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The title compound, C8H8N2O2, was prepared by dehydration of a pyrrole­oxime in the presence of triphosgene. The mol­ecules self-assemble into a layered structure through hydrogen bonding. All non-H atoms lie on a crystallographic mirror plane.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803024607/ww6137sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803024607/ww6137Isup2.hkl
Contains datablock I

CCDC reference: 227860

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.004 Å
  • R factor = 0.053
  • wR factor = 0.159
  • Data-to-parameter ratio = 12.4

checkCIF/PLATON results

No syntax errors found



Alert level B PLAT021_ALERT_1_B Ratio Unique / Expected Reflections too High ... 1.21 PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low ....... 0.99
Alert level C THETM01_ALERT_3_C The value of sine(theta_max)/wavelength is less than 0.590 Calculated sin(theta_max)/wavelength = 0.5833 PLAT023_ALERT_3_C Resolution (too) Low [sin(th)/Lambda < 0.6]..... 24.49 Deg. PLAT250_ALERT_2_C Large U3/U1 ratio for average U(i,j) tensor .... 2.52 PLAT371_ALERT_2_C Long C(sp2)-C(sp1) Bond C4 - C8 = 1.42 Ang.
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 3 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

Ethyl 5-cyano-1H-pyrrole-2-carboxylate top
Crystal data top
C8H8N2O2Dx = 1.295 Mg m3
Mr = 164.16Melting point: 392 K
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 762 reflections
a = 7.866 (3) Åθ = 2.6–24.5°
b = 6.710 (3) ŵ = 0.10 mm1
c = 15.959 (7) ÅT = 293 K
V = 842.3 (6) Å3Block, colorless
Z = 40.32 × 0.28 × 0.20 mm
F(000) = 344
Data collection top
Bruker SMART CCD area-detector
diffractometer
664 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.022
Graphite monochromatorθmax = 24.5°, θmin = 2.6°
φ and ω scansh = 59
2209 measured reflectionsk = 84
921 independent reflectionsl = 1919
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.053 w = 1/[σ2(Fo2) + (0.084P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.159(Δ/σ)max = 0.002
S = 1.12Δρmax = 0.24 e Å3
921 reflectionsΔρmin = 0.26 e Å3
74 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.5804 (3)0.75001.09215 (13)0.0422 (7)
H10.65730.75001.13040.051*
N20.2838 (4)0.75001.25259 (18)0.0785 (10)
O10.9057 (3)0.75001.02467 (14)0.0743 (9)
O20.7951 (3)0.75000.89583 (12)0.0614 (7)
C10.6089 (3)0.75001.00804 (15)0.0392 (7)
C20.4552 (4)0.75000.96829 (17)0.0451 (7)
H20.43810.75000.91060.054*
C30.3295 (4)0.75001.02884 (17)0.0473 (8)
H30.21270.75001.01970.057*
C40.4104 (4)0.75001.10534 (16)0.0426 (7)
C50.7856 (4)0.75000.97889 (18)0.0491 (8)
C60.9669 (5)0.75000.8613 (2)0.0876 (15)
H6A1.02820.86730.88010.105*
C70.9538 (6)0.75000.7708 (3)0.0944 (15)
H7A0.89350.63320.75280.142*
H7B1.06560.75000.74670.142*
C80.3400 (4)0.75001.18726 (19)0.0538 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0354 (13)0.0617 (16)0.0296 (12)0.0000.0006 (9)0.000
N20.071 (2)0.116 (3)0.0479 (16)0.0000.0235 (16)0.000
O10.0332 (13)0.138 (3)0.0517 (13)0.0000.0047 (11)0.000
O20.0400 (13)0.1052 (19)0.0390 (12)0.0000.0100 (9)0.000
C10.0351 (16)0.0516 (17)0.0308 (13)0.0000.0015 (11)0.000
C20.0399 (17)0.0626 (19)0.0328 (13)0.0000.0021 (11)0.000
C30.0316 (15)0.064 (2)0.0460 (16)0.0000.0001 (13)0.000
C40.0358 (16)0.0538 (18)0.0383 (15)0.0000.0070 (12)0.000
C50.0388 (16)0.068 (2)0.0404 (16)0.0000.0059 (13)0.000
C60.045 (2)0.165 (5)0.053 (2)0.0000.0150 (17)0.000
C70.071 (3)0.142 (4)0.071 (3)0.0000.025 (2)0.000
C80.0448 (18)0.070 (2)0.0469 (18)0.0000.0090 (15)0.000
Geometric parameters (Å, º) top
N1—C41.353 (4)C2—C31.382 (4)
N1—C11.361 (3)C2—H20.9300
N1—H10.8600C3—C41.377 (4)
N2—C81.132 (4)C3—H30.9300
O1—C51.194 (4)C4—C81.420 (4)
O2—C51.328 (3)C6—C71.449 (5)
O2—C61.460 (4)C6—H6A0.9700
C1—C21.365 (4)C7—H7A0.9597
C1—C51.466 (4)C7—H7B0.9597
C4—N1—C1108.4 (2)N1—C4—C3108.6 (2)
C4—N1—H1125.8N1—C4—C8121.9 (3)
C1—N1—H1125.8C3—C4—C8129.5 (3)
C5—O2—C6115.4 (2)O1—C5—O2124.5 (3)
N1—C1—C2108.2 (2)O1—C5—C1123.8 (3)
N1—C1—C5118.0 (2)O2—C5—C1111.7 (3)
C2—C1—C5133.8 (3)C7—C6—O2108.1 (3)
C1—C2—C3108.0 (2)C7—C6—H6A110.1
C1—C2—H2126.0O2—C6—H6A110.1
C3—C2—H2126.0C6—C7—H7A109.5
C4—C3—C2106.8 (3)C6—C7—H7B109.5
C4—C3—H3126.6H7A—C7—H7B109.5
C2—C3—H3126.6N2—C8—C4180.0 (3)
 

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