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. 2020 Mar 17;5(Pt 3):x200372. doi: 10.1107/S2414314620003727

2,5-Bis[(E)-2-phenyl­ethen­yl]-3,6-bis­(pyridin-2-yl)pyrazine

Heiner Detert a,*, Matthias Jochem a, Dieter Schollmeyer a
Editor: M Bolteb
PMCID: PMC9462200  PMID: 36339482

The title mol­ecule has inversion symmetry, adopting the shape of a St Andrew’s cross. It shows dihedral angles between adjacent aryl units of around 50° whereas torsion angles of ca 10° are found along the aryl­ene vinyl­ene path.

Keywords: crystal structure, heterocycles, conjugated oligomers

Abstract

The mol­ecule of the title compound, C30H22N4, exhibits inversion symmetry adopting the shape of a St Andrew’s Cross. It shows dihedral angles between adjacent aryl units of around 50° whereas torsion angles of ca 10° are found along the aryl­ene vinyl­ene path. graphic file with name x-05-x200372-scheme1-3D1.jpg

Structure description

The title compound 2,5-(E,E)-distyryl-3,6-di-(2-pyrid­yl)pyrazine, C30H22N4, was prepared as a reference chromophore in a project on pyrazine-centered materials, solvatochromic dyes (Schmitt et al., 2008, Wink & Detert, 2013) and liquid crystals (Röder et al., 2019; Schmitt et al., 2011).

The mol­ecule has the shape of a centrosymmetrical St Andrew’s cross (Fig. 1). The central pyrazine ring as well as the vinyl­ene groups and the peripheral pyridine and phenyl rings are totally planar. A dihedral angle of 48.07 (6)° at the teraryl axis is nearly identical to those in a related compound with phenyl rings (50.8, 48.6°, Schmitt et al., 2013). Torsion angles along the distyryl axis are −170.21 (15)°, (phenyl-vin­yl) and −169.56 (14)° (vinyl-pyrazine). The packing is shown in Fig. 2.

Figure 1.

Figure 1

Perspective view of the title compound. Displacement ellipsoids are drawn at the 50% probability level. The second part of the mol­ecule is generated by the symmetry operation 1 − x, 1 − y, 1 − z.

Figure 2.

Figure 2

Partial packing diagram of the title compound. View along the a axis.

Synthesis and crystallization

The title compound was prepared from 2,5-dimethyl-3,6-di(2-pyrid­yl)pyrazine (Kolb, 1896) (0.08 g) and benzaldehyde (0.13 g) in 35 ml of DMF by the action of 0.34 g potassium t-butyl­ate. The base was added in portions to the stirred and cooled (30 min at 273 K) solution. After 4 h at ambient temperature, the mixture was poured into water, extracted with ethyl acetate and the organic layers were washed, dried (Na2SO4) and concentrated. Purification by chromatography on solica gel with toluene/ethyl acetate (20/1) as eluent, R f = 0.33. Yield: 40 mg, 30%.

1H NMR (CDCl3, 400 MHz): 8.83 (dd, J = 4.9 Hz, J = 1.5 Hz, 2 H), 8.23 (d, J = 7.8 Hz, 2 H), 8.03 (s = 2d, J = 16.1 Hz, 4 H), 7.95 (dt, J = 7.8 Hz, J = 1.9 Hz, 2 H), 7.58 (d, 4 H), 7.43 (ddd, J = 7.8 Hz, J = 4.9 Hz, J = 1.5 Hz, 2H), 7.36 (t, J = 7.3 Hz, 4 H), 7.29 (dt, J = 7.3 Hz, J = 1.4 Hz, 2H); 13C NMR (CDCl3, 100 MHz): 157.1, 148.9, 148.3, 145.9, 137.3, 137.0, 135.2, 128.7, 127.6, 125.4, 124.7, 123.6; IR (ATR): 3009, 2988, 2926, 2853, 2688, 1473, 1448, 1276, 1254, 1135, 1086, 1040, 962, 901, 89, 752, 699, 621; MS (APCI): calculated for C30H22N4+H+): 439.1917, found 439.1908.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

Table 1. Experimental details.

Crystal data
Chemical formula C30H22N4
M r 438.51
Crystal system, space group Monoclinic, P21/c
Temperature (K) 193
a, b, c (Å) 7.0953 (8), 8.9310 (8), 18.219 (2)
β (°) 95.490 (9)
V3) 1149.2 (2)
Z 2
Radiation type Mo Kα
μ (mm−1) 0.08
Crystal size (mm) 0.53 × 0.32 × 0.06
 
Data collection
Diffractometer STOE IPDS 2T
Absorption correction
No. of measured, independent and observed [I > 2σ(I)] reflections 5878, 2718, 1622
R int 0.029
(sin θ/λ)max−1) 0.659
 
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S 0.043, 0.110, 0.99
No. of reflections 2718
No. of parameters 154
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.17, −0.14

Computer programs: X-AREA and X-RED (Stoe & Cie, 1996), SIR2004 (Burla et al., 2005), SHELXL2018 (Sheldrick, 2015) and PLATON (Spek, 2020).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2414314620003727/bt4090sup1.cif

x-05-x200372-sup1.cif (219KB, cif)

Structure factors: contains datablock(s) I. DOI: 10.1107/S2414314620003727/bt4090Isup2.hkl

x-05-x200372-Isup2.hkl (217.5KB, hkl)

Supporting information file. DOI: 10.1107/S2414314620003727/bt4090Isup3.cml

CCDC reference: 1989990

Additional supporting information: crystallographic information; 3D view; checkCIF report

full crystallographic data

Crystal data

C30H22N4 F(000) = 460
Mr = 438.51 Dx = 1.267 Mg m3
Monoclinic, P21/c Mo Kα radiation, λ = 0.71073 Å
a = 7.0953 (8) Å Cell parameters from 3402 reflections
b = 8.9310 (8) Å θ = 2.5–28.2°
c = 18.219 (2) Å µ = 0.08 mm1
β = 95.490 (9)° T = 193 K
V = 1149.2 (2) Å3 Plate, yellow
Z = 2 0.53 × 0.32 × 0.06 mm

Data collection

STOE IPDS 2T diffractometer 1622 reflections with I > 2σ(I)
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus Rint = 0.029
Detector resolution: 6.67 pixels mm-1 θmax = 27.9°, θmin = 2.5°
rotation method scans h = −9→9
5878 measured reflections k = −10→11
2718 independent reflections l = −23→21

Refinement

Refinement on F2 Primary atom site location: structure-invariant direct methods
Least-squares matrix: full Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.043 H-atom parameters constrained
wR(F2) = 0.110 w = 1/[σ2(Fo2) + (0.0551P)2] where P = (Fo2 + 2Fc2)/3
S = 0.99 (Δ/σ)max < 0.001
2718 reflections Δρmax = 0.17 e Å3
154 parameters Δρmin = −0.14 e Å3
0 restraints

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Hydrogen atoms attached to carbons were placed at calculated positions and were refined in the riding-model approximation with C–H = 0.95 Å, and with Uiso(H) = 1.2 Ueq(C).

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

x y z Uiso*/Ueq
N1 0.56710 (15) 0.38847 (13) 0.45640 (6) 0.0371 (3)
C2 0.65303 (18) 0.52229 (16) 0.46177 (7) 0.0356 (3)
C3 0.58305 (19) 0.63537 (16) 0.50618 (7) 0.0349 (3)
C4 0.82169 (19) 0.54154 (17) 0.42232 (8) 0.0377 (3)
H4 0.898305 0.627307 0.433494 0.045*
C5 0.8747 (2) 0.44665 (17) 0.37180 (8) 0.0394 (3)
H5 0.796135 0.361702 0.361337 0.047*
C6 1.04162 (19) 0.45956 (17) 0.33065 (8) 0.0385 (4)
C7 1.0601 (2) 0.3624 (2) 0.27172 (8) 0.0524 (4)
H7 0.965446 0.288996 0.259487 0.063*
C8 1.2135 (3) 0.3716 (2) 0.23111 (10) 0.0691 (6)
H8 1.223164 0.305063 0.190953 0.083*
C9 1.3524 (3) 0.4758 (3) 0.24812 (10) 0.0697 (6)
H9 1.458129 0.481619 0.219953 0.084*
C10 1.3377 (2) 0.5724 (2) 0.30648 (10) 0.0585 (5)
H10 1.433770 0.644817 0.318544 0.070*
C11 1.1840 (2) 0.56400 (19) 0.34735 (8) 0.0444 (4)
H11 1.175609 0.630726 0.387515 0.053*
C12 0.66436 (18) 0.78758 (17) 0.51362 (8) 0.0364 (3)
N13 0.69586 (16) 0.85842 (14) 0.45085 (7) 0.0415 (3)
C14 0.7551 (2) 1.00017 (19) 0.45675 (10) 0.0487 (4)
H14 0.774730 1.052537 0.412735 0.058*
C15 0.7892 (2) 1.0746 (2) 0.52227 (11) 0.0545 (5)
H15 0.831478 1.175580 0.523436 0.065*
C16 0.7610 (2) 1.0003 (2) 0.58648 (10) 0.0555 (5)
H16 0.786532 1.048282 0.632899 0.067*
C17 0.6949 (2) 0.85434 (19) 0.58234 (9) 0.0467 (4)
H17 0.671004 0.801209 0.625662 0.056*

Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23
N1 0.0403 (6) 0.0387 (7) 0.0329 (6) 0.0050 (5) 0.0070 (5) 0.0027 (5)
C2 0.0356 (7) 0.0408 (9) 0.0310 (7) 0.0055 (6) 0.0066 (6) 0.0059 (6)
C3 0.0365 (7) 0.0376 (8) 0.0312 (7) 0.0064 (6) 0.0056 (5) 0.0055 (6)
C4 0.0389 (7) 0.0382 (8) 0.0371 (7) 0.0031 (6) 0.0087 (6) 0.0026 (7)
C5 0.0414 (7) 0.0412 (8) 0.0362 (8) 0.0023 (7) 0.0069 (6) 0.0029 (7)
C6 0.0382 (7) 0.0472 (9) 0.0306 (7) 0.0095 (6) 0.0054 (5) 0.0028 (7)
C7 0.0546 (10) 0.0671 (12) 0.0359 (8) 0.0094 (8) 0.0072 (7) −0.0088 (8)
C8 0.0652 (12) 0.1046 (17) 0.0397 (9) 0.0236 (12) 0.0156 (8) −0.0111 (10)
C9 0.0503 (10) 0.1129 (18) 0.0494 (10) 0.0206 (12) 0.0227 (8) 0.0132 (12)
C10 0.0414 (8) 0.0791 (13) 0.0562 (10) 0.0031 (9) 0.0107 (7) 0.0166 (10)
C11 0.0429 (8) 0.0512 (10) 0.0400 (8) 0.0060 (7) 0.0079 (6) 0.0034 (7)
C12 0.0312 (7) 0.0392 (8) 0.0391 (8) 0.0059 (6) 0.0057 (6) 0.0000 (7)
N13 0.0395 (7) 0.0396 (7) 0.0462 (7) −0.0004 (6) 0.0073 (5) 0.0044 (6)
C14 0.0401 (8) 0.0426 (10) 0.0644 (11) 0.0005 (7) 0.0093 (7) 0.0066 (8)
C15 0.0393 (8) 0.0422 (10) 0.0820 (13) 0.0020 (7) 0.0065 (8) −0.0087 (10)
C16 0.0446 (9) 0.0606 (11) 0.0602 (11) 0.0061 (8) 0.0001 (8) −0.0226 (9)
C17 0.0437 (8) 0.0532 (10) 0.0433 (9) 0.0070 (7) 0.0049 (6) −0.0042 (8)

Geometric parameters (Å, º)

N1—C3i 1.3356 (17) C9—C10 1.381 (3)
N1—C2 1.3410 (18) C9—H9 0.9500
C2—C3 1.4136 (19) C10—C11 1.380 (2)
C2—C4 1.4638 (19) C10—H10 0.9500
C3—C12 1.478 (2) C11—H11 0.9500
C4—C5 1.332 (2) C12—N13 1.3442 (18)
C4—H4 0.9500 C12—C17 1.385 (2)
C5—C6 1.4655 (19) N13—C14 1.335 (2)
C5—H5 0.9500 C14—C15 1.368 (2)
C6—C11 1.387 (2) C14—H14 0.9500
C6—C7 1.396 (2) C15—C16 1.376 (3)
C7—C8 1.376 (2) C15—H15 0.9500
C7—H7 0.9500 C16—C17 1.385 (2)
C8—C9 1.369 (3) C16—H16 0.9500
C8—H8 0.9500 C17—H17 0.9500
C3i—N1—C2 118.95 (12) C10—C9—H9 120.2
N1—C2—C3 119.76 (12) C11—C10—C9 120.21 (17)
N1—C2—C4 117.14 (13) C11—C10—H10 119.9
C3—C2—C4 123.06 (13) C9—C10—H10 119.9
N1i—C3—C2 121.29 (13) C10—C11—C6 120.97 (16)
N1i—C3—C12 115.04 (12) C10—C11—H11 119.5
C2—C3—C12 123.65 (12) C6—C11—H11 119.5
C5—C4—C2 124.26 (14) N13—C12—C17 122.83 (15)
C5—C4—H4 117.9 N13—C12—C3 116.76 (13)
C2—C4—H4 117.9 C17—C12—C3 120.31 (14)
C4—C5—C6 126.81 (14) C14—N13—C12 117.03 (14)
C4—C5—H5 116.6 N13—C14—C15 124.01 (16)
C6—C5—H5 116.6 N13—C14—H14 118.0
C11—C6—C7 117.79 (14) C15—C14—H14 118.0
C11—C6—C5 123.22 (13) C14—C15—C16 118.66 (17)
C7—C6—C5 118.99 (14) C14—C15—H15 120.7
C8—C7—C6 120.94 (17) C16—C15—H15 120.7
C8—C7—H7 119.5 C15—C16—C17 118.92 (16)
C6—C7—H7 119.5 C15—C16—H16 120.5
C9—C8—C7 120.52 (17) C17—C16—H16 120.5
C9—C8—H8 119.7 C16—C17—C12 118.51 (16)
C7—C8—H8 119.7 C16—C17—H17 120.7
C8—C9—C10 119.56 (16) C12—C17—H17 120.7
C8—C9—H9 120.2
C3i—N1—C2—C3 −0.4 (2) C9—C10—C11—C6 −0.2 (2)
C3i—N1—C2—C4 177.52 (12) C7—C6—C11—C10 0.7 (2)
N1—C2—C3—N1i 0.4 (2) C5—C6—C11—C10 −179.48 (14)
C4—C2—C3—N1i −177.38 (12) N1i—C3—C12—N13 −130.40 (13)
N1—C2—C3—C12 −177.97 (12) C2—C3—C12—N13 48.11 (17)
C4—C2—C3—C12 4.2 (2) N1i—C3—C12—C17 46.03 (17)
N1—C2—C4—C5 12.6 (2) C2—C3—C12—C17 −135.47 (14)
C3—C2—C4—C5 −169.56 (13) C17—C12—N13—C14 −1.5 (2)
C2—C4—C5—C6 −179.88 (13) C3—C12—N13—C14 174.83 (12)
C4—C5—C6—C11 9.9 (2) C12—N13—C14—C15 1.6 (2)
C4—C5—C6—C7 −170.21 (15) N13—C14—C15—C16 −0.1 (2)
C11—C6—C7—C8 −0.8 (2) C14—C15—C16—C17 −1.6 (2)
C5—C6—C7—C8 179.34 (15) C15—C16—C17—C12 1.7 (2)
C6—C7—C8—C9 0.5 (3) N13—C12—C17—C16 −0.1 (2)
C7—C8—C9—C10 −0.1 (3) C3—C12—C17—C16 −176.32 (13)
C8—C9—C10—C11 −0.1 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

References

  1. Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381–388.
  2. Kolb, A. (1896). Justus Liebigs Ann. Chem. 291, 253–297.
  3. Röder, N., Marszalek, T., Limbach, D., Pisula, W. & Detert, H. (2019). ChemPhysChem, 20, 463–469. [DOI] [PubMed]
  4. Schmitt, V., Glang, S., Preis, J. & Detert, H. (2008). Sen Lett, 6, 524–530.
  5. Schmitt, V., Moschel, S. & Detert, H. (2013). Eur. J. Org. Chem. pp. 5655–5669.
  6. Schmitt, V., Schollmeyer, D. & Detert, H. (2011). Acta Cryst. E67, o1553. [DOI] [PMC free article] [PubMed]
  7. Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8.
  8. Spek, A. L. (2020). Acta Cryst. E76, 1–11. [DOI] [PMC free article] [PubMed]
  9. Stoe & Cie (1996). X-RED and X-AREA. Stoe & Cie, Darmstadt, Germany.
  10. Wink, C. & Detert, H. (2013). J. Phys. Org. Chem. 26, 137–143.

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2414314620003727/bt4090sup1.cif

x-05-x200372-sup1.cif (219KB, cif)

Structure factors: contains datablock(s) I. DOI: 10.1107/S2414314620003727/bt4090Isup2.hkl

x-05-x200372-Isup2.hkl (217.5KB, hkl)

Supporting information file. DOI: 10.1107/S2414314620003727/bt4090Isup3.cml

CCDC reference: 1989990

Additional supporting information: crystallographic information; 3D view; checkCIF report


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