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Acta Crystallogr Sect E Struct Rep Online. 2009 March 1; 65(Pt 3): o459.
Published online 2009 February 4. doi:  10.1107/S1600536809003730
PMCID: PMC2968459

1,4-Bis(fluoro­meth­yl)benzene

Abstract

The title compound, C8H8F2, lies across a crystallographic inversion centre. The structure features short C(...)F [2.8515 (18) Å] and F(...)F [2.490 (4) Å] contacts, which are significantly shorter than the sum of the van der Waals radii of these atoms. The F atom and methyl­ene H atoms are disordered over two positions with a site-occupancy ratio of 0.633 (3):0.367 (3). In the crystal structure, inter­molecular C—H(...)F inter­actions link neighboring mol­ecules into infinite chains along the b axis. In addition, C—H(...)π inter­actions link these mol­ecules along [10An external file that holds a picture, illustration, etc.
Object name is e-65-0o459-efi1.jpg], forming a two-dimensional network parallel to (101).

Related literature

For the structures of compounds with non-linear properties, see, for example: Chantrapromma et al. (2006 [triangle]); Fun et al. (2008 [triangle]); Patil et al. (2007 [triangle]).

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Object name is e-65-0o459-scheme1.jpg

Experimental

Crystal data

  • C8H8F2
  • M r = 143.15
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-0o459-efi2.jpg
  • a = 6.1886 (2) Å
  • b = 5.0152 (2) Å
  • c = 10.4750 (4) Å
  • β = 95.107 (2)°
  • V = 323.82 (2) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.12 mm−1
  • T = 100.0 (1) K
  • 0.55 × 0.24 × 0.14 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.935, T max = 0.982
  • 11592 measured reflections
  • 1591 independent reflections
  • 1343 reflections with I > 2σ(I)
  • R int = 0.029

Refinement

  • R[F 2 > 2σ(F 2)] = 0.074
  • wR(F 2) = 0.251
  • S = 1.18
  • 1591 reflections
  • 64 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.67 e Å−3
  • Δρmin = −0.59 e Å−3

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809003730/bq2122sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809003730/bq2122Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship. HKF also thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

As part of an ongoing investigation into compounds with non-linear optical properties (Chantrapromma et al., 2006; Fun et al., 2008; Patil et al., 2007), the crystal structure of the title compound is presented here.

The title compound, (I), lies across a crystallographic inversion centre (Fig. 1). The interesting features of the crystal structure are the short C4A···F1Ai [2.8515 (18)Å; (i) 3/2-x, 1/2+y, 3/2-z] and F1B···F1Bii [2.490 (4)Å; (ii) 1-x, 1-y, 1-z] contacts which are significantly shorter than the sum of the van der Waals radii of these atoms. The fluorine atom and methylene hydrogens are disordered over two positions with a site-occupancy ratio of 0.633 (3):0.367 (3). In the crystal structure, intermolecular C—H···F interactions link neighboring molecules into one-dimensional infinite chains along the b axis (Table 1 and Fig. 2). In addition, C—H···π interactions [C4—H4B···Cg1iii; (iii) x, 1+y, z and C4—H4C···Cg1iii; Cg1 is the centroid of the C1–C3/C1A–C3A benzene ring] link these molecules along the [101] direction, thus forming a two-dimensional network which is parallel to the (101) plane.

Experimental

Commercially available 1,4-bis(difluoromethyl) benzene was further purified by repeated recrystallization from acetone. Single crystals suitable for X-ray analysis were grown by slow evaporation of an acetone solution at room temperature.

Refinement

The hydrogen atoms bound to C1 and C3 were located from the difference Fourier map and refined freely. Hydrogen atoms of the methylene groups were positioned geometrically and constrained to refine with a riding model approximation with C—H = 0.96–0.97 Å and Uiso(H) = 1.2 Ueq(C).

Figures

Fig. 1.
The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atomic numbering. Open bonds indicate the minor disordered component.
Fig. 2.
The crystal packing of the major component of (I), viewed down the a-axis, showing a one-dimensional infinite chain of molecules along the b-axis. Intramolecular and intermolecular interactions are drawn as dashed lines.

Crystal data

C8H8F2F(000) = 148
Mr = 143.15Dx = 1.458 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3653 reflections
a = 6.1886 (2) Åθ = 2.5–34.7°
b = 5.0152 (2) ŵ = 0.12 mm1
c = 10.4750 (4) ÅT = 100 K
β = 95.107 (2)°Needle, colourless
V = 323.82 (2) Å30.55 × 0.24 × 0.14 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer1591 independent reflections
Radiation source: fine-focus sealed tube1343 reflections with I > 2σ(I)
graphiteRint = 0.029
[var phi] and ω scansθmax = 36.6°, θmin = 3.7°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −10→10
Tmin = 0.935, Tmax = 0.982k = −7→8
11592 measured reflectionsl = −17→17

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.074Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.251H atoms treated by a mixture of independent and constrained refinement
S = 1.18w = 1/[σ2(Fo2) + (0.1441P)2 + 0.1329P] where P = (Fo2 + 2Fc2)/3
1591 reflections(Δ/σ)max < 0.001
64 parametersΔρmax = 0.67 e Å3
0 restraintsΔρmin = −0.59 e Å3

Special details

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.
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)

xyzUiso*/UeqOcc. (<1)
F1A0.9163 (2)0.5267 (3)0.72717 (12)0.0219 (3)0.633 (3)
F1B0.6221 (4)0.4849 (5)0.6008 (3)0.0260 (6)0.367 (3)
C40.8122 (2)0.4155 (2)0.63866 (12)0.0204 (3)
H4C0.76400.55050.57760.025*0.633 (3)
H4D0.68470.34370.67180.025*0.633 (3)
H4A0.81290.36000.72740.025*0.367 (3)
H4B0.90520.57090.63690.025*0.367 (3)
C10.7876 (2)0.0844 (3)0.46363 (13)0.0222 (3)
C20.9095 (2)0.1998 (2)0.56704 (11)0.0194 (3)
C31.1209 (2)0.1184 (3)0.60446 (12)0.0217 (3)
H10.620 (4)0.159 (6)0.431 (2)0.037 (6)*
H31.207 (4)0.205 (5)0.682 (2)0.026 (5)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
F1A0.0227 (6)0.0216 (6)0.0215 (6)0.0012 (4)0.0030 (4)−0.0057 (4)
F1B0.0216 (10)0.0244 (11)0.0324 (12)0.0115 (8)0.0045 (8)−0.0018 (8)
C40.0224 (5)0.0170 (5)0.0227 (5)0.0024 (4)0.0064 (4)0.0013 (4)
C10.0204 (5)0.0220 (5)0.0243 (5)0.0030 (4)0.0023 (4)0.0001 (4)
C20.0208 (5)0.0176 (5)0.0204 (5)0.0020 (3)0.0048 (4)0.0013 (4)
C30.0207 (5)0.0217 (6)0.0226 (5)0.0016 (4)0.0007 (4)−0.0006 (4)

Geometric parameters (Å, °)

F1A—C41.2162 (18)C4—H4A0.9699
F1A—H4A1.0529C4—H4B0.9700
F1A—H4B0.9681C1—C21.3900 (18)
F1B—C41.257 (3)C1—C3i1.3916 (19)
F1B—H4C0.9881C1—H11.13 (3)
F1B—H4D1.0739C2—C31.3927 (18)
C4—C21.4754 (17)C3—C1i1.3916 (19)
C4—H4C0.9600C3—H31.02 (2)
C4—H4D0.9600
C4—F1A—H4A50.0C2—C4—H4A108.0
C4—F1A—H4B51.2H4C—C4—H4A144.6
H4A—F1A—H4B101.2H4D—C4—H4A58.7
C4—F1B—H4C48.9F1A—C4—H4B51.1
C4—F1B—H4D47.9F1B—C4—H4B108.2
H4C—F1B—H4D96.7C2—C4—H4B108.0
F1A—C4—F1B122.09 (16)H4C—C4—H4B64.6
F1A—C4—C2120.74 (12)H4D—C4—H4B144.8
F1B—C4—C2117.11 (16)H4A—C4—H4B107.3
F1A—C4—H4C107.2C2—C1—C3i119.09 (12)
F1B—C4—H4C50.8C2—C1—H1121.3 (14)
C2—C4—H4C107.2C3i—C1—H1119.6 (14)
F1A—C4—H4D107.0C1—C2—C3121.91 (12)
F1B—C4—H4D56.0C1—C2—C4118.92 (11)
C2—C4—H4D107.1C3—C2—C4119.17 (12)
H4C—C4—H4D106.8C1i—C3—C2119.00 (12)
F1A—C4—H4A56.2C1i—C3—H3120.6 (14)
F1B—C4—H4A107.9C2—C3—H3120.4 (14)
C3i—C1—C2—C30.1 (2)F1A—C4—C2—C31.96 (19)
C3i—C1—C2—C4179.75 (11)F1B—C4—C2—C3179.18 (17)
F1A—C4—C2—C1−177.73 (13)C1—C2—C3—C1i−0.1 (2)
F1B—C4—C2—C1−0.5 (2)C4—C2—C3—C1i−179.75 (11)

Symmetry codes: (i) −x+2, −y, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C4—H4D···F1Aii0.962.042.8515 (18)141
C4—H4B···Cg1iii0.972.843.5148 (12)128
C4—H4C···Cg1iii0.962.643.5148 (12)144

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BQ2122).

References

  • Bruker (2005). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Chantrapromma, S., Ruanwas, P., Jindawong, B., Razak, I. A. & Fun, H.-K. (2006). Acta Cryst. E62, o875–o877.
  • Fun, H.-K., Jebas, S. R., Razak, I. A., Deepak D’Silva, E., Patil, P. S. & Dharmaprakash, S. M. (2008). Acta Cryst. E64, o1195–o1196. [PMC free article] [PubMed]
  • Patil, P. S., Fun, H.-K., Chantrapromma, S. & Dharmaprakash, S. M. (2007). Acta Cryst. E63, o2497–o2498.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2003). J. Appl. Cryst.36, 7–13.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography