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The title compound, C20H14N4, shows dimorphism, with crystals obtained from different solvents displaying different crystal structures. The main structural difference between the two polymorphs concerns the crystal packing, the dihedral angle between two nearly planar molecules being distinctly different. In the polymorph reported here, the molecule lies on an inversion centre.
Supporting information
CCDC reference: 274389
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.002 Å
- R factor = 0.076
- wR factor = 0.246
- Data-to-parameter ratio = 22.6
checkCIF/PLATON results
No syntax errors found
No errors found in this datablock
Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED; data reduction: CrysAlis RED (Oxford Diffraction, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1990); software used to prepare material for publication: SHELXL97.
2-(6-(6-(pyridin-2-yl)pyridin-2-yl)pyridin-2-yl)pyridine
top
Crystal data top
C20H14N4 | F(000) = 648 |
Mr = 310.35 | Dx = 1.381 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 2162 reflections |
a = 15.327 (2) Å | θ = 2.8–26.9° |
b = 12.436 (2) Å | µ = 0.09 mm−1 |
c = 8.543 (2) Å | T = 173 K |
β = 113.50 (2)° | Plate, colourless |
V = 1493.3 (5) Å3 | 0.55 × 0.40 × 0.12 mm |
Z = 4 | |
Data collection top
Oxford Diffraction XCALIBUR diffractometer | Rint = 0.088 |
Radiation source: fine-focus sealed tube | θmax = 32.2°, θmin = 3.8° |
Graphite monochromator | h = −22→22 |
ω scans | k = −18→18 |
11056 measured reflections | l = −12→11 |
2464 independent reflections | Standard reflections: 4 frames; every 30 min |
1565 reflections with I > 2σ(I) | intensity decay: 0.0% |
Refinement top
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)] = 0.076 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.246 | H-atom parameters constrained |
S = 1.14 | w = 1/[σ2(Fo2) + (0.111P)2] where P = (Fo2 + 2Fc2)/3 |
2465 reflections | (Δ/σ)max < 0.001 |
109 parameters | Δρmax = 0.37 e Å−3 |
0 restraints | Δρmin = −0.35 e Å−3 |
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 | x | y | z | Uiso*/Ueq | |
N1 | 0.90855 (10) | 0.28567 (12) | 0.04792 (18) | 0.0269 (4) | |
N2 | 0.79875 (9) | 0.23083 (10) | 0.34117 (17) | 0.0214 (4) | |
C1 | 0.93138 (13) | 0.23444 (14) | −0.0684 (2) | 0.0302 (5) | |
C2 | 0.91809 (13) | 0.12585 (14) | −0.1026 (2) | 0.0304 (5) | |
C3 | 0.87754 (13) | 0.06626 (14) | −0.0124 (2) | 0.0309 (5) | |
C4 | 0.85211 (12) | 0.11714 (13) | 0.1070 (2) | 0.0265 (5) | |
C5 | 0.86966 (11) | 0.22665 (12) | 0.13540 (19) | 0.0210 (4) | |
C6 | 0.84761 (10) | 0.28462 (12) | 0.26743 (19) | 0.0201 (4) | |
C7 | 0.87908 (12) | 0.39013 (13) | 0.3123 (2) | 0.0243 (4) | |
C8 | 0.85963 (12) | 0.44065 (13) | 0.4391 (2) | 0.0277 (5) | |
C9 | 0.80914 (12) | 0.38514 (12) | 0.5166 (2) | 0.0262 (5) | |
C10 | 0.77858 (11) | 0.28089 (12) | 0.46240 (19) | 0.0215 (4) | |
H1 | 0.95850 | 0.27550 | −0.13140 | 0.0360* | |
H2 | 0.93620 | 0.09310 | −0.18560 | 0.0360* | |
H3 | 0.86730 | −0.00880 | −0.03230 | 0.0370* | |
H4 | 0.82310 | 0.07790 | 0.16880 | 0.0320* | |
H7 | 0.91320 | 0.42650 | 0.25670 | 0.0290* | |
H8 | 0.88050 | 0.51220 | 0.47250 | 0.0330* | |
H9 | 0.79560 | 0.41760 | 0.60520 | 0.0310* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0315 (7) | 0.0292 (7) | 0.0231 (7) | −0.0030 (5) | 0.0143 (6) | −0.0023 (5) |
N2 | 0.0247 (7) | 0.0213 (6) | 0.0208 (7) | 0.0006 (5) | 0.0118 (5) | −0.0016 (5) |
C1 | 0.0343 (9) | 0.0353 (10) | 0.0257 (9) | −0.0059 (7) | 0.0170 (7) | −0.0023 (7) |
C2 | 0.0348 (9) | 0.0335 (9) | 0.0273 (9) | 0.0004 (7) | 0.0170 (7) | −0.0070 (7) |
C3 | 0.0395 (9) | 0.0261 (8) | 0.0310 (9) | 0.0009 (6) | 0.0182 (7) | −0.0044 (7) |
C4 | 0.0353 (9) | 0.0236 (8) | 0.0249 (8) | −0.0018 (6) | 0.0165 (7) | −0.0019 (6) |
C5 | 0.0217 (7) | 0.0236 (8) | 0.0180 (7) | 0.0008 (5) | 0.0082 (6) | −0.0001 (5) |
C6 | 0.0216 (7) | 0.0208 (7) | 0.0186 (7) | 0.0015 (5) | 0.0087 (6) | 0.0002 (5) |
C7 | 0.0298 (8) | 0.0221 (7) | 0.0236 (8) | −0.0003 (6) | 0.0134 (6) | 0.0006 (6) |
C8 | 0.0358 (9) | 0.0205 (7) | 0.0298 (9) | −0.0009 (6) | 0.0164 (7) | −0.0015 (6) |
C9 | 0.0353 (9) | 0.0217 (7) | 0.0255 (8) | −0.0018 (6) | 0.0164 (7) | −0.0055 (6) |
C10 | 0.0236 (7) | 0.0226 (7) | 0.0196 (8) | 0.0000 (5) | 0.0101 (6) | −0.0014 (6) |
Geometric parameters (Å, º) top
N1—C1 | 1.339 (2) | C8—C9 | 1.387 (3) |
N1—C5 | 1.345 (2) | C9—C10 | 1.393 (2) |
N2—C6 | 1.335 (2) | C10—C10i | 1.490 (2) |
N2—C10 | 1.346 (2) | C1—H1 | 0.9500 |
C1—C2 | 1.380 (2) | C2—H2 | 0.9500 |
C2—C3 | 1.383 (3) | C3—H3 | 0.9500 |
C3—C4 | 1.382 (3) | C4—H4 | 0.9500 |
C4—C5 | 1.391 (2) | C7—H7 | 0.9500 |
C5—C6 | 1.487 (2) | C8—H8 | 0.9500 |
C6—C7 | 1.398 (2) | C9—H9 | 0.9500 |
C7—C8 | 1.384 (2) | | |
| | | |
C1—N1—C5 | 117.24 (15) | N2—C10—C10i | 116.64 (13) |
C6—N2—C10 | 118.41 (13) | C9—C10—C10i | 120.94 (15) |
N1—C1—C2 | 124.24 (17) | N1—C1—H1 | 118.00 |
C1—C2—C3 | 117.90 (17) | C2—C1—H1 | 118.00 |
C2—C3—C4 | 119.20 (16) | C1—C2—H2 | 121.00 |
C3—C4—C5 | 119.03 (16) | C3—C2—H2 | 121.00 |
N1—C5—C4 | 122.37 (15) | C2—C3—H3 | 120.00 |
N1—C5—C6 | 116.25 (14) | C4—C3—H3 | 120.00 |
C4—C5—C6 | 121.37 (15) | C3—C4—H4 | 120.00 |
N2—C6—C5 | 117.07 (13) | C5—C4—H4 | 120.00 |
N2—C6—C7 | 122.56 (15) | C6—C7—H7 | 121.00 |
C5—C6—C7 | 120.35 (15) | C8—C7—H7 | 121.00 |
C6—C7—C8 | 118.84 (16) | C7—C8—H8 | 121.00 |
C7—C8—C9 | 118.90 (15) | C9—C8—H8 | 121.00 |
C8—C9—C10 | 118.83 (15) | C8—C9—H9 | 121.00 |
N2—C10—C9 | 122.43 (16) | C10—C9—H9 | 121.00 |
| | | |
C5—N1—C1—C2 | −0.4 (3) | C4—C5—C6—N2 | −8.8 (2) |
C1—N1—C5—C4 | −0.8 (3) | C4—C5—C6—C7 | 170.04 (16) |
C1—N1—C5—C6 | 178.23 (15) | N1—C5—C6—N2 | 172.19 (15) |
C10—N2—C6—C5 | 179.34 (14) | C5—C6—C7—C8 | −178.19 (16) |
C10—N2—C6—C7 | 0.5 (2) | N2—C6—C7—C8 | 0.6 (3) |
C6—N2—C10—C9 | −1.9 (2) | C6—C7—C8—C9 | −0.4 (3) |
C6—N2—C10—C10i | 178.20 (14) | C7—C8—C9—C10 | −0.9 (3) |
N1—C1—C2—C3 | 0.8 (3) | C8—C9—C10—C10i | −178.02 (16) |
C1—C2—C3—C4 | 0.1 (3) | C8—C9—C10—N2 | 2.1 (3) |
C2—C3—C4—C5 | −1.2 (3) | N2—C10—C10i—N2i | 179.98 (17) |
C3—C4—C5—N1 | 1.6 (3) | C9—C10—C10i—N2i | 0.1 (2) |
C3—C4—C5—C6 | −177.36 (16) | C9—C10—C10i—C9i | −180.00 (16) |
N1—C5—C6—C7 | −9.0 (2) | N2—C10—C10i—C9i | −0.1 (2) |
Symmetry code: (i) −x+3/2, −y+1/2, −z+1. |
Comparative table of reduced (Niggli) cell parameters (Å2) of polymorphs
(Ia) and (Ib) topPolymorph | a.a | b.b | c.c | b.c | a.c | a.b |
(Ia) | 72.983 | 97.393 | 97.393 | 20.066 | 26.105 | 26.106 |
(Ib) | 40.297 | 66.896 | 221.831 | 0.000 | -16.662 | 0.000 |
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