Racemic 1,2,3,4,7,8,9,10-octa­fluoro-6H,12H-5,11-methano­dibenzo[b,f][1,5]diazo­cine: an octa­fluorinated analogue of Tröger's base

Vande Velde, C.M.L.; Didier, D.; Blockhuys, F.; Sergeyev, S.

doi:10.1107/S1600536808002602

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 2| February 2008| Page o538

doi:10.1107/S1600536808002602

Open

access

Racemic 1,2,3,4,7,8,9,10-octafluoro-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine: an octafluorinated analogue of Tröger's base

Christophe M. L. Vande Velde,^a Delphine Didier,^a Frank Blockhuys ^b and Sergey Sergeyev ^a ^*

^aLaboratoire de Chimie des Polymères, Université Libre de Bruxelles, CP 206/1 Boulevard du Triomphe, 1050 Bruxelles, Belgium, and ^bDepartment of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
^*Correspondence e-mail: sserguee@ulb.ac.be

(Received 4 January 2008; accepted 23 January 2008; online 30 January 2008)

The title compound, C₁₅H₆F₈N₂, possesses a non-crystallographic twofold axis. The dihedral angle between the two benzene rings is 98.4 (2)°. The crystal structure involves intermolecular C—H⋯F hydrogen bonds.

Related literature

For recent reviews on the chemistry of Tröger's base (Tröger, 1887 ; Spielman, 1935 ), see: Valík et al. (2005 ) and Dolensky et al. (2007 ). For related literature on the chirality of Tröger's base, see: Prelog & Wieland (1944 ); for molecular clefts, see: Wilcox et al. (1987 ) and Artacho et al. (2006 ) and references cited therein; for (poly)halo-substituted Tröger's base analogues, see: Jensen & Wärnmark (2001 ), Sergeyev & Diederich (2004 ), Hansson et al. (2003 ), Li et al. (2005 ) and Faroughi et al. (2006 ). For related literature, see: Zabrodsky et al. (1993 ).

Experimental

Crystal data

C₁₅H₆F₈N₂
M_r = 366.22
Monoclinic, P 2₁ /c
a = 8.075 (3) Å
b = 10.469 (2) Å
c = 17.628 (6) Å
β = 117.15 (2)°
V = 1326.0 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.19 mm⁻¹
T = 290 (1) K
0.3 × 0.2 × 0.2 mm

Data collection

Enraf–Nonius MACH3 diffractometer
Absorption correction: none
5028 measured reflections
2412 independent reflections
1353 reflections with I > 2σ(I)
R_int = 0.078
3 standard reflections every 73 reflections intensity decay: 4%

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.128
S = 1.03
2412 reflections
251 parameters
All H-atom parameters refined
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
C—H ⋯ F contacts (Å, °)

C—H⋯F	C—H	H⋯F	C⋯F	C—H⋯F
C13—H132⋯F10ⁱ	0.93 (3)	2.41 (3)	3.257 (4)	151 (3)
C13—H131⋯F1ⁱⁱ	0.98 (4)	2.46 (3)	3.287 (5)	143 (2)
C12—H122⋯F7ⁱⁱⁱ	0.98 (3)	2.52 (3)	3.336 (4)	141 (3)
Symmetry codes: (i) $[-x, -{1\over 2}+y, {1\over 2}-z]$ , (ii) x-1, y, z, (iii) $[x, {1\over 2}-y, -{1\over 2}+z]$ .

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ) and PLATON (Spek, 2003 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808002602/pk2080sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808002602/pk2080Isup2.hkl

checkCIF report

Comment top

1,2,3,4,7,8,9,10-Octafluoro-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine is a fluorinated derivative of Tröger's base (Tröger, 1887; Spielman, 1935), a polycyclic diamine which is chiral due to severely hindered inversion at the bridgehead N-atoms (Prelog & Wieland, 1944). For recent reviews on its chemistry, see Valík et al. (2005) and Dolensky et al. (2007). Recently, a considerable interest has developed in relatively unfunctionalized receptors with concave aromatic surfaces (termed molecular clefts or tweezers). Wilcox et al. (1987) pioneered the incorporation of the Tröger's base framework in chiral molecular clefts by fusing the methanodiazocine core of Tröger's base with two bicyclic aromatic building blocks. Later, molecular clefts comprising two or three fused methanodiazocine cores have been reported (Artacho et al., 2006, and references cited therein). Our interest in the title compound was raised due to the prospect of using highly fluorinated aromatic systems in the design of molecular clefts, thus providing a possibility to explore different supramolecular interactions.

Synthesis of halo-derivatives of Tröger's base was pioneered by Wärnmark (Jensen & Wärnmark, 2001). Later, a number of fluoro-, chloro-, bromo-, and iodo-derivatives of Tröger's base, with the halogen atoms in different positions on the aromatic rings were reported (Sergeyev & Diederich, 2004 and Hansson et al., 2003). However, they typically contain only one halogen atom on each aromatic ring of the methanodiazocine skeleton. Exceptions are the recently reported 2,4,8,10-tetrafluoro- (Li et al., 2005) and tetrabromo-analogs (Faroughi et al., 2006) of Tröger's base. However, polyhalo-analogs of Tröger's base such as the octafluoro analog presented here are unprecedented. To the best of our knowledge, no X-ray crystal structure of a Tröger's base analog with fluorine in the aromatic ring has been reported.

The racemic octafluoro analog of Tröger's base crystallizes in the centrosymmetric space group P2₁/c with one molecule in the asymmetric unit. The molecule has a non-crystallographic twofold symmetry axis through the bridging carbon C13. The CSM (Continuous Symmetry Measure) is 0.0183 (Zabrodsky et al., 1993). Bond lengths and angles are within expectations. TLS analysis returns quasi-isotropic values for the librational amplitudes, and the values for the resulting corrections of the bond lengths are all below the 2σ level. The dihedral angle between the two benzene rings is 98.4 (2)°, which lies within the normal range for analogs of Tröger's base (Dolensky et al., 2007). Cohesion in the structure appears to be mainly provided by aromatic π-π interactions between the fluorinated benzene rings, leading to pairwise ordering of enantiomers around the centers of inversion, with an interplanar distance of under 4 Å. The most clear examples of this in the structure are Cg(2)···Cg(2)ⁱ (ⁱ=-x,1 - y,1 - z), 3.713 (2) Å, 3.476 (3)Å perp., with a slippage of 1.305 (3) Å, and Cg(1) ··· Cg(1)ⁱⁱ (ⁱⁱ=1 - x,-y,1 - z), 4.805 (2) Å, 3.538 (3)Å perp., with a slippage of 3.251 (3) Å. Cg(x) indicates the centroid of benzene ring x, perp. indicates the perpendicular distance between the ring planes. Due to the lack of suitable hydrogen bond donors, the N-atoms display no close contacts whatsoever. There are a number of F-π contacts in the structure, e.g. F(3)···Cg(2)ⁱⁱ 3.672 (3) Å, C3—F3···Cg(2)ⁱⁱ 161.7 (2)°. Also, H—F contacts occur that are substantially shorter than the van der Waals radii, but these are not usually understood as hydrogen bonds. They are given in Table 1.

Related literature top

For recent reviews on the chemistry of Tröger's base (Tröger, 1887; Spielman, 1935), see Valík et al. (2005) and Dolensky et al. (2007). For related literature on the chirality of Tröger's base, see Prelog & Wieland (1944); for molecular clefts, see Wilcox et al. (1987) and Artacho et al. (2006) and references cited therein; for (poly)halo-substituted Tröger's base analogues, see Jensen & Wärnmark (2001), Sergeyev & Diederich (2004), Hansson et al. (2003), Li et al. (2005) and Faroughi et al. (2006).

For related literature, see: Zabrodsky et al. (1993).

Experimental top

2,3,4,5-Tetrafluoroaniline (330 mg, 2 mmol) and paraformaldehyde (120 mg, 4 mmol) were added under vigorous stirring to CF₃COOH (4 ml) at -15°C. The resulting mixture was allowed to reach room temperature and stirred for 14 days, then slowly added to a stirred mixture of ice and 30% aqueous NH₃ (7 ml). Extraction with CH₂Cl₂ (2 x 20 ml), drying of the organic layer over MgSO₄, and removal of the solvent in vacuo gave a crude product which was purified by flash chromatography (SiO₂/CH₂Cl₂). Yield of the title compound: 135 mg (37%). Crystals suitable for X-ray diffraction were grown by slow evaporation from CHCl₃solution.

¹H NMR (300 MHz, CDCl₃, 25°C): d = 4.20–4.30 (m, 4H, H61, H62, H121, H122), 4.50 (d, J = 17.5 Hz, 2H, H131, H132); ¹³C NMR (75 MHz, CDCl₃, 25°C): d = 50.1, 66.5, 111.9 (ddt, J =17.7, 3.4, 1.7 Hz), 130.8 (dddd, J = 10.6, 5.2, 3.7, 1.9 Hz), 137.3 (dddd, J = 252.0, 16.5, 13.0, 3.1 Hz), 140.2 (dddd, J = 251.3, 14.9, 13.0, 5.0 Hz), 141.7 (dddd, J = 248.2, 11.2, 4.1, 1.3 Hz), 144.0 (ddt, J = 245.2, 10.9, 3.7 Hz). HR—EI—MS: m/z: calcd. for C₁₅H₆F₈N₂ ([M]⁺): 366.0403; found: 366.0405.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

Figures top

	Fig. 1. View of the structure with 50% probability displacement ellipsoids. H atoms are numbered according to their attached C-atoms.
	Fig. 2. View of the unit cell down the b axis.

1,2,3,4,7,8,9,10-octafluoro-5,6,11,12-tetrahydro-5,11-µethanodibenzo[b,f][1,5]diazocine top

Crystal data top

C₁₅H₆F₈N₂	F(000) = 728
M_r = 366.22	D_x = 1.834 Mg m⁻³
Monoclinic, P2₁/c	Melting point: 192(1) K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 8.075 (3) Å	Cell parameters from 25 reflections
b = 10.469 (2) Å	θ = 5–12°
c = 17.628 (6) Å	µ = 0.19 mm⁻¹
β = 117.15 (2)°	T = 290 K
V = 1326.0 (8) Å³	Rhomb, colourless
Z = 4	0.3 × 0.2 × 0.2 mm

Data collection top

Enraf–Nonius MACH3 diffractometer	R_int = 0.078
Radiation source: sealed tube	θ_max = 25.3°, θ_min = 2.3°
Pyrolytic graphite monochromator	h = 0→9
profiled ω/2θ scans	k = −12→12
5028 measured reflections	l = −21→18
2412 independent reflections	3 standard reflections every 73 reflections
1353 reflections with I > 2σ(I)	intensity decay: 4%

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.044	All H-atom parameters refined
wR(F²) = 0.128	w = 1/[σ²(F_o²) + (0.06P)²] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
2412 reflections	Δρ_max = 0.20 e Å⁻³
251 parameters	Δρ_min = −0.25 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 constraints	Extinction coefficient: 0.008 (2)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₁₅H₆F₈N₂	V = 1326.0 (8) Å³
M_r = 366.22	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 8.075 (3) Å	µ = 0.19 mm⁻¹
b = 10.469 (2) Å	T = 290 K
c = 17.628 (6) Å	0.3 × 0.2 × 0.2 mm
β = 117.15 (2)°

Data collection top

Enraf–Nonius MACH3 diffractometer	R_int = 0.078
5028 measured reflections	3 standard reflections every 73 reflections
2412 independent reflections	intensity decay: 4%
1353 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.128	All H-atom parameters refined
S = 1.03	Δρ_max = 0.20 e Å⁻³
2412 reflections	Δρ_min = −0.25 e Å⁻³
251 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
H131	−0.193 (4)	0.216 (3)	0.8025 (17)	0.051 (8)*
H121	0.305 (4)	0.121 (3)	0.810 (2)	0.069 (9)*
H122	0.136 (5)	0.176 (3)	0.726 (2)	0.077 (10)*
H62	−0.105 (5)	0.310 (3)	0.9326 (17)	0.057 (9)*
H132	−0.111 (4)	0.269 (3)	0.741 (2)	0.060 (9)*
H61	0.092 (4)	0.374 (3)	0.9788 (19)	0.053 (9)*
F7	0.1474 (3)	0.21118 (18)	1.10195 (11)	0.0715 (6)
F10	0.2539 (3)	−0.08189 (16)	0.87533 (11)	0.0699 (6)
F1	0.5029 (3)	0.29145 (19)	0.78363 (12)	0.0679 (6)
F9	0.3839 (3)	−0.15905 (16)	1.03755 (11)	0.0729 (6)
N11	0.0509 (3)	0.1395 (2)	0.81513 (13)	0.0506 (6)
F8	0.3308 (3)	−0.01382 (19)	1.15148 (10)	0.0730 (6)
C12A	0.2581 (4)	0.3151 (3)	0.81963 (16)	0.0467 (7)
F4	0.1600 (3)	0.58222 (17)	0.92368 (14)	0.0845 (7)
F3	0.4753 (3)	0.66558 (18)	0.92211 (15)	0.0919 (7)
C10A	0.1288 (4)	0.1067 (3)	0.90262 (15)	0.0417 (6)
C9	0.2933 (4)	−0.0464 (3)	1.01318 (17)	0.0489 (7)
F2	0.6451 (3)	0.5220 (2)	0.85025 (14)	0.0852 (6)
C7	0.1727 (4)	0.1397 (3)	1.04471 (16)	0.0471 (7)
N5	−0.0035 (3)	0.3514 (2)	0.85287 (15)	0.0570 (7)
C4A	0.1674 (4)	0.3903 (3)	0.85490 (17)	0.0488 (7)
C1	0.4148 (4)	0.3626 (3)	0.81791 (18)	0.0510 (8)
C8	0.2668 (4)	0.0260 (3)	1.07054 (16)	0.0491 (7)
C10	0.2252 (4)	−0.0074 (3)	0.93048 (16)	0.0450 (7)
C6A	0.1055 (4)	0.1831 (3)	0.96176 (17)	0.0460 (7)
C13	−0.0834 (5)	0.2423 (4)	0.7960 (2)	0.0611 (9)
C2	0.4898 (4)	0.4799 (3)	0.8519 (2)	0.0583 (8)
C4	0.2450 (5)	0.5081 (3)	0.88958 (18)	0.0584 (8)
C3	0.4040 (5)	0.5512 (3)	0.8886 (2)	0.0616 (9)
C6	0.0168 (5)	0.3137 (3)	0.9374 (2)	0.0577 (9)
C12	0.1908 (5)	0.1805 (3)	0.78815 (19)	0.0530 (8)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
F7	0.1095 (15)	0.0648 (11)	0.0538 (10)	0.0031 (11)	0.0490 (11)	−0.0071 (9)
F10	0.1081 (15)	0.0474 (10)	0.0537 (10)	0.0049 (10)	0.0364 (10)	−0.0103 (8)
F1	0.0709 (12)	0.0683 (12)	0.0764 (12)	0.0122 (10)	0.0440 (10)	0.0101 (10)
F9	0.0981 (15)	0.0433 (10)	0.0660 (12)	0.0137 (10)	0.0276 (10)	0.0114 (9)
N11	0.0534 (14)	0.0571 (16)	0.0335 (12)	0.0002 (13)	0.0130 (10)	0.0035 (11)
F8	0.1033 (15)	0.0666 (12)	0.0379 (9)	0.0000 (11)	0.0224 (9)	0.0098 (9)
C12A	0.0484 (17)	0.0506 (16)	0.0352 (14)	0.0092 (14)	0.0139 (12)	0.0113 (13)
F4	0.1074 (17)	0.0539 (11)	0.1061 (16)	0.0224 (11)	0.0607 (14)	−0.0004 (11)
F3	0.1082 (17)	0.0477 (11)	0.1105 (17)	−0.0089 (12)	0.0419 (14)	−0.0055 (12)
C10A	0.0435 (15)	0.0430 (14)	0.0348 (14)	−0.0044 (13)	0.0144 (12)	0.0002 (12)
C9	0.0557 (17)	0.0351 (15)	0.0481 (16)	0.0008 (14)	0.0170 (14)	0.0039 (13)
F2	0.0694 (13)	0.0731 (13)	0.1142 (16)	−0.0077 (11)	0.0429 (12)	0.0129 (12)
C7	0.0589 (18)	0.0477 (17)	0.0397 (15)	−0.0058 (15)	0.0268 (13)	−0.0068 (13)
N5	0.0536 (15)	0.0572 (15)	0.0577 (15)	0.0156 (14)	0.0233 (12)	0.0161 (13)
C4A	0.0512 (17)	0.0468 (17)	0.0455 (16)	0.0137 (15)	0.0195 (14)	0.0172 (14)
C1	0.0523 (17)	0.0547 (19)	0.0478 (16)	0.0145 (16)	0.0244 (14)	0.0120 (14)
C8	0.0609 (18)	0.0467 (16)	0.0316 (14)	−0.0078 (15)	0.0140 (13)	0.0058 (13)
C10	0.0570 (17)	0.0389 (15)	0.0376 (14)	−0.0047 (14)	0.0201 (13)	−0.0074 (13)
C6A	0.0489 (17)	0.0457 (16)	0.0443 (15)	0.0000 (13)	0.0220 (13)	0.0014 (13)
C13	0.0468 (19)	0.078 (2)	0.0480 (19)	0.0021 (17)	0.0123 (15)	0.0164 (18)
C2	0.0519 (19)	0.0541 (18)	0.067 (2)	0.0070 (16)	0.0250 (16)	0.0183 (16)
C4	0.072 (2)	0.0476 (18)	0.0587 (19)	0.0222 (17)	0.0330 (17)	0.0108 (16)
C3	0.067 (2)	0.0402 (17)	0.067 (2)	0.0048 (16)	0.0217 (17)	0.0091 (15)
C6	0.058 (2)	0.058 (2)	0.064 (2)	0.0141 (17)	0.0335 (18)	0.0116 (17)
C12	0.063 (2)	0.0587 (19)	0.0358 (15)	0.0005 (16)	0.0215 (15)	0.0011 (14)

Geometric parameters (Å, º) top

F7—C7	1.345 (3)	F2—C2	1.342 (3)
F10—C10	1.347 (3)	C7—C8	1.373 (4)
F1—C1	1.348 (3)	C7—C6A	1.384 (4)
F9—C9	1.350 (3)	N5—C4A	1.423 (4)
N11—C10A	1.417 (3)	N5—C13	1.461 (4)
N11—C13	1.454 (4)	N5—C6	1.476 (4)
N11—C12	1.476 (4)	C4A—C4	1.393 (5)
F8—C8	1.343 (3)	C1—C2	1.380 (5)
C12A—C1	1.372 (4)	C6A—C6	1.513 (4)
C12A—C4A	1.400 (4)	C13—H131	0.98 (3)
C12A—C12	1.520 (4)	C13—H132	0.93 (3)
F4—C4	1.346 (3)	C2—C3	1.365 (5)
F3—C3	1.343 (4)	C4—C3	1.368 (5)
C10A—C10	1.387 (4)	C6—H62	0.95 (3)
C10A—C6A	1.393 (4)	C6—H61	0.95 (3)
C9—C8	1.357 (4)	C12—H121	1.03 (3)
C9—C10	1.365 (4)	C12—H122	0.98 (3)

C10A—N11—C13	110.2 (2)	C7—C6A—C10A	118.7 (3)
C10A—N11—C12	113.3 (2)	C7—C6A—C6	120.2 (3)
C13—N11—C12	108.1 (3)	C10A—C6A—C6	121.0 (3)
C1—C12A—C4A	118.7 (3)	N11—C13—N5	111.7 (2)
C1—C12A—C12	120.5 (3)	N11—C13—H131	112.5 (18)
C4A—C12A—C12	120.7 (3)	N5—C13—H131	106.2 (17)
C10—C10A—C6A	118.3 (2)	N11—C13—H132	105.1 (19)
C10—C10A—N11	119.5 (2)	N5—C13—H132	107 (2)
C6A—C10A—N11	122.1 (3)	H131—C13—H132	114 (3)
F9—C9—C8	119.9 (3)	F2—C2—C3	120.8 (3)
F9—C9—C10	119.8 (3)	F2—C2—C1	120.8 (3)
C8—C9—C10	120.3 (3)	C3—C2—C1	118.4 (3)
F7—C7—C8	119.0 (2)	F4—C4—C3	119.3 (3)
F7—C7—C6A	119.3 (3)	F4—C4—C4A	119.2 (3)
C8—C7—C6A	121.7 (3)	C3—C4—C4A	121.6 (3)
C4A—N5—C13	111.1 (3)	F3—C3—C2	119.2 (3)
C4A—N5—C6	113.0 (2)	F3—C3—C4	120.3 (3)
C13—N5—C6	107.1 (3)	C2—C3—C4	120.5 (3)
C4—C4A—C12A	118.1 (3)	N5—C6—C6A	110.4 (3)
C4—C4A—N5	120.1 (3)	N5—C6—H62	106.7 (17)
C12A—C4A—N5	121.8 (3)	C6A—C6—H62	109 (2)
F1—C1—C12A	119.3 (3)	N5—C6—H61	109.5 (17)
F1—C1—C2	118.0 (3)	C6A—C6—H61	109.4 (18)
C12A—C1—C2	122.7 (3)	H62—C6—H61	112 (2)
F8—C8—C9	120.2 (3)	N11—C12—C12A	110.5 (3)
F8—C8—C7	120.5 (3)	N11—C12—H121	113.2 (18)
C9—C8—C7	119.3 (2)	C12A—C12—H121	107.9 (19)
F10—C10—C9	118.6 (3)	N11—C12—H122	109 (2)
F10—C10—C10A	119.8 (2)	C12A—C12—H122	111 (2)
C9—C10—C10A	121.6 (3)	H121—C12—H122	105 (3)

C13—N11—C10A—C10	164.7 (3)	F7—C7—C6A—C6	4.4 (4)
C12—N11—C10A—C10	−74.1 (3)	C8—C7—C6A—C6	−174.9 (3)
C13—N11—C10A—C6A	−12.6 (4)	C10—C10A—C6A—C7	−2.5 (4)
C12—N11—C10A—C6A	108.7 (3)	N11—C10A—C6A—C7	174.8 (2)
C1—C12A—C4A—C4	−2.4 (4)	C10—C10A—C6A—C6	174.6 (3)
C12—C12A—C4A—C4	174.4 (3)	N11—C10A—C6A—C6	−8.1 (4)
C1—C12A—C4A—N5	175.1 (2)	C10A—N11—C13—N5	53.2 (3)
C12—C12A—C4A—N5	−8.2 (4)	C12—N11—C13—N5	−71.2 (3)
C13—N5—C4A—C4	165.8 (3)	C4A—N5—C13—N11	51.4 (3)
C6—N5—C4A—C4	−73.8 (3)	C6—N5—C13—N11	−72.5 (3)
C13—N5—C4A—C12A	−11.6 (3)	F1—C1—C2—F2	0.4 (4)
C6—N5—C4A—C12A	108.8 (3)	C12A—C1—C2—F2	178.8 (3)
C4A—C12A—C1—F1	−179.6 (2)	F1—C1—C2—C3	−178.4 (3)
C12—C12A—C1—F1	3.7 (4)	C12A—C1—C2—C3	0.0 (4)
C4A—C12A—C1—C2	2.0 (4)	C12A—C4A—C4—F4	179.9 (2)
C12—C12A—C1—C2	−174.7 (3)	N5—C4A—C4—F4	2.4 (4)
F9—C9—C8—F8	0.1 (4)	C12A—C4A—C4—C3	0.9 (4)
C10—C9—C8—F8	178.7 (3)	N5—C4A—C4—C3	−176.6 (3)
F9—C9—C8—C7	−179.3 (3)	F2—C2—C3—F3	1.1 (5)
C10—C9—C8—C7	−0.8 (4)	C1—C2—C3—F3	179.9 (3)
F7—C7—C8—F8	0.7 (4)	F2—C2—C3—C4	179.6 (3)
C6A—C7—C8—F8	179.9 (3)	C1—C2—C3—C4	−1.6 (5)
F7—C7—C8—C9	−179.8 (3)	F4—C4—C3—F3	0.7 (4)
C6A—C7—C8—C9	−0.6 (4)	C4A—C4—C3—F3	179.7 (3)
F9—C9—C10—F10	−1.3 (4)	F4—C4—C3—C2	−177.8 (3)
C8—C9—C10—F10	−179.9 (3)	C4A—C4—C3—C2	1.2 (5)
F9—C9—C10—C10A	179.0 (3)	C4A—N5—C6—C6A	−75.7 (4)
C8—C9—C10—C10A	0.5 (4)	C13—N5—C6—C6A	47.0 (3)
C6A—C10A—C10—F10	−178.4 (2)	C7—C6A—C6—N5	166.7 (3)
N11—C10A—C10—F10	4.2 (4)	C10A—C6A—C6—N5	−10.4 (4)
C6A—C10A—C10—C9	1.2 (4)	C10A—N11—C12—C12A	−75.3 (3)
N11—C10A—C10—C9	−176.2 (3)	C13—N11—C12—C12A	47.2 (3)
F7—C7—C6A—C10A	−178.5 (3)	C1—C12A—C12—N11	166.2 (2)
C8—C7—C6A—C10A	2.3 (4)	C4A—C12A—C12—N11	−10.5 (4)

Experimental details

Crystal data
Chemical formula	C₁₅H₆F₈N₂
M_r	366.22
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	290
a, b, c (Å)	8.075 (3), 10.469 (2), 17.628 (6)
β (°)	117.15 (2)
V (Å³)	1326.0 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.19
Crystal size (mm)	0.3 × 0.2 × 0.2

Data collection
Diffractometer	Enraf–Nonius MACH3 diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	5028, 2412, 1353
R_int	0.078
(sin θ/λ)_max (Å⁻¹)	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.128, 1.03
No. of reflections	2412
No. of parameters	251
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.20, −0.25

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006), WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

C—H ··· F contacts (Å, °) (i) -x, -1/2+y, 1/2-z (ii) x-1, y, z (iii) x, 1/2-y, -1/2+z top

C—H···F	C—H	H···F	C···F	C—H···F
C13—H132···F10ⁱ	0.93 (3)	2.41 (3)	3.257 (4)	151 (3)
C13—H131···F1ⁱⁱ	0.98 (4)	2.46 (3)	3.287 (5)	143 (2)
C12—H122···F7ⁱⁱⁱ	0.98 (3)	2.52 (3)	3.336 (4)	141 (3)

Acknowledgements

S. Sergeyev is grateful to Professor Y. Geerts (Université Libre de Bruxelles) for the opportunity to conduct an independent research programme in his laboratory and for generous financial support.

References

Artacho, J., Nilsson, P., Bergquist, K.-E., Wendt, O. F. & Wärnmark, K. (2006). Chem. Eur. J. 12, 2692–2701. Web of Science CSD CrossRef PubMed CAS Google Scholar
Dolensky, B., Elguero, J., Král, V., Pardo, C. & Valík, M. (2007). Adv. Heterocycl. Chem. 93, 1–56. Web of Science CrossRef CAS Google Scholar
Enraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Faroughi, M., Try, A. C. & Turner, P. (2006). Acta Cryst. E62, o3893–o3894. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Hansson, A., Jensen, J., Wendt, O. F. & Wärnmark, K. (2003). Eur. J. Org. Chem. pp. 3179–3188. Web of Science CSD CrossRef Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
Jensen, J. & Wärnmark, K. (2001). Synthesis, pp. 1873–1877. CrossRef Google Scholar
Li, Z., Xu, X., Peng, Y., Jiang, Z., Ding, C. & Qian, X. (2005). Synthesis, pp. 1228–1230. Web of Science CrossRef Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CrossRef CAS IUCr Journals Google Scholar
Prelog, V. & Wieland, P. (1944). Helv. Chim. Acta, 27, 1127–1134. CrossRef CAS Google Scholar
Sergeyev, S. & Diederich, F. (2004). Angew. Chem. Int. Ed. 43, 1738–1740. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spielman, M. A. (1935). J. Am. Chem. Soc. 57, 583–585. CrossRef CAS Google Scholar
Tröger, J. (1887). J. Prakt. Chem. 36, 225–245. CrossRef Google Scholar
Valík, M., Strongin, R. M. & Král, V. (2005). Supramol. Chem. 17, 347–367. Google Scholar
Wilcox, C. S., Greer, L. M. & Lynch, V. (1987). J. Am. Chem. Soc. 109, 1865–1867. CSD CrossRef CAS Web of Science Google Scholar
Zabrodsky, H., Peleg, S. & Avnir, D. (1993). J. Am. Chem. Soc. 115, 8278–8289. CrossRef CAS Web of Science Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.