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The title compound, 1,3,5-tris(2-cyano­ethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, C12H12N6O3, forms a layered structure stabilized by C—H...O and C—H...N hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100001396/bk1500sup1.cif
Contains datablocks f, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270100001396/bk1500Isup2.hkl
Contains datablock I

CCDC reference: 145536

Comment top

The importance of C—H···O and C—H···N hydrogen bonds in the crystal structures of organic compounds is well known (Desiraju & Steiner, 1999). In this context, the title compound, (I), is of interest because it contains activated C—H donors and carbonyl and cyano acceptors. Furthermore, the molecule has trigonal symmetry and so its crystal structure could be relevant in the context of octupolar nonlinear optical effects (Thalladi et al., 1997). \scheme

The molecular geometry of (I) is shown in Fig. 1. Two of the cyanoethyl groups are oriented on one side of the heterocyclic ring, whilst the third points in the other direction. The crystal is centrosymmetric and the molecules form a layered structure (Fig. 2). In the (011) plane, each molecule is connected to four inversion-related molecules via C—H···O hydrogen bonds [C5—H5A···O3i, C7—H7B···O1ii, C8—H8B···O2iii and C11—H11A···O3v; see Table 1; symmetry codes: (i) 1 - x, -y, 2 - z; (ii) 1 - x, 1 - y, 2 - z; (iii) 1 - x, 1 - y, 1 - z; (v) 1 - x, -y, 1 - z]. These interactions will be referred to hereinafter as i, j, k and l, respectively. Translation-related molecules are linked via C—H···N hydrogen bonds [C8—H8A···N6iii and C10—H10B···N4iv; see Table 1; symmetry code: (iv) x, y, z - 1]. These interactions interactions will be referred to hereinafter as m and n, respectively.

In order to analyse the C—H···NC hydrogen bond directionality (φ angle) at the acceptor atom, the Cambridge Structural Database (CSD version 5.17, 197481 entries; Allen & Kennard, 1993) was searched for C—H···NC geometries. Ordered crystal structures of non-metal-atom-containing compounds with R < 0.075 were considered. Structures containing charged residues were excluded. In order that acceptor directionality not be biased by steric factors, only those geometries where a single C—H group approaches a cyano group were considered. In other words, geometries with bifurcated acceptors were not selected. The H-atom positions were normalized to standard neutron values, with the H···N distance allowed to lie between 1.5 and 3.0 Å and the H···NC angle between 40 and 180°. The mean H···N distance was found to be 2.67 Å for 249 fragments and the mean H···NC angle was 132.0°. The angular distribution is shown in Fig. 3. However, after cone-correction (Kroon & Kanters, 1974) it was observed that the distribution of φ angles tends strongly towards a linear geometry at the acceptor N atom. This shows that in C—H···NC hydrogen bonds, the main acceptor centre is the lone pair on the N atom rather than the CN triple bond.

Experimental top

Colourless crystals (m.p. 502 K) of (I), which was prepared according to the method of Frazier et al. (1960) were obtained by crystallization from dimethyl formamide.

Structure description top

The importance of C—H···O and C—H···N hydrogen bonds in the crystal structures of organic compounds is well known (Desiraju & Steiner, 1999). In this context, the title compound, (I), is of interest because it contains activated C—H donors and carbonyl and cyano acceptors. Furthermore, the molecule has trigonal symmetry and so its crystal structure could be relevant in the context of octupolar nonlinear optical effects (Thalladi et al., 1997). \scheme

The molecular geometry of (I) is shown in Fig. 1. Two of the cyanoethyl groups are oriented on one side of the heterocyclic ring, whilst the third points in the other direction. The crystal is centrosymmetric and the molecules form a layered structure (Fig. 2). In the (011) plane, each molecule is connected to four inversion-related molecules via C—H···O hydrogen bonds [C5—H5A···O3i, C7—H7B···O1ii, C8—H8B···O2iii and C11—H11A···O3v; see Table 1; symmetry codes: (i) 1 - x, -y, 2 - z; (ii) 1 - x, 1 - y, 2 - z; (iii) 1 - x, 1 - y, 1 - z; (v) 1 - x, -y, 1 - z]. These interactions will be referred to hereinafter as i, j, k and l, respectively. Translation-related molecules are linked via C—H···N hydrogen bonds [C8—H8A···N6iii and C10—H10B···N4iv; see Table 1; symmetry code: (iv) x, y, z - 1]. These interactions interactions will be referred to hereinafter as m and n, respectively.

In order to analyse the C—H···NC hydrogen bond directionality (φ angle) at the acceptor atom, the Cambridge Structural Database (CSD version 5.17, 197481 entries; Allen & Kennard, 1993) was searched for C—H···NC geometries. Ordered crystal structures of non-metal-atom-containing compounds with R < 0.075 were considered. Structures containing charged residues were excluded. In order that acceptor directionality not be biased by steric factors, only those geometries where a single C—H group approaches a cyano group were considered. In other words, geometries with bifurcated acceptors were not selected. The H-atom positions were normalized to standard neutron values, with the H···N distance allowed to lie between 1.5 and 3.0 Å and the H···NC angle between 40 and 180°. The mean H···N distance was found to be 2.67 Å for 249 fragments and the mean H···NC angle was 132.0°. The angular distribution is shown in Fig. 3. However, after cone-correction (Kroon & Kanters, 1974) it was observed that the distribution of φ angles tends strongly towards a linear geometry at the acceptor N atom. This shows that in C—H···NC hydrogen bonds, the main acceptor centre is the lone pair on the N atom rather than the CN triple bond.

Computing details top

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: Xtal 3.5 (Hall et al., 1997); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLUTON-(C) (Spek, 1979-1997); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. An ORTEPII view (Johnson, 1976) and the atom-numbering scheme for (I). Displacement ellipsoids are drawn at the 35% probability level and H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. The layer structure of (I) viewed down [100]. O and N atoms are shaded. C—H···O hydrogen bonds are indicated as i, j, k and l and C—H···N hydrogen bonds are indicated m and n.
[Figure 3] Fig. 3. The distribution of φ angles for C—H···NC hydrogen bonds. The distribution is not cone-corrected and displays data from 329 non-bifurcated geometries taken from the Cambridge Structural Database (Allen & Kennard, 1993).
tris-(2-cyanoethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione top
Crystal data top
C12H12N6O3F(000) = 600
Mr = 288.28Dx = 1.435 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 9.727 (2) ÅCell parameters from 25 reflections
b = 13.781 (2) Åθ = 9–11°
c = 9.956 (2) ŵ = 0.11 mm1
β = 90.46 (2)°T = 293 K
V = 1334.6 (4) Å3Needle, colourless
Z = 40.60 × 0.48 × 0.20 mm
Data collection top
Enraf-Nonius CAD4
diffractometer
Rint = 0.009
Radiation source: fine-focus sealed tubeθmax = 30.0°, θmin = 2.5°
Graphite monochromatorh = 013
ω scank = 019
4071 measured reflectionsl = 1313
3877 independent reflections3 standard reflections every 100 reflections
2466 reflections with I > 2σ(I) intensity decay: <2%
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)] = 0.063Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.190All H-atom parameters refined
S = 1.07Calculated w = 1/[σ2(Fo2) + (0.1131P)2]
where P = (Fo2 + 2Fc2)/3
3877 reflections(Δ/σ)max = 0.001
239 parametersΔρmax = 0.42 e Å3
0 restraintsΔρmin = 0.35 e Å3
Crystal data top
C12H12N6O3V = 1334.6 (4) Å3
Mr = 288.28Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.727 (2) ŵ = 0.11 mm1
b = 13.781 (2) ÅT = 293 K
c = 9.956 (2) Å0.60 × 0.48 × 0.20 mm
β = 90.46 (2)°
Data collection top
Enraf-Nonius CAD4
diffractometer
Rint = 0.009
4071 measured reflections3 standard reflections every 100 reflections
3877 independent reflections intensity decay: <2%
2466 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0630 restraints
wR(F2) = 0.190All H-atom parameters refined
S = 1.07Δρmax = 0.42 e Å3
3877 reflectionsΔρmin = 0.35 e Å3
239 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 on F2 for ALL reflections except for 0 with very negative F2 or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating R-factor-obs 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
xyzUiso*/Ueq
N10.52324 (13)0.21961 (9)0.88234 (12)0.0320 (3)
N20.57008 (13)0.36854 (10)0.77997 (12)0.0335 (3)
N30.58906 (14)0.22449 (10)0.65698 (12)0.0329 (3)
N40.7529 (2)0.2362 (2)1.2025 (2)0.0735 (6)
N50.2423 (2)0.50605 (15)0.8464 (2)0.0688 (6)
N60.3507 (2)0.2616 (2)0.3405 (2)0.0736 (6)
O10.4922 (2)0.36075 (10)0.99425 (12)0.0500 (4)
O20.6370 (2)0.37115 (10)0.56279 (12)0.0502 (4)
O30.55985 (14)0.08116 (9)0.76524 (12)0.0471 (4)
C10.5252 (2)0.31962 (12)0.89298 (14)0.0329 (3)
C20.6009 (2)0.32434 (12)0.65919 (15)0.0339 (3)
C30.5580 (2)0.16932 (12)0.76809 (14)0.0331 (3)
C40.4777 (2)0.16261 (14)0.9982 (2)0.0398 (4)
H4A0.412 (2)0.117 (2)0.967 (2)0.061 (6)*
H4B0.4286 (19)0.2021 (15)1.0545 (18)0.036 (5)*
C50.5962 (2)0.11570 (15)1.0735 (2)0.0476 (5)
H5A0.562 (2)0.0703 (17)1.138 (2)0.056 (6)*
H5B0.651 (2)0.0825 (16)1.0157 (19)0.045 (5)*
C60.6837 (2)0.1845 (2)1.1450 (2)0.0495 (5)
C70.5907 (2)0.47405 (13)0.7898 (2)0.0405 (4)
H7A0.671 (2)0.4873 (16)0.7477 (19)0.048 (5)*
H7B0.6016 (18)0.4867 (14)0.8848 (18)0.036 (5)*
C80.4743 (2)0.53229 (15)0.7274 (2)0.0473 (5)
H8A0.497 (3)0.599 (2)0.731 (2)0.078 (8)*
H8B0.469 (2)0.5156 (16)0.638 (2)0.049 (5)*
C90.3432 (2)0.51787 (13)0.7938 (2)0.0452 (4)
C100.6230 (2)0.17185 (14)0.5334 (2)0.0400 (4)
H10A0.688 (2)0.1216 (17)0.5600 (19)0.051 (6)*
H10B0.673 (2)0.2129 (16)0.4688 (19)0.050 (6)*
C110.4950 (2)0.13159 (14)0.4639 (2)0.0418 (4)
H11A0.527 (2)0.0910 (17)0.396 (2)0.051 (6)*
H11B0.437 (2)0.0977 (17)0.5282 (19)0.051 (6)*
C120.4141 (2)0.2050 (2)0.3958 (2)0.0444 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0347 (7)0.0256 (7)0.0356 (6)0.0001 (5)0.0032 (5)0.0017 (5)
N20.0373 (7)0.0240 (6)0.0391 (6)0.0001 (5)0.0007 (5)0.0005 (5)
N30.0356 (7)0.0287 (7)0.0344 (6)0.0042 (5)0.0025 (5)0.0026 (5)
N40.0726 (14)0.0678 (14)0.0795 (13)0.0155 (11)0.0278 (11)0.0092 (11)
N60.0470 (10)0.078 (2)0.0955 (14)0.0081 (10)0.0211 (10)0.0330 (12)
N50.0531 (11)0.0471 (12)0.106 (2)0.0000 (9)0.0066 (10)0.0051 (11)
O10.0720 (9)0.0343 (7)0.0436 (6)0.0008 (6)0.0076 (6)0.0059 (5)
O20.0635 (9)0.0401 (8)0.0471 (6)0.0018 (6)0.0111 (6)0.0079 (6)
O30.0642 (9)0.0245 (6)0.0524 (7)0.0004 (6)0.0071 (6)0.0031 (5)
C10.0347 (7)0.0270 (8)0.0370 (7)0.0004 (6)0.0033 (6)0.0005 (6)
C20.0318 (7)0.0308 (8)0.0390 (7)0.0038 (6)0.0012 (6)0.0004 (6)
C30.0334 (7)0.0267 (8)0.0392 (7)0.0012 (6)0.0083 (6)0.0027 (6)
C40.0428 (9)0.0352 (9)0.0415 (8)0.0078 (8)0.0032 (7)0.0037 (7)
C50.0659 (13)0.0322 (9)0.0446 (9)0.0010 (9)0.0041 (8)0.0096 (8)
C60.0536 (11)0.0455 (11)0.0492 (9)0.0006 (9)0.0070 (8)0.0127 (8)
C70.0431 (9)0.0288 (8)0.0497 (9)0.0071 (7)0.0030 (7)0.0017 (7)
C80.0646 (12)0.0275 (9)0.0500 (9)0.0025 (8)0.0054 (8)0.0068 (7)
C90.0528 (11)0.0220 (8)0.0605 (10)0.0019 (7)0.0051 (8)0.0011 (7)
C100.0396 (9)0.0414 (10)0.0389 (8)0.0109 (8)0.0006 (6)0.0060 (7)
C110.0544 (11)0.0298 (9)0.0413 (8)0.0012 (8)0.0030 (7)0.0053 (7)
C120.0386 (9)0.0474 (11)0.0472 (9)0.0097 (8)0.0057 (7)0.0045 (8)
Geometric parameters (Å, º) top
N1—C11.382 (2)C7—C81.517 (3)
N1—C31.377 (2)C8—C91.455 (3)
N1—C41.467 (2)C10—C111.524 (3)
N2—C11.385 (2)C11—C121.447 (3)
N2—C21.383 (2)C4—H4A0.95 (2)
N2—C71.471 (2)C4—H4B0.92 (2)
N3—C21.381 (2)C5—H5A0.96 (2)
N3—C31.378 (2)C5—H5B0.91 (2)
N3—C101.468 (2)C7—H7A0.91 (2)
N4—C61.133 (3)C7—H7B0.97 (2)
N5—C91.128 (3)C8—H8A0.94 (3)
N6—C121.134 (3)C8—H8B0.92 (2)
O1—C11.203 (2)C10—H10A0.97 (2)
O2—C21.211 (2)C10—H10B0.99 (2)
O3—C31.215 (2)C11—H11A0.93 (2)
C4—C51.515 (3)C11—H11B0.98 (2)
C5—C61.455 (3)
C1—N1—C3124.18 (13)C5—C4—H4A113.0 (15)
C1—N1—C4118.53 (13)C5—C4—H4B110.4 (12)
C3—N1—C4117.27 (14)H4A—C4—H4B103.8 (18)
C1—N2—C2124.32 (14)C4—C5—H5A110.2 (14)
C1—N2—C7118.07 (13)C4—C5—H5B110.4 (13)
C2—N2—C7117.58 (13)C6—C5—H5A107.5 (13)
C2—N3—C3123.77 (13)C6—C5—H5B107.0 (14)
C2—N3—C10119.10 (13)H5A—C5—H5B107.7 (19)
C3—N3—C10116.89 (14)N2—C7—H7A106.5 (14)
O1—C1—N1122.04 (14)N2—C7—H7B104.9 (11)
O1—C1—N2122.7 (2)C8—C7—H7A110.3 (13)
N1—C1—N2115.29 (13)C8—C7—H7B112.4 (11)
O2—C2—N2121.4 (2)H7A—C7—H7B109.1 (17)
O2—C2—N3122.89 (15)C7—C8—H8A109.1 (17)
N2—C2—N3115.72 (13)C7—C8—H8B107.6 (13)
O3—C3—N1121.75 (14)C9—C8—H8A108.6 (15)
O3—C3—N3121.98 (14)C9—C8—H8B111.1 (13)
N1—C3—N3116.27 (14)H8A—C8—H8B106.9 (19)
N1—C4—C5112.59 (15)N3—C10—H10A105.9 (12)
C4—C5—C6113.8 (2)N3—C10—H10B112.2 (12)
N4—C6—C5178.3 (2)C11—C10—H10A113.0 (13)
N2—C7—C8113.3 (2)C11—C10—H10B108.6 (12)
C9—C8—C7113.3 (2)H10A—C10—H10B105.1 (17)
N5—C9—C8179.2 (2)C10—C11—H11A105.6 (14)
N3—C10—C11111.83 (14)C10—C11—H11B110.6 (12)
C10—C11—C12113.4 (2)C12—C11—H11A105.4 (13)
N6—C12—C11178.8 (2)C12—C11—H11B108.9 (13)
N1—C4—H4A107.7 (7)H11A—C11—H11B112.9 (19)
N1—C4—H4B108.9 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C5—H5A···O3i0.96 (2)2.59 (2)3.504 (2)160 (2)
C7—H7B···O1ii0.97 (2)2.59 (2)3.238 (2)124 (1)
C8—H8A···N6iii0.95 (3)2.53 (3)3.382 (3)150 (2)
C8—H8B···O2iii0.92 (2)2.73 (2)3.353 (2)126 (2)
C10—H10B···N4iv0.99 (2)2.79 (2)3.647 (3)146 (2)
C11—H11A···O3v0.93 (2)2.98 (2)3.750 (2)141 (2)
Symmetry codes: (i) x+1, y, z+2; (ii) x+1, y+1, z+2; (iii) x+1, y+1, z+1; (iv) x, y, z1; (v) x+1, y, z+1.

Experimental details

Crystal data
Chemical formulaC12H12N6O3
Mr288.28
Crystal system, space groupMonoclinic, P21/n
Temperature (K)293
a, b, c (Å)9.727 (2), 13.781 (2), 9.956 (2)
β (°) 90.46 (2)
V3)1334.6 (4)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.60 × 0.48 × 0.20
Data collection
DiffractometerEnraf-Nonius CAD4
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
4071, 3877, 2466
Rint0.009
(sin θ/λ)max1)0.703
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.063, 0.190, 1.07
No. of reflections3877
No. of parameters239
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.42, 0.35

Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, Xtal 3.5 (Hall et al., 1997), SHELXS86 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), PLUTON-(C) (Spek, 1979-1997), SHELXL97.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C5—H5A···O3i0.96 (2)2.59 (2)3.504 (2)160 (2)
C7—H7B···O1ii0.97 (2)2.59 (2)3.238 (2)124 (1)
C8—H8A···N6iii0.95 (3)2.53 (3)3.382 (3)150 (2)
C8—H8B···O2iii0.92 (2)2.73 (2)3.353 (2)126 (2)
C10—H10B···N4iv0.99 (2)2.79 (2)3.647 (3)146 (2)
C11—H11A···O3v0.93 (2)2.98 (2)3.750 (2)141 (2)
Symmetry codes: (i) x+1, y, z+2; (ii) x+1, y+1, z+2; (iii) x+1, y+1, z+1; (iv) x, y, z1; (v) x+1, y, z+1.
 

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