Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807034320/gk2079sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807034320/gk2079Isup2.hkl |
CCDC reference: 657886
The mixture of 135 mg 2,2'-(2,2'-(ethyne-1,2-diyl)bis(2,1-phenylene)dipropan-2-ol, 0.3 ml chlorotrimethylsilane, 163.9 mg LiBr and 7 ml MeCN was refluxed for 34 h under nitrogen atomsphere. The mixture was extracted with Et2O, the organic layer was washed with brine, dried over MgSO4, filtered and concentrated under reduced pressure to give 163.7 mg of product in 85% yield. Recrystallization from hexane/ethyl acetate (4:1) gave a single-crystal which was used for X-ray analysis.
H atoms were positioned geometrically and refined using a riding model with C—H bonds 0.93–0.96Å and with Uiso(H)=1.2Ueq(C) for benzene H atoms or Uiso(H)=1.5Ueq(C) for methyl groups. In the absence of signifcant anomalous scattering effects, Friedel pairs were averaged.
During our investigation of new intramolecular reductive cyclization the title compound has been synthesized unexpectedly as the product of an attempted synthesis of 1,2 -bis (2-(2-(bromopropan-2-yl)phenyl)ethyne in the reaction of 2,2'-(2,2'-(ethyne-1,2-diyl)bis(2,1-phenylene)dipropan-2-ol and chlorotrimethylsilane catalyzed by LiBr in refluxed MeCN (Scheme 2). The molecule consists of four fused rings, three six-membered rings and one five-membered ring, which show a nearly planar structure (Fig. 1). Synthesis of a similar benzofluorene derivative has been reported previously (Mitra & Ray, 1981; Bradsher & Burhans, 1940)
In the crystal structure (Fig. 2), the molecules exhibit a T-packing mode with a few intermolecular CH2—H···π interactions having H···π distances of about 2.7 Å.
For the synthesis of similar compounds, see: Mitra & Ray (1981); Bradsher & Burhans (1940).
Data collection: RAPID-AUTO (Rigaku, 2001); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1994) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97.
C20H18 | F(000) = 552 |
Mr = 258.34 | Dx = 1.190 Mg m−3 |
Orthorhombic, Pca21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2ac | Cell parameters from 3084 reflections |
a = 9.5632 (19) Å | θ = 2.2–27.5° |
b = 9.3715 (19) Å | µ = 0.07 mm−1 |
c = 16.089 (3) Å | T = 295 K |
V = 1441.9 (5) Å3 | Platelet, colorless |
Z = 4 | 0.31 × 0.26 × 0.22 mm |
Rigaku R-AXIS RAPID diffractometer | 1216 reflections with I > 2σ(I) |
Radiation source: Rotating anode | Rint = 0.019 |
Graphite monochromator | θmax = 27.5°, θmin = 2.2° |
ω scans | h = −12→12 |
3084 measured reflections | k = −12→12 |
1702 independent reflections | l = −20→20 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.067 | w = 1/[σ2(Fo2) + (0.007P)2 + 0.2P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
1702 reflections | Δρmax = 0.12 e Å−3 |
183 parameters | Δρmin = −0.11 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0309 (11) |
C20H18 | V = 1441.9 (5) Å3 |
Mr = 258.34 | Z = 4 |
Orthorhombic, Pca21 | Mo Kα radiation |
a = 9.5632 (19) Å | µ = 0.07 mm−1 |
b = 9.3715 (19) Å | T = 295 K |
c = 16.089 (3) Å | 0.31 × 0.26 × 0.22 mm |
Rigaku R-AXIS RAPID diffractometer | 1216 reflections with I > 2σ(I) |
3084 measured reflections | Rint = 0.019 |
1702 independent reflections |
R[F2 > 2σ(F2)] = 0.038 | 0 restraints |
wR(F2) = 0.067 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.12 e Å−3 |
1702 reflections | Δρmin = −0.11 e Å−3 |
183 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.3492 (3) | 0.6555 (3) | 0.74283 (17) | 0.0494 (6) | |
C2 | 0.3398 (3) | 0.7348 (3) | 0.82441 (17) | 0.0479 (6) | |
C3 | 0.2341 (3) | 0.7335 (3) | 0.88295 (17) | 0.0604 (8) | |
H3A | 0.1547 | 0.6778 | 0.8750 | 0.072* | |
C4 | 0.2484 (4) | 0.8161 (3) | 0.9532 (2) | 0.0683 (8) | |
H4A | 0.1783 | 0.8144 | 0.9933 | 0.082* | |
C5 | 0.3630 (3) | 0.9005 (3) | 0.9655 (2) | 0.0710 (9) | |
H5A | 0.3700 | 0.9562 | 1.0131 | 0.085* | |
C6 | 0.4688 (3) | 0.9028 (3) | 0.90671 (19) | 0.0632 (8) | |
H6A | 0.5471 | 0.9601 | 0.9143 | 0.076* | |
C7 | 0.4563 (3) | 0.8193 (3) | 0.83708 (17) | 0.0493 (7) | |
C8 | 0.5481 (2) | 0.8018 (3) | 0.76460 (15) | 0.0468 (6) | |
C9 | 0.6766 (2) | 0.8676 (3) | 0.74735 (19) | 0.0543 (7) | |
H9A | 0.7160 | 0.9291 | 0.7862 | 0.065* | |
C10 | 0.7438 (3) | 0.8426 (2) | 0.67483 (18) | 0.0530 (7) | |
C11 | 0.6831 (3) | 0.7487 (3) | 0.61546 (17) | 0.0486 (6) | |
C12 | 0.7497 (4) | 0.7194 (3) | 0.5390 (2) | 0.0621 (7) | |
H12A | 0.8336 | 0.7647 | 0.5264 | 0.075* | |
C13 | 0.6939 (3) | 0.6266 (4) | 0.4837 (2) | 0.0734 (9) | |
H13A | 0.7390 | 0.6099 | 0.4335 | 0.088* | |
C14 | 0.5699 (3) | 0.5561 (4) | 0.50155 (19) | 0.0684 (9) | |
H14A | 0.5338 | 0.4903 | 0.4639 | 0.082* | |
C15 | 0.5011 (3) | 0.5827 (3) | 0.57354 (18) | 0.0576 (7) | |
H15A | 0.4169 | 0.5363 | 0.5840 | 0.069* | |
C16 | 0.5541 (3) | 0.6789 (3) | 0.63294 (16) | 0.0473 (6) | |
C17 | 0.4877 (2) | 0.7098 (2) | 0.70901 (16) | 0.0433 (6) | |
C18 | 0.2245 (3) | 0.6957 (3) | 0.68713 (18) | 0.0633 (8) | |
H18A | 0.2254 | 0.7966 | 0.6769 | 0.095* | |
H18B | 0.1389 | 0.6699 | 0.7144 | 0.095* | |
H18C | 0.2314 | 0.6455 | 0.6353 | 0.095* | |
C19 | 0.3511 (3) | 0.4956 (3) | 0.75899 (18) | 0.0643 (8) | |
H19A | 0.2629 | 0.4667 | 0.7820 | 0.096* | |
H19B | 0.4246 | 0.4733 | 0.7975 | 0.096* | |
H19C | 0.3670 | 0.4458 | 0.7077 | 0.096* | |
C20 | 0.8835 (3) | 0.9111 (3) | 0.6573 (2) | 0.0769 (10) | |
H20A | 0.9137 | 0.9633 | 0.7054 | 0.115* | |
H20B | 0.8747 | 0.9751 | 0.6110 | 0.115* | |
H20C | 0.9509 | 0.8385 | 0.6444 | 0.115* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0484 (14) | 0.0450 (14) | 0.0547 (16) | −0.0066 (11) | −0.0079 (13) | 0.0020 (13) |
C2 | 0.0528 (14) | 0.0417 (13) | 0.0491 (14) | 0.0040 (12) | −0.0030 (13) | 0.0052 (13) |
C3 | 0.0603 (18) | 0.0589 (17) | 0.0620 (18) | 0.0018 (15) | 0.0006 (15) | 0.0069 (17) |
C4 | 0.078 (2) | 0.0657 (17) | 0.0608 (17) | 0.0128 (19) | 0.0070 (16) | 0.0010 (17) |
C5 | 0.087 (2) | 0.0637 (19) | 0.0619 (19) | 0.0132 (18) | −0.0064 (19) | −0.0148 (17) |
C6 | 0.0653 (19) | 0.0585 (18) | 0.0660 (19) | 0.0021 (15) | −0.0086 (16) | −0.0107 (16) |
C7 | 0.0539 (15) | 0.0404 (13) | 0.0537 (16) | 0.0041 (12) | −0.0081 (14) | −0.0004 (14) |
C8 | 0.0463 (13) | 0.0389 (13) | 0.0553 (17) | 0.0026 (11) | −0.0093 (13) | 0.0006 (13) |
C9 | 0.0502 (15) | 0.0397 (14) | 0.0730 (19) | −0.0017 (11) | −0.0102 (15) | −0.0076 (14) |
C10 | 0.0452 (14) | 0.0392 (13) | 0.075 (2) | 0.0031 (13) | −0.0024 (14) | 0.0029 (14) |
C11 | 0.0494 (14) | 0.0383 (13) | 0.0580 (16) | 0.0053 (11) | −0.0028 (13) | 0.0057 (13) |
C12 | 0.0584 (16) | 0.0615 (18) | 0.0664 (17) | 0.0051 (16) | 0.0034 (15) | 0.0059 (17) |
C13 | 0.076 (2) | 0.086 (2) | 0.059 (2) | 0.0133 (19) | 0.0049 (17) | −0.0053 (19) |
C14 | 0.075 (2) | 0.074 (2) | 0.0560 (18) | 0.0074 (19) | −0.0087 (17) | −0.0119 (16) |
C15 | 0.0607 (16) | 0.0585 (16) | 0.0535 (16) | −0.0005 (15) | −0.0084 (14) | −0.0052 (15) |
C16 | 0.0485 (14) | 0.0424 (13) | 0.0510 (16) | 0.0040 (12) | −0.0097 (13) | 0.0028 (13) |
C17 | 0.0453 (13) | 0.0359 (12) | 0.0488 (14) | 0.0014 (11) | −0.0078 (12) | 0.0030 (13) |
C18 | 0.0505 (15) | 0.0747 (18) | 0.065 (2) | −0.0061 (14) | −0.0101 (14) | 0.0042 (17) |
C19 | 0.0790 (18) | 0.0483 (14) | 0.0657 (19) | −0.0099 (14) | 0.0001 (16) | 0.0009 (16) |
C20 | 0.0545 (17) | 0.0645 (19) | 0.112 (3) | −0.0106 (15) | 0.0074 (18) | −0.007 (2) |
C1—C2 | 1.511 (3) | C11—C12 | 1.412 (4) |
C1—C17 | 1.519 (3) | C11—C16 | 1.424 (3) |
C1—C19 | 1.522 (4) | C12—C13 | 1.353 (4) |
C1—C18 | 1.539 (3) | C12—H12A | 0.9300 |
C2—C7 | 1.382 (4) | C13—C14 | 1.387 (4) |
C2—C3 | 1.382 (4) | C13—H13A | 0.9300 |
C3—C4 | 1.377 (4) | C14—C15 | 1.355 (4) |
C3—H3A | 0.9300 | C14—H14A | 0.9300 |
C4—C5 | 1.366 (4) | C15—C16 | 1.409 (4) |
C4—H4A | 0.9300 | C15—H15A | 0.9300 |
C5—C6 | 1.385 (4) | C16—C17 | 1.409 (3) |
C5—H5A | 0.9300 | C18—H18A | 0.9600 |
C6—C7 | 1.372 (4) | C18—H18B | 0.9600 |
C6—H6A | 0.9300 | C18—H18C | 0.9600 |
C7—C8 | 1.469 (3) | C19—H19A | 0.9600 |
C8—C17 | 1.370 (3) | C19—H19B | 0.9600 |
C8—C9 | 1.402 (3) | C19—H19C | 0.9600 |
C9—C10 | 1.353 (4) | C20—H20A | 0.9600 |
C9—H9A | 0.9300 | C20—H20B | 0.9600 |
C10—C11 | 1.422 (4) | C20—H20C | 0.9600 |
C10—C20 | 1.509 (3) | ||
C2—C1—C17 | 101.4 (2) | C13—C12—C11 | 121.3 (3) |
C2—C1—C19 | 109.7 (2) | C13—C12—H12A | 119.4 |
C17—C1—C19 | 112.4 (2) | C11—C12—H12A | 119.4 |
C2—C1—C18 | 109.9 (2) | C12—C13—C14 | 120.5 (3) |
C17—C1—C18 | 112.7 (2) | C12—C13—H13A | 119.7 |
C19—C1—C18 | 110.5 (2) | C14—C13—H13A | 119.7 |
C7—C2—C3 | 119.6 (3) | C15—C14—C13 | 120.2 (3) |
C7—C2—C1 | 111.2 (2) | C15—C14—H14A | 119.9 |
C3—C2—C1 | 129.1 (3) | C13—C14—H14A | 119.9 |
C4—C3—C2 | 118.8 (3) | C14—C15—C16 | 121.5 (3) |
C4—C3—H3A | 120.6 | C14—C15—H15A | 119.2 |
C2—C3—H3A | 120.6 | C16—C15—H15A | 119.2 |
C5—C4—C3 | 121.6 (3) | C17—C16—C15 | 124.0 (2) |
C5—C4—H4A | 119.2 | C17—C16—C11 | 117.9 (2) |
C3—C4—H4A | 119.2 | C15—C16—C11 | 118.2 (2) |
C4—C5—C6 | 119.8 (3) | C8—C17—C16 | 120.4 (2) |
C4—C5—H5A | 120.1 | C8—C17—C1 | 110.2 (2) |
C6—C5—H5A | 120.1 | C16—C17—C1 | 129.4 (2) |
C7—C6—C5 | 119.0 (3) | C1—C18—H18A | 109.5 |
C7—C6—H6A | 120.5 | C1—C18—H18B | 109.5 |
C5—C6—H6A | 120.5 | H18A—C18—H18B | 109.5 |
C6—C7—C2 | 121.2 (3) | C1—C18—H18C | 109.5 |
C6—C7—C8 | 131.3 (3) | H18A—C18—H18C | 109.5 |
C2—C7—C8 | 107.5 (2) | H18B—C18—H18C | 109.5 |
C17—C8—C9 | 121.1 (2) | C1—C19—H19A | 109.5 |
C17—C8—C7 | 109.7 (2) | C1—C19—H19B | 109.5 |
C9—C8—C7 | 129.2 (2) | H19A—C19—H19B | 109.5 |
C10—C9—C8 | 120.7 (3) | C1—C19—H19C | 109.5 |
C10—C9—H9A | 119.6 | H19A—C19—H19C | 109.5 |
C8—C9—H9A | 119.6 | H19B—C19—H19C | 109.5 |
C9—C10—C11 | 119.5 (2) | C10—C20—H20A | 109.5 |
C9—C10—C20 | 120.5 (3) | C10—C20—H20B | 109.5 |
C11—C10—C20 | 119.9 (3) | H20A—C20—H20B | 109.5 |
C12—C11—C10 | 121.4 (3) | C10—C20—H20C | 109.5 |
C12—C11—C16 | 118.2 (2) | H20A—C20—H20C | 109.5 |
C10—C11—C16 | 120.3 (2) | H20B—C20—H20C | 109.5 |
D—H···A | D—H | H···A | D···A | D—H···A |
C20—H20A···C8i | 0.96 | 2.72 | 3.563 (4) | 147 |
Symmetry code: (i) x+1/2, −y+2, z. |
Experimental details
Crystal data | |
Chemical formula | C20H18 |
Mr | 258.34 |
Crystal system, space group | Orthorhombic, Pca21 |
Temperature (K) | 295 |
a, b, c (Å) | 9.5632 (19), 9.3715 (19), 16.089 (3) |
V (Å3) | 1441.9 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.31 × 0.26 × 0.22 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3084, 1702, 1216 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.067, 1.07 |
No. of reflections | 1702 |
No. of parameters | 183 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.12, −0.11 |
Computer programs: RAPID-AUTO (Rigaku, 2001), RAPID-AUTO, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL/PC (Sheldrick, 1994) and Mercury (Macrae et al., 2006), SHELXL97.
D—H···A | D—H | H···A | D···A | D—H···A |
C20—H20A···C8i | 0.96 | 2.72 | 3.563 (4) | 147 |
Symmetry code: (i) x+1/2, −y+2, z. |
During our investigation of new intramolecular reductive cyclization the title compound has been synthesized unexpectedly as the product of an attempted synthesis of 1,2 -bis (2-(2-(bromopropan-2-yl)phenyl)ethyne in the reaction of 2,2'-(2,2'-(ethyne-1,2-diyl)bis(2,1-phenylene)dipropan-2-ol and chlorotrimethylsilane catalyzed by LiBr in refluxed MeCN (Scheme 2). The molecule consists of four fused rings, three six-membered rings and one five-membered ring, which show a nearly planar structure (Fig. 1). Synthesis of a similar benzofluorene derivative has been reported previously (Mitra & Ray, 1981; Bradsher & Burhans, 1940)
In the crystal structure (Fig. 2), the molecules exhibit a T-packing mode with a few intermolecular CH2—H···π interactions having H···π distances of about 2.7 Å.