649 | 0.0140 | 0.062* | |
H15 | 0.2891 | 0.2170 | 0.1162 | 0.050* | |
H16 | 0.6202 | 0.1709 | 0.4139 | 0.072* | |
H17 | 0.7879 | 0.1974 | 0.3615 | 0.072* | |
H18 | 0.7430 | 0.3081 | 0.4249 | 0.072* | |
H19 | 0.4176 | 0.3536 | 0.3906 | 0.057* | |
H20 | 0.3733 | 0.4337 | 0.5616 | 0.074* | |
H21 | 0.2510 | 0.2962 | 0.6902 | 0.074* | |
H22 | 0.1594 | 0.0784 | 0.6447 | 0.075* | |
H23 | 0.2002 | −0.0029 | 0.4746 | 0.064* | |
H24 | 0.0880 | −0.2152 | 0.3551 | 0.055* | |
H25 | 0.0114 | −0.4194 | 0.4171 | 0.067* | |
H26 | 0.1370 | −0.5698 | 0.3571 | 0.078* | |
H27 | 0.3312 | −0.5167 | 0.2303 | 0.089* | |
H28 | 0.4065 | −0.3133 | 0.1645 | 0.071* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.043 (1) | 0.039 (1) | 0.044 (1) | 0.011 (1) | −0.001 (1) | 0.001 (1) |
C2 | 0.044 (1) | 0.043 (1) | 0.058 (2) | 0.012 (1) | −0.005 (1) | 0.001 (1) |
C3 | 0.045 (1) | 0.046 (1) | 0.045 (1) | 0.015 (1) | 0.004 (1) | 0.000 (1) |
C4 | 0.047 (1) | 0.048 (1) | 0.040 (1) | 0.007 (1) | 0.000 (1) | 0.005 (1) |
C5 | 0.043 (1) | 0.062 (2) | 0.047 (1) | 0.013 (1) | −0.004 (1) | 0.005 (1) |
C6 | 0.044 (1) | 0.063 (2) | 0.058 (2) | 0.022 (1) | 0.003 (1) | 0.012 (1) |
C7 | 0.049 (1) | 0.047 (1) | 0.052 (1) | 0.016 (1) | 0.006 (1) | 0.006 (1) |
C8 | 0.040 (1) | 0.038 (1) | 0.042 (1) | 0.011 (1) | 0.004 (1) | 0.005 (1) |
C9 | 0.042 (1) | 0.041 (1) | 0.038 (1) | 0.010 (1) | 0.006 (1) | 0.007 (1) |
C10 | 0.062 (2) | 0.069 (2) | 0.064 (2) | 0.023 (1) | 0.020 (1) | 0.005 (1) |
C11 | 0.072 (2) | 0.056 (2) | 0.057 (2) | 0.011 (1) | −0.013 (1) | −0.007 (1) |
C12 | 0.047 (1) | 0.040 (1) | 0.045 (1) | 0.010 (1) | 0.003 (1) | −0.001 (1) |
C13 | 0.051 (1) | 0.053 (2) | 0.055 (2) | 0.008 (1) | 0.003 (1) | −0.004 (1) |
C14 | 0.053 (2) | 0.064 (2) | 0.080 (2) | −0.003 (1) | 0.011 (1) | −0.003 (2) |
C15 | 0.077 (2) | 0.057 (2) | 0.073 (2) | 0.002 (2) | 0.023 (2) | 0.010 (1) |
C16 | 0.072 (2) | 0.053 (2) | 0.057 (2) | 0.010 (1) | 0.013 (1) | 0.009 (1) |
C17 | 0.056 (1) | 0.044 (1) | 0.048 (1) | 0.011 (1) | 0.005 (1) | 0.003 (1) |
C18 | 0.049 (2) | 0.088 (2) | 0.072 (2) | 0.010 (1) | −0.013 (1) | −0.002 (2) |
C19 | 0.044 (1) | 0.047 (1) | 0.043 (1) | 0.011 (1) | 0.001 (1) | 0.006 (1) |
C20 | 0.064 (2) | 0.049 (2) | 0.057 (2) | 0.010 (1) | 0.012 (1) | 0.002 (1) |
C21 | 0.085 (2) | 0.063 (2) | 0.067 (2) | 0.011 (2) | 0.017 (2) | −0.015 (2) |
C22 | 0.074 (2) | 0.093 (2) | 0.050 (2) | 0.018 (2) | 0.010 (1) | −0.007 (2) |
C23 | 0.086 (2) | 0.084 (2) | 0.056 (2) | 0.019 (2) | 0.019 (2) | 0.015 (2) |
C24 | 0.080 (2) | 0.056 (2) | 0.056 (2) | 0.014 (1) | 0.012 (1) | 0.008 (1) |
C25 | 0.050 (1) | 0.042 (1) | 0.048 (1) | 0.017 (1) | −0.005 (1) | −0.003 (1) |
C26 | 0.063 (2) | 0.043 (1) | 0.057 (2) | 0.014 (1) | 0.001 (1) | 0.005 (1) |
C27 | 0.074 (2) | 0.049 (2) | 0.071 (2) | 0.008 (1) | −0.007 (2) | 0.007 (1) |
C28 | 0.092 (2) | 0.047 (2) | 0.093 (2) | 0.018 (2) | −0.015 (2) | 0.011 (2) |
C29 | 0.107 (3) | 0.053 (2) | 0.116 (3) | 0.042 (2) | 0.002 (2) | 0.001 (2) |
C30 | 0.081 (2) | 0.058 (2) | 0.084 (2) | 0.036 (2) | 0.010 (2) | −0.001 (2) |
C1—C2 | 1.564 (3) | C14—H12 | 0.96 |
C1—C8 | 1.529 (4) | C15—C16 | 1.372 (5) |
C1—C12 | 1.543 (4) | C15—H13 | 0.96 |
C1—C19 | 1.548 (3) | C16—C17 | 1.380 (4) |
C2—C3 | 1.562 (4) | C16—H14 | 0.96 |
C2—H1 | 0.96 | C17—H15 | 0.96 |
C2—H2 | 0.96 | C18—H16 | 0.96 |
C3—C9 | 1.522 (3) | C18—H17 | 0.96 |
C3—C10 | 1.536 (4) | C18—H18 | 0.96 |
C3—C25 | 1.525 (4) | C19—C20 | 1.381 (4) |
C4—C5 | 1.391 (3) | C19—C24 | 1.388 (4) |
C4—C9 | 1.402 (4) | C20—C21 | 1.392 (4) |
C4—C11 | 1.510 (4) | C20—H19 | 0.96 |
C5—C6 | 1.383 (4) | C21—C22 | 1.361 (5) |
C5—H3 | 0.96 | C21—H20 | 0.96 |
C6—C7 | 1.383 (4) | C22—C23 | 1.366 (6) |
C6—H4 | 0.96 | C22—H21 | 0.96 |
C7—C8 | 1.389 (3) | C23—C24 | 1.381 (4) |
C7—H5 | 0.96 | C23—H22 | 0.96 |
C8—C9 | 1.387 (3) | C24—H23 | 0.96 |
C10—H6 | 0.96 | C25—C26 | 1.389 (4) |
C10—H7 | 0.96 | C25—C30 | 1.387 (4) |
C10—H8 | 0.96 | C26—C27 | 1.382 (4) |
C11—H9 | 0.96 | C26—H24 | 0.96 |
C11—H10 | 0.96 | C27—C28 | 1.370 (4) |
C11—H11 | 0.96 | C27—H25 | 0.96 |
C12—C13 | 1.404 (4) | C28—C29 | 1.364 (6) |
C12—C17 | 1.395 (3) | C28—H26 | 0.96 |
C13—C14 | 1.392 (4) | C29—C30 | 1.391 (5) |
C13—C18 | 1.520 (4) | C29—H27 | 0.96 |
C14—C15 | 1.380 (4) | C30—H28 | 0.96 |
C12—C1—C2 | 110.2 (2) | H12—C14—C13 | 118.9 |
C8—C1—C2 | 100.7 (2) | C15—C14—C13 | 122.5 (3) |
C8—C1—C12 | 112.2 (2) | C15—C14—H12 | 118.7 |
C19—C1—C2 | 113.0 (2) | C16—C15—H13 | 120.4 |
C19—C1—C12 | 111.7 (2) | C14—C15—H13 | 120.5 |
C19—C1—C8 | 108.5 (2) | C14—C15—C16 | 119.1 (3) |
H2—C2—C1 | 109.8 | C17—C16—C15 | 119.2 (3) |
H1—C2—C1 | 109.8 | H14—C16—C15 | 120.4 |
H1—C2—H2 | 109.5 | H14—C16—C17 | 120.3 |
C3—C2—C1 | 108.0 (2) | H15—C17—C16 | 118.5 |
C3—C2—H2 | 109.9 | C12—C17—C16 | 122.9 (3) |
C3—C2—H1 | 109.8 | C12—C17—H15 | 118.6 |
C2—C3—C9 | 101.8 (2) | H17—C18—C13 | 109.3 |
C25—C3—C9 | 112.6 (2) | H18—C18—C13 | 109.5 |
C25—C3—C2 | 109.3 (2) | H18—C18—H17 | 109.5 |
C10—C3—C9 | 109.1 (2) | H16—C18—C13 | 109.6 |
C10—C3—C2 | 109.8 (2) | H16—C18—H17 | 109.5 |
C10—C3—C25 | 113.5 (2) | H16—C18—H18 | 109.5 |
C5—C4—C9 | 117.5 (2) | C1—C19—C20 | 122.0 (2) |
C11—C4—C9 | 123.1 (2) | C24—C19—C20 | 117.4 (2) |
C11—C4—C5 | 119.4 (3) | C24—C19—C1 | 120.4 (2) |
H3—C5—C4 | 119.1 | C21—C20—H19 | 119.6 |
C6—C5—C4 | 121.8 (3) | C19—C20—H19 | 119.4 |
C6—C5—H3 | 119.1 | C19—C20—C21 | 121.0 (3) |
C5—C6—C7 | 120.3 (2) | C20—C21—H20 | 119.7 |
H4—C6—C7 | 119.9 | C22—C21—H20 | 119.8 |
H4—C6—C5 | 119.9 | C22—C21—C20 | 120.5 (3) |
C8—C7—C6 | 118.9 (2) | C21—C22—H21 | 120.4 |
H5—C7—C6 | 120.5 | C23—C22—H21 | 120.2 |
H5—C7—C8 | 120.6 | C23—C22—C21 | 119.4 (3) |
C9—C8—C1 | 112.6 (2) | H22—C23—C22 | 119.8 |
C7—C8—C1 | 126.6 (2) | C24—C23—C22 | 120.5 (3) |
C7—C8—C9 | 120.8 (2) | C24—C23—H22 | 119.6 |
C3—C9—C4 | 127.9 (2) | C19—C24—H23 | 119.4 |
C8—C9—C4 | 120.7 (2) | C23—C24—H23 | 119.5 |
C8—C9—C3 | 111.4 (2) | C23—C24—C19 | 121.1 (3) |
H6—C10—H7 | 109.5 | C3—C25—C26 | 119.6 (2) |
H8—C10—H7 | 109.5 | C30—C25—C26 | 117.2 (2) |
H8—C10—H6 | 109.5 | C30—C25—C3 | 123.2 (2) |
C3—C10—H7 | 109.4 | H24—C26—C25 | 119.0 |
C3—C10—H6 | 109.5 | C27—C26—C25 | 121.9 (2) |
C3—C10—H8 | 109.4 | C27—C26—H24 | 119.1 |
H10—C11—H11 | 109.5 | C26—C27—H25 | 120.0 |
C4—C11—H11 | 109.5 | C28—C27—H25 | 120.0 |
C4—C11—H10 | 109.4 | C28—C27—C26 | 120.0 (3) |
H9—C11—H11 | 109.5 | C27—C28—H26 | 120.3 |
H9—C11—H10 | 109.5 | C29—C28—H26 | 120.5 |
H9—C11—C4 | 109.6 | C29—C28—C27 | 119.2 (3) |
C17—C12—C1 | 120.3 (2) | H27—C29—C30 | 119.5 |
C13—C12—C1 | 122.1 (2) | C28—C29—C30 | 121.2 (3) |
C13—C12—C17 | 117.5 (2) | C28—C29—H27 | 119.3 |
C12—C13—C18 | 123.7 (3) | H28—C30—C29 | 119.8 |
C14—C13—C18 | 117.5 (3) | C25—C30—C29 | 120.5 (3) |
C14—C13—C12 | 118.7 (2) | C25—C30—H28 | 119.8 |
Experimental details
Crystal data | |
Chemical formula | C30H28 |
Mr | 388.55 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 8.577 (2), 10.997 (3), 12.327 (3) |
α, β, γ (°) | 92.56 (2), 93.38 (2), 106.67 (2) |
V (Å3) | 1109.6 (5) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 0.49 |
Crystal size (mm) | 0.35 × 0.20 × 0.15 |
Data collection | |
Diffractometer | Rigaku AFC-5 four-circle diffractometer |
Absorption correction | Empirical (using intensity measurements) (North et al., 1968) |
Tmin, Tmax | 0.931, 1.000 |
No. of measured, independent and observed [F > 6σ(F)] reflections | 3828, 3495, 2397 |
Rint | 0.029 |
θmax (°) | 62.0 |
(sin θ/λ)max (Å−1) | 0.573 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.057, 0.94 |
No. of reflections | 2397 |
No. of parameters | 271 |
No. of restraints | ? |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.17 |
Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Coorporation, 1988), MSC/AFC Diffractometer Control Software, TEXSAN (Molecular Structure Coorporation, 1985), SIR97 (Altomare et al., 1999), CAOS (Camalli & Spagna, 1994), CAOS.
The hole catalyst tris(2,4-dibromophenyl)aminium hexachloroantimonate [2,4-Br2C6H3)3N+SbCl6, A; Ered = 1.66 versus SCE; Baker et al., 1965] has been successfully employed for accomplishing novel, selective and highly efficient chemical transformations on a great variety of electron-rich substrates (Bauld, 1989; Nelsen, 1987; Lopez et al., 1994; Caló et al., 1995). Among them, we recently reported the facile aminium salt (A) induced cyclodimerization of several 1-aryl-1-phenylethylenes, leading, in dichloromethane solutions, to mixtures of two pairs of diastereoisomeric indan derivatives (Ciminale et al., 1996). On the contrary, a similar reaction, carried out in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFP) solution of 1-o-tolyl-1-phenylethylene, afforded only the cis isomer of the title compound, (I) (Lopez et al., unpublished results).
The crystal structure of (I) consists of discrete molecules of C30H28. The bond distances and angles are in agreement with accepted values. The atoms of the indan group, with the exception of C2, are almost coplanar, with an average deviation of 0.012 (3) Å. The conformation of the the five-membered ring of the indan group can be described as an envelope (Evans & Boeyens, 1989). The out-of-plane displacements from the least-squares plane are 0.121 (3), -0.148 (3), 0,120 (3), -0.049 (3) and -0.044 (3) Å for C1, C2, C3, C8 and C9, respectively. C2, at the apex, deviates from the best plane of the other four atoms by 0.371 (2) Å; this compares with an average distance for the other atoms of 0.002 (3) Å. This plane makes an angle of 23.8 (1)° with the C1/C2/C3 plane.
The phenyl rings are cis with respect to the indan group. The angle between their least-squares planes is 35.3 (1)°. The C3—C25 and C1—C19 bonds make angles of 44.5 (1) and 43.4 (1)°, respectively, with the best plane of the indan group, while bonds C3—C10 and C1—C19 form angles of 68.9 (2) and 66.8 (1)°. Furthermore, the distance between C19 and C25 is 4.717 (4) Å compared with a distance between C10 and C12 of 3.519 (4) Å, thus relieving steric strain between the two phenyl groups.