organic compounds
3-Phenyl-4H,6H-1,2,4-oxadiazol-5-one
aSchool of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, Scotland, bDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland, and cInstituto de Química, Departamento de Química Inorgânica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro, RJ, Brazil
*Correspondence e-mail: cg@st-andrews.ac.uk
Molecules of the title compound, C9H8N2O2, are linked into complex sheets by a combination of N—H⋯O, C—H⋯N and C—H⋯O hydrogen bonds.
Comment
The title compound, (I) (Fig. 1), is a lactam which was obtained on the attempted recrystallization of H2N(Ph)C=NOCH2COOH from hot water.
The bond distances within the heterocyclic ring of (I) (Table 1) show very strong bond fixation in the C—N bonds. Thus, N2—C3 is very much shorter than C3—N4, which is rather long for its type (Allen et al., 1987). These values effectively preclude any electron delocalization in the N2—C3—N4 fragment. The ring puckering parameters (Cremer & Pople, 1975) of θ = 66.5 (2)° and φ = 335.9 (2)° for the atom sequence O1—N2—C3—N4—C5—C6 indicate a screw-boat conformation for the heterocyclic ring (Evans & Boeyens, 1989). The torsion angles within this ring (Table 1) indicate the near-planarity of the O1—N2—C3—N4 fragment containing the N2=C3 double bond, and of the cis-amidic fragment C3—N4—C5—C6.
The molecules of (I) are linked into a sheet of some complexity via a combination of N—H⋯O, C—H⋯O and C—H⋯N hydrogen bonds (Table 2). The formation of the sheet can most readily be analysed and described in terms of two one-dimensional substructures.
Atom N4 in the molecule at (x, y, z) acts as hydrogen-bond donor to carbonyl atom O5 in the molecule at ( − x, − y, 1 − z), so generating a centrosymmetric R22(8) (Bernstein et al., 1995) dimer centred at (, −, ) (Fig. 2). The formation of this dimer is reinforced by the C—H⋯O hydrogen bond which links the same two molecules in an R22(14) motif, in which the R22(8) ring is embedded, so producing two additional rings, of R21(7) type (Fig. 2).
These dimers are linked into [130] chains by one of the C—H⋯N hydrogen bonds. Aryl atom C36 in the molecule at (x, y, z) acts as donor to ring atom N2 in the molecule at (1 − x, 1 − y, 1 − z), so generating a centrosymmetric R22(10) motif, centred at (, , ), and linking pairs of the R22(8) dimers into a chain of centrosymmetric rings running parallel to the [130] direction (Fig. 2).
A second chain motif is generated by the combined action of the two C—H⋯N hydrogen bonds, which unexpectedly have the same acceptor, viz. ring atom N2. Ring atom C6 in the molecule at (x, y, z) acts as hydrogen-bond donor, via the axial atom H6A, to atom N2 in the molecule at (1 − x, −y, 1 − z), so generating a centrosymmetric R22(8) ring centred at (, 0, ). This motif, in combination with the R22(10) motif, also generated by paired C—H⋯N hydrogen bonds, produces a chain of spiro-fused rings running parallel to the [010] direction (Fig. 3). The combination of the [130] and [010] chains generates an (001) sheet, but there are no direction-specific interactions between adjacent sheets.
Experimental
The title compound was obtained on the attempted recrystallization of H2N(Ph)C=NOCH2COOH (Forrester et al., 1979) from hot water.
Crystal data
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Refinement
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The Cc and C2/c as possible space groups; C2/c was selected and confirmed by the subsequent structure analysis. All H atoms were located from difference maps and then treated as riding, with C—H distances of 0.95 (aromatic) or 0.99 Å (CH2) and an N—H distance of 0.85 Å, and with Uiso(H) = 1.2Ueq(C,N).
permittedData collection: COLLECT (Hooft, 1999); cell DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Supporting information
10.1107/S0108270104023406/sk1774sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S0108270104023406/sk1774Isup2.hkl
The title compound was obtained on the attempted recrystallization of H2N(Ph)C═NOCH2COOH (Forrester et al., 1979) from hot water.
The
permitted Cc and C2/c as possible space groups; C2/c was selected, and confirmed by the subsequent structure analysis. All H atoms were located from difference maps and then treated as riding, with C—H distances of 0.95 (aromatic) or 0.99 Å (CH2) and an N—H distance of 0.85 Å, and with Uiso(H) = 1.2Ueq(C,N).Data collection: COLLECT (Hooft, 1999); cell
DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).Fig. 1. The molecule of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. | |
Fig. 2. A stereoview of part of the crystal structure of (I), showing the formation of a [130] chain of edge-fused rings. For the sake of clarity, H atoms not involved in the motifs shown have been omitted. | |
Fig. 3. Part of the crystal structure of (I), showing the formation of an [010] chain of spiro-fused rings. For the sake of clarity, H atoms not involved in the motifs shown have been omitted. Atoms marked with an asterisk (*), hash (#), dollar sign () or ampersand () are at the symmetry positions (1 − x, 1 − y, 1 − z), (1 − x, −y, 1 − z) (x, 1 + y, z) and (x, y − 1, z), respectively. |
C9H8N2O2 | F(000) = 736 |
Mr = 176.17 | Dx = 1.420 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 1903 reflections |
a = 18.910 (1) Å | θ = 3.2–27.6° |
b = 5.1093 (2) Å | µ = 0.10 mm−1 |
c = 17.0632 (9) Å | T = 120 K |
β = 90.885 (3)° | Lath, colourless |
V = 1648.40 (14) Å3 | 0.55 × 0.12 × 0.03 mm |
Z = 8 |
Nonius KappaCCD area-detector diffractometer | 1903 independent reflections |
Radiation source: Bruker-Nonius FR591 rotating anode | 1200 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.066 |
Detector resolution: 9.091 pixels mm-1 | θmax = 27.6°, θmin = 3.2° |
ϕ and ω scans | h = −24→24 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | k = −6→6 |
Tmin = 0.954, Tmax = 0.997 | l = −20→22 |
10146 measured reflections |
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)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.136 | H-atom parameters constrained |
S = 0.98 | w = 1/[σ2(Fo2) + (0.0779P)2] where P = (Fo2 + 2Fc2)/3 |
1903 reflections | (Δ/σ)max < 0.001 |
118 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
C9H8N2O2 | V = 1648.40 (14) Å3 |
Mr = 176.17 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 18.910 (1) Å | µ = 0.10 mm−1 |
b = 5.1093 (2) Å | T = 120 K |
c = 17.0632 (9) Å | 0.55 × 0.12 × 0.03 mm |
β = 90.885 (3)° |
Nonius KappaCCD area-detector diffractometer | 1903 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | 1200 reflections with I > 2σ(I) |
Tmin = 0.954, Tmax = 0.997 | Rint = 0.066 |
10146 measured reflections |
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.136 | H-atom parameters constrained |
S = 0.98 | Δρmax = 0.23 e Å−3 |
1903 reflections | Δρmin = −0.27 e Å−3 |
118 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.43308 (6) | 0.1136 (2) | 0.40375 (7) | 0.0266 (4) | |
O5 | 0.30092 (6) | −0.3600 (2) | 0.42484 (7) | 0.0272 (4) | |
N2 | 0.43312 (8) | 0.2398 (3) | 0.47870 (9) | 0.0240 (4) | |
N4 | 0.32837 (7) | −0.0004 (3) | 0.49774 (8) | 0.0222 (4) | |
C3 | 0.37966 (9) | 0.1813 (3) | 0.52107 (11) | 0.0200 (4) | |
C5 | 0.34240 (9) | −0.1851 (3) | 0.44265 (10) | 0.0222 (4) | |
C6 | 0.41412 (9) | −0.1560 (3) | 0.40829 (11) | 0.0243 (5) | |
C31 | 0.37249 (9) | 0.3179 (3) | 0.59706 (10) | 0.0207 (4) | |
C32 | 0.32239 (9) | 0.2428 (4) | 0.65152 (11) | 0.0253 (5) | |
C33 | 0.31777 (10) | 0.3726 (4) | 0.72243 (11) | 0.0280 (5) | |
C34 | 0.36309 (10) | 0.5784 (4) | 0.74019 (11) | 0.0284 (5) | |
C35 | 0.41289 (10) | 0.6536 (4) | 0.68611 (11) | 0.0272 (5) | |
C36 | 0.41785 (10) | 0.5258 (3) | 0.61516 (11) | 0.0246 (5) | |
H4 | 0.2896 | −0.0106 | 0.5221 | 0.027* | |
H6A | 0.4493 | −0.2506 | 0.4412 | 0.029* | |
H6B | 0.4143 | −0.2341 | 0.3552 | 0.029* | |
H32 | 0.2912 | 0.1018 | 0.6400 | 0.030* | |
H33 | 0.2833 | 0.3204 | 0.7592 | 0.034* | |
H34 | 0.3600 | 0.6668 | 0.7890 | 0.034* | |
H35 | 0.4440 | 0.7947 | 0.6979 | 0.033* | |
H36 | 0.4523 | 0.5794 | 0.5785 | 0.030* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0312 (7) | 0.0264 (7) | 0.0223 (7) | −0.0068 (6) | 0.0039 (6) | −0.0006 (6) |
O5 | 0.0238 (7) | 0.0293 (8) | 0.0286 (8) | −0.0070 (6) | 0.0019 (6) | −0.0062 (6) |
N2 | 0.0265 (9) | 0.0240 (9) | 0.0215 (9) | −0.0030 (7) | 0.0016 (7) | −0.0024 (7) |
N4 | 0.0175 (8) | 0.0256 (9) | 0.0237 (9) | −0.0035 (6) | 0.0033 (7) | −0.0030 (7) |
C3 | 0.0176 (9) | 0.0181 (9) | 0.0244 (10) | −0.0002 (7) | −0.0012 (8) | 0.0026 (8) |
C5 | 0.0221 (10) | 0.0234 (10) | 0.0209 (10) | −0.0024 (8) | −0.0011 (8) | 0.0007 (8) |
C6 | 0.0245 (10) | 0.0226 (10) | 0.0258 (11) | −0.0049 (8) | 0.0033 (8) | −0.0034 (8) |
C31 | 0.0201 (9) | 0.0200 (10) | 0.0219 (10) | 0.0016 (7) | −0.0011 (8) | 0.0011 (8) |
C32 | 0.0228 (10) | 0.0247 (10) | 0.0284 (11) | −0.0041 (8) | −0.0011 (8) | −0.0024 (9) |
C33 | 0.0270 (10) | 0.0318 (11) | 0.0254 (11) | −0.0022 (8) | 0.0036 (9) | −0.0011 (9) |
C34 | 0.0310 (11) | 0.0269 (11) | 0.0271 (11) | 0.0025 (9) | −0.0031 (9) | −0.0062 (9) |
C35 | 0.0277 (11) | 0.0239 (10) | 0.0298 (11) | −0.0047 (8) | −0.0051 (9) | −0.0043 (9) |
C36 | 0.0232 (9) | 0.0225 (10) | 0.0282 (11) | −0.0019 (8) | 0.0008 (8) | 0.0028 (8) |
O1—N2 | 1.4320 (18) | C33—C34 | 1.387 (3) |
N2—C3 | 1.287 (2) | C33—H33 | 0.95 |
C3—N4 | 1.396 (2) | C34—C35 | 1.383 (3) |
N4—C5 | 1.361 (2) | C34—H34 | 0.95 |
C5—C6 | 1.493 (2) | C35—C36 | 1.380 (3) |
C6—O1 | 1.426 (2) | C35—H35 | 0.95 |
C3—C31 | 1.481 (3) | C36—H36 | 0.95 |
C31—C32 | 1.391 (2) | N4—H4 | 0.85 |
C31—C36 | 1.397 (2) | C5—O5 | 1.2243 (19) |
C32—C33 | 1.384 (3) | C6—H6A | 0.99 |
C32—H32 | 0.95 | C6—H6B | 0.99 |
C6—O1—N2 | 112.52 (13) | C36—C35—H35 | 119.7 |
C3—N2—O1 | 114.05 (14) | C34—C35—H35 | 119.7 |
N2—C3—N4 | 122.85 (17) | C35—C36—C31 | 120.26 (17) |
N2—C3—C31 | 117.77 (16) | C35—C36—H36 | 119.9 |
N4—C3—C31 | 119.38 (16) | C31—C36—H36 | 119.9 |
C32—C31—C36 | 118.96 (17) | C5—N4—C3 | 121.07 (15) |
C32—C31—C3 | 121.84 (16) | C5—N4—H4 | 118.3 |
C36—C31—C3 | 119.19 (16) | C3—N4—H4 | 120.1 |
C33—C32—C31 | 120.32 (17) | O5—C5—N4 | 123.13 (16) |
C33—C32—H32 | 119.8 | O5—C5—C6 | 123.88 (16) |
C31—C32—H32 | 119.8 | N4—C5—C6 | 112.97 (15) |
C32—C33—C34 | 120.48 (18) | O1—C6—C5 | 110.36 (14) |
C32—C33—H33 | 119.8 | O1—C6—H6A | 109.6 |
C34—C33—H33 | 119.8 | C5—C6—H6A | 109.6 |
C35—C34—C33 | 119.31 (18) | O1—C6—H6B | 109.6 |
C35—C34—H34 | 120.3 | C5—C6—H6B | 109.6 |
C33—C34—H34 | 120.3 | H6A—C6—H6B | 108.1 |
C36—C35—C34 | 120.67 (17) | ||
O1—N2—C3—N4 | 3.4 (2) | C3—C31—C32—C33 | 179.12 (16) |
N2—C3—N4—C5 | 21.4 (2) | C31—C32—C33—C34 | −0.2 (3) |
C3—N4—C5—C6 | −4.0 (2) | C32—C33—C34—C35 | 0.3 (3) |
N4—C5—C6—O1 | −33.9 (2) | C33—C34—C35—C36 | −0.1 (3) |
C5—C6—O1—N2 | 58.6 (2) | C34—C35—C36—C31 | 0.0 (3) |
C6—O1—N2—C3 | −43.56 (19) | C32—C31—C36—C35 | 0.1 (3) |
O1—N2—C3—C31 | −175.50 (13) | C3—C31—C36—C35 | −179.03 (16) |
N2—C3—C31—C32 | −170.97 (16) | C31—C3—N4—C5 | −159.71 (15) |
N4—C3—C31—C32 | 10.1 (2) | C3—N4—C5—O5 | 174.28 (15) |
N2—C3—C31—C36 | 8.2 (2) | N2—O1—C6—C5 | 58.59 (19) |
N4—C3—C31—C36 | −170.81 (15) | O5—C5—C6—O1 | 147.78 (16) |
C36—C31—C32—C33 | 0.0 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H4···O5i | 0.85 | 2.06 | 2.886 (2) | 165 |
C32—H32···O5i | 0.95 | 2.39 | 3.296 (2) | 159 |
C6—H6A···N2ii | 0.99 | 2.59 | 3.475 (2) | 148 |
C36—H36···N2iii | 0.95 | 2.56 | 3.476 (2) | 161 |
Symmetry codes: (i) −x+1/2, −y−1/2, −z+1; (ii) −x+1, −y, −z+1; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C9H8N2O2 |
Mr | 176.17 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 120 |
a, b, c (Å) | 18.910 (1), 5.1093 (2), 17.0632 (9) |
β (°) | 90.885 (3) |
V (Å3) | 1648.40 (14) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.55 × 0.12 × 0.03 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2003) |
Tmin, Tmax | 0.954, 0.997 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10146, 1903, 1200 |
Rint | 0.066 |
(sin θ/λ)max (Å−1) | 0.652 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.136, 0.98 |
No. of reflections | 1903 |
No. of parameters | 118 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.27 |
Computer programs: COLLECT (Hooft, 1999), DENZO (Otwinowski & Minor, 1997) and COLLECT, DENZO and COLLECT, OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997), OSCAIL and SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXL97 and PRPKAPPA (Ferguson, 1999).
O1—N2 | 1.4320 (18) | N4—C5 | 1.361 (2) |
N2—C3 | 1.287 (2) | C5—C6 | 1.493 (2) |
C3—N4 | 1.396 (2) | C6—O1 | 1.426 (2) |
O1—N2—C3—N4 | 3.4 (2) | N4—C5—C6—O1 | −33.9 (2) |
N2—C3—N4—C5 | 21.4 (2) | C5—C6—O1—N2 | 58.6 (2) |
C3—N4—C5—C6 | −4.0 (2) | C6—O1—N2—C3 | −43.56 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H4···O5i | 0.85 | 2.06 | 2.886 (2) | 165 |
C32—H32···O5i | 0.95 | 2.39 | 3.296 (2) | 159 |
C6—H6A···N2ii | 0.99 | 2.59 | 3.475 (2) | 148 |
C36—H36···N2iii | 0.95 | 2.56 | 3.476 (2) | 161 |
Symmetry codes: (i) −x+1/2, −y−1/2, −z+1; (ii) −x+1, −y, −z+1; (iii) −x+1, −y+1, −z+1. |
Acknowledgements
The X-ray data were collected at the EPSRC X-ray Crystallographic Service, University of Southampton, England; the authors thank the staff for all their help and advice. JNL thanks NCR Self-Service, Dundee, for grants which have provided computing facilities for this work. JLW thanks CNPq and FAPERJ for financial support.
References
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The title compound, (I) (Fig. 1), is a lactam, which was obtained on the attempted recrystallization of H2N(Ph)C═NOCH2COOH from hot water. \sch
The bond distances within the heterocyclic ring of (I) (Table 1) show very strong bond fixation in the C—N bonds. Thus, N2—C3 is very much shorter than C3—N4, which is rather long for its type (Allen et al., 1987). These values effectively preclude any electron delocalization in the N2—C3—N4 fragment. The ring puckering parameters (Cremer & Pople, 1975) of θ = 66.5 (2)° and ϕ = 335.9 (2)° for the atom-sequence O1/N2/C3/N4/C5/C6 indicate a screw-boat conformation for the heterocyclic ring (Evans & Boeyens, 1989). The torsion angles within this ring (Table 1) indicate the near-planarity of the O1—N2—C3—N4 fragment containing the N2═C3 double bond, and of the cis-amidic fragment C3—N4—C5—C6.
The molecules of (I) are linked into a sheet of some complexity via a combination of N—H···O, C—H···O and C—H···N hydrogen bonds (Table 2). The formation of the sheet can most readily be analysed and described in terms of two one-dimensional sub-structures.
Atom N4 in the molecule at (x, y, z) acts as hydrogen-bond donor to carbonyl atom O5 in the molecule at (1/2 − x, −1/2 − y, 1 − z), so generating a centrosymmetric R22(8) (Bernstein et al., 1995) dimer centred at (1/4, −1/4, 1/2) (Fig. 2). The formation of this dimer is reinforced by the C—H···O hydrogen bond which links the same two molecules in an R22(14) motif, in which the R22(8) ring is embedded, so producing two additional rings, of R21(7) type (Fig. 2).
These dimers are linked into [130] chains by one of the C—H···N hydrogen bonds. Aryl atom C36 in the molecule at (x, y, z) acts as donor to ring atom N2 in the molecule at (1 − x, 1 − y, 1 − z), so generating a centrosymmetric R22(10) motif, centred at (1/2, 1/2, 1/2), and linking pairs of the R22(8) dimers into a chain of centrosymmetric rings running parallel to the [130] direction (Fig. 2).
A second chain motif is generated by the combined action of the two C—H···N hydrogen bonds, which unexpectedly have the same acceptor, ring atom N2. Ring atom C6 in the molecule at (x, y, z) acts as hydrogen-bond donor, via the axial atom H6A, to atom N2 in the molecule at (1 − x, −y, 1 − z), so generating a centrosymmetric R22(8) ring centred at (1/2, 0, 1/2). This motif, in combination with the R22(10) motif, also generated by paired C—H···N hydrogen bonds, produces a chain of spiro-fused rings running parallel to the [010] direction (Fig. 3). The combination of the [130] and [010] chains generates an (001) sheet, but there are no direction-specific interactions between adjacent sheets.