organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

1,4-Bis(fluoro­meth­yl)benzene

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bDepartment of Physics, K. L. E. Society's K. L. E. Institute of Technology, Gokul, Hubli 580 030, India, and cDepartment of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore 574 199, India
*Correspondence e-mail: hkfun@usm.my

(Received 16 January 2009; accepted 30 January 2009; online 4 February 2009)

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 [10[\overline{1}]], 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[Chantrapromma, S., Ruanwas, P., Jindawong, B., Razak, I. A. & Fun, H.-K. (2006). Acta Cryst. E62, o875-o877.]); Fun et al. (2008[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.]); Patil et al. (2007[Patil, P. S., Fun, H.-K., Chantrapromma, S. & Dharmaprakash, S. M. (2007). Acta Cryst. E63, o2497-o2498.]).

[Scheme 1]

Experimental

Crystal data
  • C8H8F2

  • Mr = 143.15

  • Monoclinic, P 21 /n

  • 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[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.935, Tmax = 0.982

  • 11592 measured reflections

  • 1591 independent reflections

  • 1343 reflections with I > 2σ(I)

  • Rint = 0.029

Refinement
  • R[F2 > 2σ(F2)] = 0.074

  • wR(F2) = 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

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C4—H4D⋯F1Ai 0.96 2.04 2.8515 (18) 141
C4—H4BCg1ii 0.97 2.84 3.5148 (12) 128
C4—H4CCg1ii 0.96 2.64 3.5148 (12) 144
Symmetry codes: (i) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) x, y+1, z. Cg1 is the centroid of the C1–C3/C1A–C3A benzene ring.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

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.

Related literature top

For the structures of compounds with non-linear properties, see, for example: Chantrapromma et al. (2006); Fun et al. (2008); Patil et al. (2007). Cg1 is the centroid of the C1–C3/C1A–C3A benzene ring.

Experimental top

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 top

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).

Computing details top

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

Figures top
[Figure 1] 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.
[Figure 2] 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.
1,4-Bis(fluoromethyl)benzene top
Crystal data top
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 top
Bruker APEXII CCD area-detector
diffractometer
1591 independent reflections
Radiation source: fine-focus sealed tube1343 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.029
ϕ and ω scansθmax = 36.6°, θmin = 3.7°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 1010
Tmin = 0.935, Tmax = 0.982k = 78
11592 measured reflectionsl = 1717
Refinement top
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 = 1.18 w = 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
Crystal data top
C8H8F2V = 323.82 (2) Å3
Mr = 143.15Z = 2
Monoclinic, P21/nMo Kα radiation
a = 6.1886 (2) ŵ = 0.12 mm1
b = 5.0152 (2) ÅT = 100 K
c = 10.4750 (4) Å0.55 × 0.24 × 0.14 mm
β = 95.107 (2)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
1591 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
1343 reflections with I > 2σ(I)
Tmin = 0.935, Tmax = 0.982Rint = 0.029
11592 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0740 restraints
wR(F2) = 0.251H atoms treated by a mixture of independent and constrained refinement
S = 1.18Δρmax = 0.67 e Å3
1591 reflectionsΔρmin = 0.59 e Å3
64 parameters
Special details top

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) top
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) top
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, º) top
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—C1177.73 (13)C1—C2—C3—C1i0.1 (2)
F1B—C4—C2—C10.5 (2)C4—C2—C3—C1i179.75 (11)
Symmetry code: (i) x+2, y, z+1.
Hydrogen-bond geometry (Å, º) top
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, y1/2, z+3/2; (iii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC8H8F2
Mr143.15
Crystal system, space groupMonoclinic, P21/n
Temperature (K)100
a, b, c (Å)6.1886 (2), 5.0152 (2), 10.4750 (4)
β (°) 95.107 (2)
V3)323.82 (2)
Z2
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.55 × 0.24 × 0.14
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.935, 0.982
No. of measured, independent and
observed [I > 2σ(I)] reflections
11592, 1591, 1343
Rint0.029
(sin θ/λ)max1)0.839
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.074, 0.251, 1.18
No. of reflections1591
No. of parameters64
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.67, 0.59

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4D···F1Ai0.96002.042.8515 (18)141
C4—H4B···Cg1ii0.97002.843.5148 (12)128
C4—H4C···Cg1ii0.96002.643.5148 (12)144
Symmetry codes: (i) x+3/2, y1/2, z+3/2; (ii) x, y+1, z.
 

Footnotes

Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore 574 199, India.

Acknowledgements

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.

References

First citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChantrapromma, S., Ruanwas, P., Jindawong, B., Razak, I. A. & Fun, H.-K. (2006). Acta Cryst. E62, o875–o877.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFun, H.-K., Jebas, S. R., Razak, I. A., Deepak D'Silva, E., Patil, P. S. & Dharmaprakash, S. M. (2008). Acta Cryst. E64, o1195–o1196.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationPatil, P. S., Fun, H.-K., Chantrapromma, S. & Dharmaprakash, S. M. (2007). Acta Cryst. E63, o2497–o2498.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
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