Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680001850X/cf6003sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053680001850X/cf6003Isup2.hkl |
CCDC reference: 155854
Chloroacetamide and sodium azide were mixed in water and stirred until the water evaporated. The residue was dissolved in acetone and the solution filtered and allowed to evaporate. Azidoacetamide was obtained as colourless crystals. Single crystals were prepared by recrystallization from benzene.
The H atoms were refined and the C—H and N—H distances are in the range 0.89 (2)–1.01 (1) Å. The H–atom Uiso values are <0.038 Å2.
Azide compounds constitute a category of energetic materials. Since their properties are of great interest, much effort has been devoted to clarify their decomposition processes, conformation and molecular structures with molecular orbital calculations. However, there have been few experimental studies of the molecular structures in crystals, since azide compounds are potentially explosive and it is difficult to safely treat crystals. In this study, the structure determination of the title compound, azidoacetamide, (I), was carried out to obtain more knowledge about azide compounds.
Azidoacetamide is the smallest compound of the neutral organic azides whose crystal structures have been determined. In this study, it was revealed that non-H atoms were close to planar as the maximum deviation from the least-squares plane was <0.184 Å.
Azideacetamide easily releases the N6—N7 part as a nitrogen molecule. However, the N6—N7 bond length of 1.130 (2) Å is longer than the N≡N bond length of 1.0977 Å (Sasada, 1984). The N5—N6 bond length of 1.231 (2) Å is slightly shorter than the N═N bond length of 1.247 Å in azomethane (CH3N═NCH3) (Sasada, 1984). Therefore, the bond lengths are influenced by the resonance effect.
Table 4 summarizes the bond lengths and angles of the azide groups in organic azide compounds whose structures have already been determined. In C3N3(N3)3 (Knaggs, 1935) and [(H2N)2CN3]Cl (Henke & Bärnighausen, 1972), the conjugated systems were extended over the molecules. CH3N3 (Livingston & Rao, 1960) is the archetypical alkyl azide. Since the table indicates that the bond lengths in azide groups are almost the same, it could be said that these parameters would be characteristic of organic azide compounds.
The molecular arrangement indicates that two acetamide groups are favourably located so that the H atoms form hydrogen bonds in the bc plane. The O···HN distances are typical hydrogen-bond distances. The same interactions can be found in the intramolecular N5···H3B—N3 arrangement. However, H3B is not in an effective position to form a hydrogen bond. Therefore, H3B—N3 is shorter than H3A—N3.
Data collection: DIP Image Plate Control Software (MacScience, 1992); cell refinement: MAC-DENZO (Otwinowski & Minor, 1996); data reduction: maXus (Mackay et al., 1997); program(s) used to solve structure: maXus; program(s) used to refine structure: maXus; molecular graphics: maXus; software used to prepare material for publication: maXus.
C2H4N4O | Dx = 1.509 Mg m−3 |
Mr = 100.08 | Mo Kα radiation, λ = 0.71073 Å |
Monoclinic, P21/n | Cell parameters from 192 reflections |
a = 6.648 (4) Å | θ = 1.0–26.4° |
b = 5.1190 (9) Å | µ = 0.13 mm−1 |
c = 13.124 (5) Å | T = 100 K |
β = 99.36 (2)° | Prism, colourless |
V = 440.7 (5) Å3 | 0.2 × 0.2 × 0.2 mm |
Z = 4 |
DIP Image Plate diffractometer | Rint = 0.029 |
φ scans | θmax = 26.4° |
1544 measured reflections | h = 0→8 |
848 independent reflections | k = −6→6 |
848 reflections with I > 0 | l = −16→16 |
Refinement on F2 | All H-atom parameters refined |
R[F2 > 2σ(F2)] = 0.050 | Weighting scheme based on measured s.u.'s w = 1/[σ2(Fo) + 0.03Fo2] |
wR(F2) = 0.095 | (Δ/σ)max < 0.001 |
S = 1.14 | Δρmax = 0.22 e Å−3 |
848 reflections | Δρmin = −0.29 e Å−3 |
80 parameters |
C2H4N4O | V = 440.7 (5) Å3 |
Mr = 100.08 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 6.648 (4) Å | µ = 0.13 mm−1 |
b = 5.1190 (9) Å | T = 100 K |
c = 13.124 (5) Å | 0.2 × 0.2 × 0.2 mm |
β = 99.36 (2)° |
DIP Image Plate diffractometer | 848 reflections with I > 0 |
1544 measured reflections | Rint = 0.029 |
848 independent reflections |
R[F2 > 2σ(F2)] = 0.050 | 80 parameters |
wR(F2) = 0.095 | All H-atom parameters refined |
S = 1.14 | Δρmax = 0.22 e Å−3 |
848 reflections | Δρmin = −0.29 e Å−3 |
x | y | z | Uiso*/Ueq | ||
O1 | 0.7318 (1) | 0.0469 (1) | 0.13075 (4) | 0.0258 (3) | |
N3 | 0.7744 (1) | 0.4839 (1) | 0.14557 (6) | 0.0169 (3) | |
N5 | 0.7519 (1) | 0.5552 (1) | −0.05640 (5) | 0.0231 (4) | |
N6 | 0.6982 (1) | 0.5954 (1) | −0.14931 (6) | 0.0206 (3) | |
N7 | 0.6518 (1) | 0.6566 (2) | −0.23253 (6) | 0.0368 (4) | |
C2 | 0.7489 (1) | 0.2646 (1) | 0.09127 (6) | 0.0135 (3) | |
C4 | 0.7399 (2) | 0.2802 (1) | −0.02374 (6) | 0.0165 (4) | |
H3A | 0.772 (2) | 0.482 (2) | 0.2186 (8) | 0.028 (3)* | |
H3B | 0.777 (2) | 0.635 (2) | 0.1125 (8) | 0.038 (3)* | |
H4A | 0.610 (2) | 0.196 (2) | −0.0601 (7) | 0.028 (2)* | |
H4B | 0.857 (2) | 0.181 (2) | −0.0425 (8) | 0.036 (3)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0551 (5) | 0.0086 (2) | 0.0121 (3) | 0.0008 (3) | 0.0015 (3) | 0.0025 (2) |
N3 | 0.0321 (5) | 0.0089 (3) | 0.0088 (4) | −0.0024 (3) | 0.0023 (3) | −0.0016 (2) |
N5 | 0.0421 (5) | 0.0162 (3) | 0.0099 (4) | −0.0035 (3) | 0.0024 (3) | 0.0036 (3) |
N6 | 0.0266 (5) | 0.0173 (3) | 0.0179 (4) | 0.0022 (3) | 0.0075 (3) | 0.0048 (3) |
N7 | 0.0508 (7) | 0.0381 (4) | 0.0203 (5) | 0.0041 (4) | 0.0039 (4) | 0.0149 (3) |
C2 | 0.0194 (5) | 0.0112 (3) | 0.0091 (4) | 0.0012 (3) | −0.0007 (3) | −0.0005 (3) |
C4 | 0.0281 (5) | 0.0102 (3) | 0.0104 (4) | 0.0008 (3) | 0.0020 (3) | 0.0007 (3) |
O1—C2 | 1.242 (1) | C2—C4 | 1.503 (2) |
N3—C2 | 1.326 (1) | N3—H3A | 0.96 (2) |
N5—N6 | 1.231 (2) | N3—H3B | 0.89 (2) |
N5—C4 | 1.478 (1) | C4—H4A | 1.01 (1) |
N6—N7 | 1.130 (2) | C4—H4B | 0.99 (2) |
O1···N3i | 2.899 (1) | N7···H4Bv | 2.946 (9) |
O1···N3ii | 2.960 (1) | C2···H3Aii | 2.906 (9) |
O1···H3Aii | 2.01 (1) | H3A···H3Aii | 2.72 (1) |
O1···H3Bi | 2.15 (1) | H3A···H3Avii | 2.72 (1) |
O1···H4Aiii | 2.626 (9) | H3A···H3Bii | 2.90 (1) |
N6···N7iv | 2.991 (1) | H3B···H4Avi | 2.70 (1) |
N7···N7iv | 2.943 (1) | H3B···H4Bviii | 2.90 (1) |
N7···N7v | 2.943 (1) | H4B···H4Bix | 2.76 (1) |
N7···H3Avi | 2.94 (1) | ||
N6—N5—C4 | 115.2 (1) | C2—N3—H3B | 119.1 (7) |
N5—N6—N7 | 173.5 (1) | H3A—N3—H3B | 119.9 (9) |
O1—C2—N3 | 123.2 (1) | N5—C4—H4A | 110.6 (5) |
O1—C2—C4 | 118.4 (1) | N5—C4—H4B | 109.6 (6) |
N3—C2—C4 | 118.4 (1) | C2—C4—H4A | 110.1 (6) |
N5—C4—C2 | 110.3 (1) | C2—C4—H4B | 108.5 (6) |
C2—N3—H3A | 120.5 (5) | H4A—C4—H4B | 107.8 (8) |
N6—N5—C4—C2 | −163.6 (1) | N6—N5—C4—H4A | −41.6 (6) |
O1—C2—C4—N5 | 176.9 (1) | N6—N5—C4—H4B | 77.1 (7) |
N3—C2—C4—N5 | −2.9 (1) | O1—C2—C4—H4A | 54.7 (6) |
H3A—N3—C2—O1 | −4.1 (7) | O1—C2—C4—H4B | −63.0 (7) |
H3A—N3—C2—C4 | 175.8 (7) | N3—C2—C4—H4A | −125.2 (6) |
H3B—N3—C2—O1 | −175.6 (8) | N3—C2—C4—H4B | 117.1 (7) |
H3B—N3—C2—C4 | 4.3 (8) |
Symmetry codes: (i) x, y−1, z; (ii) −x+3/2, y−1/2, −z+1/2; (iii) −x+1, −y, −z; (iv) −x+3/2, y−1/2, −z−1/2; (v) −x+3/2, y+1/2, −z−1/2; (vi) −x+1, −y+1, −z; (vii) −x+3/2, y+1/2, −z+1/2; (viii) −x+2, −y+1, −z; (ix) −x+2, −y, −z. |
D—H···A | D—H | H···A | D···A |
N3ii—H3Aii···O1 | 0.96 (2) | 2.01 (1) | 2.960 (1) |
N3i—H3Bi···O1 | 0.89 (2) | 2.15 (1) | 2.899 (1) |
N3—H3B···N5 | 0.89 (2) | 2.23 (1) | 2.656 (1) |
Symmetry codes: (i) x, y−1, z; (ii) −x+3/2, y−1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C2H4N4O |
Mr | 100.08 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 100 |
a, b, c (Å) | 6.648 (4), 5.1190 (9), 13.124 (5) |
β (°) | 99.36 (2) |
V (Å3) | 440.7 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.13 |
Crystal size (mm) | 0.2 × 0.2 × 0.2 |
Data collection | |
Diffractometer | DIP Image Plate |
Absorption correction | – |
No. of measured, independent and observed (I > 0) reflections | 1544, 848, 848 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.626 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.050, 0.095, 1.14 |
No. of reflections | 848 |
No. of parameters | 80 |
No. of restraints | ? |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.22, −0.29 |
Computer programs: DIP Image Plate Control Software (MacScience, 1992), MAC-DENZO (Otwinowski & Minor, 1996), maXus (Mackay et al., 1997), maXus.
O1—C2 | 1.242 (1) | N5—C4 | 1.478 (1) |
N3—C2 | 1.326 (1) | N6—N7 | 1.130 (2) |
N5—N6 | 1.231 (2) | C2—C4 | 1.503 (2) |
O1···N3i | 2.899 (1) | N7···H4Bv | 2.946 (9) |
O1···N3ii | 2.960 (1) | C2···H3Aii | 2.906 (9) |
O1···H3Aii | 2.01 (1) | H3A···H3Aii | 2.72 (1) |
O1···H3Bi | 2.15 (1) | H3A···H3Avii | 2.72 (1) |
O1···H4Aiii | 2.626 (9) | H3A···H3Bii | 2.90 (1) |
N6···N7iv | 2.991 (1) | H3B···H4Avi | 2.70 (1) |
N7···N7iv | 2.943 (1) | H3B···H4Bviii | 2.90 (1) |
N7···N7v | 2.943 (1) | H4B···H4Bix | 2.76 (1) |
N7···H3Avi | 2.94 (1) | ||
N6—N5—C4 | 115.2 (1) | O1—C2—C4 | 118.4 (1) |
N5—N6—N7 | 173.5 (1) | N3—C2—C4 | 118.4 (1) |
O1—C2—N3 | 123.2 (1) | N5—C4—C2 | 110.3 (1) |
N6—N5—C4—C2 | −163.6 (1) | N3—C2—C4—N5 | −2.9 (1) |
O1—C2—C4—N5 | 176.9 (1) |
Symmetry codes: (i) x, y−1, z; (ii) −x+3/2, y−1/2, −z+1/2; (iii) −x+1, −y, −z; (iv) −x+3/2, y−1/2, −z−1/2; (v) −x+3/2, y+1/2, −z−1/2; (vi) −x+1, −y+1, −z; (vii) −x+3/2, y+1/2, −z+1/2; (viii) −x+2, −y+1, −z; (ix) −x+2, −y, −z. |
D—H···A | D—H | H···A | D···A |
N3ii—H3Aii···O1 | 0.96 (2) | 2.01 (1) | 2.960 (1) |
N3i—H3Bi···O1 | 0.89 (2) | 2.15 (1) | 2.899 (1) |
N3—H3B···N5 | 0.89 (2) | 2.23 (1) | 2.656 (1) |
Symmetry codes: (i) x, y−1, z; (ii) −x+3/2, y−1/2, −z+1/2. |
C—N | N—N | N—N | C—N—N | N—N—N | |
CH3N3 | 1.47 (2) | 1.24 (1) | 1.12 (1) | 120 (2) | 180 |
C3N3(N3)3 | 1.38 | 1.26 | 1.11 | 114 | 180 |
[(H2N)2CN3]Cl | 1.393 (4) | 1.265 (4) | 1.110 (4) | 114.2 (3) | 170.8 (3) |
This work | 1.478 (1) | 1.231 (2) | 1.130 (2) | 115.2 (1) | 173.5 (1) |
Azide compounds constitute a category of energetic materials. Since their properties are of great interest, much effort has been devoted to clarify their decomposition processes, conformation and molecular structures with molecular orbital calculations. However, there have been few experimental studies of the molecular structures in crystals, since azide compounds are potentially explosive and it is difficult to safely treat crystals. In this study, the structure determination of the title compound, azidoacetamide, (I), was carried out to obtain more knowledge about azide compounds.
Azidoacetamide is the smallest compound of the neutral organic azides whose crystal structures have been determined. In this study, it was revealed that non-H atoms were close to planar as the maximum deviation from the least-squares plane was <0.184 Å.
Azideacetamide easily releases the N6—N7 part as a nitrogen molecule. However, the N6—N7 bond length of 1.130 (2) Å is longer than the N≡N bond length of 1.0977 Å (Sasada, 1984). The N5—N6 bond length of 1.231 (2) Å is slightly shorter than the N═N bond length of 1.247 Å in azomethane (CH3N═NCH3) (Sasada, 1984). Therefore, the bond lengths are influenced by the resonance effect.
Table 4 summarizes the bond lengths and angles of the azide groups in organic azide compounds whose structures have already been determined. In C3N3(N3)3 (Knaggs, 1935) and [(H2N)2CN3]Cl (Henke & Bärnighausen, 1972), the conjugated systems were extended over the molecules. CH3N3 (Livingston & Rao, 1960) is the archetypical alkyl azide. Since the table indicates that the bond lengths in azide groups are almost the same, it could be said that these parameters would be characteristic of organic azide compounds.
The molecular arrangement indicates that two acetamide groups are favourably located so that the H atoms form hydrogen bonds in the bc plane. The O···HN distances are typical hydrogen-bond distances. The same interactions can be found in the intramolecular N5···H3B—N3 arrangement. However, H3B is not in an effective position to form a hydrogen bond. Therefore, H3B—N3 is shorter than H3A—N3.