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The title compound, C13H7F6N5, is one of a series of hindered tris-imine ligands for meridonial co­ordination to transition metals. The mol­ecule has crystallographic C2 symmetry, the pyrazole and pyridine rings adopting a near-coplanar transoid conformation.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199013852/bm1377sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270199013852/bm1377Isup2.hkl
Contains datablock I

CCDC reference: 142760

Comment top

Metal complexes of 3,3''-disubstituted-2,6-dipyrazol-1-ylpyridines are finding increasing use in biomimetic chemistry (Blake et al., 1998), photochemistry (Jameson et al., 1989; Catelano et al., 1999) and as catalysts (Christenson et al., 1995). An attractive feature of these ligands is that the pyrazole substituents can be varied in a synthetically facile way (Jameson & Goldsby, 1990), so that the donor properties of the ligands, and the steric environment of a coordinated metal ion, can be intimately controlled. We are presently investigating the effects of distal ligand substitution on the electronic properties and solid state dynamic behaviour of [CuL2]2+ complexes, where L is a meridional tris-imine ligand (Solanki et al., 1998; Leech et al., 1999). As a part of this work, we have synthesized the title compound, (I).

The compound crystallizes in space group C2/c, with the molecule lying across the crystallographic C2 axis which passes through N1, C4 and H4. The pyridine and pyrazole rings of the molecule adopt a transoid disposition, as is observed for the unsubstituted derivative 2,6-dipyrazol-1-ylpyridine (Bessel et al., 1992) and are essentially coplanar, the dihedral angle between the least-squares planes of the two rings being 7.8 (2)°. The C7—C8 and C8—C9 distances are respectively 0.018 (4) and 0.016 (4) Å longer than the equivalent distances in the literature structure, reflecting the electron-withdrawing power of the CF3 substituents. All other metric parameters show minimal differences between the two structures. The structural indices of Llamas-Saiz et al. (1994) for this compound are ΔA(N) = 6.8°, 102ΔR(CN) = 3.9 Å, ΔA(C) = 5.8° and 102ΔR(CC) = 4.5 Å, all of which lie within the ranges previously observed for N-aryl and N-heterocyclic pyrazoles.

In the lattice, the molecules are arranged into columns generated by the c-glide operation. Adjacent molecules are strictly coplanar by symmetry and the interplanar distance is 3.46 Å. The centroids of the pyridine rings of adjacent molecules are offset by 2.22 Å, which is close to the ideal value for an attractive ππ stacking interaction (Hunter & Sanders, 1990). There are no unusually close intermolecular contacts between these stacks of molecules.

Experimental top

The compound was prepared by the reaction of 2,6-dibromopyridine with 2.5 molar equivalents of potassium 3{5}-trifluoromethylpyrazolide in diglyme under N2 at 403 K for 5 d. The crude solid was isolated by quenching the cooled reaction mixture with water. Recrystallization was from CDCl3. Found: C 45.1; H 2.1; N 20.4%: Calculated for C13H7F6N5: C 45.0, H 2.0, N 20.2%.

Refinement top

All H atoms were located in a Fourier difference map, and were allowed to refine freely.

Computing details top

Data collection: COLLECT (Nonius, 1999); cell refinement: DENZO-SMN (Otwinowski & Minor, 1996); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEX (McArdle, 1995); software used to prepare material for publication: local program.

Figures top
[Figure 1] Fig. 1. Molecular structure showing 50% probability displacement ellipsoids, showing the atom-numbering scheme employed. Symmetry code: (i) −x, y, −3/2 − z.
2,6-Bis-(3-{trifluoromethyl}pyrazol-1-yl)pyridine top
Crystal data top
C13H7F6N5F(000) = 696
Mr = 347.24Dx = 1.711 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 15.5849 (11) ÅCell parameters from 8690 reflections
b = 11.6404 (6) Åθ = 2.3–27.5°
c = 8.1150 (7) ŵ = 0.17 mm1
β = 113.738 (3)°T = 150 K
V = 1347.63 (17) Å3Block, colourless
Z = 40.36 × 0.27 × 0.24 mm
Data collection top
Nonius KappaCCD area detector
diffractometer
1534 independent reflections
Radiation source: fine-focus sealed tube1116 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.056
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 2.3°
area detector scansh = 2017
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
k = 1514
Tmin = 0.943, Tmax = 0.961l = 910
8690 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: located in Fourier map
R[F2 > 2σ(F2)] = 0.047All H-atom parameters refined
wR(F2) = 0.139 w = 1/[σ2(Fo2) + (0.0701P)2 + 0.7815P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max = 0.01
1534 reflectionsΔρmax = 0.30 e Å3
125 parametersΔρmin = 0.27 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods
Crystal data top
C13H7F6N5V = 1347.63 (17) Å3
Mr = 347.24Z = 4
Monoclinic, C2/cMo Kα radiation
a = 15.5849 (11) ŵ = 0.17 mm1
b = 11.6404 (6) ÅT = 150 K
c = 8.1150 (7) Å0.36 × 0.27 × 0.24 mm
β = 113.738 (3)°
Data collection top
Nonius KappaCCD area detector
diffractometer
1534 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
1116 reflections with I > 2σ(I)
Tmin = 0.943, Tmax = 0.961Rint = 0.056
8690 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.139All H-atom parameters refined
S = 1.06Δρmax = 0.30 e Å3
1534 reflectionsΔρmin = 0.27 e Å3
125 parameters
Special details top

Experimental. Detector set at 30 mm from sample with different 2theta offsets 1 degree phi exposures for chi=0 degree settings 1 degree omega exposures for chi=90 degree settings

The unit cell was refined using all data.

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.

Structure solution was achieved by direct methods using SHELXS97 (Sheldrick, 1990), while least squares refinement used SHELXL97 (Sheldrick, 1997).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.00000.90938 (19)0.75000.0301 (5)
C20.06745 (12)0.97009 (15)0.6249 (2)0.0290 (4)
C30.07162 (13)1.08899 (17)0.6184 (3)0.0333 (5)
H30.1197 (16)1.1240 (18)0.529 (3)0.038 (6)*
C40.00001.1483 (2)0.75000.0343 (6)
H40.00001.233 (3)0.75000.035 (7)*
N50.13781 (10)0.90447 (14)0.4909 (2)0.0307 (4)
N60.21342 (11)0.95933 (13)0.3675 (2)0.0334 (4)
C70.26270 (13)0.87541 (15)0.2613 (3)0.0325 (5)
C80.22009 (13)0.76699 (17)0.3129 (3)0.0344 (5)
H80.2437 (16)0.693 (2)0.255 (3)0.049 (6)*
C90.13995 (13)0.78912 (16)0.4608 (3)0.0332 (5)
H90.0889 (15)0.7429 (18)0.537 (3)0.033 (5)*
C100.35415 (14)0.90242 (17)0.1116 (3)0.0377 (5)
F110.35959 (10)0.85857 (12)0.04485 (18)0.0583 (5)
F120.42573 (9)0.85687 (15)0.1378 (2)0.0719 (6)
F130.36999 (9)1.01383 (11)0.0842 (2)0.0638 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0245 (10)0.0333 (12)0.0300 (12)0.0000.0082 (9)0.000
C20.0247 (9)0.0329 (10)0.0274 (10)0.0007 (7)0.0085 (8)0.0017 (7)
C30.0288 (9)0.0334 (10)0.0314 (10)0.0034 (8)0.0056 (8)0.0023 (8)
C40.0339 (14)0.0304 (14)0.0342 (15)0.0000.0090 (12)0.000
N50.0256 (8)0.0312 (8)0.0299 (9)0.0007 (6)0.0057 (7)0.0007 (6)
N60.0265 (8)0.0345 (9)0.0319 (9)0.0008 (6)0.0041 (7)0.0005 (6)
C70.0283 (9)0.0323 (10)0.0323 (10)0.0020 (7)0.0076 (8)0.0014 (8)
C80.0321 (9)0.0323 (10)0.0346 (11)0.0022 (8)0.0093 (8)0.0029 (8)
C90.0298 (9)0.0306 (10)0.0350 (11)0.0013 (8)0.0086 (8)0.0004 (8)
C100.0334 (10)0.0353 (11)0.0360 (11)0.0059 (8)0.0053 (8)0.0023 (8)
F110.0579 (9)0.0625 (9)0.0369 (8)0.0007 (7)0.0006 (6)0.0085 (6)
F120.0290 (7)0.1090 (13)0.0636 (11)0.0092 (7)0.0039 (7)0.0290 (9)
F130.0503 (8)0.0374 (8)0.0665 (10)0.0062 (6)0.0153 (7)0.0038 (6)
Geometric parameters (Å, º) top
N1—C21.333 (2)C7—C81.409 (3)
C2—C31.386 (3)C7—C101.487 (3)
C2—N51.417 (2)C8—H80.98 (2)
C3—H30.90 (2)C8—C91.364 (3)
C3—C41.380 (2)C9—H90.95 (2)
C4—H40.98 (3)C10—F131.322 (2)
N5—N61.360 (2)C10—F121.327 (2)
N5—C91.363 (2)C10—F111.339 (2)
N6—C71.324 (2)
C2—N1—C2i116.0 (2)N6—C7—C10119.31 (16)
N1—C2—C3124.69 (17)C8—C7—C10127.88 (17)
N1—C2—N5115.35 (17)H8—C8—C9128.4 (13)
C3—C2—N5119.96 (16)H8—C8—C7127.3 (13)
H3—C3—C4123.2 (14)C9—C8—C7104.32 (17)
H3—C3—C2119.5 (14)H9—C9—C8133.8 (12)
C4—C3—C2117.36 (18)H9—C9—N5119.2 (12)
H4—C4—C3120.03 (13)C8—C9—N5106.96 (16)
C3i—C4—C3119.9 (3)F13—C10—F12107.86 (18)
N6—N5—C9112.27 (15)F13—C10—F11106.15 (17)
N6—N5—C2119.05 (16)F12—C10—F11105.23 (17)
C9—N5—C2128.63 (15)F13—C10—C7113.42 (16)
C7—N6—N5103.68 (15)F12—C10—C7112.07 (17)
N6—C7—C8112.77 (17)F11—C10—C7111.60 (17)
Symmetry code: (i) x, y, z3/2.

Experimental details

Crystal data
Chemical formulaC13H7F6N5
Mr347.24
Crystal system, space groupMonoclinic, C2/c
Temperature (K)150
a, b, c (Å)15.5849 (11), 11.6404 (6), 8.1150 (7)
β (°) 113.738 (3)
V3)1347.63 (17)
Z4
Radiation typeMo Kα
µ (mm1)0.17
Crystal size (mm)0.36 × 0.27 × 0.24
Data collection
DiffractometerNonius KappaCCD area detector
diffractometer
Absorption correctionMulti-scan
(SORTAV; Blessing, 1995)
Tmin, Tmax0.943, 0.961
No. of measured, independent and
observed [I > 2σ(I)] reflections
8690, 1534, 1116
Rint0.056
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.139, 1.06
No. of reflections1534
No. of parameters125
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.30, 0.27

Computer programs: COLLECT (Nonius, 1999), DENZO-SMN (Otwinowski & Minor, 1996), DENZO-SMN, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEX (McArdle, 1995), local program.

Selected geometric parameters (Å, º) top
N1—C21.333 (2)N5—C91.363 (2)
C2—C31.386 (3)N6—C71.324 (2)
C2—N51.417 (2)C7—C81.409 (3)
C3—C41.380 (2)C7—C101.487 (3)
N5—N61.360 (2)C8—C91.364 (3)
C2—N1—C2i116.0 (2)C9—N5—C2128.63 (15)
N1—C2—C3124.69 (17)C7—N6—N5103.68 (15)
N1—C2—N5115.35 (17)N6—C7—C8112.77 (17)
C3—C2—N5119.96 (16)N6—C7—C10119.31 (16)
C4—C3—C2117.36 (18)C8—C7—C10127.88 (17)
C3i—C4—C3119.9 (3)C9—C8—C7104.32 (17)
N6—N5—C9112.27 (15)C8—C9—N5106.96 (16)
N6—N5—C2119.05 (16)
Symmetry code: (i) x, y, z3/2.
 

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