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The positions of the C=C double bonds in the title compound, C
16H
16N
4, the subject of some dispute in the literature, have been clearly identified. The cyclohexene ring has a distorted half-chair conformation and the cyclopentene and cyclopentane rings adopt envelope conformations. The dihedral angles between planar fragments of the cyclohexene and cyclopentene rings and of the cyclohexene and cyclopentane rings are 7.5 (1) and 86.98 (9)°, respectively. In the crystal, intermolecular N—H
N hydrogen bonds link the molecules into infinite chains running in the [
10] direction.
Supporting information
CCDC reference: 147662
The title compound, (I), was obtained as described by Mirek & Milart (1986). Colourless crystals were obtained by isothermal evaporation from an ethanolic solution of (I).
Data collection: P3 (Siemens, 1989); cell refinement: P3; data reduction: SHELXTL (Sheldrick, 1994); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXL97.
Crystal data top
C16H16N4 | Z = 2 |
Mr = 264.33 | F(000) = 280 |
Triclinic, P1 | Dx = 1.286 Mg m−3 |
a = 6.417 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.963 (4) Å | Cell parameters from 24 reflections |
c = 11.902 (6) Å | θ = 11–12° |
α = 93.35 (4)° | µ = 0.08 mm−1 |
β = 90.89 (4)° | T = 193 K |
γ = 92.88 (4)° | Parallelepiped prism, colourless |
V = 682.4 (6) Å3 | 0.50 × 0.35 × 0.25 mm |
Data collection top
Siemens P3/PC diffractometer | Rint = 0.029 |
Radiation source: fine-focus sealed tube | θmax = 28.1°, θmin = 3.4° |
Graphite monochromator | h = −8→8 |
θ/2θ scan | k = −11→11 |
3498 measured reflections | l = −15→15 |
3216 independent reflections | 3 standard reflections every 97 reflections |
2400 reflections with I > 2σ(I) | intensity decay: 5% |
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)] = 0.047 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.122 | All H-atom parameters refined |
S = 1.02 | w = 1/[σ2(Fo2) + (0.055P)2 + 0.2P] where P = (Fo2 + 2Fc2)/3 |
3216 reflections | (Δ/σ)max = 0.004 |
245 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.17 e Å−3 |
Crystal data top
C16H16N4 | γ = 92.88 (4)° |
Mr = 264.33 | V = 682.4 (6) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.417 (3) Å | Mo Kα radiation |
b = 8.963 (4) Å | µ = 0.08 mm−1 |
c = 11.902 (6) Å | T = 193 K |
α = 93.35 (4)° | 0.50 × 0.35 × 0.25 mm |
β = 90.89 (4)° | |
Data collection top
Siemens P3/PC diffractometer | Rint = 0.029 |
3498 measured reflections | 3 standard reflections every 97 reflections |
3216 independent reflections | intensity decay: 5% |
2400 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.047 | 0 restraints |
wR(F2) = 0.122 | All H-atom parameters refined |
S = 1.02 | Δρmax = 0.27 e Å−3 |
3216 reflections | Δρmin = −0.17 e Å−3 |
245 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. All H atoms were located from a difference Fourier map and were refined isotropically. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
N1 | 0.3093 (2) | 0.76596 (15) | 0.42156 (12) | 0.0285 (3) | |
N2 | 0.2241 (3) | 1.02541 (17) | 0.22712 (14) | 0.0422 (4) | |
N3 | −0.2449 (2) | 0.93172 (15) | 0.45577 (12) | 0.0335 (3) | |
N4 | 0.3518 (2) | 0.37751 (15) | 0.44728 (12) | 0.0350 (3) | |
C1 | 0.1424 (2) | 0.70019 (15) | 0.36676 (11) | 0.0214 (3) | |
C2 | 0.0948 (2) | 0.54913 (15) | 0.35809 (12) | 0.0223 (3) | |
C2A | −0.0880 (2) | 0.48318 (16) | 0.29893 (12) | 0.0240 (3) | |
C3 | −0.1461 (3) | 0.33856 (18) | 0.27656 (14) | 0.0317 (3) | |
C4 | −0.3478 (3) | 0.32078 (19) | 0.21135 (16) | 0.0365 (4) | |
C5 | −0.3813 (3) | 0.47985 (19) | 0.17435 (16) | 0.0360 (4) | |
C5A | −0.2448 (2) | 0.58567 (16) | 0.25528 (12) | 0.0253 (3) | |
C6 | −0.1355 (2) | 0.72511 (16) | 0.20727 (12) | 0.0239 (3) | |
C7 | −0.0012 (2) | 0.80486 (15) | 0.30746 (11) | 0.0215 (3) | |
C8 | −0.2932 (3) | 0.83275 (19) | 0.16157 (14) | 0.0325 (4) | |
C9 | −0.2928 (4) | 0.8039 (3) | 0.03414 (16) | 0.0499 (5) | |
C10 | −0.0713 (4) | 0.7701 (3) | 0.00784 (16) | 0.0521 (6) | |
C11 | 0.0057 (3) | 0.68415 (19) | 0.10640 (13) | 0.0311 (3) | |
C12 | 0.1284 (2) | 0.93017 (16) | 0.26289 (13) | 0.0271 (3) | |
C13 | −0.1394 (2) | 0.87512 (15) | 0.39206 (12) | 0.0236 (3) | |
C14 | 0.2361 (2) | 0.45343 (16) | 0.40849 (12) | 0.0249 (3) | |
H11 | 0.322 (3) | 0.869 (2) | 0.4362 (16) | 0.033 (5)* | |
H12 | 0.395 (3) | 0.712 (2) | 0.4665 (17) | 0.040 (5)* | |
H3 | −0.071 (3) | 0.258 (2) | 0.3011 (18) | 0.044 (5)* | |
H41 | −0.458 (4) | 0.284 (2) | 0.2584 (19) | 0.052 (6)* | |
H42 | −0.342 (3) | 0.253 (2) | 0.1469 (19) | 0.046 (6)* | |
H51 | −0.328 (3) | 0.487 (2) | 0.098 (2) | 0.046 (6)* | |
H52 | −0.530 (3) | 0.509 (2) | 0.1765 (17) | 0.042 (5)* | |
H5A | −0.328 (3) | 0.621 (2) | 0.3202 (15) | 0.029 (4)* | |
H81 | −0.241 (3) | 0.938 (2) | 0.1822 (18) | 0.045 (5)* | |
H82 | −0.432 (3) | 0.816 (2) | 0.1959 (17) | 0.042 (5)* | |
H91 | −0.385 (5) | 0.709 (3) | 0.012 (2) | 0.083 (9)* | |
H92 | −0.326 (4) | 0.892 (3) | −0.001 (2) | 0.058 (6)* | |
H101 | 0.019 (4) | 0.874 (3) | 0.005 (2) | 0.068 (7)* | |
H102 | −0.053 (4) | 0.719 (3) | −0.065 (2) | 0.066 (7)* | |
H111 | −0.004 (3) | 0.572 (2) | 0.0898 (16) | 0.039 (5)* | |
H112 | 0.163 (3) | 0.709 (2) | 0.1245 (18) | 0.048 (6)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0281 (6) | 0.0208 (6) | 0.0363 (7) | 0.0045 (5) | −0.0097 (5) | −0.0016 (5) |
N2 | 0.0463 (9) | 0.0345 (8) | 0.0466 (9) | −0.0010 (7) | 0.0010 (7) | 0.0128 (7) |
N3 | 0.0327 (7) | 0.0282 (7) | 0.0386 (7) | 0.0031 (6) | 0.0044 (6) | −0.0081 (6) |
N4 | 0.0398 (8) | 0.0259 (7) | 0.0399 (8) | 0.0062 (6) | −0.0087 (6) | 0.0051 (6) |
C1 | 0.0224 (7) | 0.0217 (7) | 0.0205 (6) | 0.0066 (5) | 0.0003 (5) | 0.0007 (5) |
C2 | 0.0246 (7) | 0.0198 (6) | 0.0229 (7) | 0.0050 (5) | 0.0000 (5) | 0.0011 (5) |
C2A | 0.0260 (7) | 0.0230 (7) | 0.0230 (7) | 0.0030 (5) | 0.0010 (5) | 0.0003 (5) |
C3 | 0.0370 (9) | 0.0233 (7) | 0.0342 (8) | 0.0013 (6) | −0.0004 (7) | −0.0018 (6) |
C4 | 0.0360 (9) | 0.0301 (8) | 0.0414 (9) | −0.0038 (7) | −0.0021 (7) | −0.0087 (7) |
C5 | 0.0341 (9) | 0.0338 (9) | 0.0385 (9) | 0.0001 (7) | −0.0102 (7) | −0.0080 (7) |
C5A | 0.0244 (7) | 0.0250 (7) | 0.0261 (7) | 0.0030 (6) | −0.0023 (6) | −0.0038 (5) |
C6 | 0.0266 (7) | 0.0241 (7) | 0.0210 (6) | 0.0068 (5) | −0.0038 (5) | −0.0022 (5) |
C7 | 0.0237 (7) | 0.0186 (6) | 0.0226 (6) | 0.0048 (5) | 0.0002 (5) | −0.0002 (5) |
C8 | 0.0342 (9) | 0.0327 (8) | 0.0311 (8) | 0.0116 (7) | −0.0083 (7) | 0.0013 (6) |
C9 | 0.0683 (14) | 0.0505 (12) | 0.0324 (9) | 0.0177 (11) | −0.0149 (9) | 0.0074 (8) |
C10 | 0.0811 (16) | 0.0515 (12) | 0.0269 (9) | 0.0243 (11) | 0.0085 (9) | 0.0095 (8) |
C11 | 0.0384 (9) | 0.0324 (8) | 0.0229 (7) | 0.0085 (7) | 0.0040 (6) | −0.0021 (6) |
C12 | 0.0297 (7) | 0.0237 (7) | 0.0285 (7) | 0.0063 (6) | −0.0012 (6) | 0.0031 (6) |
C13 | 0.0248 (7) | 0.0188 (6) | 0.0267 (7) | 0.0020 (5) | −0.0034 (6) | −0.0014 (5) |
C14 | 0.0301 (7) | 0.0202 (7) | 0.0243 (7) | 0.0013 (6) | −0.0018 (6) | 0.0010 (5) |
Geometric parameters (Å, º) top
N1—C1 | 1.338 (2) | C5—H52 | 1.00 (2) |
N1—H11 | 0.933 (19) | C5A—C6 | 1.545 (2) |
N1—H12 | 0.93 (2) | C5A—H5A | 0.993 (18) |
N2—C12 | 1.133 (2) | C6—C8 | 1.547 (2) |
N3—C13 | 1.139 (2) | C6—C11 | 1.553 (2) |
N4—C14 | 1.142 (2) | C6—C7 | 1.576 (2) |
C1—C2 | 1.370 (2) | C7—C13 | 1.485 (2) |
C1—C7 | 1.540 (2) | C7—C12 | 1.491 (2) |
C2—C14 | 1.428 (2) | C8—C9 | 1.524 (3) |
C2—C2A | 1.441 (2) | C8—H81 | 1.00 (2) |
C2A—C3 | 1.341 (2) | C8—H82 | 1.00 (2) |
C2A—C5A | 1.503 (2) | C9—C10 | 1.502 (3) |
C3—C4 | 1.496 (3) | C9—H91 | 1.03 (3) |
C3—H3 | 0.94 (2) | C9—H92 | 0.95 (2) |
C4—C5 | 1.541 (3) | C10—C11 | 1.530 (3) |
C4—H41 | 0.97 (2) | C10—H101 | 1.07 (3) |
C4—H42 | 0.95 (2) | C10—H102 | 0.97 (3) |
C5—C5A | 1.542 (2) | C11—H111 | 1.02 (2) |
C5—H51 | 0.98 (2) | C11—H112 | 1.04 (2) |
| | | |
C1—N1—H11 | 121.5 (12) | C5A—C6—C7 | 105.94 (12) |
C1—N1—H12 | 121.5 (13) | C8—C6—C7 | 110.54 (12) |
H11—N1—H12 | 114.2 (17) | C11—C6—C7 | 110.44 (12) |
N1—C1—C2 | 124.95 (13) | C13—C7—C12 | 105.92 (12) |
N1—C1—C7 | 116.14 (12) | C13—C7—C1 | 108.96 (12) |
C2—C1—C7 | 118.88 (13) | C12—C7—C1 | 109.10 (12) |
C1—C2—C14 | 117.97 (13) | C13—C7—C6 | 110.20 (12) |
C1—C2—C2A | 123.08 (13) | C12—C7—C6 | 108.47 (12) |
C14—C2—C2A | 118.95 (13) | C1—C7—C6 | 113.88 (11) |
C3—C2A—C2 | 129.63 (14) | C9—C8—C6 | 105.08 (14) |
C3—C2A—C5A | 112.07 (14) | C9—C8—H81 | 109.8 (12) |
C2—C2A—C5A | 118.29 (12) | C6—C8—H81 | 108.5 (12) |
C2A—C3—C4 | 111.59 (15) | C9—C8—H82 | 114.2 (12) |
C2A—C3—H3 | 124.1 (13) | C6—C8—H82 | 110.5 (12) |
C4—C3—H3 | 124.2 (13) | H81—C8—H82 | 108.5 (17) |
C3—C4—C5 | 103.36 (14) | C10—C9—C8 | 104.61 (16) |
C3—C4—H41 | 110.3 (13) | C10—C9—H91 | 107.6 (16) |
C5—C4—H41 | 112.6 (13) | C8—C9—H91 | 109.0 (17) |
C3—C4—H42 | 112.9 (13) | C10—C9—H92 | 108.6 (15) |
C5—C4—H42 | 110.0 (12) | C8—C9—H92 | 109.8 (14) |
H41—C4—H42 | 107.7 (18) | H91—C9—H92 | 117 (2) |
C4—C5—C5A | 105.65 (14) | C9—C10—C11 | 105.49 (16) |
C4—C5—H51 | 107.9 (12) | C9—C10—H101 | 108.6 (13) |
C5A—C5—H51 | 108.6 (13) | C11—C10—H101 | 109.4 (14) |
C4—C5—H52 | 114.0 (11) | C9—C10—H102 | 114.6 (15) |
C5A—C5—H52 | 110.3 (12) | C11—C10—H102 | 113.9 (15) |
H51—C5—H52 | 110.1 (16) | H101—C10—H102 | 105 (2) |
C2A—C5A—C5 | 102.55 (13) | C10—C11—C6 | 106.39 (14) |
C2A—C5A—C6 | 111.08 (12) | C10—C11—H111 | 112.7 (11) |
C5—C5A—C6 | 118.01 (14) | C6—C11—H111 | 109.3 (11) |
C2A—C5A—H5A | 107.4 (10) | C10—C11—H112 | 111.8 (12) |
C5—C5A—H5A | 110.1 (11) | C6—C11—H112 | 112.6 (12) |
C6—C5A—H5A | 107.2 (10) | H111—C11—H112 | 104.2 (16) |
C5A—C6—C8 | 112.27 (13) | N2—C12—C7 | 178.54 (17) |
C5A—C6—C11 | 112.41 (12) | N3—C13—C7 | 178.55 (16) |
C8—C6—C11 | 105.33 (13) | N4—C14—C2 | 178.71 (17) |
| | | |
N1—C1—C2—C14 | −1.8 (2) | N1—C1—C7—C6 | 156.38 (13) |
C7—C1—C2—C14 | 176.62 (12) | C2—C1—C7—C6 | −22.16 (18) |
N1—C1—C2—C2A | 179.46 (14) | C5A—C6—C7—C13 | −71.26 (14) |
C7—C1—C2—C2A | −2.1 (2) | C8—C6—C7—C13 | 50.60 (16) |
C1—C2—C2A—C3 | 174.53 (16) | C11—C6—C7—C13 | 166.77 (12) |
C14—C2—C2A—C3 | −4.2 (2) | C5A—C6—C7—C12 | 173.21 (11) |
C1—C2—C2A—C5A | −6.6 (2) | C8—C6—C7—C12 | −64.93 (15) |
C14—C2—C2A—C5A | 174.63 (13) | C11—C6—C7—C12 | 51.23 (15) |
C2—C2A—C3—C4 | −179.36 (15) | C5A—C6—C7—C1 | 51.53 (15) |
C5A—C2A—C3—C4 | 1.7 (2) | C8—C6—C7—C1 | 173.39 (12) |
C2A—C3—C4—C5 | 12.0 (2) | C11—C6—C7—C1 | −70.45 (15) |
C3—C4—C5—C5A | −20.37 (18) | C5A—C6—C8—C9 | −102.10 (17) |
C3—C2A—C5A—C5 | −14.64 (18) | C11—C6—C8—C9 | 20.55 (19) |
C2—C2A—C5A—C5 | 166.32 (13) | C7—C6—C8—C9 | 139.85 (15) |
C3—C2A—C5A—C6 | −141.62 (14) | C6—C8—C9—C10 | −34.8 (2) |
C2—C2A—C5A—C6 | 39.34 (18) | C8—C9—C10—C11 | 35.6 (2) |
C4—C5—C5A—C2A | 21.11 (17) | C9—C10—C11—C6 | −22.5 (2) |
C4—C5—C5A—C6 | 143.51 (14) | C5A—C6—C11—C10 | 123.49 (16) |
C2A—C5A—C6—C8 | 179.95 (12) | C8—C6—C11—C10 | 0.93 (19) |
C5—C5A—C6—C8 | 61.99 (17) | C7—C6—C11—C10 | −118.43 (16) |
C2A—C5A—C6—C11 | 61.40 (16) | C13—C7—C12—N2 | −97 (7) |
C5—C5A—C6—C11 | −56.56 (18) | C1—C7—C12—N2 | 146 (7) |
C2A—C5A—C6—C7 | −59.31 (14) | C6—C7—C12—N2 | 21 (7) |
C5—C5A—C6—C7 | −177.27 (12) | C12—C7—C13—N3 | 25 (6) |
N1—C1—C7—C13 | −80.16 (16) | C1—C7—C13—N3 | 142 (6) |
C2—C1—C7—C13 | 101.30 (15) | C6—C7—C13—N3 | −92 (6) |
N1—C1—C7—C12 | 35.05 (17) | C1—C2—C14—N4 | −70 (7) |
C2—C1—C7—C12 | −143.49 (13) | C2A—C2—C14—N4 | 109 (7) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H11···N3i | 0.93 (2) | 2.22 (2) | 3.052 (2) | 148 (2) |
N1—H12···N4ii | 0.93 (2) | 2.12 (2) | 3.038 (2) | 166 (2) |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data |
Chemical formula | C16H16N4 |
Mr | 264.33 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 193 |
a, b, c (Å) | 6.417 (3), 8.963 (4), 11.902 (6) |
α, β, γ (°) | 93.35 (4), 90.89 (4), 92.88 (4) |
V (Å3) | 682.4 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.50 × 0.35 × 0.25 |
|
Data collection |
Diffractometer | Siemens P3/PC diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3498, 3216, 2400 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.662 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.047, 0.122, 1.02 |
No. of reflections | 3216 |
No. of parameters | 245 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.27, −0.17 |
Selected geometric parameters (Å, º) topN1—C1 | 1.338 (2) | C2—C2A | 1.441 (2) |
N2—C12 | 1.133 (2) | C2A—C3 | 1.341 (2) |
N3—C13 | 1.139 (2) | C2A—C5A | 1.503 (2) |
N4—C14 | 1.142 (2) | C5A—C6 | 1.545 (2) |
C1—C2 | 1.370 (2) | C6—C7 | 1.576 (2) |
C1—C7 | 1.540 (2) | C7—C13 | 1.485 (2) |
C2—C14 | 1.428 (2) | C7—C12 | 1.491 (2) |
| | | |
N1—C1—C2 | 124.95 (13) | C2A—C3—C4 | 111.59 (15) |
N1—C1—C7 | 116.14 (12) | C2A—C5A—C5 | 102.55 (13) |
C2—C1—C7 | 118.88 (13) | C2A—C5A—C6 | 111.08 (12) |
C1—C2—C14 | 117.97 (13) | C5—C5A—C6 | 118.01 (14) |
C1—C2—C2A | 123.08 (13) | C5A—C6—C7 | 105.94 (12) |
C14—C2—C2A | 118.95 (13) | C1—C7—C6 | 113.88 (11) |
C3—C2A—C2 | 129.63 (14) | N2—C12—C7 | 178.54 (17) |
C3—C2A—C5A | 112.07 (14) | N3—C13—C7 | 178.55 (16) |
C2—C2A—C5A | 118.29 (12) | N4—C14—C2 | 178.71 (17) |
| | | |
C7—C1—C2—C2A | −2.1 (2) | C2—C2A—C5A—C6 | 39.34 (18) |
C1—C2—C2A—C3 | 174.53 (16) | C4—C5—C5A—C2A | 21.11 (17) |
C1—C2—C2A—C5A | −6.6 (2) | C2A—C5A—C6—C7 | −59.31 (14) |
C2A—C3—C4—C5 | 12.0 (2) | C2—C1—C7—C6 | −22.16 (18) |
C3—C4—C5—C5A | −20.37 (18) | C5A—C6—C7—C1 | 51.53 (15) |
C3—C2A—C5A—C5 | −14.64 (18) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H11···N3i | 0.93 (2) | 2.22 (2) | 3.052 (2) | 148 (2) |
N1—H12···N4ii | 0.93 (2) | 2.12 (2) | 3.038 (2) | 166 (2) |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) −x+1, −y+1, −z+1. |
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The large number of publications concerned with dimerization of carbo- and heterocyclic ilidenmalononitriles indicate a consistent interest in this type of compound (Post, 1953; Weir & Hyne, 1963, 1964, 1965; Mirek et al., 1980; Baty et al., 1969; Mirek & Milart, 1986; Sofan et al., 1989). This interest arises from the properties of the compounds, such as light sensitivity and polymerization under UV-radiation (Tafeenko et al., 1994). In spite of the published information on the synthesis and spectroscopic studies of the title compound there are differing opinions about its structure: the assignment by Baty et al. (1969) and Mirek et al. (1986), (I), differs from that proposed by Dyachenko & Litvinov (1997), (II), in the position of double bonds. \sch
In order to clarify this matter, a crystal structure analysis was undertaken and showed (Figure 1, Table 1) that the molecule has the structure represented by (I) with the double bonds identified between C1 and C2 [1.370 (2) Å], and between C2A and C3 [1.341 (2) Å] rather than between C2A and C5A [1.503 (2) Å].
The substituted cyclohexene ring has a distorted half-chair conformation, with C5A and C6 displaced by 0.193 (3) and −0.579 (3) Å, respectively, from the least-squares mean plane [r.m.s. deviation 0.007 (7) Å] defined by C2A, C2, C1 and C7. The cyclopentene ring has an envelope conformation with C5 displaced by −0.346 (3) Å from the least-squares mean plane defined by C4, C3, C2A and C5A [this plane also has an r.m.s. deviation of 0.007 (7) Å]. The dihedral angle between these planes is 7.5 (1)°, so that these two fragments are nearly coplanar. The spirolinked cyclopentane ring adopts an envelope conformation, with C9 located 0.535 (4) Å out of the plane of the other atoms of the ring [this plane has an r.m.s. deviation of 0.005 (8) Å]. The dihedral angle between the cyclopentane ring and the planar region of the cyclohexene ring is 86.98 (9)°. Steric overload in the cyclohexene ring causes increases in the bond lengths C1—C7 and C6—C7 up to 1.540 (2) and 1.576 (2) Å, respectively, compared to expected bond lengths of 1.507 for Csp2—Csp3 and 1.540 Å for Csp3—Csp3 (Allen et al., 1987). It is probable that the electron acceptor cyano groups on C7 (Fig. 1) also exert an influence on the bond lengths. We have previously observed similar increases in bond lengths (Nesterov, Struchkov et al., 1989; Nesterov, Shklover et al., 1989) as have other authors (Tafeenko et al., 1994) in related compounds.
The intermolecular hydrogen bonding described in Table 2 comprises pairs of pairwise N1—H12···N4ii interactions [graph-set notation R22(12)] which link molecules into infinite chains along [110], as shown in Fig. 2.