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Volume 69 
Part 3 
Page o376  
March 2013  

Received 29 October 2012
Accepted 31 January 2013
Online 13 February 2013

Key indicators
Single-crystal X-ray study
T = 293 K
Mean [sigma](C-C) = 0.002 Å
R = 0.043
wR = 0.140
Data-to-parameter ratio = 14.8
Details
Open access

6,7-Difluoro-1,2,3,4-tetrahydroquinoxaline-5,8-dicarbonitrile

aKey Laboratory of Fine Petrochemical Technology, Changzhou University, Changzhou 213164, People's Republic of China, and bTianjin Entry-Exit Inspection and Quarantine Bureau, Tianjin 300457, People's Republic of China
Correspondence e-mail: hemingyangjpu@yahoo.com

In the title compound, C10H6F2N4, the Car-N bonds are slightly shortened with respect to a standard aniline C-N bond [1.3580 (16) and 1.3618 (16) versus 1.39 Å], thus indicating some [pi]-[pi] conjgation with the electron-acceptor CN groups. The molecule, except for two C atom of the ethylene bridge, is nearly planar, the largest deviation of the other non-H atoms from the mean plane being 0.309 (2) Å. The N-C-C-N torsion angle involving the ethylene bridge is 50.23 (18)°. In the crystal, molecules are connected by pairs of N-H...N hydrogen bonds into chains along [21-1].

Related literature

For general background to the synthesis and use of tetrafluoroterephthalonitrile and its derivatives, see: Meazza et al. (2007[Meazza, G., Bettarini, F. & Fornara, L. (2007). WO Patent No. 2007101587.]). For reference structural data on tetrafluoroterephthalic acid, see: Orthaber et al. (2010[Orthaber, A., Seidel, C., Belaj, F., Albering, J. H., Pietschnig, R. & Ruschewitz, U. (2010). Inorg. Chem. 49, 9350-9357.]). For standard bond lengths, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]). For hydrogen bonding graph-set descriptors, see: Etter (1990[Etter, M. C. (1990). Acc. Chem. Res. 23, 120-126.]).

[Scheme 1]

Experimental

Crystal data
  • C10H6F2N4

  • Mr = 220.19

  • Triclinic, [P \overline 1]

  • a = 5.2173 (9) Å

  • b = 8.7011 (15) Å

  • c = 11.1453 (19) Å

  • [alpha] = 75.545 (2)°

  • [beta] = 81.854 (2)°

  • [gamma] = 76.427 (2)°

  • V = 474.40 (14) Å3

  • Z = 2

  • Mo K[alpha] radiation

  • [mu] = 0.13 mm-1

  • T = 293 K

  • 0.28 × 0.24 × 0.16 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany.]) Tmin = 0.964, Tmax = 0.980

  • 4155 measured reflections

  • 2141 independent reflections

  • 1816 reflections with I > 2[sigma](I)

  • Rint = 0.026

Refinement
  • R[F2 > 2[sigma](F2)] = 0.043

  • wR(F2) = 0.140

  • S = 1.06

  • 2141 reflections

  • 145 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.29 e Å-3

  • [Delta][rho]min = -0.23 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
N3-H3...N1i 0.86 2.29 3.075 (2) 152
N4-H4...N2ii 0.86 2.21 3.0358 (19) 160
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x-1, -y, -z+2.

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). APEX2 and SAINT. 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 and DIAMOND (Brandenburg, 2005[Brandenburg, K. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXTL.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: YK2078 ).


References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.
Brandenburg, K. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Etter, M. C. (1990). Acc. Chem. Res. 23, 120-126.  [CrossRef] [ChemPort] [ISI]
Meazza, G., Bettarini, F. & Fornara, L. (2007). WO Patent No. 2007101587.
Orthaber, A., Seidel, C., Belaj, F., Albering, J. H., Pietschnig, R. & Ruschewitz, U. (2010). Inorg. Chem. 49, 9350-9357.  [ISI] [CSD] [CrossRef] [ChemPort] [PubMed]
Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]


Acta Cryst (2013). E69, o376  [ doi:10.1107/S1600536813003206 ]

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