3,5-Di­fluoro­benzo­nitrile

The title compound, C₇H₃F₂N, packs with slightly puckered molecular sheets [mol­ecules tilted by 8.1 (1)° with respect to the sheets]. Two of the H atoms in the mol­ecule are in contact with N atoms in adjacent mol­ecules, while the remaining H atom is in contact with two F atoms in adjacent molecules.

Key indicators

• Single-crystal X-ray study
• T = 172 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.041
• wR factor = 0.120
• Data-to-parameter ratio = 13.3

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_371  Alert C Long   C(sp2)-C(sp1) Bond  C(1)   -   C(7)   =       1.45 Ang.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: TEXSAN (Molecular Structure Corporation, 1985); program(s) used to solve structure: MITHRIL (Gilmore, 1984) and DIRDIF (Buerskens, 1984); program(s) used to refine structure: SHELXTL (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

3,5-Difluorobenzonitrile

Crystal data

C7H3F2N	Dx = 1.506 Mg m^−3
Mr = 139.10	Melting point = 357–359 K
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
a = 3.730 (4) Å	Cell parameters from 24 reflections
b = 7.486 (4) Å	θ = 22–27°
c = 11.019 (5) Å	µ = 0.13 mm^−1
β = 94.34 (7)°	T = 172 K
V = 306.8 (4) Å^3	Prism, colorless
Z = 2	0.50 × 0.35 × 0.30 mm
F(000) = 140

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.056
Radiation source: fine-focus sealed tube	θmax = 27.9°, θmin = 1.9°
Graphite monochromator	h = −4→4
ω–2θ scans	k = −9→9
2908 measured reflections	l = −14→14
784 independent reflections	3 standard reflections every 70 min min
654 reflections with I > 2σ(I)	intensity decay: 1%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.120	All H-atom parameters refined
S = 1.06	w = 1/[σ^2(Fo^2) + (0.066P)^2 + 0.057P] where P = (Fo^2 + 2Fc^2)/3
784 reflections	(Δ/σ)max = 0.001
59 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.19 e Å^−3

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

	x	y	z	Uiso*/Ueq
F3	0.2916 (3)	0.56191 (11)	0.11214 (8)	0.0441 (3)
N1	0.9543 (5)	0.2500	0.55650 (14)	0.0388 (4)
C1	0.6306 (4)	0.2500	0.34033 (14)	0.0239 (4)
C2	0.5478 (3)	0.41278 (15)	0.28415 (11)	0.0270 (3)
H2	0.601 (4)	0.527 (2)	0.3219 (14)	0.034 (4)*
C3	0.3767 (3)	0.40645 (15)	0.16851 (11)	0.0275 (3)
C4	0.2893 (4)	0.2500	0.10805 (15)	0.0272 (4)
H4	0.180 (7)	0.2500	0.031 (2)	0.042 (6)*
C7	0.8123 (5)	0.2500	0.46135 (15)	0.0292 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F3	0.0590 (7)	0.0279 (5)	0.0434 (5)	0.0066 (4)	−0.0080 (4)	0.0089 (3)
N1	0.0366 (9)	0.0485 (10)	0.0302 (8)	0.000	−0.0043 (6)	0.000
C1	0.0175 (7)	0.0313 (8)	0.0228 (7)	0.000	0.0014 (5)	0.000
C2	0.0260 (7)	0.0259 (6)	0.0290 (6)	−0.0010 (4)	0.0018 (4)	−0.0035 (4)
C3	0.0267 (6)	0.0260 (6)	0.0297 (6)	0.0028 (5)	0.0015 (4)	0.0038 (4)
C4	0.0241 (9)	0.0328 (9)	0.0242 (8)	0.000	−0.0012 (6)	0.000
C7	0.0241 (8)	0.0355 (9)	0.0282 (8)	0.000	0.0021 (6)	0.000

Geometric parameters (Å, º)

F3—C3	1.3458 (14)	C2—C3	1.3820 (19)
N1—C7	1.138 (2)	C2—H2	0.967 (18)
C1—C2^i	1.3910 (15)	C3—C4	1.3744 (15)
C1—C2	1.3910 (15)	C4—C3^i	1.3744 (15)
C1—C7	1.449 (2)	C4—H4	0.92 (2)
C2^i—C1—C2	122.35 (15)	F3—C3—C2	118.17 (11)
C2^i—C1—C7	118.83 (8)	C4—C3—C2	123.52 (11)
C2—C1—C7	118.83 (8)	C3—C4—C3^i	116.89 (15)
C3—C2—C1	116.86 (11)	C3—C4—H4	121.55 (8)
C3—C2—H2	119.5 (10)	C3^i—C4—H4	121.56 (8)
C1—C2—H2	123.6 (10)	N1—C7—C1	179.85 (18)
F3—C3—C4	118.31 (12)

Symmetry code: (i) x, −y+1/2, z.