Acta Cryst. (2008). E64, o1685 [ doi:10.1107/S1600536808023842 ]
The structure of acetoguanamine (or 2,4-diamino-6-methyl-1,3,5-triazine) has been determined as the N,N-dimethylformamide solvate, C4H7N5·C3H7NO. The molecular components are associated in the crystal structure to form ribbons stabilized by three N-H
N and one N-HO hydrogen bonds which involve NH groups as donors and the N atoms of the heterocyclic ring and the carbonyl O atom of the solvent as acceptors.
Acetoguanamine (0.1 mmol, Sigma Aldrich at 98% purity) was dissolved in N,N-dimethylformamide (9 ml) and heated under reflux for 3 h. After cooling the solution to an ambient temperature, crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation of the solvent after a few days.
All H atoms were found in a difference map, positioned with idealized geometry, and refined isotropically using a riding model (N–H = 0.82–0.89 Å, C–H = 0.93–0.97 Å). Their Uiso values were kept equal to 1.2Ueq(N), 1.5Ueq(C), 2.0Ueq(C) of the solvent molecule. In the absence of significant anomalous scattering, Friedel pairs were merged.
Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: WinGX (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
![[Figure 1]](./tk2285fig1thm.gif)
| Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. Displacements ellipsoids are at the 50% probability level. |
![[Figure 2]](./tk2285fig2thm.gif)
| Fig. 2. Crystal packing diagram for (I) viewed approximately down the c-axis. All atoms are shown as small spheres of arbitrary radii. For the sake of clarity, only H atoms involved in hydrogen bonding are shown. Hydrogen bonding is indicated by dashed lines. |
| C4H7N5·C3H7NO | F000 = 1696 |
| Mr = 198.24 | Dx = 1.230 Mg m−3 |
| Orthorhombic, Fdd2 | Mo Kα radiation λ = 0.71073 Å |
| Hall symbol: F 2 -2d | Cell parameters from 11018 reflections |
| a = 25.548 (2) Å | θ = 3.0–25.6º |
| b = 23.0626 (19) Å | µ = 0.09 mm−1 |
| c = 7.2689 (9) Å | T = 298 (2) K |
| V = 4282.8 (7) Å3 | Tablets, colourless |
| Z = 16 | 0.15 × 0.14 × 0.14 mm |
| Oxford Diffraction Xcalibur S CCD diffractometer | 1127 independent reflections |
| Radiation source: Enhance (Mo) X-ray source | 698 reflections with I > 2σ(I) |
| Monochromator: graphite | Rint = 0.064 |
| Detector resolution: 16.0696 pixels mm-1 | θmax = 25.9º |
| T = 298(2) K | θmin = 3.0º |
| ω and φ scans | h = −31→31 |
| Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006) | k = −27→28 |
| Tmin = 0.985, Tmax = 0.990 | l = −8→8 |
| 27177 measured reflections |
| 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)] = 0.047 | H-atom parameters constrained |
| wR(F2) = 0.127 | w = 1/[σ2(Fo2) + (0.0841P)2] where P = (Fo2 + 2Fc2)/3 |
| S = 0.91 | (Δ/σ)max < 0.001 |
| 1127 reflections | Δρmax = 0.15 e Å−3 |
| 132 parameters | Δρmin = −0.14 e Å−3 |
| 1 restraint | Extinction correction: none |
| Primary atom site location: structure-invariant direct methods |
| C4H7N5·C3H7NO | V = 4282.8 (7) Å3 |
| Mr = 198.24 | Z = 16 |
| Orthorhombic, Fdd2 | Mo Kα |
| a = 25.548 (2) Å | µ = 0.09 mm−1 |
| b = 23.0626 (19) Å | T = 298 (2) K |
| c = 7.2689 (9) Å | 0.15 × 0.14 × 0.14 mm |
| Oxford Diffraction Xcalibur S CCD diffractometer | 1127 independent reflections |
| Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006) | 698 reflections with I > 2σ(I) |
| Tmin = 0.985, Tmax = 0.990 | Rint = 0.064 |
| 27177 measured reflections |
| R[F2 > 2σ(F2)] = 0.047 | H-atom parameters constrained |
| wR(F2) = 0.127 | Δρmax = 0.15 e Å−3 |
| S = 0.91 | Δρmin = −0.14 e Å−3 |
| 1127 reflections | Absolute structure: ? |
| 132 parameters | Flack parameter: ? |
| 1 restraint | Rogers parameter: ? |
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 | ||
| N1 | 0.63312 (11) | 0.10945 (11) | 0.5765 (4) | 0.0495 (9) | |
| C2 | 0.58170 (12) | 0.10315 (14) | 0.6030 (6) | 0.0431 (9) | |
| N3 | 0.55453 (10) | 0.05414 (12) | 0.5797 (4) | 0.0447 (8) | |
| C4 | 0.58328 (13) | 0.00862 (13) | 0.5267 (5) | 0.0416 (9) | |
| N5 | 0.63552 (11) | 0.01049 (12) | 0.4927 (5) | 0.0471 (8) | |
| C6 | 0.65836 (13) | 0.06118 (15) | 0.5210 (5) | 0.0463 (9) | |
| N6 | 0.55533 (11) | 0.15017 (12) | 0.6581 (5) | 0.0592 (10) | |
| H6A | 0.5721 | 0.1836 | 0.6753 | 0.071* | |
| H6B | 0.5210 | 0.14808 | 0.6776 | 0.071* | |
| N7 | 0.55992 (11) | −0.04163 (11) | 0.5010 (5) | 0.0598 (10) | |
| H7A | 0.5282 | −0.04463 | 0.5175 | 0.072* | |
| H7B | 0.5771 | −0.0700 | 0.4684 | 0.072* | |
| C8 | 0.71557 (14) | 0.06575 (18) | 0.4923 (7) | 0.0710 (13) | |
| H8A | 0.7319 | 0.0329 | 0.5395 | 0.106* | |
| H8B | 0.7282 | 0.0985 | 0.5522 | 0.106* | |
| H8C | 0.7226 | 0.0687 | 0.3671 | 0.106* | |
| O1 | 0.44754 (15) | 0.1783 (2) | 0.7397 (7) | 0.1196 (16) | |
| N8 | 0.36343 (14) | 0.20435 (17) | 0.7802 (5) | 0.0738 (11) | |
| C9 | 0.4016 (3) | 0.1667 (3) | 0.7697 (9) | 0.113 (2) | |
| H9 | 0.3931 | 0.1279 | 0.7864 | 0.226* | |
| C10 | 0.3107 (3) | 0.1868 (4) | 0.8156 (11) | 0.160 (4) | |
| H10A | 0.2905 | 0.1891 | 0.7028 | 0.319* | |
| H10B | 0.2954 | 0.2122 | 0.9074 | 0.319* | |
| H10C | 0.3105 | 0.1472 | 0.8606 | 0.319* | |
| C11 | 0.3722 (4) | 0.2647 (2) | 0.7568 (11) | 0.140 (3) | |
| H11A | 0.3839 | 0.2813 | 0.8722 | 0.279* | |
| H11B | 0.3399 | 0.2833 | 0.7189 | 0.279* | |
| H11C | 0.3988 | 0.2706 | 0.6634 | 0.279* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| N1 | 0.0426 (16) | 0.0337 (16) | 0.072 (2) | −0.0041 (13) | −0.0033 (15) | −0.0092 (16) |
| C2 | 0.0385 (18) | 0.0307 (18) | 0.060 (2) | −0.0004 (15) | −0.0048 (19) | −0.0032 (16) |
| N3 | 0.0391 (14) | 0.0311 (14) | 0.0638 (19) | −0.0001 (13) | −0.0004 (15) | −0.0059 (14) |
| C4 | 0.0400 (19) | 0.0273 (17) | 0.057 (2) | −0.0005 (14) | 0.0046 (18) | −0.0045 (15) |
| N5 | 0.0406 (16) | 0.0310 (15) | 0.070 (2) | −0.0008 (12) | −0.0009 (16) | −0.0103 (15) |
| C6 | 0.0399 (17) | 0.0381 (19) | 0.061 (2) | −0.0037 (16) | −0.0027 (18) | −0.0038 (18) |
| N6 | 0.0457 (17) | 0.0298 (15) | 0.102 (3) | 0.0009 (13) | −0.0020 (18) | −0.0156 (17) |
| N7 | 0.0414 (16) | 0.0319 (15) | 0.106 (3) | −0.0013 (13) | 0.0115 (19) | −0.0126 (18) |
| C8 | 0.042 (2) | 0.062 (2) | 0.108 (4) | −0.0064 (19) | 0.006 (3) | −0.019 (3) |
| O1 | 0.063 (2) | 0.153 (4) | 0.143 (4) | 0.013 (2) | −0.005 (3) | −0.037 (3) |
| N8 | 0.070 (2) | 0.072 (3) | 0.079 (3) | 0.006 (2) | 0.0083 (19) | −0.012 (2) |
| C9 | 0.133 (6) | 0.109 (5) | 0.096 (5) | 0.018 (5) | −0.008 (4) | −0.017 (4) |
| C10 | 0.101 (5) | 0.266 (10) | 0.112 (5) | −0.053 (6) | 0.036 (4) | −0.050 (6) |
| C11 | 0.242 (9) | 0.073 (4) | 0.104 (5) | −0.002 (4) | 0.001 (5) | 0.008 (4) |
| N1—C2 | 1.336 (4) | C8—H8B | 0.9300 |
| N1—C6 | 1.348 (5) | C8—H8C | 0.9300 |
| C2—N3 | 1.337 (4) | O1—C9 | 1.223 (7) |
| C2—N6 | 1.338 (4) | N8—C9 | 1.307 (7) |
| N3—C4 | 1.338 (4) | N8—C11 | 1.419 (6) |
| C4—N7 | 1.317 (4) | N8—C10 | 1.429 (7) |
| C4—N5 | 1.358 (4) | C9—H9 | 0.9300 |
| N5—C6 | 1.323 (4) | C10—H10A | 0.9700 |
| C6—C8 | 1.480 (5) | C10—H10B | 0.9700 |
| N6—H6A | 0.8907 | C10—H10C | 0.9700 |
| N6—H6B | 0.8907 | C11—H11A | 0.9700 |
| N7—H7A | 0.8226 | C11—H11B | 0.9700 |
| N7—H7B | 0.8226 | C11—H11C | 0.9700 |
| C8—H8A | 0.9300 | ||
| C2—N1—C6 | 115.1 (3) | C6—C8—H8C | 109.5 |
| N1—C2—N3 | 125.8 (3) | H8A—C8—H8C | 109.5 |
| N1—C2—N6 | 116.8 (3) | H8B—C8—H8C | 109.5 |
| N3—C2—N6 | 117.5 (3) | C9—N8—C11 | 121.7 (6) |
| C2—N3—C4 | 114.5 (3) | C9—N8—C10 | 121.7 (6) |
| N7—C4—N3 | 118.9 (3) | C11—N8—C10 | 116.6 (6) |
| N7—C4—N5 | 116.6 (3) | O1—C9—N8 | 125.6 (7) |
| N3—C4—N5 | 124.5 (3) | O1—C9—H9 | 117.2 |
| C6—N5—C4 | 115.7 (3) | N8—C9—H9 | 117.2 |
| N5—C6—N1 | 124.4 (3) | N8—C10—H10A | 109.5 |
| N5—C6—C8 | 118.5 (3) | N8—C10—H10B | 109.5 |
| N1—C6—C8 | 117.1 (3) | H10A—C10—H10B | 109.5 |
| C2—N6—H6A | 120.0 | N8—C10—H10C | 109.5 |
| C2—N6—H6B | 120.0 | H10A—C10—H10C | 109.5 |
| H6A—N6—H6B | 120.0 | H10B—C10—H10C | 109.5 |
| C4—N7—H7A | 120.0 | N8—C11—H11A | 109.5 |
| C4—N7—H7B | 120.0 | N8—C11—H11B | 109.5 |
| H7A—N7—H7B | 120.0 | H11A—C11—H11B | 109.5 |
| C6—C8—H8A | 109.5 | N8—C11—H11C | 109.5 |
| C6—C8—H8B | 109.5 | H11A—C11—H11C | 109.5 |
| H8A—C8—H8B | 109.5 | H11B—C11—H11C | 109.5 |
| C6—N1—C2—N3 | 0.2 (6) | N3—C4—N5—C6 | 2.1 (5) |
| C6—N1—C2—N6 | 180.0 (4) | C4—N5—C6—N1 | −1.2 (6) |
| N1—C2—N3—C4 | 0.6 (6) | C4—N5—C6—C8 | 178.1 (4) |
| N6—C2—N3—C4 | −179.2 (3) | C2—N1—C6—N5 | 0.2 (6) |
| C2—N3—C4—N7 | 179.7 (4) | C2—N1—C6—C8 | −179.2 (4) |
| C2—N3—C4—N5 | −1.8 (5) | C11—N8—C9—O1 | 0.0 (10) |
| N7—C4—N5—C6 | −179.4 (4) | C10—N8—C9—O1 | 179.9 (6) |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N6—H6B···O1 | 0.89 | 2.05 | 2.890 (5) | 157 |
| N6—H6A···N5i | 0.89 | 2.13 | 3.022 (4) | 174 |
| N7—H7B···N1ii | 0.82 | 2.18 | 2.989 (4) | 168 |
| N7—H7A···N3iii | 0.82 | 2.17 | 2.993 (4) | 176 |
| Symmetry codes: (i) −x+5/4, y+1/4, z+1/4; (ii) −x+5/4, y−1/4, z−1/4; (iii) −x+1, −y, z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N6—H6B···O1 | 0.89 | 2.05 | 2.890 (5) | 157 |
| N6—H6A···N5i | 0.89 | 2.13 | 3.022 (4) | 174 |
| N7—H7B···N1ii | 0.82 | 2.18 | 2.989 (4) | 168 |
| N7—H7A···N3iii | 0.82 | 2.17 | 2.993 (4) | 176 |
| Symmetry codes: (i) −x+5/4, y+1/4, z+1/4; (ii) −x+5/4, y−1/4, z−1/4; (iii) −x+1, −y, z. |
We thank MIUR (Rome) for 2006 financial support of the project 'X-ray diffractometry and spectrometry'.
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As a part of a more general study of multiple-hydrogen-bonding DNA/RNA nucleobases as potential supramolecular reagents (Portalone et al., 1999; Portalone & Colapietro, 2007a, b), this work is a continuation of our studies on crystal adducts of DNA/RNA pyrimidine bases coupled with amino-derivatives of aromatic N-heterocycles via multiple hydrogen bonds to mimic the base-pairing of nucleic acids.
The asymmetric unit of (I) comprises a planar independent molecule of acetoguanamine hydrogen-bonded to N,N-dimethylformamide (DMF) (Fig. 1). A comparison of the molecular geometry of acetoguanamine with that reported for the corresponding molecule in the 1:1 monohydrated molecular adduct formed between acetoguanaminium chloride and acetoguanamine (Portalone & Colapietro, 2007a) shows that the corresponding bond lengths and angles are equal within experimental error. An analysis of the crystal packing of (I) shows (Table 1) that adjacent molecules of acetoguanamine are linked into ribbons (Fig. 2) by three independent intermolecular N—H···N hydrogen bonds between NH moieties and N atoms of the heterocyclic ring to form hydrogen-bonded rings (one centrosymmetric) of descriptor R22(8) (Etter et al., 1990; Bernstein et al., 1995; Motherwell et al., 1999). These hydrogen bonds that lead to two-dimensional arrays in the ab plane are bridged by DMF molecules via N–H ···O interactions forming C11(3) chains.