Crystals of orthorhombic acetamide, C
2H
5NO, were obtained from a mixture of ethyl acetate and dilute ammonia. The previously reported structure [Hamilton (1965).
Acta Cryst.
18, 866–870] was confirmed, with two molecules in the asymmetric unit. The molecules are hydrogen bonded to form columns. Neighboring columns are connected by weak intermolecular C—H
O interactions.
Supporting information
CCDC reference: 225718
Key indicators
- Single-crystal X-ray study
- T = 146 K
- Mean (C-C) = 0.002 Å
- R factor = 0.058
- wR factor = 0.116
- Data-to-parameter ratio = 19.4
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low ....... 0.99
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........ 4
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
2 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
0 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
1 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Sheldrick, 1996); software used to prepare material for publication: SHELXL97.
Crystal data top
C2H5NO | F(000) = 512 |
Mr = 59.07 | Dx = 1.169 Mg m−3 |
Orthorhombic, Pccn | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ab 2ac | Cell parameters from 213 reflections |
a = 19.021 (4) Å | θ = 3–26° |
b = 7.5084 (14) Å | µ = 0.09 mm−1 |
c = 9.4038 (16) Å | T = 146 K |
V = 1343.0 (4) Å3 | Rod, colorless |
Z = 16 | 0.50 × 0.16 × 0.08 mm |
Data collection top
SIEMENS_SMART_1K_CCD diffractometer | 1134 reflections with I > 2σ(I) |
Radiation source: normal-focus sealed tube | Rint = 0.074 |
Graphite monochromator | θmax = 29.0°, θmin = 2.1° |
ω scans | h = −26→23 |
12606 measured reflections | k = −10→9 |
1767 independent reflections | l = −12→12 |
Refinement top
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)] = 0.058 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.116 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | w = 1/[σ2(Fo2) + (0.05P)2] where P = (Fo2 + 2Fc2)/3 |
1767 reflections | (Δ/σ)max = 0.001 |
91 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
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 | x | y | z | Uiso*/Ueq | |
O1 | 0.55232 (6) | 0.14563 (14) | 0.29156 (11) | 0.0318 (3) | |
N1 | 0.57489 (8) | 0.17989 (19) | 0.52416 (15) | 0.0298 (4) | |
C1 | 0.53372 (8) | 0.19720 (19) | 0.41127 (15) | 0.0252 (4) | |
C2 | 0.46294 (8) | 0.2816 (2) | 0.43387 (17) | 0.0338 (4) | |
H2A | 0.4575 | 0.3828 | 0.3689 | 0.054* | |
H2B | 0.4592 | 0.3233 | 0.5323 | 0.054* | |
H2C | 0.4260 | 0.1938 | 0.4151 | 0.054* | |
H01 | 0.6181 (10) | 0.134 (2) | 0.5123 (19) | 0.041 (5)* | |
H02 | 0.5617 (8) | 0.228 (3) | 0.604 (2) | 0.044 (5)* | |
O2 | 0.71375 (6) | 0.02080 (16) | 0.48261 (11) | 0.0377 (3) | |
N2 | 0.70150 (8) | 0.03422 (18) | 0.24500 (14) | 0.0315 (4) | |
C3 | 0.73947 (8) | 0.00898 (19) | 0.36143 (16) | 0.0265 (4) | |
C4 | 0.81577 (9) | −0.0366 (2) | 0.34175 (17) | 0.0359 (4) | |
H4A | 0.8449 | 0.0640 | 0.3724 | 0.057* | |
H4B | 0.8249 | −0.0619 | 0.2412 | 0.057* | |
H4C | 0.8274 | −0.1418 | 0.3989 | 0.057* | |
H03 | 0.6530 (10) | 0.058 (2) | 0.2564 (18) | 0.045 (5)* | |
H04 | 0.7234 (8) | 0.024 (2) | 0.1652 (18) | 0.035 (5)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0333 (7) | 0.0419 (7) | 0.0202 (6) | 0.0015 (5) | 0.0009 (5) | 0.0004 (5) |
N1 | 0.0289 (9) | 0.0404 (8) | 0.0202 (7) | 0.0042 (6) | 0.0015 (6) | −0.0021 (6) |
C1 | 0.0290 (9) | 0.0237 (8) | 0.0229 (8) | −0.0030 (7) | 0.0034 (7) | 0.0035 (6) |
C2 | 0.0291 (9) | 0.0352 (9) | 0.0372 (10) | 0.0039 (7) | 0.0002 (7) | −0.0005 (7) |
O2 | 0.0305 (7) | 0.0606 (8) | 0.0221 (6) | 0.0069 (5) | −0.0009 (5) | −0.0019 (5) |
N2 | 0.0251 (8) | 0.0489 (9) | 0.0204 (8) | 0.0012 (6) | 0.0011 (6) | −0.0005 (6) |
C3 | 0.0268 (9) | 0.0284 (8) | 0.0242 (8) | −0.0005 (7) | 0.0003 (7) | −0.0021 (6) |
C4 | 0.0277 (9) | 0.0446 (10) | 0.0353 (10) | 0.0017 (8) | −0.0008 (7) | −0.0021 (8) |
Geometric parameters (Å, º) top
O1—C1 | 1.2419 (17) | O2—C3 | 1.2433 (18) |
N1—C1 | 1.326 (2) | N2—C3 | 1.3253 (19) |
N1—H01 | 0.898 (18) | N2—H03 | 0.945 (19) |
N1—H02 | 0.87 (2) | N2—H04 | 0.862 (17) |
C1—C2 | 1.503 (2) | C3—C4 | 1.503 (2) |
C2—H2A | 0.9800 | C4—H4A | 0.9800 |
C2—H2B | 0.9800 | C4—H4B | 0.9800 |
C2—H2C | 0.9800 | C4—H4C | 0.9800 |
| | | |
C1—N1—H01 | 118.6 (11) | C3—N2—H03 | 117.7 (11) |
C1—N1—H02 | 118.8 (11) | C3—N2—H04 | 116.3 (11) |
H01—N1—H02 | 121.9 (16) | H03—N2—H04 | 126.0 (15) |
O1—C1—N1 | 121.81 (15) | O2—C3—N2 | 122.17 (15) |
O1—C1—C2 | 120.98 (14) | O2—C3—C4 | 120.62 (14) |
N1—C1—C2 | 117.20 (14) | N2—C3—C4 | 117.21 (14) |
C1—C2—H2A | 109.5 | C3—C4—H4A | 109.5 |
C1—C2—H2B | 109.5 | C3—C4—H4B | 109.5 |
H2A—C2—H2B | 109.5 | H4A—C4—H4B | 109.5 |
C1—C2—H2C | 109.5 | C3—C4—H4C | 109.5 |
H2A—C2—H2C | 109.5 | H4A—C4—H4C | 109.5 |
H2B—C2—H2C | 109.5 | H4B—C4—H4C | 109.5 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H01···O2 | 0.90 (2) | 2.03 (2) | 2.925 (2) | 177.6 (15) |
N1—H02···O1i | 0.87 (2) | 2.01 (2) | 2.868 (2) | 168.1 (15) |
N2—H03···O1 | 0.95 (2) | 2.05 (2) | 2.991 (2) | 171.6 (14) |
N2—H04···O2ii | 0.86 (2) | 2.09 (2) | 2.949 (2) | 172.7 (14) |
C2—H2A···O1iii | 0.98 | 2.49 | 3.471 (2) | 178 |
C4—H4B···O2ii | 0.98 | 2.62 | 3.451 (2) | 143 |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+3/2, y, z−1/2; (iii) −x+1, y+1/2, −z+1/2. |