In the title compound, C
20H
12N
2, the bond lengths in the cyclopropane ring are 1.526, 1.532 and 1.541 (2) Å. The molecules are linked by two C—H
N contacts.
Supporting information
CCDC reference: 204693
Key indicators
- Single-crystal X-ray study
- T = 178 K
- Mean (C-C) = 0.002 Å
- R factor = 0.040
- wR factor = 0.111
- Data-to-parameter ratio = 12.8
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Compound (1) was irradiated for 4 h at room temperature using a 450 W mercury high-pressure lamp, forming (2) in 65% yield (Witulski, 1992). The product was crystallized from chloroform/pentane.
H atoms were included using a riding model with fixed C—H bond lengths (sp2-C—H = 0.95 Å and methine = 1.00 Å); Usio(H) values were fixed at 1.2Ueq of the parent atom.
Data collection: P3 (Nicolet, 1987); cell refinement: P3; data reduction: XDISK (Nicolet, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.
9,10-Dicyano-dibenzoisobullvalene
top
Crystal data top
C20H12N2 | Z = 2 |
Mr = 280.32 | F(000) = 292 |
Triclinic, P1 | Dx = 1.286 Mg m−3 |
a = 6.722 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.154 (3) Å | Cell parameters from 50 reflections |
c = 12.143 (4) Å | θ = 10–12° |
α = 96.85 (3)° | µ = 0.08 mm−1 |
β = 90.65 (3)° | T = 178 K |
γ = 102.51 (3)° | Prism, colourless |
V = 723.7 (5) Å3 | 0.7 × 0.4 × 0.2 mm |
Data collection top
Nicolet R3 diffractometer | Rint = 0.016 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 3.0° |
Graphite monochromator | h = −7→2 |
ω scans | k = −10→10 |
3368 measured reflections | l = −14→14 |
2539 independent reflections | 3 standard reflections every 147 reflections |
1923 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.111 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0631P)2 + 0.0943P] where P = (Fo2 + 2Fc2)/3 |
2539 reflections | (Δ/σ)max < 0.001 |
199 parameters | Δρmax = 0.14 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
Crystal data top
C20H12N2 | γ = 102.51 (3)° |
Mr = 280.32 | V = 723.7 (5) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.722 (3) Å | Mo Kα radiation |
b = 9.154 (3) Å | µ = 0.08 mm−1 |
c = 12.143 (4) Å | T = 178 K |
α = 96.85 (3)° | 0.7 × 0.4 × 0.2 mm |
β = 90.65 (3)° | |
Data collection top
Nicolet R3 diffractometer | Rint = 0.016 |
3368 measured reflections | 3 standard reflections every 147 reflections |
2539 independent reflections | intensity decay: none |
1923 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.111 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.14 e Å−3 |
2539 reflections | Δρmin = −0.19 e Å−3 |
199 parameters | |
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 | x | y | z | Uiso*/Ueq | |
C1 | 0.0414 (3) | 0.41201 (17) | 0.29653 (13) | 0.0338 (4) | |
H1 | −0.0858 | 0.4411 | 0.2940 | 0.041* | |
C2 | 0.0870 (3) | 0.36070 (18) | 0.38951 (13) | 0.0364 (4) | |
H2 | −0.0104 | 0.3631 | 0.4454 | 0.044* | |
C3 | 0.2631 (3) | 0.30107 (18) | 0.41978 (13) | 0.0346 (4) | |
C4 | 0.3735 (2) | 0.22503 (17) | 0.34350 (13) | 0.0312 (4) | |
C5 | 0.3123 (2) | 0.19330 (16) | 0.22141 (12) | 0.0282 (4) | |
H5 | 0.4095 | 0.1365 | 0.1841 | 0.034* | |
C6 | 0.0981 (2) | 0.10131 (16) | 0.19116 (12) | 0.0277 (4) | |
C7 | 0.0002 (2) | 0.16378 (16) | 0.11276 (12) | 0.0282 (4) | |
C8 | 0.1255 (2) | 0.31159 (16) | 0.09186 (12) | 0.0287 (4) | |
H8 | 0.1293 | 0.3436 | 0.0159 | 0.034* | |
C9 | 0.1645 (2) | 0.42951 (16) | 0.19593 (12) | 0.0288 (4) | |
C10 | 0.3209 (2) | 0.33435 (16) | 0.16302 (12) | 0.0277 (4) | |
C11 | 0.3204 (3) | 0.3167 (2) | 0.53256 (14) | 0.0497 (5) | |
H11 | 0.2454 | 0.3656 | 0.5854 | 0.060* | |
C12 | 0.4832 (3) | 0.2630 (2) | 0.56888 (16) | 0.0579 (6) | |
H12 | 0.5193 | 0.2752 | 0.6458 | 0.070* | |
C13 | 0.5929 (3) | 0.1917 (2) | 0.49344 (16) | 0.0532 (5) | |
H13 | 0.7062 | 0.1559 | 0.5180 | 0.064* | |
C14 | 0.5374 (3) | 0.1721 (2) | 0.38130 (14) | 0.0410 (4) | |
H14 | 0.6127 | 0.1218 | 0.3296 | 0.049* | |
C15 | 0.0033 (3) | −0.03372 (17) | 0.22732 (13) | 0.0337 (4) | |
H15 | 0.0681 | −0.0756 | 0.2819 | 0.040* | |
C16 | −0.1880 (3) | −0.10647 (18) | 0.18220 (14) | 0.0385 (4) | |
H16 | −0.2543 | −0.1995 | 0.2057 | 0.046* | |
C17 | −0.2840 (3) | −0.04492 (18) | 0.10301 (14) | 0.0380 (4) | |
H17 | −0.4147 | −0.0967 | 0.0727 | 0.046* | |
C18 | −0.1908 (2) | 0.09185 (17) | 0.06762 (13) | 0.0333 (4) | |
H18 | −0.2565 | 0.1346 | 0.0139 | 0.040* | |
C19 | 0.2195 (2) | 0.58454 (18) | 0.17152 (13) | 0.0332 (4) | |
C20 | 0.5186 (3) | 0.41121 (17) | 0.13149 (12) | 0.0309 (4) | |
N1 | 0.2657 (2) | 0.70710 (16) | 0.15399 (12) | 0.0446 (4) | |
N2 | 0.6789 (2) | 0.47187 (17) | 0.11101 (12) | 0.0433 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0304 (9) | 0.0312 (8) | 0.0382 (9) | 0.0059 (7) | 0.0046 (7) | −0.0010 (7) |
C2 | 0.0378 (10) | 0.0349 (9) | 0.0324 (9) | 0.0015 (7) | 0.0099 (7) | −0.0015 (7) |
C3 | 0.0370 (10) | 0.0337 (9) | 0.0288 (8) | −0.0030 (7) | 0.0015 (7) | 0.0066 (6) |
C4 | 0.0305 (9) | 0.0298 (8) | 0.0310 (8) | −0.0018 (7) | 0.0000 (7) | 0.0102 (6) |
C5 | 0.0297 (8) | 0.0279 (8) | 0.0285 (8) | 0.0083 (6) | 0.0048 (6) | 0.0065 (6) |
C6 | 0.0311 (9) | 0.0257 (7) | 0.0259 (7) | 0.0066 (6) | 0.0039 (6) | 0.0010 (6) |
C7 | 0.0308 (9) | 0.0270 (8) | 0.0260 (7) | 0.0059 (7) | 0.0036 (6) | 0.0008 (6) |
C8 | 0.0292 (9) | 0.0294 (8) | 0.0271 (7) | 0.0054 (7) | −0.0001 (6) | 0.0045 (6) |
C9 | 0.0297 (9) | 0.0260 (8) | 0.0306 (8) | 0.0059 (6) | 0.0001 (7) | 0.0035 (6) |
C10 | 0.0278 (8) | 0.0292 (8) | 0.0262 (7) | 0.0050 (6) | 0.0028 (6) | 0.0052 (6) |
C11 | 0.0585 (13) | 0.0556 (11) | 0.0282 (9) | −0.0022 (10) | 0.0025 (9) | 0.0049 (8) |
C12 | 0.0580 (13) | 0.0729 (14) | 0.0339 (10) | −0.0121 (11) | −0.0128 (10) | 0.0206 (9) |
C13 | 0.0402 (11) | 0.0667 (13) | 0.0515 (12) | −0.0032 (10) | −0.0104 (9) | 0.0314 (10) |
C14 | 0.0337 (10) | 0.0465 (10) | 0.0437 (10) | 0.0032 (8) | −0.0014 (8) | 0.0202 (8) |
C15 | 0.0433 (10) | 0.0284 (8) | 0.0298 (8) | 0.0085 (7) | 0.0047 (7) | 0.0045 (6) |
C16 | 0.0444 (10) | 0.0264 (8) | 0.0406 (9) | −0.0010 (7) | 0.0088 (8) | 0.0032 (7) |
C17 | 0.0336 (9) | 0.0349 (9) | 0.0397 (9) | −0.0005 (7) | 0.0010 (8) | −0.0034 (7) |
C18 | 0.0330 (9) | 0.0332 (8) | 0.0324 (8) | 0.0064 (7) | −0.0014 (7) | 0.0003 (7) |
C19 | 0.0338 (9) | 0.0328 (9) | 0.0328 (8) | 0.0074 (7) | −0.0027 (7) | 0.0038 (7) |
C20 | 0.0322 (9) | 0.0334 (8) | 0.0282 (8) | 0.0070 (7) | 0.0006 (7) | 0.0090 (6) |
N1 | 0.0494 (10) | 0.0327 (8) | 0.0518 (9) | 0.0073 (7) | −0.0016 (7) | 0.0090 (7) |
N2 | 0.0345 (9) | 0.0474 (9) | 0.0488 (9) | 0.0047 (7) | 0.0053 (7) | 0.0175 (7) |
Geometric parameters (Å, º) top
C1—C2 | 1.331 (2) | C9—C19 | 1.454 (2) |
C1—C9 | 1.488 (2) | C9—C10 | 1.532 (2) |
C1—H1 | 0.9500 | C10—C20 | 1.442 (2) |
C2—C3 | 1.467 (3) | C11—C12 | 1.381 (3) |
C2—H2 | 0.9500 | C11—H11 | 0.9500 |
C3—C11 | 1.401 (2) | C12—C13 | 1.375 (3) |
C3—C4 | 1.407 (2) | C12—H12 | 0.9500 |
C4—C14 | 1.390 (2) | C13—C14 | 1.388 (3) |
C4—C5 | 1.511 (2) | C13—H13 | 0.9500 |
C5—C6 | 1.519 (2) | C14—H14 | 0.9500 |
C5—C10 | 1.536 (2) | C15—C16 | 1.387 (2) |
C5—H5 | 1.0000 | C15—H15 | 0.9500 |
C6—C15 | 1.386 (2) | C16—C17 | 1.390 (2) |
C6—C7 | 1.395 (2) | C16—H16 | 0.9500 |
C7—C18 | 1.383 (2) | C17—C18 | 1.393 (2) |
C7—C8 | 1.482 (2) | C17—H17 | 0.9500 |
C8—C10 | 1.526 (2) | C18—H18 | 0.9500 |
C8—C9 | 1.541 (2) | C19—N1 | 1.144 (2) |
C8—H8 | 1.0000 | C20—N2 | 1.145 (2) |
| | | |
C2—C1—C9 | 128.14 (16) | C1—C9—C8 | 122.47 (13) |
C2—C1—H1 | 115.9 | C10—C9—C8 | 59.54 (10) |
C9—C1—H1 | 115.9 | C20—C10—C8 | 124.02 (13) |
C1—C2—C3 | 130.54 (16) | C20—C10—C9 | 117.86 (13) |
C1—C2—H2 | 114.7 | C8—C10—C9 | 60.54 (10) |
C3—C2—H2 | 114.7 | C20—C10—C5 | 116.99 (13) |
C11—C3—C4 | 118.02 (17) | C8—C10—C5 | 108.49 (13) |
C11—C3—C2 | 117.62 (16) | C9—C10—C5 | 116.98 (12) |
C4—C3—C2 | 124.32 (15) | C12—C11—C3 | 121.67 (19) |
C14—C4—C3 | 119.60 (15) | C12—C11—H11 | 119.2 |
C14—C4—C5 | 118.91 (15) | C3—C11—H11 | 119.2 |
C3—C4—C5 | 121.43 (15) | C13—C12—C11 | 119.87 (17) |
C4—C5—C6 | 116.61 (13) | C13—C12—H12 | 120.1 |
C4—C5—C10 | 114.76 (12) | C11—C12—H12 | 120.1 |
C6—C5—C10 | 102.94 (12) | C12—C13—C14 | 119.74 (19) |
C4—C5—H5 | 107.3 | C12—C13—H13 | 120.1 |
C6—C5—H5 | 107.3 | C14—C13—H13 | 120.1 |
C10—C5—H5 | 107.3 | C13—C14—C4 | 121.07 (19) |
C15—C6—C7 | 120.35 (15) | C13—C14—H14 | 119.5 |
C15—C6—C5 | 127.79 (14) | C4—C14—H14 | 119.5 |
C7—C6—C5 | 111.76 (13) | C6—C15—C16 | 118.67 (15) |
C18—C7—C6 | 121.22 (14) | C6—C15—H15 | 120.7 |
C18—C7—C8 | 128.14 (14) | C16—C15—H15 | 120.7 |
C6—C7—C8 | 110.61 (14) | C15—C16—C17 | 120.83 (15) |
C7—C8—C10 | 105.60 (12) | C15—C16—H16 | 119.6 |
C7—C8—C9 | 113.32 (12) | C17—C16—H16 | 119.6 |
C10—C8—C9 | 59.92 (10) | C16—C17—C18 | 120.73 (16) |
C7—C8—H8 | 120.8 | C16—C17—H17 | 119.6 |
C10—C8—H8 | 120.8 | C18—C17—H17 | 119.6 |
C9—C8—H8 | 120.8 | C7—C18—C17 | 118.19 (15) |
C19—C9—C1 | 113.08 (13) | C7—C18—H18 | 120.9 |
C19—C9—C10 | 114.98 (13) | C17—C18—H18 | 120.9 |
C1—C9—C10 | 122.88 (13) | N1—C19—C9 | 178.63 (17) |
C19—C9—C8 | 113.88 (13) | N2—C20—C10 | 176.98 (16) |
| | | |
C9—C1—C2—C3 | −2.8 (3) | C9—C8—C10—C20 | −105.44 (16) |
C1—C2—C3—C11 | 152.47 (18) | C7—C8—C10—C9 | −108.25 (13) |
C1—C2—C3—C4 | −29.7 (3) | C7—C8—C10—C5 | 2.87 (15) |
C11—C3—C4—C14 | −1.8 (2) | C9—C8—C10—C5 | 111.13 (13) |
C2—C3—C4—C14 | −179.55 (15) | C19—C9—C10—C20 | 11.23 (19) |
C11—C3—C4—C5 | 175.52 (14) | C1—C9—C10—C20 | −133.46 (15) |
C2—C3—C4—C5 | −2.3 (2) | C8—C9—C10—C20 | 115.36 (15) |
C14—C4—C5—C6 | 119.09 (16) | C19—C9—C10—C8 | −104.13 (15) |
C3—C4—C5—C6 | −58.22 (19) | C1—C9—C10—C8 | 111.19 (16) |
C14—C4—C5—C10 | −120.45 (16) | C19—C9—C10—C5 | 158.91 (13) |
C3—C4—C5—C10 | 62.23 (19) | C1—C9—C10—C5 | 14.2 (2) |
C4—C5—C6—C15 | −49.2 (2) | C8—C9—C10—C5 | −96.96 (15) |
C10—C5—C6—C15 | −175.76 (14) | C4—C5—C10—C20 | 79.58 (17) |
C4—C5—C6—C7 | 134.56 (14) | C6—C5—C10—C20 | −152.68 (13) |
C10—C5—C6—C7 | 7.99 (16) | C4—C5—C10—C8 | −134.07 (14) |
C15—C6—C7—C18 | −1.3 (2) | C6—C5—C10—C8 | −6.33 (15) |
C5—C6—C7—C18 | 175.23 (13) | C4—C5—C10—C9 | −68.39 (18) |
C15—C6—C7—C8 | 176.80 (13) | C6—C5—C10—C9 | 59.35 (16) |
C5—C6—C7—C8 | −6.64 (17) | C4—C3—C11—C12 | 1.6 (3) |
C18—C7—C8—C10 | −179.81 (14) | C2—C3—C11—C12 | 179.48 (16) |
C6—C7—C8—C10 | 2.22 (16) | C3—C11—C12—C13 | −0.2 (3) |
C18—C7—C8—C9 | 116.69 (17) | C11—C12—C13—C14 | −1.0 (3) |
C6—C7—C8—C9 | −61.28 (17) | C12—C13—C14—C4 | 0.7 (3) |
C2—C1—C9—C19 | −119.42 (18) | C3—C4—C14—C13 | 0.7 (2) |
C2—C1—C9—C10 | 25.9 (2) | C5—C4—C14—C13 | −176.68 (15) |
C2—C1—C9—C8 | 98.1 (2) | C7—C6—C15—C16 | 1.4 (2) |
C7—C8—C9—C19 | −158.92 (13) | C5—C6—C15—C16 | −174.56 (14) |
C10—C8—C9—C19 | 105.99 (15) | C6—C15—C16—C17 | −0.5 (2) |
C7—C8—C9—C1 | −16.8 (2) | C15—C16—C17—C18 | −0.4 (2) |
C10—C8—C9—C1 | −111.85 (16) | C6—C7—C18—C17 | 0.4 (2) |
C7—C8—C9—C10 | 95.09 (14) | C8—C7—C18—C17 | −177.42 (14) |
C7—C8—C10—C20 | 146.31 (14) | C16—C17—C18—C7 | 0.5 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C18—H18···N1i | 0.95 | 2.65 | 3.526 (2) | 154 |
C8—H8···N2ii | 1.00 | 2.57 | 3.440 (2) | 145 |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x+1, −y+1, −z. |
Experimental details
Crystal data |
Chemical formula | C20H12N2 |
Mr | 280.32 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 178 |
a, b, c (Å) | 6.722 (3), 9.154 (3), 12.143 (4) |
α, β, γ (°) | 96.85 (3), 90.65 (3), 102.51 (3) |
V (Å3) | 723.7 (5) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.7 × 0.4 × 0.2 |
|
Data collection |
Diffractometer | Nicolet R3 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3368, 2539, 1923 |
Rint | 0.016 |
(sin θ/λ)max (Å−1) | 0.594 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.111, 1.03 |
No. of reflections | 2539 |
No. of parameters | 199 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.19 |
Selected geometric parameters (Å, º) topC8—C10 | 1.526 (2) | C9—C10 | 1.532 (2) |
C8—C9 | 1.541 (2) | | |
| | | |
C10—C8—C9 | 59.92 (10) | C8—C10—C9 | 60.54 (10) |
C10—C9—C8 | 59.54 (10) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C18—H18···N1i | 0.95 | 2.65 | 3.526 (2) | 154 |
C8—H8···N2ii | 1.00 | 2.57 | 3.440 (2) | 145 |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x+1, −y+1, −z. |
Prebullvalene, bicyclo[4.2.2]deca-2,4,7,9-tetraene, is a (CH)10 hydrocarbon whose photoisomerization behaviour has been investigated (for a review see Scott & Jones, 1972). Our studies of the addition of cyanoacetylene to aromatic compounds (Hopf & Witulski, 1995) furnished us with the dibenzoprebullvalenedicarbonitrile, (1), and we have investigated its photochemical behaviour in acetone solution with light of wavelength > 300 nm. The photoisomerization yielded the title compound (2), and we here present its crystal structure.
Whereas the parent hydrocarbon prebullvalene isomerizes to bullvalene when irradiated (Scott & Jones, 1972; Jones & Scott, 1967), the photorearrangement of (1) takes a completely different course. To rationalize the formation of (2), we propose that the process is initiated by a [1,3] carbon shift followed by a di-π-methane rearrangement.
The structure of (2) is shown in Fig. 1. Molecular dimensions are normal. Bond lengths in the cyclopropane ring (Table 1) are somewhat greater than the average value of 1.509 Å e stablished by Allen (1980); see also Rozsondai (1995).
The molecules are linked to form columns parallel to the x axis by two C—H···N interactions (Fig. 2 and Table 2).