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

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3,3,4,4-Tetra­fluoro-1-[2-(3,3,4,4-tetra­fluoro­pyrrolidin-1-yl)phen­yl]pyrrolidine

aSchool of Chemistry and Environment, South China Normal University, Guangzhou 510006, People's Republic of China, and bKey Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China
*Correspondence e-mail: zhuosioc@yahoo.com.cn

(Received 6 August 2011; accepted 18 August 2011; online 27 August 2011)

The asymmetric unit of the title compound, C14H12F8N2, contains one tetra­fluoro­pyrrolidine system and one half-mol­ecule of benzene; the latter, together with a second heterocyclic unit, are completed by symmetry, with a twofold crystallographic axis crossing through both the middle of the bond between the C atoms bearing the heterocyclic rings and the opposite C—C bonds of the whole benzene mol­ecule. The pyrrolidine ring shows an envelope conformation with the apex at the N atom. The dihedral angle between the least-squares plane of this ring and the benzene ring is 36.9 (5)°. There are intra­molecular C—H⋯N inter­actions generating S(6) ring motifs. In the crystal structure, the mol­ecules are linked by C—H⋯F inter­actions, forming chains parallel to [010].

Related literature

For background to the properties of fluorinated and alkyl-fluorinated heterocyclic compounds, see: Babudri et al. (2007[Babudri, F., Farinola, G. M., Naso, F. & Ragni, R. (2007). Chem. Commun. pp. 1003-1022.]). For applications of compounds with fluorinated rings, see: Brambilla (2001[Brambilla, E. (2001). Caries Res. 35, 6-9.]); Hagan (2008[Hagan, O. D. (2008). Chem. Soc. Rev. 37, 308-319.]). For the synthesis of related compounds, see: Zeng & Shreeve (2009[Zeng, Z. & Shreeve, J. M. (2009). J. Fluorine Chem. 130, 727-732.]). For a description of hydrogen-bonding motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • C14H12F8N2

  • Mr = 360.26

  • Orthorhombic, P b c n

  • a = 8.678 (3) Å

  • b = 9.818 (3) Å

  • c = 17.088 (5) Å

  • V = 1455.9 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.17 mm−1

  • T = 293 K

  • 0.44 × 0.37 × 0.22 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.928, Tmax = 0.963

  • 6762 measured reflections

  • 1283 independent reflections

  • 878 reflections with I > 2σ(I)

  • Rint = 0.036

Refinement
  • R[F2 > 2σ(F2)] = 0.071

  • wR(F2) = 0.129

  • S = 0.92

  • 1283 reflections

  • 109 parameters

  • H-atom parameters constrained

  • Δρmax = 0.50 e Å−3

  • Δρmin = −0.41 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C1—H1⋯F3i 0.93 2.54 3.398 (4) 154
C7—H7B⋯N1ii 0.97 2.45 3.020 (4) 117
Symmetry codes: (i) x, y-1, z; (ii) [-x, y, -z-{\script{1\over 2}}].

Data collection: SMART (Bruker, 1997[Bruker (1997). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1997[Bruker (1997). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

It is well known that the introduction of a fluorine atom or a fluoroalkyl group into heterocyclic compounds has a profound influence on their chemical, physical and biological properties (Hagan, 2008). Fluorinated ring play an important role in the pharmaceutical and advanced materials fields (Babudri et al., 2007). Many forms of systemic or topical fluoride have been studied and tested for clinical application (Brambilla, 2001). As a part of our studies in this area, we now report the synthesis and structure of the title compound.

An ORTEP view of the title compound, C14H12F8N2, is depicted in Fig. 1. The asymmetric unit contains one tetrafluoropyrrolidin system and a half-molecule of benzene. The whole molecule is generated by rotation around a 2-fold crystallographic axis crossing through, both, the middle of the bond between the carbon atoms bearing the heterocyclic rings (C3 and C3a) and the opposite C1—C1a bond. The pyrrolidine ring shows an envelope conformation with the apex at the N1 atom, the dihedral angle between the least-squares plane of this ring and the benzene moiety is 36.9 (5)°.

Intramolecular C7—H7B···N1 interactions generating S(6) ring motifs are present (Table 1). In the crystal the molecules are linked by C1—H1···F3 interactions (symmetry operation x, y - 1, z) forming chains parallel to [010] direction (Table 1 and Fig. 2).

Related literature top

For background on the properties of fluorinated and alkyl-fluorinated heterocyclic compounds, see: Babudri et al. (2007). For applications of compounds with fluorinated rings, see: Brambilla (2001); Hagan (2008). For the synthesis of related compounds, see: Zeng & Shreeve (2009). For the description of hydrogen-bonding motifs, see: Bernstein et al. (1995).

Experimental top

The compound was prepared using a slightly variation of our previously reported procedure (Zeng & Shreeve, 2009). Single crystals of the title compound were obtained by slow evaporation from dichloromethane at room temperature.

Refinement top

H atoms were placed in calculated positions C—H = 0.93 or 0.97 Å and refined as riding with Uiso(H) = 1.2 Uiso(C). The 200 reflection with Δ F2/ e.s.d. = 14.8 has been omitted from the refinement.

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SMART (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. An ORTEP view of the title compound. Ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Perspective view of the crystal packing.
3,3,4,4-Tetrafluoro-1-[2-(3,3,4,4-tetrafluoropyrrolidin-1-yl)phenyl]pyrrolidine top
Crystal data top
C14H12F8N2F(000) = 728
Mr = 360.26Dx = 1.644 Mg m3
Orthorhombic, PbcnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2abCell parameters from 1256 reflections
a = 8.678 (3) Åθ = 2.4–20.4°
b = 9.818 (3) ŵ = 0.17 mm1
c = 17.088 (5) ÅT = 293 K
V = 1455.9 (8) Å3Block, colourless
Z = 40.44 × 0.37 × 0.22 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
1283 independent reflections
Radiation source: fine-focus sealed tube878 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.036
ϕ and ω scansθmax = 25.0°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 810
Tmin = 0.928, Tmax = 0.963k = 1011
6762 measured reflectionsl = 2016
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)] = 0.071Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.129H-atom parameters constrained
S = 0.92 w = 1/[σ2(Fo2) + (0.005P)2 + 3.940P]
where P = (Fo2 + 2Fc2)/3
1283 reflections(Δ/σ)max = 0.022
109 parametersΔρmax = 0.50 e Å3
0 restraintsΔρmin = 0.41 e Å3
Crystal data top
C14H12F8N2V = 1455.9 (8) Å3
Mr = 360.26Z = 4
Orthorhombic, PbcnMo Kα radiation
a = 8.678 (3) ŵ = 0.17 mm1
b = 9.818 (3) ÅT = 293 K
c = 17.088 (5) Å0.44 × 0.37 × 0.22 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
1283 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
878 reflections with I > 2σ(I)
Tmin = 0.928, Tmax = 0.963Rint = 0.036
6762 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0710 restraints
wR(F2) = 0.129H-atom parameters constrained
S = 0.92Δρmax = 0.50 e Å3
1283 reflectionsΔρmin = 0.41 e Å3
109 parameters
Special details top

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*/Ueq
F10.1645 (4)0.1228 (3)0.4379 (2)0.1363 (14)
F20.0115 (4)0.1911 (3)0.51367 (13)0.1146 (11)
F30.0249 (6)0.0376 (3)0.34538 (19)0.181 (2)
F40.2023 (4)0.0915 (4)0.42295 (19)0.1626 (19)
N10.0183 (3)0.3376 (3)0.33165 (14)0.0491 (7)
C10.0181 (5)0.7079 (3)0.2889 (2)0.0673 (11)
H10.03380.78970.31510.081*
C20.0311 (4)0.5864 (3)0.3283 (2)0.0586 (10)
H20.05290.58720.38150.070*
C30.0126 (4)0.4627 (3)0.29036 (18)0.0472 (8)
C40.0670 (5)0.3406 (4)0.4133 (2)0.0697 (12)
H4A0.17510.36460.41790.084*
H4B0.00600.40470.44340.084*
C50.0388 (5)0.1976 (4)0.4393 (2)0.0663 (11)
C60.0846 (6)0.1425 (4)0.3851 (2)0.0743 (12)
C70.1226 (5)0.2548 (4)0.3301 (2)0.0636 (10)
H7A0.21100.30650.34810.076*
H7B0.14320.22040.27790.076*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
F10.089 (2)0.106 (2)0.214 (4)0.0321 (19)0.015 (2)0.049 (2)
F20.171 (3)0.124 (2)0.0491 (14)0.027 (2)0.0102 (17)0.0096 (14)
F30.380 (7)0.0575 (16)0.106 (2)0.053 (3)0.059 (3)0.0167 (16)
F40.153 (3)0.208 (4)0.127 (3)0.099 (3)0.046 (2)0.102 (3)
N10.0642 (19)0.0434 (14)0.0395 (14)0.0035 (14)0.0065 (14)0.0017 (12)
C10.075 (3)0.0410 (18)0.086 (3)0.005 (2)0.006 (2)0.0105 (18)
C20.069 (3)0.0468 (19)0.060 (2)0.0026 (18)0.0019 (19)0.0090 (17)
C30.052 (2)0.0416 (17)0.0478 (17)0.0006 (16)0.0009 (16)0.0011 (14)
C40.097 (3)0.063 (2)0.049 (2)0.005 (2)0.020 (2)0.0015 (19)
C50.084 (3)0.069 (2)0.047 (2)0.009 (2)0.003 (2)0.0102 (18)
C60.107 (4)0.058 (2)0.058 (2)0.016 (2)0.002 (2)0.011 (2)
C70.078 (3)0.053 (2)0.060 (2)0.012 (2)0.009 (2)0.0106 (18)
Geometric parameters (Å, º) top
F1—C51.315 (5)C2—C31.385 (4)
F2—C51.344 (4)C2—H20.9300
F3—C61.337 (5)C3—C3i1.397 (6)
F4—C61.309 (5)C4—C51.493 (5)
N1—C31.418 (4)C4—H4A0.9700
N1—C41.458 (4)C4—H4B0.9700
N1—C71.468 (5)C5—C61.516 (6)
C1—C1i1.364 (7)C6—C71.485 (5)
C1—C21.374 (5)C7—H7A0.9700
C1—H10.9300C7—H7B0.9700
C3—N1—C4117.9 (3)F1—C5—F2105.1 (3)
C3—N1—C7116.2 (3)F1—C5—C4112.5 (4)
C4—N1—C7105.7 (3)F2—C5—C4112.3 (3)
C1i—C1—C2119.7 (2)F1—C5—C6112.0 (4)
C1i—C1—H1120.1F2—C5—C6109.4 (4)
C2—C1—H1120.1C4—C5—C6105.6 (3)
C1—C2—C3121.5 (3)F4—C6—F3105.0 (4)
C1—C2—H2119.3F4—C6—C7115.0 (4)
C3—C2—H2119.3F3—C6—C7109.7 (3)
C2—C3—C3i118.7 (2)F4—C6—C5112.6 (3)
C2—C3—N1121.5 (3)F3—C6—C5108.2 (4)
C3i—C3—N1119.80 (16)C7—C6—C5106.2 (3)
N1—C4—C5102.6 (3)N1—C7—C6102.4 (3)
N1—C4—H4A111.2N1—C7—H7A111.3
C5—C4—H4A111.2C6—C7—H7A111.3
N1—C4—H4B111.2N1—C7—H7B111.3
C5—C4—H4B111.2C6—C7—H7B111.3
H4A—C4—H4B109.2H7A—C7—H7B109.2
C1i—C1—C2—C31.8 (8)F2—C5—C6—F45.7 (5)
C1—C2—C3—C3i3.0 (7)C4—C5—C6—F4126.7 (4)
C1—C2—C3—N1176.7 (4)F1—C5—C6—F35.1 (5)
C4—N1—C3—C29.0 (5)F2—C5—C6—F3121.2 (4)
C7—N1—C3—C2118.0 (4)C4—C5—C6—F3117.7 (4)
C4—N1—C3—C3i171.2 (4)F1—C5—C6—C7122.8 (4)
C7—N1—C3—C3i61.8 (5)F2—C5—C6—C7121.1 (4)
C3—N1—C4—C5172.8 (3)C4—C5—C6—C70.0 (5)
C7—N1—C4—C540.9 (4)C3—N1—C7—C6173.7 (3)
N1—C4—C5—F198.1 (4)C4—N1—C7—C640.8 (4)
N1—C4—C5—F2143.5 (4)F4—C6—C7—N1149.4 (4)
N1—C4—C5—C624.4 (4)F3—C6—C7—N192.5 (4)
F1—C5—C6—F4110.5 (5)C5—C6—C7—N124.1 (4)
Symmetry code: (i) x, y, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···F3ii0.932.543.398 (4)154
C7—H7B···N1i0.972.453.020 (4)117
Symmetry codes: (i) x, y, z1/2; (ii) x, y1, z.

Experimental details

Crystal data
Chemical formulaC14H12F8N2
Mr360.26
Crystal system, space groupOrthorhombic, Pbcn
Temperature (K)293
a, b, c (Å)8.678 (3), 9.818 (3), 17.088 (5)
V3)1455.9 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.17
Crystal size (mm)0.44 × 0.37 × 0.22
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.928, 0.963
No. of measured, independent and
observed [I > 2σ(I)] reflections
6762, 1283, 878
Rint0.036
(sin θ/λ)max1)0.594
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.071, 0.129, 0.92
No. of reflections1283
No. of parameters109
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.50, 0.41

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···F3i0.932.543.398 (4)153.7
C7—H7B···N1ii0.972.453.020 (4)117.1
Symmetry codes: (i) x, y1, z; (ii) x, y, z1/2.
 

Acknowledgements

The authors gratefully acknowledge the support of the Department of Science and Technology, Guangdong Province (grant Nos. 2010 A020507001-76, 5300410 and FIPL-05-003).

References

First citationBabudri, F., Farinola, G. M., Naso, F. & Ragni, R. (2007). Chem. Commun. pp. 1003–1022.  CrossRef Google Scholar
First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
First citationBrambilla, E. (2001). Caries Res. 35, 6–9.  CrossRef CAS Google Scholar
First citationBruker (1997). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationHagan, O. D. (2008). Chem. Soc. Rev. 37, 308–319.  Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationZeng, Z. & Shreeve, J. M. (2009). J. Fluorine Chem. 130, 727–732.  CrossRef CAS Google Scholar

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