The effect of Cl...π interactions on the conformations of 4-chloro-5-(2-phenoxyethoxy)phthalonitrile and 4-chloro-5-[2-(pentafluorophenoxy)ethoxy]phthalonitrile

4-Chloro-5-(2-phen­oxy­eth­oxy)phthalonitrile, C₁₆H₁₁ClN₂O₂, (I), and 4-chloro-5-[2-(penta­fluoro­phen­oxy)eth­oxy]phthalo­nitrile, C₁₆H₆ClF₅N₂O₂, (II), show different types of electrostatic inter­action. In (I), the phen­oxy and phthalonitrile (benzene-1,2-dicarbonitrile) moieties are well separated in an open conformation and inter­molecular C—H...π inter­actions are observed in the crystal packing. On the other hand, in (II), the penta­fluoro­phen­oxy moiety inter­acts closely with the Cl atom to form a folded conformation containing an intra­molecular halogen–π inter­action.

S1. Comment

The anion–π interaction has been found and discussed as one of the most interesting topics regarding electrostatic interactions in the last decade. The provocative title of a paper, `Anion–π interactions: do they exist?', which was a theoretical study of the interaction reported by Quiñonero et al. (2002), attracted the interest of many chemists (Schottel et al., 2008). Since π-conjugated molecules show remarkable electrostatic interactions because of their quadrupole moments (i.e. negative charge of the aromatic centre), benzene molecules show cation–π, C—H···π and the sliding conformation of π–π interactions (Doerksenm & Thakkar, 1999). On the other hand, fluorinated compounds such as hexafluorobenzene have the opposite quadrupole moment (i.e. positive charge of the aromatic centre induced by the surrounding F atoms) and show the opposite electrostatic interactions, e.g. anion···C₆F₆ (anion–π), CF···C₆F₆ (CF–π) and the sliding conformation of C₆F₆···C₆F₆ (π–π) interactions. Several papers then demonstrated the existence of anion–π interactions between anion sources and aromatic moieties (Demeshko et al., 2004; de Hoog et al., 2004; Berryman et al., 2006; Dawson et al., 2010), which includes noncovalent π-interactions between lone-pair electrons of electronegative atoms (F, Cl, Br, O, S and N) and perfluorobenzene derivatives (Quiñonero et al., 2002). These studies of quadrupole moment and electrostatic interactions prompted us to compare them with the crystal structures of fluorinated compounds, which also show several unique electrostatic interactions in the crystalline state (Hori et al., 2007; Hori & Naganuma, 2010), e.g. the arene–perfluoroarene interaction (Patrick & Prosser, 1960; Williams, 1993) and C—H···F interactions (Desiraju, 1996; Thalladi et al., 1998). In this paper, we discuss the halogen–π interaction, classified as an anion–π interaction, between the pentafluorophenoxy group and Cl atoms in 4-chloro-5-[2-(pentafluorophenoxy)ethoxy]phthalonitrile, (II), in order to understand fluorine-substituted effects, given that no halogen–π interactions are observed in the nonfluorinated compound 4-chloro-5-(2-phenoxyethoxy)phthalonitrile, (I).

The molecular conformations of (I) and (II) are different (Fig. 1), viz. open in (I) and folded in (II), and the folded structure of (II) shows an apparently attractive interaction between atom Cl1 and the pentafluorophenoxy moiety (ring B). The Cl1···CgB distance in (II) is 3.7253 (12) Å, where CgB is the centroid of ring B. Two intramolecular aromatic rings (A and B) are linked by the ethoxy moiety, and significant conformational differences of trans–gauche–trans and trans–gauche–gauche conformations are observed in the C5/O1/C9/C10/O2/C11 ethoxy moiety of (I) and (II), respectively. The C9—C10—O2—C11 torsion angles in (I) and (II) are trans [173.89 (10)°] and gauche [77.06 (18)°], respectively. The thermodynamically unfavourable gauche–gauche conformation is realised in (II) because of the intramolecular interaction between atom Cl1 and ring B. The O1—C9—C10—O2 torsion angles have the same gauche configuration, viz. 75.96 (13)° in (I) and 71.99 (17)° in (II), and the C5—O1—C9—C10 torsion angles are trans, viz. 171.51 (11)° in (I) and 179.93 (13)° in (II). The dihedral angle between the aromatic rings (A and B) of (II) is 68.75 (4)°, which is smaller than the corresponding angle in (I) [70.89 (5)°]. The C4—Cl1 bond distance of 1.7256 (16) Å in (II) is slightly longer than that of 1.7168 (14) Å in (I), although the C10—O2 bond in (II) is longer than that in (I) [1.454 (2) versus 1.4309 (16) Å]. The C≡N bond distances in (I) and (II) are almost the same [C7≡N1 = 1.1458 (19) and C8≡N2 = 1.144 (2) Å for (I), and C7≡N1 = 1.144 (2) and C8≡N2 = 1.149 (2) Å for (II)]. The C5—O1 bond distances are also the same, i.e. 1.3535 (16) and 1.3524 (18) Å for (I) and (II), respectively.

In the crystal structure of (I), no π–π stacking is observed, but inversion-related pairs of molecules are linked by a C—H···π interaction (Fig. 2); atom H3 of ring A at (x, y, z) interacts closely with a phenoxy moiety at (-x + 2, -y + 1, -z + 1) [symmetry code (i)]. The intermolecular Cl1···Cl1ⁱ distance in the pair is short, at 3.274 (1) Å. The formation of the pair allows stabilization of the gauche configuration of O1/C9/C10/O2 to give the trans–gauche–trans conformation in (I). Further, the H atoms in ethoxy moieties C10—H10A and C10—H10B interact with rings Bⁱⁱ [symmetry code: (ii) -x + 1, -y, -z + 1] and Aⁱⁱⁱ [symmetry code: (iii) x, y - 1, z], respectively, through C—H···π interactions; H10A···CgBⁱⁱ = 2.59 Å [C10···CgBⁱⁱ = 3.477 (2) Å] and H10B···CgAⁱⁱⁱ = 2.71 Å [C10···CgAⁱⁱⁱ = 3.492 (2) Å]. Accordingly, the molecules are in a head-to-tail arrangement along the a axis and, further, they form zigzag arrangements along the c axis.

In (II), the molecules are aligned parallel to the a axis. In this direction, atom F5 in the pentafluorophenoxy group interacts with ethoxy atom H9B of a neighbouring molecule through a weak C—H···F contact (Howard et al., 1996), with F5···H9B^iv = 2.51 Å [symmetry code: (iv) x - 1, y, z]. The F5···C5^iv distance is also short, at 2.950 (2) Å. Because the pentafluorophenoxy groups are aligned in the same direction, the F substituents are located close to one another, with F1···F5^v = 2.8625 (15) Å and F2···F4^v = 2.8914 (17) Å [symmetry code: (v) x + 1, y, z]. Similarly, the molecules are aligned along the b axis and the F3···F4^vi distance is short, at 2.7756 (17) Å [symmetry code: (vi) -x, -y, -z + 1]. No π–π stacking is observed in the crystal packing of (II).

In conclusion, the structures of (I) and (II) demonstrate that ring fluorination is associated with the folded structure of (II) through the halogen–π interaction. Since no strong intermolecular interactions are observed between the molecules in either structure, the halogen–π interaction may be the dominant driving force for the folding in (II).

Related literature

For related literature, see: Berryman et al. (2006); Dawson et al. (2010); Demeshko et al. (2004); Desiraju (1996); Doerksenm & Thakkar (1999); Hoog et al. (2004); Hori & Naganuma (2010); Hori et al. (2007); Howard et al. (1996); Patrick & Prosser (1960); Quiñonero et al. (2002); Schottel et al. (2008); Thalladi et al. (1998); Williams (1993).

S2. Experimental

Compounds (I) and (II) were prepared in one step using general procedures (Durmus et al., 2009). Typically, K₂CO₃ (11 g, 81 mol) was added in portions over a period of 2 h to a dry dimethylformamide solution (60 ml) of 4,5-dichlorophthalonitrile (4.0 g, 20 mol) and 2-phenoxyethanol (5.1 ml, 40 mol) under an N₂ atmosphere. The reaction mixture was then stirred at 333 K for 2 d. The mixture was evaporated to remove the solvent and the residue was extracted by CHCl₃. The product was further purified by column chromatography (silica gel, CHCl₃/MeOH) and recycled gas-phase chromatography (CHCl₃) to give (I) as a white powder. Compound (II) was obtained from 2-(pentafluorophenoxy)ethanol using the same procedure as (I). Each compound was crystallized from CHCl₃ by the vapour diffusion of MeOH to give colourless crystals. Data for (I): yield 23%, m.p. 397–398 K; ¹H NMR (400 MHz, CDCl₃, TMS, δ, p.p.m.): 7.79 (s, Ar), 7.41 (s, Ar), 7.32 (t, J = 7.8 Hz, Ar), 7.01 (t, J = 7.8 Hz, Ar), 6.93 (d, J = 7.8 Hz, Ar), 4.54–4.51 (m, CH₂), 4.44–4.41 (m, CH₂); EI-MS: 298 m/z (M⁺); elemental analysis, calculated for C₁₆H₁₁ClN₂O₂: C 64.3, H 3.7, N 9.4%; found: C 64.2, H 3.7, N 9.4%. Data for (II): yield 32%, m.p. 405–207 K; ¹H NMR (400 MHz, CDCl₃, TMS, δ, p.p.m.): 7.80 (s, Ar), 7.31 (s, Ar), 4.62–4.60 (m, CH₂), 4.49–4.47 (m, CH₂); EI-MS: 388 m/z (M⁺); elemental analysis, calculated for C₁₆H₆ClF₅N₂O₂: C 49.4, H 1.6, N 7.2%; found: C 49.4, H 1.5, N 7.1%.

S3. Refinement

All H atoms were placed in geometrically idealized positions and refined as riding, with aromatic C—H = 0.95 Å and aliphatic C—H = 0.99 Å, and with U_iso(H) = 1.2U_eq(C).

Computing details

For both compounds, data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); 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

	Fig. 1. The molecular structures of (a) (I) and (b) (II), both at 100 K, showing the atom-labelling schemes. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The pair of (I) formed through C—H···π interactions. The unit-cell outline and H atoms not involved in the motif shown have been omitted for clarity. [Symmetry code: (i) -x + 2, -y + 1, -z + 1.]

(I) 4-Chloro-5-(2-phenoxyethoxy)benzene-1,2-dicarbonitrile

Crystal data

C16H11ClN2O2	F(000) = 616
Mr = 298.72	Dx = 1.404 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5581 reflections
a = 9.808 (4) Å	θ = 2.7–27.9°
b = 6.555 (3) Å	µ = 0.28 mm^−1
c = 22.018 (9) Å	T = 100 K
β = 93.259 (4)°	Prismatic, colourless
V = 1413.2 (10) Å^3	0.20 × 0.10 × 0.10 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	3228 independent reflections
Radiation source: fine-focus sealed tube	2744 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 8.333 pixels mm^-1	θmax = 27.5°, θmin = 2.7°
φ and ω scans	h = −12→12
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	k = −8→8
Tmin = 0.947, Tmax = 0.973	l = −28→28
15329 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.087	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0367P)^2 + 0.8106P] where P = (Fo^2 + 2Fc^2)/3
3228 reflections	(Δ/σ)max = 0.001
190 parameters	Δρmax = 0.46 e Å^−3
0 restraints	Δρmin = −0.56 e Å^−3

Special details

Experimental. IR (KBr disk, cm^-1):3447, 3107, 2922, 2359, 2232, 1599, 1584, 1499, 1491, 1451, 1254, 1051, 758, 692, 532.

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.74491 (14)	0.9594 (2)	0.31436 (6)	0.0158 (3)
C2	0.86918 (14)	1.0586 (2)	0.32848 (6)	0.0175 (3)
C3	0.95904 (14)	0.9762 (2)	0.37340 (7)	0.0198 (3)
H3	1.0439	1.0411	0.3835	0.024*
C4	0.92400 (14)	0.8000 (2)	0.40310 (6)	0.0188 (3)
C5	0.79972 (13)	0.6987 (2)	0.38881 (6)	0.0151 (3)
C6	0.70992 (14)	0.7809 (2)	0.34416 (6)	0.0154 (3)
H6	0.6251	0.7157	0.3340	0.018*
C7	0.64887 (14)	1.0428 (2)	0.26899 (6)	0.0184 (3)
C8	0.90211 (15)	1.2475 (2)	0.29898 (7)	0.0215 (3)
C9	0.64597 (13)	0.4259 (2)	0.40987 (6)	0.0164 (3)
H9A	0.6280	0.4018	0.3658	0.020*
H9B	0.5713	0.5111	0.4246	0.020*
C10	0.65352 (14)	0.2262 (2)	0.44356 (6)	0.0157 (3)
H10A	0.5790	0.1349	0.4280	0.019*
H10B	0.7418	0.1583	0.4372	0.019*
C11	0.65911 (13)	0.0998 (2)	0.54506 (6)	0.0142 (3)
C12	0.65391 (14)	0.1413 (2)	0.60719 (6)	0.0170 (3)
H12	0.6369	0.2762	0.6205	0.020*
C13	0.67362 (14)	−0.0145 (2)	0.64915 (6)	0.0202 (3)
H13	0.6693	0.0140	0.6913	0.024*
C14	0.69975 (14)	−0.2132 (2)	0.63016 (7)	0.0206 (3)
H14	0.7143	−0.3194	0.6592	0.025*
C15	0.70417 (14)	−0.2537 (2)	0.56855 (7)	0.0199 (3)
H15	0.7216	−0.3886	0.5553	0.024*
C16	0.68337 (14)	−0.0984 (2)	0.52585 (6)	0.0172 (3)
H16	0.6858	−0.1277	0.4837	0.021*
Cl1	1.03241 (4)	0.70258 (6)	0.459822 (19)	0.03207 (12)
N1	0.57125 (13)	1.1075 (2)	0.23319 (6)	0.0255 (3)
N2	0.92533 (15)	1.4003 (2)	0.27667 (6)	0.0315 (3)
O1	0.77600 (9)	0.52762 (14)	0.42099 (4)	0.0168 (2)
O2	0.64098 (10)	0.26465 (14)	0.50697 (4)	0.0155 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0185 (7)	0.0164 (6)	0.0128 (6)	0.0037 (5)	0.0022 (5)	0.0004 (5)
C2	0.0198 (7)	0.0157 (6)	0.0177 (6)	0.0014 (5)	0.0066 (5)	0.0029 (5)
C3	0.0140 (6)	0.0198 (7)	0.0257 (7)	−0.0015 (5)	0.0024 (5)	0.0052 (6)
C4	0.0129 (6)	0.0214 (7)	0.0218 (7)	0.0015 (5)	−0.0010 (5)	0.0067 (6)
C5	0.0151 (6)	0.0148 (6)	0.0159 (6)	0.0017 (5)	0.0041 (5)	0.0022 (5)
C6	0.0157 (6)	0.0165 (6)	0.0141 (6)	−0.0002 (5)	0.0014 (5)	−0.0006 (5)
C7	0.0225 (7)	0.0169 (7)	0.0162 (6)	0.0001 (5)	0.0032 (5)	0.0015 (5)
C8	0.0216 (7)	0.0217 (7)	0.0214 (7)	0.0015 (6)	0.0044 (6)	0.0033 (6)
C9	0.0138 (6)	0.0171 (7)	0.0179 (6)	−0.0028 (5)	−0.0010 (5)	0.0018 (5)
C10	0.0178 (6)	0.0151 (6)	0.0142 (6)	−0.0018 (5)	0.0012 (5)	−0.0004 (5)
C11	0.0117 (6)	0.0147 (6)	0.0164 (6)	−0.0021 (5)	0.0016 (5)	0.0019 (5)
C12	0.0163 (6)	0.0168 (6)	0.0181 (7)	−0.0009 (5)	0.0020 (5)	−0.0022 (5)
C13	0.0198 (7)	0.0254 (7)	0.0154 (6)	−0.0036 (6)	0.0018 (5)	0.0002 (6)
C14	0.0199 (7)	0.0202 (7)	0.0217 (7)	−0.0025 (6)	0.0009 (5)	0.0069 (6)
C15	0.0200 (7)	0.0144 (6)	0.0257 (7)	−0.0008 (5)	0.0040 (6)	0.0004 (6)
C16	0.0191 (7)	0.0162 (6)	0.0165 (6)	−0.0029 (5)	0.0033 (5)	−0.0011 (5)
Cl1	0.01731 (18)	0.0337 (2)	0.0436 (2)	−0.00739 (15)	−0.01191 (15)	0.02295 (18)
N1	0.0283 (7)	0.0268 (7)	0.0212 (6)	0.0018 (5)	−0.0010 (5)	0.0067 (5)
N2	0.0389 (8)	0.0229 (7)	0.0337 (8)	−0.0009 (6)	0.0105 (6)	0.0087 (6)
O1	0.0140 (5)	0.0162 (5)	0.0198 (5)	−0.0031 (4)	−0.0014 (4)	0.0065 (4)
O2	0.0193 (5)	0.0128 (4)	0.0145 (5)	0.0000 (4)	0.0018 (4)	0.0002 (4)

Geometric parameters (Å, º)

C1—C6	1.3940 (19)	C9—H9B	0.9900
C1—C2	1.401 (2)	C10—O2	1.4309 (16)
C1—C7	1.4410 (19)	C10—H10A	0.9900
C2—C3	1.395 (2)	C10—H10B	0.9900
C2—C8	1.444 (2)	C11—O2	1.3735 (16)
C3—C4	1.380 (2)	C11—C16	1.3904 (19)
C3—H3	0.9500	C11—C12	1.3984 (19)
C4—C5	1.408 (2)	C12—C13	1.383 (2)
C4—Cl1	1.7168 (14)	C12—H12	0.9500
C5—O1	1.3535 (16)	C13—C14	1.396 (2)
C5—C6	1.3907 (19)	C13—H13	0.9500
C6—H6	0.9500	C14—C15	1.385 (2)
C7—N1	1.1458 (19)	C14—H14	0.9500
C8—N2	1.144 (2)	C15—C16	1.393 (2)
C9—O1	1.4474 (16)	C15—H15	0.9500
C9—C10	1.5046 (19)	C16—H16	0.9500
C9—H9A	0.9900
C6—C1—C2	121.30 (12)	O2—C10—C9	108.84 (11)
C6—C1—C7	118.41 (13)	O2—C10—H10A	109.9
C2—C1—C7	120.28 (13)	C9—C10—H10A	109.9
C3—C2—C1	118.97 (13)	O2—C10—H10B	109.9
C3—C2—C8	120.16 (13)	C9—C10—H10B	109.9
C1—C2—C8	120.82 (13)	H10A—C10—H10B	108.3
C4—C3—C2	119.68 (13)	O2—C11—C16	124.58 (12)
C4—C3—H3	120.2	O2—C11—C12	115.69 (12)
C2—C3—H3	120.2	C16—C11—C12	119.72 (12)
C3—C4—C5	121.65 (13)	C13—C12—C11	119.87 (13)
C3—C4—Cl1	119.68 (11)	C13—C12—H12	120.1
C5—C4—Cl1	118.66 (11)	C11—C12—H12	120.1
O1—C5—C6	124.76 (12)	C12—C13—C14	120.65 (13)
O1—C5—C4	116.50 (12)	C12—C13—H13	119.7
C6—C5—C4	118.72 (13)	C14—C13—H13	119.7
C5—C6—C1	119.67 (13)	C15—C14—C13	119.24 (13)
C5—C6—H6	120.2	C15—C14—H14	120.4
C1—C6—H6	120.2	C13—C14—H14	120.4
N1—C7—C1	179.14 (16)	C14—C15—C16	120.63 (13)
N2—C8—C2	177.85 (16)	C14—C15—H15	119.7
O1—C9—C10	107.41 (11)	C16—C15—H15	119.7
O1—C9—H9A	110.2	C11—C16—C15	119.87 (13)
C10—C9—H9A	110.2	C11—C16—H16	120.1
O1—C9—H9B	110.2	C15—C16—H16	120.1
C10—C9—H9B	110.2	C5—O1—C9	117.97 (10)
H9A—C9—H9B	108.5	C11—O2—C10	116.22 (10)

(II) 4-chloro-5-[2-(pentafluorophenoxy)ethoxy]benzene-1,2-dicarbonitrile

Crystal data

C16H6ClF5N2O2	F(000) = 776
Mr = 388.68	Dx = 1.728 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5920 reflections
a = 5.8272 (13) Å	θ = 2.6–27.7°
b = 13.319 (3) Å	µ = 0.33 mm^−1
c = 19.380 (4) Å	T = 100 K
β = 96.544 (2)°	Prismatic, colourless
V = 1494.3 (6) Å^3	0.24 × 0.10 × 0.08 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	3408 independent reflections
Radiation source: fine-focus sealed tube	2890 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 8.333 pixels mm^-1	θmax = 27.5°, θmin = 2.6°
φ and ω scans	h = −7→7
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	k = −17→17
Tmin = 0.925, Tmax = 0.974	l = −24→25
16533 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.088	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0382P)^2 + 1.0883P] where P = (Fo^2 + 2Fc^2)/3
3408 reflections	(Δ/σ)max < 0.001
235 parameters	Δρmax = 0.43 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Experimental. IR (KBr disk, cm^-1): 3105, 2931, 2361, 2241, 2230, 1589, 1524, 1514, 1497, 1395, 1310, 1275, 1263, 1071, 993, 980, 905, 789, 534.

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.8254 (3)	0.27727 (12)	0.27255 (8)	0.0182 (3)
C2	0.8091 (3)	0.17269 (12)	0.26444 (8)	0.0185 (3)
C3	0.6456 (3)	0.11995 (12)	0.29730 (8)	0.0190 (3)
H3	0.6328	0.0491	0.2923	0.023*
C4	0.5020 (3)	0.17142 (12)	0.33720 (8)	0.0180 (3)
C5	0.5150 (3)	0.27615 (12)	0.34450 (8)	0.0172 (3)
C6	0.6782 (3)	0.32895 (12)	0.31177 (8)	0.0181 (3)
H6	0.6890	0.3999	0.3162	0.022*
C7	1.0028 (3)	0.33312 (12)	0.24306 (8)	0.0199 (3)
C8	0.9638 (3)	0.12052 (12)	0.22354 (9)	0.0210 (3)
C9	0.3848 (3)	0.42571 (12)	0.39501 (8)	0.0186 (3)
H9A	0.3615	0.4617	0.3501	0.022*
H9B	0.5400	0.4427	0.4183	0.022*
C10	0.2010 (3)	0.45551 (13)	0.44015 (8)	0.0210 (3)
H10A	0.1853	0.5295	0.4396	0.025*
H10B	0.0512	0.4267	0.4204	0.025*
C11	0.2175 (3)	0.32331 (12)	0.52643 (8)	0.0188 (3)
C12	0.3881 (3)	0.27177 (13)	0.56812 (9)	0.0213 (3)
C13	0.3618 (3)	0.17320 (14)	0.58745 (9)	0.0233 (4)
C14	0.1595 (3)	0.12251 (12)	0.56594 (9)	0.0234 (4)
C15	−0.0159 (3)	0.17253 (13)	0.52634 (9)	0.0226 (4)
C16	0.0125 (3)	0.27144 (13)	0.50756 (8)	0.0201 (3)
Cl1	0.30422 (7)	0.10616 (3)	0.37969 (2)	0.02216 (11)
F1	0.58648 (17)	0.31911 (8)	0.59067 (5)	0.0289 (2)
F2	0.53286 (19)	0.12730 (8)	0.62754 (6)	0.0318 (3)
F3	0.1311 (2)	0.02670 (8)	0.58397 (6)	0.0318 (3)
F4	−0.21748 (18)	0.12623 (8)	0.50688 (6)	0.0308 (3)
F5	−0.16755 (17)	0.31781 (8)	0.47097 (5)	0.0264 (2)
N1	1.1470 (3)	0.37862 (11)	0.22243 (8)	0.0258 (3)
N2	1.0870 (3)	0.07993 (12)	0.19061 (8)	0.0272 (3)
O1	0.36507 (19)	0.31921 (8)	0.38395 (6)	0.0188 (2)
O2	0.2528 (2)	0.42182 (9)	0.51158 (6)	0.0222 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0187 (8)	0.0204 (8)	0.0156 (7)	0.0007 (6)	0.0018 (6)	0.0014 (6)
C2	0.0192 (8)	0.0207 (8)	0.0156 (7)	0.0031 (6)	0.0012 (6)	−0.0019 (6)
C3	0.0221 (8)	0.0169 (8)	0.0176 (7)	0.0011 (6)	0.0008 (6)	−0.0011 (6)
C4	0.0184 (7)	0.0190 (8)	0.0167 (7)	−0.0015 (6)	0.0023 (6)	0.0006 (6)
C5	0.0175 (7)	0.0189 (8)	0.0151 (7)	0.0030 (6)	0.0013 (6)	−0.0009 (6)
C6	0.0212 (8)	0.0161 (7)	0.0168 (7)	0.0009 (6)	0.0016 (6)	−0.0002 (6)
C7	0.0239 (8)	0.0186 (8)	0.0175 (8)	0.0032 (7)	0.0034 (6)	−0.0011 (6)
C8	0.0226 (8)	0.0199 (8)	0.0203 (8)	−0.0014 (6)	0.0018 (7)	−0.0018 (6)
C9	0.0205 (8)	0.0145 (7)	0.0215 (8)	0.0021 (6)	0.0051 (6)	0.0027 (6)
C10	0.0262 (8)	0.0186 (8)	0.0189 (8)	0.0047 (7)	0.0059 (6)	0.0026 (6)
C11	0.0234 (8)	0.0186 (8)	0.0156 (7)	0.0020 (6)	0.0077 (6)	−0.0003 (6)
C12	0.0185 (8)	0.0268 (9)	0.0194 (8)	−0.0008 (6)	0.0053 (6)	0.0009 (7)
C13	0.0254 (9)	0.0269 (9)	0.0186 (8)	0.0089 (7)	0.0068 (7)	0.0045 (7)
C14	0.0347 (10)	0.0171 (8)	0.0203 (8)	0.0011 (7)	0.0117 (7)	0.0008 (6)
C15	0.0243 (8)	0.0246 (9)	0.0199 (8)	−0.0044 (7)	0.0075 (7)	−0.0060 (7)
C16	0.0222 (8)	0.0225 (8)	0.0157 (7)	0.0051 (6)	0.0023 (6)	−0.0013 (6)
Cl1	0.0239 (2)	0.0186 (2)	0.0253 (2)	−0.00235 (15)	0.00838 (15)	0.00136 (15)
F1	0.0204 (5)	0.0367 (6)	0.0292 (6)	−0.0042 (4)	0.0008 (4)	0.0055 (5)
F2	0.0305 (6)	0.0356 (6)	0.0295 (6)	0.0126 (5)	0.0050 (5)	0.0121 (5)
F3	0.0493 (7)	0.0180 (5)	0.0298 (6)	−0.0011 (5)	0.0123 (5)	0.0020 (4)
F4	0.0305 (6)	0.0320 (6)	0.0301 (6)	−0.0102 (5)	0.0048 (4)	−0.0075 (5)
F5	0.0233 (5)	0.0297 (6)	0.0250 (5)	0.0037 (4)	−0.0024 (4)	0.0009 (4)
N1	0.0286 (8)	0.0257 (8)	0.0243 (8)	−0.0001 (6)	0.0079 (6)	0.0006 (6)
N2	0.0286 (8)	0.0269 (8)	0.0271 (8)	0.0008 (6)	0.0082 (6)	−0.0050 (6)
O1	0.0216 (6)	0.0156 (5)	0.0205 (6)	0.0015 (4)	0.0073 (5)	−0.0012 (4)
O2	0.0301 (6)	0.0187 (6)	0.0181 (6)	−0.0001 (5)	0.0044 (5)	0.0004 (5)

Geometric parameters (Å, º)

C1—C6	1.392 (2)	C9—H9B	0.9900
C1—C2	1.404 (2)	C10—O2	1.454 (2)
C1—C7	1.443 (2)	C10—H10A	0.9900
C2—C3	1.395 (2)	C10—H10B	0.9900
C2—C8	1.444 (2)	C11—O2	1.364 (2)
C3—C4	1.384 (2)	C11—C12	1.389 (2)
C3—H3	0.9500	C11—C16	1.392 (2)
C4—C5	1.403 (2)	C12—F1	1.3455 (19)
C4—Cl1	1.7256 (16)	C12—C13	1.379 (2)
C5—O1	1.3524 (18)	C13—F2	1.3396 (19)
C5—C6	1.392 (2)	C13—C14	1.381 (3)
C6—H6	0.9500	C14—F3	1.3383 (19)
C7—N1	1.144 (2)	C14—C15	1.378 (3)
C8—N2	1.149 (2)	C15—F4	1.342 (2)
C9—O1	1.4373 (19)	C15—C16	1.382 (2)
C9—C10	1.511 (2)	C16—F5	1.3475 (19)
C9—H9A	0.9900
C6—C1—C2	120.93 (15)	O2—C10—C9	112.73 (13)
C6—C1—C7	118.37 (15)	O2—C10—H10A	109.0
C2—C1—C7	120.64 (14)	C9—C10—H10A	109.0
C3—C2—C1	119.32 (14)	O2—C10—H10B	109.0
C3—C2—C8	120.66 (15)	C9—C10—H10B	109.0
C1—C2—C8	120.01 (15)	H10A—C10—H10B	107.8
C4—C3—C2	119.59 (15)	O2—C11—C12	118.91 (15)
C4—C3—H3	120.2	O2—C11—C16	124.56 (15)
C2—C3—H3	120.2	C12—C11—C16	116.31 (15)
C3—C4—C5	121.30 (15)	F1—C12—C13	118.42 (15)
C3—C4—Cl1	119.75 (13)	F1—C12—C11	119.27 (15)
C5—C4—Cl1	118.94 (12)	C13—C12—C11	122.31 (16)
O1—C5—C6	124.20 (14)	F2—C13—C12	119.60 (16)
O1—C5—C4	116.59 (14)	F2—C13—C14	120.34 (16)
C6—C5—C4	119.21 (14)	C12—C13—C14	120.06 (16)
C1—C6—C5	119.64 (15)	F3—C14—C15	120.03 (16)
C1—C6—H6	120.2	F3—C14—C13	120.94 (16)
C5—C6—H6	120.2	C15—C14—C13	119.03 (16)
N1—C7—C1	177.14 (18)	F4—C15—C14	120.28 (16)
N2—C8—C2	179.29 (19)	F4—C15—C16	119.44 (16)
O1—C9—C10	107.18 (13)	C14—C15—C16	120.26 (16)
O1—C9—H9A	110.3	F5—C16—C15	117.78 (15)
C10—C9—H9A	110.3	F5—C16—C11	120.27 (15)
O1—C9—H9B	110.3	C15—C16—C11	121.94 (15)
C10—C9—H9B	110.3	C5—O1—C9	117.18 (12)
H9A—C9—H9B	108.5	C11—O2—C10	118.56 (13)