1-(2,4-Difluoro­phen­yl)-2-(1H-imidazol-1-yl)ethanone

In the mol­ecule of the title compound, C₁₁H₈F₂N₂O, the dihedral angle between the planar rings is 89.53 (4)°. Inter­molecular C—H...O hydrogen bonds link the mol­ecules and may be effective in the stabilization of the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.039
• wR factor = 0.107
• Data-to-parameter ratio = 7.8

checkCIF/PLATON results

No syntax errors found



Alert level C
STRVA01_ALERT_2_C           Chirality of atom sites is inverted?
           From the CIF: _refine_ls_abs_structure_Flack   10.000
           From the CIF: _refine_ls_abs_structure_Flack_su   10.000
PLAT032_ALERT_4_C Std. Uncertainty in Flack Parameter too High ...      10.00
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero .......      10.00
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.80

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.96
           From the CIF: _reflns_number_total               1139
           Count of symmetry unique reflns         1138
           Completeness (_total/calc)            100.09%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         1
           Fraction of Friedel pairs measured     0.001
           Are heavy atom types Z>Si present         no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   1 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
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL.

1-(2',4'-Difluorophenyl)-2-(1H-imidazol-1-yl)ethanone

Crystal data

C11H8F2N2O	Dx = 1.486 Mg m^−3
Mr = 222.19	Melting point = 521–522 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 25 reflections
a = 8.0770 (16) Å	θ = 10–13°
b = 10.045 (2) Å	µ = 0.12 mm^−1
c = 12.238 (2) Å	T = 294 K
V = 992.9 (3) Å^3	Needle, yellow
Z = 4	0.40 × 0.20 × 0.20 mm
F(000) = 456

Data collection

Enraf–Nonius CAD-4 diffractometer	833 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.032
Graphite monochromator	θmax = 26.0°, θmin = 2.6°
ω/2θ scans	h = −9→0
Absorption correction: ψ scan (North et al., 1968)	k = −12→12
Tmin = 0.952, Tmax = 0.976	l = −15→0
2161 measured reflections	3 standard reflections every 120 min
1139 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.039	w = 1/[σ^2(Fo^2) + (0.0575P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.107	(Δ/σ)max < 0.001
S = 1.02	Δρmax = 0.11 e Å^−3
1139 reflections	Δρmin = −0.12 e Å^−3
146 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.030 (6)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983) with 798 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 10 (10)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
F1	0.1078 (3)	0.7475 (2)	1.06630 (16)	0.0857 (7)
F2	0.4088 (3)	0.3530 (2)	1.04860 (15)	0.0756 (7)
O	0.1547 (3)	0.2453 (2)	0.76858 (16)	0.0640 (6)
N1	0.3421 (3)	0.0378 (3)	0.8333 (2)	0.0550 (7)
N2	0.3896 (5)	−0.1026 (3)	0.6977 (3)	0.0822 (10)
C1	0.2461 (4)	−0.0713 (3)	0.8515 (3)	0.0638 (9)
H1A	0.1738	−0.0848	0.9096	0.077*
C2	0.2770 (5)	−0.1559 (3)	0.7683 (3)	0.0711 (10)
H2B	0.2282	−0.2392	0.7602	0.085*
C3	0.4245 (5)	0.0143 (4)	0.7401 (3)	0.0710 (10)
H3A	0.4984	0.0742	0.7088	0.085*
C4	0.3440 (4)	0.1593 (3)	0.8972 (3)	0.0571 (8)
H4A	0.4558	0.1947	0.8985	0.068*
H4B	0.3126	0.1388	0.9719	0.068*
C5	0.2289 (4)	0.2637 (3)	0.8530 (2)	0.0456 (7)
C6	0.2036 (4)	0.3910 (3)	0.9136 (2)	0.0450 (7)
C7	0.0810 (4)	0.4782 (3)	0.8757 (2)	0.0514 (8)
H7A	0.0204	0.4546	0.8140	0.062*
C8	0.0472 (4)	0.5970 (3)	0.9261 (2)	0.0593 (9)
H8A	−0.0352	0.6532	0.8999	0.071*
C9	0.1385 (5)	0.6301 (3)	1.0162 (3)	0.0599 (9)
C10	0.2596 (5)	0.5502 (3)	1.0580 (3)	0.0605 (9)
H10A	0.3197	0.5750	1.1195	0.073*
C11	0.2891 (4)	0.4317 (3)	1.0056 (3)	0.0533 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.1085 (18)	0.0658 (12)	0.0826 (12)	0.0024 (14)	0.0028 (13)	−0.0157 (11)
F2	0.0723 (13)	0.0869 (14)	0.0675 (12)	0.0145 (13)	−0.0327 (11)	−0.0063 (11)
O	0.0700 (15)	0.0745 (14)	0.0474 (11)	0.0131 (14)	−0.0146 (11)	−0.0049 (12)
N1	0.0513 (16)	0.0515 (14)	0.0620 (17)	0.0035 (13)	−0.0038 (15)	0.0079 (13)
N2	0.086 (2)	0.0672 (19)	0.093 (2)	0.0119 (19)	0.018 (2)	−0.0051 (18)
C1	0.0535 (19)	0.0562 (19)	0.082 (2)	−0.0034 (18)	0.002 (2)	0.0129 (19)
C2	0.064 (2)	0.0518 (19)	0.097 (3)	0.003 (2)	0.003 (2)	0.000 (2)
C3	0.066 (2)	0.065 (2)	0.081 (2)	−0.0006 (19)	0.016 (2)	0.007 (2)
C4	0.0526 (19)	0.0571 (19)	0.0616 (19)	−0.0001 (16)	−0.0070 (17)	0.0056 (17)
C5	0.0403 (15)	0.0565 (17)	0.0400 (14)	−0.0026 (15)	0.0018 (13)	0.0072 (14)
C6	0.0421 (16)	0.0545 (17)	0.0385 (14)	−0.0031 (14)	0.0016 (13)	0.0060 (13)
C7	0.0471 (17)	0.0632 (18)	0.0440 (15)	0.0008 (16)	−0.0051 (16)	0.0062 (15)
C8	0.064 (2)	0.0568 (19)	0.0570 (19)	0.0064 (17)	0.0015 (17)	0.0074 (17)
C9	0.073 (2)	0.053 (2)	0.0537 (19)	−0.0030 (18)	0.0101 (18)	−0.0021 (16)
C10	0.063 (2)	0.069 (2)	0.0498 (17)	−0.010 (2)	−0.0031 (18)	−0.0031 (16)
C11	0.0482 (17)	0.0631 (19)	0.0487 (16)	−0.0028 (16)	−0.0052 (15)	0.0077 (16)

Geometric parameters (Å, º)

F1—C9	1.352 (4)	C4—H4A	0.9700
F2—C11	1.355 (4)	C4—H4B	0.9700
O—C5	1.209 (3)	C5—C6	1.492 (4)
N1—C3	1.341 (4)	C6—C11	1.382 (4)
N1—C1	1.362 (4)	C6—C7	1.401 (4)
N1—C4	1.450 (4)	C7—C8	1.371 (4)
N2—C3	1.314 (4)	C7—H7A	0.9300
N2—C2	1.364 (5)	C8—C9	1.367 (5)
C1—C2	1.350 (5)	C8—H8A	0.9300
C1—H1A	0.9300	C9—C10	1.365 (5)
C2—H2B	0.9300	C10—C11	1.372 (4)
C3—H3A	0.9300	C10—H10A	0.9300
C4—C5	1.502 (4)
C3—N1—C1	106.3 (3)	O—C5—C4	120.5 (3)
C3—N1—C4	127.1 (3)	C6—C5—C4	120.2 (2)
C1—N1—C4	126.5 (3)	C11—C6—C7	116.0 (3)
C3—N2—C2	104.1 (3)	C11—C6—C5	126.2 (3)
C2—C1—N1	106.1 (3)	C7—C6—C5	117.9 (3)
C2—C1—H1A	126.9	C8—C7—C6	122.4 (3)
N1—C1—H1A	126.9	C8—C7—H7A	118.8
C1—C2—N2	110.7 (3)	C6—C7—H7A	118.8
C1—C2—H2B	124.6	C9—C8—C7	117.9 (3)
N2—C2—H2B	124.6	C9—C8—H8A	121.1
N2—C3—N1	112.8 (4)	C7—C8—H8A	121.1
N2—C3—H3A	123.6	F1—C9—C10	118.3 (3)
N1—C3—H3A	123.6	F1—C9—C8	118.6 (3)
N1—C4—C5	112.7 (3)	C10—C9—C8	123.0 (3)
N1—C4—H4A	109.0	C9—C10—C11	117.4 (3)
C5—C4—H4A	109.0	C9—C10—H10A	121.3
N1—C4—H4B	109.0	C11—C10—H10A	121.3
C5—C4—H4B	109.0	F2—C11—C10	116.6 (3)
H4A—C4—H4B	107.8	F2—C11—C6	120.0 (3)
O—C5—C6	119.2 (3)	C10—C11—C6	123.4 (3)
C3—N1—C1—C2	0.5 (4)	C4—C5—C6—C7	−172.7 (3)
C4—N1—C1—C2	175.9 (3)	C11—C6—C7—C8	0.1 (4)
N1—C1—C2—N2	−0.3 (4)	C5—C6—C7—C8	179.4 (3)
C3—N2—C2—C1	−0.1 (4)	C6—C7—C8—C9	0.4 (5)
C2—N2—C3—N1	0.4 (4)	C7—C8—C9—F1	179.4 (3)
C1—N1—C3—N2	−0.6 (4)	C7—C8—C9—C10	−0.6 (5)
C4—N1—C3—N2	−176.0 (3)	F1—C9—C10—C11	−179.8 (3)
C3—N1—C4—C5	81.5 (4)	C8—C9—C10—C11	0.2 (5)
C1—N1—C4—C5	−93.0 (4)	C9—C10—C11—F2	−179.5 (3)
N1—C4—C5—O	−4.6 (4)	C9—C10—C11—C6	0.4 (5)
N1—C4—C5—C6	174.8 (2)	C7—C6—C11—F2	179.4 (3)
O—C5—C6—C11	−174.1 (3)	C5—C6—C11—F2	0.1 (4)
C4—C5—C6—C11	6.5 (4)	C7—C6—C11—C10	−0.5 (4)
O—C5—C6—C7	6.6 (4)	C5—C6—C11—C10	−179.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8A···O^i	0.93	2.46	3.249 (4)	143
C10—H10A···O^ii	0.93	2.57	3.368 (4)	143

Symmetry codes: (i) −x, y+1/2, −z+3/2; (ii) −x+1/2, −y+1, z+1/2.