supplementary materials
2,3,5-Triphenylpyrazine
In the title molecule, C22H16N2, the pyrazine ring deviates very slightly from planarity [maximum deviation 0.044 (3) Å], tending towards a twist-boat conformation. The phenyl ring at position 3 makes dihedral angles of 64.0 (2) and 45.8 (2)°, respectively, with the phenyl rings at positions 2 and 5. The dihedral angle between the phenyl rings at positions 2 and 5 is 49.7 (2)°. A C-H
![[pi]](/logos/entities/pi_rmgif.gif)
interaction is found in the crystal structure, but no classical hydrogen bonds form.
To a homogeneous solution of benzil (1.05 g, 0.005 mol) and
1-phenylethanediamine dihydrochloride (1.04 g, 0.005 mol) in ethanol,
sodium acetate trihydrate (2.04 g, 0.015 mol) was added.
The precipitated sodium chloride was filtered off and
the filtrate was refluxed for 2 h.
On completion of the reaction, as indicated by TLC,
the reaction mixture was poured into crushed ice and the resulting
solid was filtered off and purified by column chromatography on
silica gel.
Elution with benzene: petroleum ether (4:1 v/v) at 333–353 K gave the
product in pure form. Yield 1.6 g (80%).
H atoms were positioned geometrically and allowed to ride on their parent atoms,
with C—H = 0.93 Å and Uiso(H) = 1.2 times Ueq(C). In the
absence of significant anomalous scattering effects Friedel pairs have been
merged.
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-NT (Bruker, 2004); data reduction: SAINT-NT (Bruker, 2004); 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: PLATON (Spek, 2003).
2,3,5-Triphenylpyrazine
top
Crystal data top
| C22H16N2 | Dx = 1.260 Mg m−3 |
| Mr = 308.37 | Melting point: 421 K |
| Orthorhombic, Pna21 | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: P 2c -2n | Cell parameters from 2955 reflections |
| a = 15.563 (2) Å | θ = 2.4–21.2° |
| b = 6.2005 (9) Å | µ = 0.07 mm−1 |
| c = 16.845 (3) Å | T = 296 K |
| V = 1625.5 (4) Å3 | Chunk, colourless |
| Z = 4 | 0.44 × 0.35 × 0.21 mm |
| F(000) = 648 | |
Data collection top
Bruker APEXII CCD
diffractometer | 1730 independent reflections |
| Radiation source: fine-focus sealed tube | 1109 reflections with I > 2σ(I) |
| graphite | Rint = 0.091 |
| φ and ω scans | θmax = 26.5°, θmin = 2.4° |
Absorption correction: multi-scan
(SADABS; Bruker, 2004) | h = −19→19 |
| Tmin = 0.968, Tmax = 0.985 | k = −7→7 |
| 17890 measured reflections | l = −20→19 |
Refinement top
| Refinement on F2 | Secondary atom site location: difference Fourier map |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.050 | H-atom parameters constrained |
| wR(F2) = 0.129 | w = 1/[σ2(Fo2) + (0.0653P)2 + 0.1081P]
where P = (Fo2 + 2Fc2)/3 |
| S = 1.02 | (Δ/σ)max = 0.001 |
| 1730 reflections | Δρmax = 0.13 e Å−3 |
| 218 parameters | Δρmin = −0.13 e Å−3 |
| 1 restraint | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.015 (3) |
Crystal data top
| C22H16N2 | V = 1625.5 (4) Å3 |
| Mr = 308.37 | Z = 4 |
| Orthorhombic, Pna21 | Mo Kα radiation |
| a = 15.563 (2) Å | µ = 0.07 mm−1 |
| b = 6.2005 (9) Å | T = 296 K |
| c = 16.845 (3) Å | 0.44 × 0.35 × 0.21 mm |
Data collection top
Bruker APEXII CCD
diffractometer | 1730 independent reflections |
Absorption correction: multi-scan
(SADABS; Bruker, 2004) | 1109 reflections with I > 2σ(I) |
| Tmin = 0.968, Tmax = 0.985 | Rint = 0.091 |
| 17890 measured reflections | θmax = 26.5° |
Refinement top
| R[F2 > 2σ(F2)] = 0.050 | H-atom parameters constrained |
| wR(F2) = 0.129 | Δρmax = 0.13 e Å−3 |
| S = 1.02 | Δρmin = −0.13 e Å−3 |
| 1730 reflections | Absolute structure: ? |
| 218 parameters | Flack parameter: ? |
| 1 restraint | Rogers parameter: ? |
Special details top
Geometry. Bond distances, angles etc. have been calculated using the rounded
fractional coordinates. All su's are estimated from the variances of the
(full) variance-covariance matrix. The cell e.s.d.'s are taken into account in
the estimation of distances, angles and torsion angles |
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 >
2σ(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 | 0.2355 (2) | 0.1296 (5) | 0.19242 (19) | 0.0547 (12) | |
| N4 | 0.3436 (2) | −0.1252 (5) | 0.10173 (19) | 0.0487 (11) | |
| C2 | 0.2412 (3) | 0.1612 (5) | 0.1141 (2) | 0.0463 (12) | |
| C3 | 0.3009 (3) | 0.0395 (6) | 0.0686 (2) | 0.0447 (12) | |
| C5 | 0.3329 (3) | −0.1640 (6) | 0.1791 (2) | 0.0477 (12) | |
| C6 | 0.2822 (3) | −0.0252 (7) | 0.2244 (3) | 0.0557 (14) | |
| C21 | 0.1810 (3) | 0.3188 (6) | 0.0793 (2) | 0.0480 (12) | |
| C22 | 0.1658 (3) | 0.5110 (6) | 0.1192 (3) | 0.0547 (16) | |
| C23 | 0.1074 (3) | 0.6577 (7) | 0.0897 (3) | 0.0670 (17) | |
| C24 | 0.0622 (3) | 0.6125 (8) | 0.0212 (3) | 0.0717 (17) | |
| C25 | 0.0760 (3) | 0.4218 (8) | −0.0185 (3) | 0.0683 (19) | |
| C26 | 0.1359 (3) | 0.2775 (8) | 0.0110 (3) | 0.0610 (17) | |
| C31 | 0.3243 (3) | 0.0908 (7) | −0.0142 (2) | 0.0500 (14) | |
| C32 | 0.3486 (3) | 0.2977 (7) | −0.0358 (3) | 0.0583 (16) | |
| C33 | 0.3772 (3) | 0.3414 (7) | −0.1116 (3) | 0.0653 (17) | |
| C34 | 0.3783 (3) | 0.1810 (8) | −0.1676 (3) | 0.0660 (17) | |
| C35 | 0.3525 (3) | −0.0229 (8) | −0.1474 (3) | 0.0687 (17) | |
| C36 | 0.3261 (3) | −0.0692 (6) | −0.0714 (2) | 0.0577 (16) | |
| C51 | 0.3770 (3) | −0.3528 (6) | 0.2136 (2) | 0.0483 (12) | |
| C52 | 0.4302 (3) | −0.4792 (7) | 0.1662 (3) | 0.0610 (17) | |
| C53 | 0.4682 (3) | −0.6620 (7) | 0.1961 (3) | 0.0730 (19) | |
| C54 | 0.4543 (3) | −0.7247 (8) | 0.2734 (3) | 0.0747 (19) | |
| C55 | 0.4017 (4) | −0.6012 (8) | 0.3210 (3) | 0.0770 (19) | |
| C56 | 0.3635 (3) | −0.4195 (7) | 0.2911 (3) | 0.0667 (17) | |
| H6 | 0.28114 | −0.04259 | 0.27921 | 0.0669* | |
| H22 | 0.19510 | 0.54089 | 0.16601 | 0.0653* | |
| H23 | 0.09840 | 0.78757 | 0.11605 | 0.0803* | |
| H24 | 0.02234 | 0.71109 | 0.00186 | 0.0859* | |
| H25 | 0.04549 | 0.39011 | −0.06447 | 0.0819* | |
| H26 | 0.14584 | 0.14928 | −0.01612 | 0.0727* | |
| H32 | 0.34552 | 0.40842 | 0.00137 | 0.0699* | |
| H33 | 0.39584 | 0.47943 | −0.12464 | 0.0783* | |
| H34 | 0.39640 | 0.21058 | −0.21902 | 0.0788* | |
| H35 | 0.35281 | −0.13135 | −0.18555 | 0.0820* | |
| H36 | 0.30936 | −0.20876 | −0.05833 | 0.0693* | |
| H52 | 0.44015 | −0.43949 | 0.11371 | 0.0731* | |
| H53 | 0.50365 | −0.74446 | 0.16366 | 0.0872* | |
| H54 | 0.48007 | −0.84883 | 0.29325 | 0.0894* | |
| H55 | 0.39220 | −0.64112 | 0.37352 | 0.0927* | |
| H56 | 0.32749 | −0.33888 | 0.32367 | 0.0800* | |
Atomic displacement parameters (Å2) top| | U11 | U22 | U33 | U12 | U13 | U23 |
| N1 | 0.062 (2) | 0.052 (2) | 0.050 (2) | 0.0055 (17) | 0.0027 (16) | −0.0004 (16) |
| N4 | 0.0533 (19) | 0.0458 (18) | 0.047 (2) | 0.0009 (15) | 0.0024 (15) | 0.0030 (15) |
| C2 | 0.057 (2) | 0.042 (2) | 0.040 (2) | −0.0052 (18) | 0.0015 (17) | −0.0036 (18) |
| C3 | 0.055 (2) | 0.039 (2) | 0.040 (2) | 0.0020 (18) | 0.0004 (16) | −0.0025 (16) |
| C5 | 0.055 (2) | 0.047 (2) | 0.041 (2) | −0.0069 (18) | −0.0003 (17) | 0.0022 (18) |
| C6 | 0.069 (3) | 0.057 (2) | 0.041 (2) | −0.002 (2) | −0.0020 (19) | −0.001 (2) |
| C21 | 0.051 (2) | 0.047 (2) | 0.046 (2) | −0.0008 (17) | 0.0017 (18) | −0.0008 (18) |
| C22 | 0.060 (3) | 0.050 (2) | 0.054 (3) | 0.000 (2) | 0.0030 (19) | −0.0013 (19) |
| C23 | 0.067 (3) | 0.055 (3) | 0.079 (3) | 0.011 (2) | 0.007 (3) | 0.001 (2) |
| C24 | 0.066 (3) | 0.077 (3) | 0.072 (3) | 0.013 (3) | 0.002 (3) | 0.008 (3) |
| C25 | 0.067 (3) | 0.085 (4) | 0.053 (3) | 0.012 (3) | −0.006 (2) | 0.004 (2) |
| C26 | 0.067 (3) | 0.062 (3) | 0.054 (3) | 0.002 (2) | −0.004 (2) | −0.002 (2) |
| C31 | 0.054 (2) | 0.054 (3) | 0.042 (2) | 0.0078 (19) | −0.0010 (18) | 0.0036 (18) |
| C32 | 0.077 (3) | 0.047 (2) | 0.051 (3) | 0.003 (2) | 0.009 (2) | 0.002 (2) |
| C33 | 0.077 (3) | 0.056 (3) | 0.063 (3) | 0.006 (2) | 0.012 (2) | 0.015 (2) |
| C34 | 0.076 (3) | 0.076 (3) | 0.046 (3) | 0.015 (3) | 0.009 (2) | 0.014 (3) |
| C35 | 0.089 (3) | 0.070 (3) | 0.047 (3) | 0.017 (3) | 0.001 (2) | −0.006 (2) |
| C36 | 0.079 (3) | 0.046 (2) | 0.048 (3) | 0.009 (2) | 0.001 (2) | −0.004 (2) |
| C51 | 0.049 (2) | 0.045 (2) | 0.051 (2) | −0.0034 (18) | −0.0025 (18) | 0.0050 (19) |
| C52 | 0.064 (3) | 0.056 (3) | 0.063 (3) | −0.001 (2) | 0.005 (2) | 0.013 (2) |
| C53 | 0.066 (3) | 0.061 (3) | 0.092 (4) | 0.012 (2) | 0.008 (3) | 0.011 (3) |
| C54 | 0.075 (3) | 0.056 (3) | 0.093 (4) | 0.007 (3) | −0.019 (3) | 0.019 (3) |
| C55 | 0.098 (4) | 0.072 (3) | 0.061 (3) | 0.010 (3) | −0.013 (3) | 0.012 (3) |
| C56 | 0.085 (3) | 0.064 (3) | 0.051 (3) | 0.013 (2) | −0.010 (2) | 0.006 (2) |
Geometric parameters (Å, °) top
| N1—C2 | 1.337 (5) | C51—C56 | 1.386 (6) |
| N1—C6 | 1.319 (6) | C52—C53 | 1.374 (6) |
| N4—C3 | 1.340 (5) | C53—C54 | 1.376 (7) |
| N4—C5 | 1.336 (5) | C54—C55 | 1.378 (7) |
| C2—C3 | 1.421 (6) | C55—C56 | 1.370 (7) |
| C2—C21 | 1.475 (6) | C6—H6 | 0.9300 |
| C3—C31 | 1.476 (5) | C22—H22 | 0.9300 |
| C5—C6 | 1.395 (6) | C23—H23 | 0.9300 |
| C5—C51 | 1.476 (6) | C24—H24 | 0.9300 |
| C21—C22 | 1.389 (6) | C25—H25 | 0.9300 |
| C21—C26 | 1.372 (6) | C26—H26 | 0.9300 |
| C22—C23 | 1.379 (6) | C32—H32 | 0.9300 |
| C23—C24 | 1.380 (7) | C33—H33 | 0.9300 |
| C24—C25 | 1.375 (7) | C34—H34 | 0.9300 |
| C25—C26 | 1.384 (7) | C35—H35 | 0.9300 |
| C31—C32 | 1.386 (6) | C36—H36 | 0.9300 |
| C31—C36 | 1.383 (5) | C52—H52 | 0.9300 |
| C32—C33 | 1.379 (7) | C53—H53 | 0.9300 |
| C33—C34 | 1.371 (7) | C54—H54 | 0.9300 |
| C34—C35 | 1.370 (7) | C55—H55 | 0.9300 |
| C35—C36 | 1.375 (6) | C56—H56 | 0.9300 |
| C51—C52 | 1.392 (6) | | |
| | | |
| N1···N4 | 2.768 (4) | C34···H54viii | 3.0900 |
| N4···N1 | 2.768 (4) | C35···H54viii | 2.9000 |
| N1···H22 | 2.6600 | C35···H56v | 3.0600 |
| N1···H35i | 2.8800 | C51···H22ii | 3.0200 |
| N4···H36 | 2.8000 | C52···H23vii | 3.0000 |
| N4···H52 | 2.4700 | C56···H6 | 2.6700 |
| C5···C22ii | 3.441 (6) | H6···C56 | 2.6700 |
| C6···C34iii | 3.587 (7) | H6···H56 | 2.1100 |
| C6···C54iv | 3.366 (7) | H22···N1 | 2.6600 |
| C21···C32 | 3.253 (6) | H22···C5iv | 2.8300 |
| C22···C5iv | 3.441 (6) | H22···C51iv | 3.0200 |
| C26···C32 | 3.405 (7) | H23···C52ix | 3.0000 |
| C26···C31 | 3.181 (7) | H25···C33ix | 3.0900 |
| C31···C26 | 3.181 (7) | H26···C3 | 2.8900 |
| C32···C26 | 3.405 (7) | H26···C31 | 2.8000 |
| C32···C21 | 3.253 (6) | H32···C2 | 2.9300 |
| C34···C6v | 3.587 (7) | H32···C21 | 2.9300 |
| C35···C56v | 3.576 (7) | H32···H52iv | 2.5800 |
| C54···C6ii | 3.366 (7) | H35···N1x | 2.8800 |
| C56···C35iii | 3.576 (7) | H36···N4 | 2.8000 |
| C2···H32 | 2.9300 | H52···N4 | 2.4700 |
| C3···H26 | 2.8900 | H52···H32ii | 2.5800 |
| C5···H22ii | 2.8300 | H54···C34xi | 3.0900 |
| C6···H56 | 2.6600 | H54···C35xi | 2.9000 |
| C21···H32 | 2.9300 | H55···C24xii | 3.0000 |
| C24···H55vi | 3.0000 | H56···C6 | 2.6600 |
| C31···H26 | 2.8000 | H56···H6 | 2.1100 |
| C33···H25vii | 3.0900 | H56···C35iii | 3.0600 |
| | | |
| C2—N1—C6 | 118.2 (4) | C54—C55—C56 | 120.1 (5) |
| C3—N4—C5 | 118.8 (3) | C51—C56—C55 | 121.8 (4) |
| N1—C2—C3 | 119.9 (3) | N1—C6—H6 | 119.00 |
| N1—C2—C21 | 116.6 (3) | C5—C6—H6 | 119.00 |
| C3—C2—C21 | 123.5 (3) | C21—C22—H22 | 120.00 |
| N4—C3—C2 | 120.3 (3) | C23—C22—H22 | 120.00 |
| N4—C3—C31 | 115.8 (4) | C22—C23—H23 | 120.00 |
| C2—C3—C31 | 123.8 (3) | C24—C23—H23 | 120.00 |
| N4—C5—C6 | 119.6 (4) | C23—C24—H24 | 120.00 |
| N4—C5—C51 | 118.0 (3) | C25—C24—H24 | 120.00 |
| C6—C5—C51 | 122.5 (3) | C24—C25—H25 | 120.00 |
| N1—C6—C5 | 122.5 (4) | C26—C25—H25 | 120.00 |
| C2—C21—C22 | 119.0 (3) | C21—C26—H26 | 119.00 |
| C2—C21—C26 | 122.3 (4) | C25—C26—H26 | 119.00 |
| C22—C21—C26 | 118.6 (4) | C31—C32—H32 | 119.00 |
| C21—C22—C23 | 120.3 (4) | C33—C32—H32 | 120.00 |
| C22—C23—C24 | 120.2 (4) | C32—C33—H33 | 120.00 |
| C23—C24—C25 | 120.1 (4) | C34—C33—H33 | 120.00 |
| C24—C25—C26 | 119.1 (5) | C33—C34—H34 | 120.00 |
| C21—C26—C25 | 121.7 (4) | C35—C34—H34 | 120.00 |
| C3—C31—C32 | 121.0 (4) | C34—C35—H35 | 120.00 |
| C3—C31—C36 | 120.6 (4) | C36—C35—H35 | 120.00 |
| C32—C31—C36 | 118.4 (4) | C31—C36—H36 | 120.00 |
| C31—C32—C33 | 120.9 (4) | C35—C36—H36 | 120.00 |
| C32—C33—C34 | 119.9 (4) | C51—C52—H52 | 120.00 |
| C33—C34—C35 | 119.7 (5) | C53—C52—H52 | 120.00 |
| C34—C35—C36 | 120.8 (4) | C52—C53—H53 | 120.00 |
| C31—C36—C35 | 120.3 (4) | C54—C53—H53 | 120.00 |
| C5—C51—C52 | 119.8 (3) | C53—C54—H54 | 120.00 |
| C5—C51—C56 | 122.5 (4) | C55—C54—H54 | 120.00 |
| C52—C51—C56 | 117.6 (4) | C54—C55—H55 | 120.00 |
| C51—C52—C53 | 120.7 (4) | C56—C55—H55 | 120.00 |
| C52—C53—C54 | 120.8 (4) | C51—C56—H56 | 119.00 |
| C53—C54—C55 | 119.1 (5) | C55—C56—H56 | 119.00 |
| | | |
| C6—N1—C2—C3 | −4.3 (6) | C2—C21—C22—C23 | −177.5 (4) |
| C6—N1—C2—C21 | 173.4 (4) | C26—C21—C22—C23 | −0.9 (7) |
| C2—N1—C6—C5 | −3.9 (6) | C2—C21—C26—C25 | 176.3 (4) |
| C5—N4—C3—C2 | −4.0 (6) | C22—C21—C26—C25 | −0.2 (7) |
| C5—N4—C3—C31 | 172.3 (4) | C21—C22—C23—C24 | 1.4 (7) |
| C3—N4—C5—C6 | −4.0 (6) | C22—C23—C24—C25 | −0.8 (7) |
| C3—N4—C5—C51 | 176.9 (4) | C23—C24—C25—C26 | −0.3 (7) |
| N1—C2—C3—N4 | 8.5 (6) | C24—C25—C26—C21 | 0.8 (7) |
| N1—C2—C3—C31 | −167.5 (4) | C3—C31—C32—C33 | 174.6 (4) |
| C21—C2—C3—N4 | −169.0 (4) | C36—C31—C32—C33 | −2.6 (7) |
| C21—C2—C3—C31 | 15.0 (6) | C3—C31—C36—C35 | −176.4 (4) |
| N1—C2—C21—C22 | 42.2 (6) | C32—C31—C36—C35 | 0.8 (7) |
| N1—C2—C21—C26 | −134.2 (4) | C31—C32—C33—C34 | 2.8 (7) |
| C3—C2—C21—C22 | −140.2 (4) | C32—C33—C34—C35 | −1.3 (7) |
| C3—C2—C21—C26 | 43.4 (6) | C33—C34—C35—C36 | −0.5 (7) |
| N4—C3—C31—C32 | −126.1 (4) | C34—C35—C36—C31 | 0.7 (7) |
| N4—C3—C31—C36 | 51.0 (6) | C5—C51—C52—C53 | −176.5 (4) |
| C2—C3—C31—C32 | 50.0 (7) | C56—C51—C52—C53 | −0.6 (7) |
| C2—C3—C31—C36 | −132.9 (5) | C5—C51—C56—C55 | 176.7 (5) |
| N4—C5—C6—N1 | 8.4 (7) | C52—C51—C56—C55 | 0.9 (7) |
| C51—C5—C6—N1 | −172.6 (4) | C51—C52—C53—C54 | 0.3 (7) |
| N4—C5—C51—C52 | 2.3 (6) | C52—C53—C54—C55 | −0.2 (7) |
| N4—C5—C51—C56 | −173.5 (4) | C53—C54—C55—C56 | 0.5 (8) |
| C6—C5—C51—C52 | −176.8 (4) | C54—C55—C56—C51 | −0.9 (8) |
| C6—C5—C51—C56 | 7.5 (7) | | |
| Symmetry codes: (i) −x+1/2, y+1/2, z+1/2; (ii) x, y−1, z; (iii) −x+1/2, y−1/2, z+1/2; (iv) x, y+1, z; (v) −x+1/2, y+1/2, z−1/2; (vi) −x+1/2, y+3/2, z−1/2; (vii) x+1/2, −y+1/2, z; (viii) −x+1, −y−1, z−1/2; (ix) x−1/2, −y+1/2, z; (x) −x+1/2, y−1/2, z−1/2; (xi) −x+1, −y−1, z+1/2; (xii) −x+1/2, y−3/2, z+1/2. |
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| C53—H53···Cgxiii | 0.93 | 2.98 | 3.909 (5) | 174 |
| Symmetry codes: (xiii) x+1/2, −y−1/2, z. |
Table 1
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| C53—H53···Cgi | 0.93 | 2.98 | 3.909 (5) | 174 |
| Symmetry codes: (i) x+1/2, −y−1/2, z. |
AT thanks the UGC, India, for the award of a Minor Research Project [File No.
MRP-2355/06(UGC-SERO), Link No. 2355, 10/01/2007]. RJB acknowledges the
NSF–MRI program for funding to purchase the X-ray CCD diffractometer.
Bruker (2004). APEX2, SAINT-NT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Foks, H., Trapkaoska, I., Janowiec, M., Zwolska, Z. & Augustynowicz-Kopec, E. (2004). Chem. Heterocycl. Cmpd, 40, 1185–1193.
Premkumar, T. & Govindarajan, S. (2005). World J. Microbiol. Biotechnol. 21, 479–480.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Sondhi, S. M., Singh, N., Rajvanshi, S. & Johar, M. (2005). Indian J. Chem. 44B, 387–399.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13.
![[Figure 1]](./wn2297fig1thm.gif)
Pyrazines are heterocycles which exhibit nutty, roasted or earth flavouring agents. 2-Cyanopyrazine derivatives show anticancer, anti-inflammatory and analgesic activities (Sondhi et al., 2005). Pyrazine derivatives exhibit tuberculostatic activity (Foks et al., 2004) and antimicrobial activity (Premkumar & Govindarajan, 2005).
In the title molecule, C22H16N2, (Fig. 1), the pyrazine ring deviates very slightly from planarity, tending towards a twist-boat conformation. The phenyl ring at position 3 makes dihedral angles of 64.0 (2)° and 45.8 (2)° with the phenyl rings at positions 2 and 5, respectively. The dihedral angle between the phenyl rings at positions 2 and 5 is 49.7 (2)°. A C53—H53···π interaction involving the phenyl (C21–C26) ring at position 2 is found in the crystal structure, but no classical hydrogen bonds.