N-(2,3,5,6-Tetrafluoropyridin-4-yl)formamide

The title compound, C₆H₂F₄N₂O, displays amide bond lengths of 1.218 (3) Å and 1.366 (3) Å for the C=O and C—N bonds, respectively. The C_p—N—C—O (p = pyridine) torsion angle of 179.0 (2)° indicates an anti-conformation for the grouping. Inter­molecular hydrogen bonding is observed between the amine N—H group and the carbonyl O atom, which generates chains of mol­ecules propagating along the b-axis direction.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.028
• wR factor = 0.066
• Data-to-parameter ratio = 10.7

checkCIF/PLATON results

No syntax errors found



Alert level C
STRVA01_ALERT_4_C           Flack test results are meaningless.
           From the CIF: _refine_ls_abs_structure_Flack   -0.100
           From the CIF: _refine_ls_abs_structure_Flack_su    0.600

Author Response: While the s.u. value on the Flack parameter of -0.1(6) shows a high uncertainty from the use of Mo radiation, the absolute structure is likely correct, and is not used to establish the absolute configuration of any chiral center.

PLAT048_ALERT_1_C MoietyFormula Not Given (or Incomplete) ........     Please Check
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax < 18) ........       6.60 Note

Author Response: When using the full set of 1309 reflections (as opposed to the merged value of 806 reflections used by CheckCIF), the data to parameter ratio is 10.73.

Alert level G
PLAT032_ALERT_4_G Std. Uncertainty on Flack Parameter Value High .      0.600 Report
PLAT432_ALERT_2_G Short Inter X...Y Contact  N1       ..C5       .       3.03 Ang.
                                            1/2+x,1/2-y,1-z  =      4_556 Check
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Theta(Min).          1 Note
PLAT916_ALERT_2_G Hooft y and Flack x Parameter Values Differ by .       0.17 Check
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          3 Info

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 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: APEX3 (Bruker, 2018); cell refinement: SAINT (Bruker, 2018); data reduction: SAINT (Bruker, 2018); program(s) used to solve structure: SHELXT2014/5 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016/6 (Sheldrick, 2015b); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

N-(2,3,5,6-Tetrafluoropyridin-4-yl)formamide

Crystal data

C6H2F4N2O	Dx = 1.947 Mg m^−3
Mr = 194.10	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 2461 reflections
a = 5.1183 (4) Å	θ = 3.4–26.0°
b = 6.2707 (6) Å	µ = 0.21 mm^−1
c = 20.6294 (16) Å	T = 100 K
V = 662.11 (10) Å^3	Column, colourless
Z = 4	0.28 × 0.06 × 0.05 mm
F(000) = 384

Data collection

Bruker D8 Venture Photon 2 diffractometer	1200 reflections with I > 2σ(I)
Radiation source: Incoatec IµS	Rint = 0.029
φ and ω scans	θmax = 26.0°, θmin = 3.4°
Absorption correction: multi-scan (SADABS; Bruker, 2018)	h = −6→6
Tmin = 0.897, Tmax = 1.000	k = −7→7
3556 measured reflections	l = −25→25
1309 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.028	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.066	w = 1/[σ^2(Fo^2) + (0.0317P)^2 + 0.041P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
1309 reflections	Δρmax = 0.14 e Å^−3
122 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Absolute structure: Flack x determined using 424 quotients [(I^+)-(I^-)]/[(I^+)+(I^-)] (Parsons et al., 2013)
Primary atom site location: dual	Absolute structure parameter: −0.1 (6)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.9516 (3)	−0.1033 (2)	0.60146 (7)	0.0280 (4)
F2	0.5417 (3)	−0.0546 (2)	0.68314 (6)	0.0218 (4)
F3	0.3999 (3)	0.6218 (2)	0.58674 (7)	0.0246 (4)
F4	0.8168 (3)	0.5429 (2)	0.51143 (7)	0.0246 (4)
O1	−0.0674 (4)	0.4673 (3)	0.73924 (8)	0.0239 (4)
N1	0.8836 (4)	0.2207 (3)	0.55635 (10)	0.0194 (5)
N2	0.2513 (4)	0.3050 (3)	0.68341 (10)	0.0176 (5)
H2	0.208 (6)	0.193 (5)	0.7052 (15)	0.030 (8)*
C1	0.8095 (5)	0.0761 (4)	0.59878 (12)	0.0186 (6)
C2	0.6040 (5)	0.0998 (4)	0.64033 (11)	0.0172 (5)
C3	0.4581 (5)	0.2879 (4)	0.64007 (11)	0.0153 (5)
C4	0.5327 (5)	0.4385 (4)	0.59394 (11)	0.0168 (5)
C5	0.7440 (5)	0.3963 (4)	0.55472 (11)	0.0188 (6)
C6	0.1120 (5)	0.4818 (4)	0.70070 (12)	0.0195 (6)
H6	0.155131	0.616615	0.682599	0.023*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0275 (9)	0.0267 (8)	0.0299 (8)	0.0124 (7)	0.0063 (8)	0.0033 (6)
F2	0.0255 (8)	0.0183 (7)	0.0215 (7)	0.0018 (7)	0.0038 (7)	0.0059 (6)
F3	0.0292 (9)	0.0193 (7)	0.0253 (8)	0.0059 (7)	0.0041 (8)	0.0053 (6)
F4	0.0272 (8)	0.0280 (8)	0.0187 (7)	−0.0051 (7)	0.0039 (7)	0.0064 (6)
O1	0.0232 (10)	0.0228 (9)	0.0255 (9)	0.0014 (9)	0.0100 (9)	−0.0038 (7)
N1	0.0152 (11)	0.0287 (11)	0.0143 (10)	−0.0001 (9)	−0.0007 (10)	−0.0007 (8)
N2	0.0183 (11)	0.0174 (10)	0.0170 (10)	−0.0002 (9)	0.0036 (11)	0.0011 (8)
C1	0.0167 (13)	0.0196 (12)	0.0195 (12)	0.0029 (10)	−0.0009 (12)	−0.0008 (10)
C2	0.0183 (13)	0.0185 (12)	0.0149 (12)	−0.0013 (10)	−0.0003 (12)	0.0013 (9)
C3	0.0146 (11)	0.0197 (11)	0.0117 (11)	−0.0002 (10)	−0.0011 (11)	−0.0029 (8)
C4	0.0182 (13)	0.0176 (11)	0.0146 (11)	0.0010 (11)	−0.0021 (11)	0.0005 (9)
C5	0.0211 (13)	0.0220 (12)	0.0132 (12)	−0.0055 (11)	−0.0026 (12)	0.0026 (10)
C6	0.0198 (14)	0.0183 (12)	0.0205 (12)	0.0005 (11)	0.0016 (13)	−0.0021 (9)

Geometric parameters (Å, º)

F1—C1	1.341 (3)	N2—C3	1.390 (3)
F2—C2	1.348 (3)	N2—H2	0.87 (3)
F3—C4	1.343 (3)	C1—C2	1.365 (3)
F4—C5	1.335 (3)	C2—C3	1.396 (3)
O1—C6	1.218 (3)	C3—C4	1.394 (3)
N1—C5	1.313 (3)	C4—C5	1.376 (4)
N1—C1	1.316 (3)	C6—H6	0.9500
N2—C6	1.366 (3)
C5—N1—C1	116.0 (2)	N2—C3—C2	118.0 (2)
C6—N2—C3	128.9 (2)	C4—C3—C2	115.4 (2)
C6—N2—H2	113 (2)	F3—C4—C5	119.8 (2)
C3—N2—H2	118 (2)	F3—C4—C3	121.1 (2)
N1—C1—F1	116.7 (2)	C5—C4—C3	119.1 (2)
N1—C1—C2	124.4 (2)	N1—C5—F4	116.3 (2)
F1—C1—C2	118.9 (2)	N1—C5—C4	125.0 (2)
F2—C2—C1	121.0 (2)	F4—C5—C4	118.7 (2)
F2—C2—C3	118.9 (2)	O1—C6—N2	120.2 (2)
C1—C2—C3	120.1 (2)	O1—C6—H6	119.9
N2—C3—C4	126.5 (2)	N2—C6—H6	119.9
C5—N1—C1—F1	−179.4 (2)	N2—C3—C4—F3	−1.1 (4)
C5—N1—C1—C2	−0.8 (4)	C2—C3—C4—F3	176.8 (2)
N1—C1—C2—F2	−179.1 (2)	N2—C3—C4—C5	179.8 (2)
F1—C1—C2—F2	−0.6 (3)	C2—C3—C4—C5	−2.3 (3)
N1—C1—C2—C3	−0.7 (4)	C1—N1—C5—F4	−179.5 (2)
F1—C1—C2—C3	177.9 (2)	C1—N1—C5—C4	0.7 (4)
C6—N2—C3—C4	−15.2 (4)	F3—C4—C5—N1	−178.2 (2)
C6—N2—C3—C2	167.0 (2)	C3—C4—C5—N1	0.9 (4)
F2—C2—C3—N2	−1.3 (3)	F3—C4—C5—F4	2.0 (3)
C1—C2—C3—N2	−179.8 (2)	C3—C4—C5—F4	−178.9 (2)
F2—C2—C3—C4	−179.3 (2)	C3—N2—C6—O1	179.0 (2)
C1—C2—C3—C4	2.2 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O1^i	0.87 (3)	1.96 (3)	2.814 (3)	171 (3)

Symmetry code: (i) −x, y−1/2, −z+3/2.