Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The positions of the C=C double bonds in the title compound, C16H16N4, 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 [\overline 110] direction.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100004832/bm1407sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270100004832/bm1407Isup2.hkl
Contains datablock I

CCDC reference: 147662

Comment top

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.

Experimental top

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).

Computing details top

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.

Figures top
[Figure 1] Fig. 1. A view of (I) with the atom-numbering scheme. The non-H atoms are shown with displacement ellipsoids drawn at the 50% probability level. H atoms are drawn as circles of arbitrary small radius for clarity.
[Figure 2] Fig. 2. A projection onto the bc plane showing the hydrogen-bonding scheme. [Symmetry codes: (i) −x, 2 − y, 1 − z; (ii) 1 − x, 1 − y, 1 − z.]
(I) top
Crystal data top
C16H16N4Z = 2
Mr = 264.33F(000) = 280
Triclinic, P1Dx = 1.286 Mg m3
a = 6.417 (3) ÅMo Kα radiation, λ = 0.71073 Å
b = 8.963 (4) ÅCell parameters from 24 reflections
c = 11.902 (6) Åθ = 11–12°
α = 93.35 (4)°µ = 0.08 mm1
β = 90.89 (4)°T = 193 K
γ = 92.88 (4)°Parallelepiped prism, colourless
V = 682.4 (6) Å30.50 × 0.35 × 0.25 mm
Data collection top
Siemens P3/PC
diffractometer
Rint = 0.029
Radiation source: fine-focus sealed tubeθmax = 28.1°, θmin = 3.4°
Graphite monochromatorh = 88
θ/2θ scank = 1111
3498 measured reflectionsl = 1515
3216 independent reflections3 standard reflections every 97 reflections
2400 reflections with I > 2σ(I) intensity decay: 5%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: difference Fourier map
wR(F2) = 0.122All 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 parametersΔρmax = 0.27 e Å3
0 restraintsΔρmin = 0.17 e Å3
Crystal data top
C16H16N4γ = 92.88 (4)°
Mr = 264.33V = 682.4 (6) Å3
Triclinic, P1Z = 2
a = 6.417 (3) ÅMo Kα radiation
b = 8.963 (4) ŵ = 0.08 mm1
c = 11.902 (6) ÅT = 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 reflections3 standard reflections every 97 reflections
3216 independent reflections intensity decay: 5%
2400 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.122All H-atom parameters refined
S = 1.02Δρmax = 0.27 e Å3
3216 reflectionsΔρmin = 0.17 e Å3
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
xyzUiso*/Ueq
N10.3093 (2)0.76596 (15)0.42156 (12)0.0285 (3)
N20.2241 (3)1.02541 (17)0.22712 (14)0.0422 (4)
N30.2449 (2)0.93172 (15)0.45577 (12)0.0335 (3)
N40.3518 (2)0.37751 (15)0.44728 (12)0.0350 (3)
C10.1424 (2)0.70019 (15)0.36676 (11)0.0214 (3)
C20.0948 (2)0.54913 (15)0.35809 (12)0.0223 (3)
C2A0.0880 (2)0.48318 (16)0.29893 (12)0.0240 (3)
C30.1461 (3)0.33856 (18)0.27656 (14)0.0317 (3)
C40.3478 (3)0.32078 (19)0.21135 (16)0.0365 (4)
C50.3813 (3)0.47985 (19)0.17435 (16)0.0360 (4)
C5A0.2448 (2)0.58567 (16)0.25528 (12)0.0253 (3)
C60.1355 (2)0.72511 (16)0.20727 (12)0.0239 (3)
C70.0012 (2)0.80486 (15)0.30746 (11)0.0215 (3)
C80.2932 (3)0.83275 (19)0.16157 (14)0.0325 (4)
C90.2928 (4)0.8039 (3)0.03414 (16)0.0499 (5)
C100.0713 (4)0.7701 (3)0.00784 (16)0.0521 (6)
C110.0057 (3)0.68415 (19)0.10640 (13)0.0311 (3)
C120.1284 (2)0.93017 (16)0.26289 (13)0.0271 (3)
C130.1394 (2)0.87512 (15)0.39206 (12)0.0236 (3)
C140.2361 (2)0.45343 (16)0.40849 (12)0.0249 (3)
H110.322 (3)0.869 (2)0.4362 (16)0.033 (5)*
H120.395 (3)0.712 (2)0.4665 (17)0.040 (5)*
H30.071 (3)0.258 (2)0.3011 (18)0.044 (5)*
H410.458 (4)0.284 (2)0.2584 (19)0.052 (6)*
H420.342 (3)0.253 (2)0.1469 (19)0.046 (6)*
H510.328 (3)0.487 (2)0.098 (2)0.046 (6)*
H520.530 (3)0.509 (2)0.1765 (17)0.042 (5)*
H5A0.328 (3)0.621 (2)0.3202 (15)0.029 (4)*
H810.241 (3)0.938 (2)0.1822 (18)0.045 (5)*
H820.432 (3)0.816 (2)0.1959 (17)0.042 (5)*
H910.385 (5)0.709 (3)0.012 (2)0.083 (9)*
H920.326 (4)0.892 (3)0.001 (2)0.058 (6)*
H1010.019 (4)0.874 (3)0.005 (2)0.068 (7)*
H1020.053 (4)0.719 (3)0.065 (2)0.066 (7)*
H1110.004 (3)0.572 (2)0.0898 (16)0.039 (5)*
H1120.163 (3)0.709 (2)0.1245 (18)0.048 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0281 (6)0.0208 (6)0.0363 (7)0.0045 (5)0.0097 (5)0.0016 (5)
N20.0463 (9)0.0345 (8)0.0466 (9)0.0010 (7)0.0010 (7)0.0128 (7)
N30.0327 (7)0.0282 (7)0.0386 (7)0.0031 (6)0.0044 (6)0.0081 (6)
N40.0398 (8)0.0259 (7)0.0399 (8)0.0062 (6)0.0087 (6)0.0051 (6)
C10.0224 (7)0.0217 (7)0.0205 (6)0.0066 (5)0.0003 (5)0.0007 (5)
C20.0246 (7)0.0198 (6)0.0229 (7)0.0050 (5)0.0000 (5)0.0011 (5)
C2A0.0260 (7)0.0230 (7)0.0230 (7)0.0030 (5)0.0010 (5)0.0003 (5)
C30.0370 (9)0.0233 (7)0.0342 (8)0.0013 (6)0.0004 (7)0.0018 (6)
C40.0360 (9)0.0301 (8)0.0414 (9)0.0038 (7)0.0021 (7)0.0087 (7)
C50.0341 (9)0.0338 (9)0.0385 (9)0.0001 (7)0.0102 (7)0.0080 (7)
C5A0.0244 (7)0.0250 (7)0.0261 (7)0.0030 (6)0.0023 (6)0.0038 (5)
C60.0266 (7)0.0241 (7)0.0210 (6)0.0068 (5)0.0038 (5)0.0022 (5)
C70.0237 (7)0.0186 (6)0.0226 (6)0.0048 (5)0.0002 (5)0.0002 (5)
C80.0342 (9)0.0327 (8)0.0311 (8)0.0116 (7)0.0083 (7)0.0013 (6)
C90.0683 (14)0.0505 (12)0.0324 (9)0.0177 (11)0.0149 (9)0.0074 (8)
C100.0811 (16)0.0515 (12)0.0269 (9)0.0243 (11)0.0085 (9)0.0095 (8)
C110.0384 (9)0.0324 (8)0.0229 (7)0.0085 (7)0.0040 (6)0.0021 (6)
C120.0297 (7)0.0237 (7)0.0285 (7)0.0063 (6)0.0012 (6)0.0031 (6)
C130.0248 (7)0.0188 (6)0.0267 (7)0.0020 (5)0.0034 (6)0.0014 (5)
C140.0301 (7)0.0202 (7)0.0243 (7)0.0013 (6)0.0018 (6)0.0010 (5)
Geometric parameters (Å, º) top
N1—C11.338 (2)C5—H521.00 (2)
N1—H110.933 (19)C5A—C61.545 (2)
N1—H120.93 (2)C5A—H5A0.993 (18)
N2—C121.133 (2)C6—C81.547 (2)
N3—C131.139 (2)C6—C111.553 (2)
N4—C141.142 (2)C6—C71.576 (2)
C1—C21.370 (2)C7—C131.485 (2)
C1—C71.540 (2)C7—C121.491 (2)
C2—C141.428 (2)C8—C91.524 (3)
C2—C2A1.441 (2)C8—H811.00 (2)
C2A—C31.341 (2)C8—H821.00 (2)
C2A—C5A1.503 (2)C9—C101.502 (3)
C3—C41.496 (3)C9—H911.03 (3)
C3—H30.94 (2)C9—H920.95 (2)
C4—C51.541 (3)C10—C111.530 (3)
C4—H410.97 (2)C10—H1011.07 (3)
C4—H420.95 (2)C10—H1020.97 (3)
C5—C5A1.542 (2)C11—H1111.02 (2)
C5—H510.98 (2)C11—H1121.04 (2)
C1—N1—H11121.5 (12)C5A—C6—C7105.94 (12)
C1—N1—H12121.5 (13)C8—C6—C7110.54 (12)
H11—N1—H12114.2 (17)C11—C6—C7110.44 (12)
N1—C1—C2124.95 (13)C13—C7—C12105.92 (12)
N1—C1—C7116.14 (12)C13—C7—C1108.96 (12)
C2—C1—C7118.88 (13)C12—C7—C1109.10 (12)
C1—C2—C14117.97 (13)C13—C7—C6110.20 (12)
C1—C2—C2A123.08 (13)C12—C7—C6108.47 (12)
C14—C2—C2A118.95 (13)C1—C7—C6113.88 (11)
C3—C2A—C2129.63 (14)C9—C8—C6105.08 (14)
C3—C2A—C5A112.07 (14)C9—C8—H81109.8 (12)
C2—C2A—C5A118.29 (12)C6—C8—H81108.5 (12)
C2A—C3—C4111.59 (15)C9—C8—H82114.2 (12)
C2A—C3—H3124.1 (13)C6—C8—H82110.5 (12)
C4—C3—H3124.2 (13)H81—C8—H82108.5 (17)
C3—C4—C5103.36 (14)C10—C9—C8104.61 (16)
C3—C4—H41110.3 (13)C10—C9—H91107.6 (16)
C5—C4—H41112.6 (13)C8—C9—H91109.0 (17)
C3—C4—H42112.9 (13)C10—C9—H92108.6 (15)
C5—C4—H42110.0 (12)C8—C9—H92109.8 (14)
H41—C4—H42107.7 (18)H91—C9—H92117 (2)
C4—C5—C5A105.65 (14)C9—C10—C11105.49 (16)
C4—C5—H51107.9 (12)C9—C10—H101108.6 (13)
C5A—C5—H51108.6 (13)C11—C10—H101109.4 (14)
C4—C5—H52114.0 (11)C9—C10—H102114.6 (15)
C5A—C5—H52110.3 (12)C11—C10—H102113.9 (15)
H51—C5—H52110.1 (16)H101—C10—H102105 (2)
C2A—C5A—C5102.55 (13)C10—C11—C6106.39 (14)
C2A—C5A—C6111.08 (12)C10—C11—H111112.7 (11)
C5—C5A—C6118.01 (14)C6—C11—H111109.3 (11)
C2A—C5A—H5A107.4 (10)C10—C11—H112111.8 (12)
C5—C5A—H5A110.1 (11)C6—C11—H112112.6 (12)
C6—C5A—H5A107.2 (10)H111—C11—H112104.2 (16)
C5A—C6—C8112.27 (13)N2—C12—C7178.54 (17)
C5A—C6—C11112.41 (12)N3—C13—C7178.55 (16)
C8—C6—C11105.33 (13)N4—C14—C2178.71 (17)
N1—C1—C2—C141.8 (2)N1—C1—C7—C6156.38 (13)
C7—C1—C2—C14176.62 (12)C2—C1—C7—C622.16 (18)
N1—C1—C2—C2A179.46 (14)C5A—C6—C7—C1371.26 (14)
C7—C1—C2—C2A2.1 (2)C8—C6—C7—C1350.60 (16)
C1—C2—C2A—C3174.53 (16)C11—C6—C7—C13166.77 (12)
C14—C2—C2A—C34.2 (2)C5A—C6—C7—C12173.21 (11)
C1—C2—C2A—C5A6.6 (2)C8—C6—C7—C1264.93 (15)
C14—C2—C2A—C5A174.63 (13)C11—C6—C7—C1251.23 (15)
C2—C2A—C3—C4179.36 (15)C5A—C6—C7—C151.53 (15)
C5A—C2A—C3—C41.7 (2)C8—C6—C7—C1173.39 (12)
C2A—C3—C4—C512.0 (2)C11—C6—C7—C170.45 (15)
C3—C4—C5—C5A20.37 (18)C5A—C6—C8—C9102.10 (17)
C3—C2A—C5A—C514.64 (18)C11—C6—C8—C920.55 (19)
C2—C2A—C5A—C5166.32 (13)C7—C6—C8—C9139.85 (15)
C3—C2A—C5A—C6141.62 (14)C6—C8—C9—C1034.8 (2)
C2—C2A—C5A—C639.34 (18)C8—C9—C10—C1135.6 (2)
C4—C5—C5A—C2A21.11 (17)C9—C10—C11—C622.5 (2)
C4—C5—C5A—C6143.51 (14)C5A—C6—C11—C10123.49 (16)
C2A—C5A—C6—C8179.95 (12)C8—C6—C11—C100.93 (19)
C5—C5A—C6—C861.99 (17)C7—C6—C11—C10118.43 (16)
C2A—C5A—C6—C1161.40 (16)C13—C7—C12—N297 (7)
C5—C5A—C6—C1156.56 (18)C1—C7—C12—N2146 (7)
C2A—C5A—C6—C759.31 (14)C6—C7—C12—N221 (7)
C5—C5A—C6—C7177.27 (12)C12—C7—C13—N325 (6)
N1—C1—C7—C1380.16 (16)C1—C7—C13—N3142 (6)
C2—C1—C7—C13101.30 (15)C6—C7—C13—N392 (6)
N1—C1—C7—C1235.05 (17)C1—C2—C14—N470 (7)
C2—C1—C7—C12143.49 (13)C2A—C2—C14—N4109 (7)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H11···N3i0.93 (2)2.22 (2)3.052 (2)148 (2)
N1—H12···N4ii0.93 (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 formulaC16H16N4
Mr264.33
Crystal system, space groupTriclinic, 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)
V3)682.4 (6)
Z2
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.50 × 0.35 × 0.25
Data collection
DiffractometerSiemens P3/PC
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
3498, 3216, 2400
Rint0.029
(sin θ/λ)max1)0.662
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.122, 1.02
No. of reflections3216
No. of parameters245
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.27, 0.17

Computer programs: P3 (Siemens, 1989), P3, SHELXTL (Sheldrick, 1994), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL, SHELXL97.

Selected geometric parameters (Å, º) top
N1—C11.338 (2)C2—C2A1.441 (2)
N2—C121.133 (2)C2A—C31.341 (2)
N3—C131.139 (2)C2A—C5A1.503 (2)
N4—C141.142 (2)C5A—C61.545 (2)
C1—C21.370 (2)C6—C71.576 (2)
C1—C71.540 (2)C7—C131.485 (2)
C2—C141.428 (2)C7—C121.491 (2)
N1—C1—C2124.95 (13)C2A—C3—C4111.59 (15)
N1—C1—C7116.14 (12)C2A—C5A—C5102.55 (13)
C2—C1—C7118.88 (13)C2A—C5A—C6111.08 (12)
C1—C2—C14117.97 (13)C5—C5A—C6118.01 (14)
C1—C2—C2A123.08 (13)C5A—C6—C7105.94 (12)
C14—C2—C2A118.95 (13)C1—C7—C6113.88 (11)
C3—C2A—C2129.63 (14)N2—C12—C7178.54 (17)
C3—C2A—C5A112.07 (14)N3—C13—C7178.55 (16)
C2—C2A—C5A118.29 (12)N4—C14—C2178.71 (17)
C7—C1—C2—C2A2.1 (2)C2—C2A—C5A—C639.34 (18)
C1—C2—C2A—C3174.53 (16)C4—C5—C5A—C2A21.11 (17)
C1—C2—C2A—C5A6.6 (2)C2A—C5A—C6—C759.31 (14)
C2A—C3—C4—C512.0 (2)C2—C1—C7—C622.16 (18)
C3—C4—C5—C5A20.37 (18)C5A—C6—C7—C151.53 (15)
C3—C2A—C5A—C514.64 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H11···N3i0.93 (2)2.22 (2)3.052 (2)148 (2)
N1—H12···N4ii0.93 (2)2.12 (2)3.038 (2)166 (2)
Symmetry codes: (i) x, y+2, z+1; (ii) x+1, y+1, z+1.
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds