organic compounds
4′-[2-(Trifluoromethyl)phenyl]-2,2′:6′,2′′-terpyridine
aSchool of Chemical and Physical Sciences, University of KwaZulu–Natal, Scottsville 3209, South Africa
*Correspondence e-mail: stewart@ukzn.ac.za
The title compound, C22H14F3N3, is a versatile tridentate N-donor ligand consisting of a terpyridyl (terpy) molecule substituted in the 4′-position by a phenyl group, itself substituted in an ortho-position by a bulky trifluoromethyl group. The phenyl ring is twisted as a result of steric interactions involving the bulky trifluoromethyl substituent. This is reflected in the dihedral angle between the mean plane through the C atoms of the phenyl ring and the terpyridyl unit being 69.2 (1)°. The contains no short van der Waals contacts. However, the terpy units stack in a head-to-tail orientation perpendicular to the c axis. The structure is is loosely stabilized by π–π interactions between the terminal pyridine rings of adjacent molecules along the stack. The perpendicular distance between the mean planes through the terpy moieties of adjacent molecules is 3.4 (1) Å.
Related literature
For related structures, see: Bessel et al. (1992); Brandt et al. (1954); Dwyer & Mellor (1964); Field et al. (2002); Gillard (1983); Lindoy & Livingstone (1967); Morgan & Burstall (1932, 1934, 1938); Serpone et al. (1983); Storrier et al. (1997). For background, see Constable et al. (1990, 1992); Hunter & Sanders (1990); Kröhnke (1976); Thummel & Jahng (1985).
Experimental
Crystal data
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Data collection: CrysAlis CCD (Oxford Diffraction, 2003); cell CrysAlis RED (Oxford Diffraction, 2003); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
10.1107/S1600536809002384/hg2469sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809002384/hg2469Isup2.hkl
4'-(2'''-trifluoromethylphenyl)-2,2':6',2''-terpyridine was synthesized by the method of Kröhnke (Field et al., 2002; Kröhnke, 1976).
N-{1-(2'-pyridyl)-1-oxo-2-ethyl}pyridinium iodide (0.68 g, 2.2 mmol) and ammonium acetate (10 g, excess) were added to a suspension of 2-R-{3-(2-pyridyl)-3-oxopropenyl}benzene (2.0 mmol) in absolute ethanol (8 ml) and the mixture heated at reflux for 40 min. An off-white solid precipitated on cooling. This was collected by filtration, washed with 50% aqueous ethanol and dried in vacuo. Recrystallization from ethanol afforded colourless crystals of the desired ligands.
Yield: (0.41 g, 54%). m.p. (148 °C). Anal. (Calcd. For C22H14F3N3: C 70.0; H 3.7; N 11.1. Found: C 69.9; H 3.9; N 11.0%). MS(EI) m/z: 377, M+). 1H NMR (CDCl3): [δ 8.72 (m, 2H, H6,6''); 8.70 (m, 2H, H3,3''); 8.54 (s, 2H, H3',5'); 7.84 (m, 2H, H4,4''); 7.54 (m, 4H, C6H4); 7.35 (m, 2 H, H5,5'')]. UV/vis (CH3CN): λmax/nm (ε/M-1 cm-1): [303 (sh, 1.3 × 104); 277 (2.9 × 104); 239 (3.4 × 104); 208 (3.6 × 104)].
All H atoms were positioned in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances in the range 0.95–1.00 Å. and Uiso(H) = 1.2–1.5Ueq(C).
Data collection: CrysAlis CCD (Oxford Diffraction, 2003); cell
CrysAlis RED (Oxford Diffraction, 2003); data reduction: CrysAlis RED (Oxford Diffraction, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).C22H14F3N3 | Z = 2 |
Mr = 377.36 | F(000) = 388 |
Triclinic, P1 | Dx = 1.391 Mg m−3 |
Hall symbol: -P 1 | Melting point: 421.15 K |
a = 7.767 (5) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 10.923 (3) Å | Cell parameters from 3155 reflections |
c = 11.748 (3) Å | θ = 2.4–25° |
α = 75.64 (2)° | µ = 0.11 mm−1 |
β = 74.03 (4)° | T = 293 K |
γ = 72.93 (4)° | Square planar, colourless |
V = 900.8 (7) Å3 | 0.60 × 0.30 × 0.30 mm |
Oxford Diffraction Xcalibur2 CCD diffractometer | 3155 independent reflections |
Radiation source: Enhance (Mo)X-Ray Source | 2840 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
Detector resolution: 8.4190 pixels mm-1 | θmax = 25.0°, θmin = 2.4° |
ω/2θ scans | h = −4→9 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2003) | k = −12→12 |
Tmin = 0.930, Tmax = 0.969 | l = −13→13 |
3953 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.148 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0902P)2 + 0.255P] where P = (Fo2 + 2Fc2)/3 |
3155 reflections | (Δ/σ)max < 0.001 |
254 parameters | Δρmax = 0.43 e Å−3 |
0 restraints | Δρmin = −0.32 e Å−3 |
C22H14F3N3 | γ = 72.93 (4)° |
Mr = 377.36 | V = 900.8 (7) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.767 (5) Å | Mo Kα radiation |
b = 10.923 (3) Å | µ = 0.11 mm−1 |
c = 11.748 (3) Å | T = 293 K |
α = 75.64 (2)° | 0.60 × 0.30 × 0.30 mm |
β = 74.03 (4)° |
Oxford Diffraction Xcalibur2 CCD diffractometer | 3155 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2003) | 2840 reflections with I > 2σ(I) |
Tmin = 0.930, Tmax = 0.969 | Rint = 0.032 |
3953 measured reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.148 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.43 e Å−3 |
3155 reflections | Δρmin = −0.32 e Å−3 |
254 parameters |
Experimental. CrysAlis RED, Oxford Diffraction Ltd., Version 170. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. |
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. |
x | y | z | Uiso*/Ueq | ||
F1 | 0.5317 (2) | 0.91636 (13) | 0.35582 (14) | 0.0845 (5) | |
F2 | 0.71339 (15) | 0.74840 (14) | 0.42847 (12) | 0.0725 (4) | |
F3 | 0.4702 (2) | 0.83636 (18) | 0.54344 (13) | 0.0926 (6) | |
N1 | 1.1281 (2) | 0.32563 (14) | 0.24320 (14) | 0.0467 (4) | |
N2 | 1.02318 (17) | 0.64584 (13) | 0.06447 (11) | 0.0340 (3) | |
N3 | 0.79020 (19) | 0.97634 (14) | −0.03608 (13) | 0.0426 (4) | |
C1 | 1.1511 (2) | 0.42440 (15) | 0.15132 (14) | 0.0357 (4) | |
C2 | 1.3124 (2) | 0.41901 (18) | 0.06241 (16) | 0.0429 (4) | |
H2 | 1.3249 | 0.4894 | −0.0002 | 0.0564 (15)* | |
C3 | 1.4538 (2) | 0.30759 (19) | 0.06833 (18) | 0.0511 (5) | |
H3 | 1.5638 | 0.3026 | 0.0106 | 0.0564 (15)* | |
C4 | 1.4302 (3) | 0.20463 (19) | 0.1601 (2) | 0.0536 (5) | |
H4 | 1.5217 | 0.1275 | 0.1648 | 0.0564 (15)* | |
C5 | 1.2666 (3) | 0.21853 (19) | 0.2456 (2) | 0.0549 (5) | |
H5 | 1.2518 | 0.1491 | 0.3088 | 0.0564 (15)* | |
C6 | 0.9941 (2) | 0.54241 (15) | 0.14861 (13) | 0.0333 (3) | |
C7 | 0.8263 (2) | 0.54237 (16) | 0.23130 (14) | 0.0363 (4) | |
H7 | 0.8088 | 0.4674 | 0.2867 | 0.0564 (15)* | |
C8 | 0.6857 (2) | 0.65547 (16) | 0.22996 (13) | 0.0341 (4) | |
C9 | 0.7156 (2) | 0.76331 (15) | 0.14389 (14) | 0.0345 (4) | |
H9 | 0.6248 | 0.8409 | 0.1413 | 0.0564 (15)* | |
C10 | 0.8849 (2) | 0.75402 (15) | 0.06062 (13) | 0.0328 (4) | |
C11 | 0.9179 (2) | 0.86326 (15) | −0.04004 (14) | 0.0334 (4) | |
C12 | 1.0712 (2) | 0.84656 (17) | −0.13472 (15) | 0.0410 (4) | |
H12 | 1.1568 | 0.7666 | −0.1354 | 0.0564 (15)* | |
C13 | 1.0949 (2) | 0.94940 (19) | −0.22719 (16) | 0.0476 (4) | |
H13 | 1.1972 | 0.9404 | −0.2909 | 0.0564 (15)* | |
C14 | 0.9649 (3) | 1.06607 (18) | −0.22414 (17) | 0.0495 (4) | |
H14 | 0.9767 | 1.1375 | −0.2856 | 0.0564 (15)* | |
C15 | 0.8167 (3) | 1.07390 (18) | −0.12736 (17) | 0.0492 (4) | |
H15 | 0.7290 | 1.1529 | −0.1257 | 0.0564 (15)* | |
C16 | 0.5028 (2) | 0.65338 (15) | 0.31581 (13) | 0.0341 (4) | |
C17 | 0.4308 (2) | 0.72287 (15) | 0.41048 (14) | 0.0351 (4) | |
C18 | 0.2588 (2) | 0.71521 (17) | 0.48555 (15) | 0.0414 (4) | |
H18 | 0.2120 | 0.7612 | 0.5488 | 0.0564 (15)* | |
C19 | 0.1581 (2) | 0.64052 (19) | 0.46690 (16) | 0.0473 (4) | |
H19 | 0.0426 | 0.6373 | 0.5163 | 0.0564 (15)* | |
C20 | 0.2281 (3) | 0.5707 (2) | 0.37529 (17) | 0.0526 (5) | |
H20 | 0.1606 | 0.5192 | 0.3631 | 0.0564 (15)* | |
C21 | 0.3993 (2) | 0.57662 (19) | 0.30069 (16) | 0.0459 (4) | |
H21 | 0.4459 | 0.5282 | 0.2392 | 0.0564 (15)* | |
C22 | 0.5349 (2) | 0.80526 (19) | 0.43493 (16) | 0.0481 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.1039 (11) | 0.0570 (8) | 0.1051 (11) | −0.0432 (8) | −0.0206 (9) | −0.0113 (7) |
F2 | 0.0405 (6) | 0.1046 (10) | 0.0925 (10) | −0.0248 (6) | −0.0147 (6) | −0.0448 (8) |
F3 | 0.0829 (10) | 0.1468 (14) | 0.0763 (9) | −0.0633 (10) | 0.0233 (7) | −0.0738 (10) |
N1 | 0.0386 (8) | 0.0444 (8) | 0.0533 (9) | −0.0056 (6) | −0.0115 (6) | −0.0057 (7) |
N2 | 0.0272 (6) | 0.0400 (7) | 0.0361 (7) | −0.0077 (5) | −0.0057 (5) | −0.0112 (6) |
N3 | 0.0359 (7) | 0.0409 (8) | 0.0466 (8) | −0.0062 (6) | −0.0045 (6) | −0.0089 (6) |
C1 | 0.0325 (8) | 0.0396 (9) | 0.0391 (8) | −0.0072 (6) | −0.0108 (6) | −0.0128 (7) |
C2 | 0.0349 (8) | 0.0485 (10) | 0.0443 (9) | −0.0048 (7) | −0.0064 (7) | −0.0154 (7) |
C3 | 0.0331 (9) | 0.0588 (11) | 0.0607 (11) | −0.0009 (8) | −0.0070 (8) | −0.0257 (9) |
C4 | 0.0388 (9) | 0.0459 (10) | 0.0775 (13) | 0.0035 (8) | −0.0220 (9) | −0.0197 (9) |
C5 | 0.0469 (10) | 0.0452 (10) | 0.0688 (13) | −0.0050 (8) | −0.0202 (9) | −0.0027 (9) |
C6 | 0.0296 (8) | 0.0401 (8) | 0.0333 (8) | −0.0085 (6) | −0.0074 (6) | −0.0113 (6) |
C7 | 0.0326 (8) | 0.0414 (9) | 0.0351 (8) | −0.0102 (6) | −0.0063 (6) | −0.0071 (6) |
C8 | 0.0277 (7) | 0.0436 (9) | 0.0335 (8) | −0.0112 (6) | −0.0034 (6) | −0.0121 (6) |
C9 | 0.0268 (7) | 0.0377 (8) | 0.0393 (8) | −0.0069 (6) | −0.0043 (6) | −0.0120 (6) |
C10 | 0.0268 (7) | 0.0396 (8) | 0.0353 (8) | −0.0099 (6) | −0.0053 (6) | −0.0119 (6) |
C11 | 0.0267 (7) | 0.0396 (8) | 0.0372 (8) | −0.0093 (6) | −0.0081 (6) | −0.0105 (6) |
C12 | 0.0301 (8) | 0.0476 (9) | 0.0420 (9) | −0.0079 (7) | −0.0043 (6) | −0.0081 (7) |
C13 | 0.0384 (9) | 0.0601 (11) | 0.0399 (9) | −0.0157 (8) | −0.0014 (7) | −0.0046 (8) |
C14 | 0.0521 (10) | 0.0501 (10) | 0.0454 (10) | −0.0181 (8) | −0.0133 (8) | 0.0029 (8) |
C15 | 0.0485 (10) | 0.0401 (9) | 0.0533 (10) | −0.0060 (8) | −0.0103 (8) | −0.0053 (8) |
C16 | 0.0275 (7) | 0.0402 (8) | 0.0340 (8) | −0.0107 (6) | −0.0053 (6) | −0.0043 (6) |
C17 | 0.0270 (7) | 0.0403 (8) | 0.0362 (8) | −0.0086 (6) | −0.0045 (6) | −0.0058 (6) |
C18 | 0.0302 (8) | 0.0497 (9) | 0.0382 (8) | −0.0086 (7) | −0.0001 (6) | −0.0070 (7) |
C19 | 0.0303 (8) | 0.0657 (11) | 0.0426 (9) | −0.0209 (8) | −0.0033 (7) | 0.0019 (8) |
C20 | 0.0468 (10) | 0.0716 (13) | 0.0498 (10) | −0.0368 (9) | −0.0091 (8) | −0.0042 (9) |
C21 | 0.0462 (9) | 0.0571 (11) | 0.0415 (9) | −0.0253 (8) | −0.0032 (7) | −0.0132 (8) |
C22 | 0.0403 (9) | 0.0588 (11) | 0.0489 (10) | −0.0186 (8) | 0.0036 (7) | −0.0235 (9) |
F1—C22 | 1.331 (2) | C9—C10 | 1.400 (2) |
F2—C22 | 1.332 (2) | C9—H9 | 0.9300 |
F3—C22 | 1.325 (2) | C10—C11 | 1.484 (2) |
N1—C5 | 1.337 (2) | C11—C12 | 1.390 (2) |
N1—C1 | 1.338 (2) | C12—C13 | 1.372 (2) |
N2—C6 | 1.333 (2) | C12—H12 | 0.9300 |
N2—C10 | 1.344 (2) | C13—C14 | 1.376 (3) |
N3—C15 | 1.330 (2) | C13—H13 | 0.9300 |
N3—C11 | 1.340 (2) | C14—C15 | 1.377 (3) |
C1—C2 | 1.389 (2) | C14—H14 | 0.9300 |
C1—C6 | 1.493 (2) | C15—H15 | 0.9300 |
C2—C3 | 1.381 (3) | C16—C21 | 1.388 (2) |
C2—H2 | 0.9300 | C16—C17 | 1.398 (2) |
C3—C4 | 1.368 (3) | C17—C18 | 1.397 (2) |
C3—H3 | 0.9300 | C17—C22 | 1.493 (2) |
C4—C5 | 1.381 (3) | C18—C19 | 1.372 (3) |
C4—H4 | 0.9300 | C18—H18 | 0.9300 |
C5—H5 | 0.9300 | C19—C20 | 1.370 (3) |
C6—C7 | 1.395 (2) | C19—H19 | 0.9300 |
C7—C8 | 1.388 (2) | C20—C21 | 1.387 (3) |
C7—H7 | 0.9300 | C20—H20 | 0.9300 |
C8—C9 | 1.380 (2) | C21—H21 | 0.9300 |
C8—C16 | 1.501 (2) | ||
C5—N1—C1 | 117.21 (16) | C13—C12—C11 | 119.27 (16) |
C6—N2—C10 | 118.17 (13) | C13—C12—H12 | 120.4 |
C15—N3—C11 | 116.89 (15) | C11—C12—H12 | 120.4 |
N1—C1—C2 | 122.33 (15) | C12—C13—C14 | 118.93 (16) |
N1—C1—C6 | 116.64 (15) | C12—C13—H13 | 120.5 |
C2—C1—C6 | 121.03 (15) | C14—C13—H13 | 120.5 |
C3—C2—C1 | 119.02 (17) | C13—C14—C15 | 118.00 (16) |
C3—C2—H2 | 120.5 | C13—C14—H14 | 121.0 |
C1—C2—H2 | 120.5 | C15—C14—H14 | 121.0 |
C4—C3—C2 | 119.23 (17) | N3—C15—C14 | 124.54 (17) |
C4—C3—H3 | 120.4 | N3—C15—H15 | 117.7 |
C2—C3—H3 | 120.4 | C14—C15—H15 | 117.7 |
C3—C4—C5 | 118.07 (17) | C21—C16—C17 | 117.94 (14) |
C3—C4—H4 | 121.0 | C21—C16—C8 | 117.85 (14) |
C5—C4—H4 | 121.0 | C17—C16—C8 | 124.21 (14) |
N1—C5—C4 | 124.10 (19) | C18—C17—C16 | 120.11 (15) |
N1—C5—H5 | 118.0 | C18—C17—C22 | 118.44 (15) |
C4—C5—H5 | 118.0 | C16—C17—C22 | 121.44 (14) |
N2—C6—C7 | 122.53 (15) | C19—C18—C17 | 120.60 (16) |
N2—C6—C1 | 116.83 (14) | C19—C18—H18 | 119.7 |
C7—C6—C1 | 120.63 (15) | C17—C18—H18 | 119.7 |
C8—C7—C6 | 119.27 (15) | C20—C19—C18 | 119.89 (15) |
C8—C7—H7 | 120.4 | C20—C19—H19 | 120.1 |
C6—C7—H7 | 120.4 | C18—C19—H19 | 120.1 |
C9—C8—C7 | 118.43 (14) | C19—C20—C21 | 120.07 (16) |
C9—C8—C16 | 122.38 (14) | C19—C20—H20 | 120.0 |
C7—C8—C16 | 119.04 (15) | C21—C20—H20 | 120.0 |
C8—C9—C10 | 118.93 (14) | C20—C21—C16 | 121.37 (17) |
C8—C9—H9 | 120.5 | C20—C21—H21 | 119.3 |
C10—C9—H9 | 120.5 | C16—C21—H21 | 119.3 |
N2—C10—C9 | 122.57 (15) | F3—C22—F2 | 105.78 (17) |
N2—C10—C11 | 116.41 (13) | F3—C22—F1 | 107.02 (17) |
C9—C10—C11 | 120.99 (14) | F2—C22—F1 | 104.80 (16) |
N3—C11—C12 | 122.37 (15) | F3—C22—C17 | 112.81 (14) |
N3—C11—C10 | 116.52 (14) | F2—C22—C17 | 113.43 (15) |
C12—C11—C10 | 121.08 (14) | F1—C22—C17 | 112.38 (16) |
C5—N1—C1—C2 | −1.2 (2) | C9—C10—C11—C12 | −168.23 (14) |
C5—N1—C1—C6 | 178.95 (15) | N3—C11—C12—C13 | 0.7 (2) |
N1—C1—C2—C3 | 0.4 (2) | C10—C11—C12—C13 | 178.79 (15) |
C6—C1—C2—C3 | −179.75 (14) | C11—C12—C13—C14 | −0.7 (3) |
C1—C2—C3—C4 | 1.2 (3) | C12—C13—C14—C15 | 0.3 (3) |
C2—C3—C4—C5 | −2.0 (3) | C11—N3—C15—C14 | 0.0 (3) |
C1—N1—C5—C4 | 0.4 (3) | C13—C14—C15—N3 | 0.1 (3) |
C3—C4—C5—N1 | 1.2 (3) | C9—C8—C16—C21 | 109.60 (18) |
C10—N2—C6—C7 | 0.5 (2) | C7—C8—C16—C21 | −65.9 (2) |
C10—N2—C6—C1 | −179.33 (12) | C9—C8—C16—C17 | −70.9 (2) |
N1—C1—C6—N2 | 173.37 (13) | C7—C8—C16—C17 | 113.59 (18) |
C2—C1—C6—N2 | −6.5 (2) | C21—C16—C17—C18 | −0.8 (2) |
N1—C1—C6—C7 | −6.5 (2) | C8—C16—C17—C18 | 179.76 (14) |
C2—C1—C6—C7 | 173.69 (14) | C21—C16—C17—C22 | 178.55 (16) |
N2—C6—C7—C8 | −2.7 (2) | C8—C16—C17—C22 | −0.9 (2) |
C1—C6—C7—C8 | 177.13 (13) | C16—C17—C18—C19 | −0.5 (2) |
C6—C7—C8—C9 | 1.9 (2) | C22—C17—C18—C19 | −179.83 (16) |
C6—C7—C8—C16 | 177.55 (13) | C17—C18—C19—C20 | 1.3 (3) |
C7—C8—C9—C10 | 0.9 (2) | C18—C19—C20—C21 | −0.7 (3) |
C16—C8—C9—C10 | −174.63 (13) | C19—C20—C21—C16 | −0.6 (3) |
C6—N2—C10—C9 | 2.5 (2) | C17—C16—C21—C20 | 1.3 (3) |
C6—N2—C10—C11 | −175.44 (12) | C8—C16—C21—C20 | −179.21 (17) |
C8—C9—C10—N2 | −3.2 (2) | C18—C17—C22—F3 | 15.5 (2) |
C8—C9—C10—C11 | 174.63 (13) | C16—C17—C22—F3 | −163.81 (17) |
C15—N3—C11—C12 | −0.4 (2) | C18—C17—C22—F2 | 135.79 (17) |
C15—N3—C11—C10 | −178.53 (14) | C16—C17—C22—F2 | −43.6 (2) |
N2—C10—C11—N3 | −172.12 (13) | C18—C17—C22—F1 | −105.57 (18) |
C9—C10—C11—N3 | 9.9 (2) | C16—C17—C22—F1 | 75.1 (2) |
N2—C10—C11—C12 | 9.7 (2) |
Experimental details
Crystal data | |
Chemical formula | C22H14F3N3 |
Mr | 377.36 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 7.767 (5), 10.923 (3), 11.748 (3) |
α, β, γ (°) | 75.64 (2), 74.03 (4), 72.93 (4) |
V (Å3) | 900.8 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.60 × 0.30 × 0.30 |
Data collection | |
Diffractometer | Oxford Diffraction Xcalibur2 CCD diffractometer |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2003) |
Tmin, Tmax | 0.930, 0.969 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3953, 3155, 2840 |
Rint | 0.032 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.148, 1.06 |
No. of reflections | 3155 |
No. of parameters | 254 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.43, −0.32 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2003), CrysAlis RED (Oxford Diffraction, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).
Acknowledgements
The authors acknowledge financial support from the South African National Research Foundation and the Department of Labour. We also extend our appreciation to Professor John Field for helpful discussions and guidance.
References
Bessel, C. A., See, R. F., Jameson, D. L., Churchill, M. R. & Takeuchi, K. J. (1992). J. Chem. Soc. Dalton Trans. pp. 3223–3228. CSD CrossRef Web of Science Google Scholar
Brandt, W. W., Dwyer, F. P. & Gyarfas, E. C. (1954). Chem. Rev. 54, 959–1017. CrossRef CAS Web of Science Google Scholar
Constable, E. C., Khan, F. K., Marquez, V. E. & Raithby, P. R. (1992). Acta Cryst. C48, 932–934. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Constable, E. C., Lewis, J., Liptrot, M. C. & Raithby, P. R. (1990). Inorg. Chim. Acta, 178, 47–54. CSD CrossRef CAS Web of Science Google Scholar
Dwyer, F. P. & Mellor, D. P. (1964). In Chelating Agents and Metal Chelates. Orlando: Academic Press. 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
Field, J. S., Haines, R. J., McMillin, D. R. & Summerton, G. C. (2002). J. Chem. Soc. Dalton Trans. pp. 1369–1376. Web of Science CSD CrossRef Google Scholar
Gillard, R. D. (1983). Coord. Chem. Rev. 50, 303–309. CrossRef CAS Google Scholar
Hunter, C. A. & Sanders, J. K. M. (1990). J. Am. Chem. Soc. 112, 5525–5534. CrossRef CAS Web of Science Google Scholar
Kröhnke, F. (1976). Synthesis, pp. 1–24. Google Scholar
Lindoy, L. F. & Livingstone, S. E. (1967). Coord. Chem. Rev. 2, 173–193. CrossRef CAS Google Scholar
Morgan, G. T. & Burstall, F. H. (1932). J. Chem. Soc. pp. 20–30. CrossRef Google Scholar
Morgan, G. T. & Burstall, F. H. (1934). J. Chem. Soc. pp. 1498–1500. CrossRef Google Scholar
Morgan, G. T. & Burstall, F. H. (1938). J. Chem. Soc. pp. 1675–1678. CrossRef Google Scholar
Oxford Diffraction (2003). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England. Google Scholar
Serpone, N., Ponterini, G., Jamieson, M. A., Bolletta, F. & Maestri, M. (1983). Coord. Chem. Rev. 50, 209–302. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Storrier, G. D., Colbran, S. B. & Craig, D. C. (1997). J. Chem. Soc. Dalton Trans. pp. 3011–3028. CSD CrossRef Web of Science Google Scholar
Thummel, R. P. & Jahng, Y. (1985). J. Org. Chem. 50, 2407–2013. 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.
The tridentate coordinating ligand 2,2':6',2''-terpyridine (terpy) was first isolated by Morgan & Burstall (1932, 1934, 1938) as one of the numerous products from the reaction of pyridine with iron(III) chloride.
Since the 1930s, numerous groups have examined terpy, prompted by the use of related ligands 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen), in photochemical and photophysical processes (Brandt et al., 1954; Dwyer & Mellor, 1964; Gillard, 1983; Lindoy & Livingstone, 1967; Serpone et al., 1983).
Reported here is the crystal structure of the tridentate terpyridyl ligand substituted in the 4'-position by a phenyl group, itself substituted in an ortho-position by a bulky trifluoromethyl group. Ortho-substitution of the 4'-phenyl ring was chosen since steric interactions between the bulky group and the 3'(5')-proton on the central pyridine ring are expected to force the 4'-substituent to rotate around the interannular bond i.e. the ligand will become non-planar.
In the crystal structure of 4'-(2'''-trifluoromethylphenyl)-2, 2':6',2''-terpyridine, the three pyridyl rings of the terpyridyl moiety are essentially co-planar as is preferred for maximum conjugative interaction (Thummel & Jahng, 1985). This is reflected by torsion angles between the two outer rings and the central ring of -6.5 (2)° and 9.9 (2)° for N1—C1—C6—C7 and C9—C10—C11—N3 respectively.
The terminal pyridine rings adopt a trans–trans conformation about the interannular bonds C1—C6 and C10—C11. Several derivatized terpy ligands have been found to adopt this trans–trans geometry by X-ray crystal analysis (Constable et al., 1990) which is more energetically favourable when compared to other conformations as a result of the minimal nitrogen lone pair repulsions (Thummel & Jahng, 1985).
The interannular bond distances C1—C6 and C10—C11 are 1.493 (2) Å and 1.484 (2) Å respectively; these distances are comparable with the averaged values of 1.49 (1) Å and 1.49 (1) Å measured for the terpy (Bessel et al., 1992) and 4'-(Ph)-terpy (Constable et al., 1990) ligands respectively.
As previously postulated, the o-tolyl moiety is twisted about the interannular bond C8—C16, as reflected in a dihedral angle between the mean plane through the carbon atoms of the 4'-substituted and the terpyridyl moiety of 69.2 (1)°. This angle may be compared with those adopted by terpyridyl ligands containing similar substituents in the 4'-position of the terpy moiety in molecules such as the free 4'-phenyl-terpyridine (10.9°) (Constable et al., 1990), 6,6''-dibromo-4'-phenyl-terpyridine (35.1°) (Constable et al, 1992) and 4'-(4-anilino)-terpyridine (27.2°) (Storrier et al., 1997). The larger angle witnessed in the title compound is consistent with the bulky nature of the trifluoro group and the fact that it substitutes the ortho-position of the phenyl moiety. Clearly, substitution of a trifluoro group in the ortho-position of the 4'-phenyl group causes a larger rotation about the interannular bond because of steric interactions between the CF3 group and a hydrogen atom of the central pyridine ring that is also ortho with respect to the interannular bond.
There are no short van der Waals contacts less than the sum of the van der Waals radii in this system. However it is worth noting, that the terpy units stack in a head to tail orientation perpendicular to the [c]-axis, presumably as a result of minimizing steric interactions between the bulky trifluoromethyl substituents on adjacent molecules. However it is clear that this arrangement is not entirely successful and that poor packing does result from the presence of these bulky substituents reflected in the large solvent accessible void of 31 Å3. This packing orientation allows for π–π interactions between the terminal pyridine rings of adjacent molecules along the stack. The perpendicular distance between the mean planes through the terpy moieties of adjacent molecules is 3.4 (1)Å which is short enough to support π–π interactions being well within the upper distance limit of 3.8 Å for π–π interactions between organic molecules (Hunter & Sanders, 1990).
The stucture of the title compound is shown in Fig. 1. Fig. 2 shows a view perpendicular to the mean plane through the atoms comprising the terpyridyl (terpy) moiety of two adjacent terpy units in the crystals of the 4'-(2'''-trifluoromethylphenyl)-2, 2':6', 2''-terpyridine ligand. Note that the successive molecules are related by a centre of inversion.