Ace­naphtho[1,2 b]pyrazine

organic papers

Acta Cryst.(2006). E62, o1291–o1292 doi:10.1107/S1600536806007823 Thorupet al. _C

14H8N2

o1291

Structure Reports Online

ISSN 1600-5368

Acenaphtho[1,2-

b

]pyrazine

Niels Thorup,a* Jørgen Eskildsenb‡ and Jørn B. Christensenb

a_{Department of Chemistry, Technical University}

of Denmark, Kemitorvet, DTU-207, DK-2800 Kgs. Lyngby, Denmark, andb_{Department of}

Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark

‡ Present address: Acadia Pharmaceuticals AB PA, Hanssonsva¨g 35, S-20512 Malmo¨, Sweden.

Correspondence e-mail: [email protected]

Key indicators

Single-crystal X-ray study

T= 120 K

Mean(C–C) = 0.002 A˚

Rfactor = 0.043

wRfactor = 0.099

Data-to-parameter ratio = 11.7

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

Received 2 March 2006 Accepted 3 March 2006

#2006 International Union of Crystallography All rights reserved

In the crystal structure of acenaphtho[1,2-b]pyrazine (or 7,10-diazafluoranthene), C14H8N2, the molecule has crystallo-graphicmsymmetry, but the observed symmetry is very close to mm2. The structure contains dimers of face-to-face antiparallel molecules.

Comment

Fluoranthene forms a series of 2:1 radical cation salts with anions such as PF6and AsF6(Enkelmannet al., 1982). 10c -Azoniafluoranthene forms a 1:1 radical cation salt with the anion PF6 _{(Boubekeuret al., 1989). The present molecule,}

7,10-diazafluoranthene or acenaphtho[1,2-b]pyrazine, (I), is of interest as a modified fluoranthene with nitrogen substitution along the periphery.

The molecule has crystallographic m symmetry. As expected, the observed symmetry is very close tomm2 (C2v).

The structure contains dimers of face-to-face antiparallel

Figure 1

molecules. The interplanar distance within a dimer is 3.417 (2) A˚ . The dimers probably interact via a weak C— H N hydrogen bond (see Table 2). The interacting dimers are stacked orthogonally to each other (see Fig. 2). The intermolecular attractions appear to be rather weak, which is in good accordance with the observed low melting point (ca 419 K).

Experimental

Acenaphtho[1,2-b]pyrazine was prepared as previously reported by Eskildsen & Christensen (2004). Crystals for X-ray analysis were obtained by slow evaporation of a solution in ethanol of a sublimed sample.

Crystal data

C14H8N2

Mr= 204.22 Tetragonal,P42=mbc

a= 11.9243 (2) A˚

c= 14.4040 (3) A˚

V= 2048.09 (6) A˚3

Z= 8

Dx= 1.325 Mg m 3

MoKradiation Cell parameters from 7188

reflections = 2.4–26.4 = 0.08 mm1

T= 120 (2) K Prism, yellow 0.300.090.06 mm

Data collection

Bruker SMART 1K CCD area-detector diffractometer !scans

Absorption correction: multi-scan (SADABS; Sheldrick, 2003)

Tmin= 0.900,Tmax= 0.995

17778 measured reflections

1088 independent reflections 910 reflections withI> 2(I)

Rint= 0.052

max= 26.4

h=14!14

k=14!14

l=17!17

Refinement

Refinement onF2 R[F2_{> 2(F}2_{)] = 0.043}

wR(F2) = 0.099

S= 1.14 1088 reflections 93 parameters

All H-atom parameters refined

w= 1/[2

(Fo2) + (0.041P)2

+ 0.8729P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 0.27 e A˚

3

min=0.20 e A˚

3

Extinction correction:SHELXTL

Extinction coefficient: 0.0035 (6)

Table 1

Selected geometric parameters (A˚ ,_).

N1—C1 1.3347 (17) N1—C8 1.3489 (18) C1—C1i

1.428 (3) C1—C2 1.4734 (19) C2—C3 1.376 (2) C2—C7 1.4179 (17)

C3—C4 1.424 (2) C4—C5 1.382 (2) C5—C6 1.4251 (18) C6—C7 1.406 (3) C8—C8i

1.392 (3)

C1—N1—C8 113.94 (12) N1—C1—C1i

122.76 (8) N1—C1—C2 128.87 (12) C1i

—C1—C2 108.36 (8) C3—C2—C7 119.34 (13) C3—C2—C1 135.20 (13) C7—C2—C1 105.45 (12) C2—C3—C4 117.84 (14)

C5—C4—C3 122.91 (14) C4—C5—C6 120.27 (15) C7—C6—C5 115.83 (10) C5—C6—C5i

128.3 (2) C6—C7—C2 123.81 (9) C2i—C7—C2 112.38 (17) N1—C8—C8i

123.29 (8)

Symmetry code: (i)x;y;z.

Table 2

Hydrogen-bond geometry (A˚ ,_).

D—H A D—H H A D A D—H A

C3—H3 N1ii 0.982 (17) 2.605 (16) 3.3663 (19) 134.5 (12) Symmetry code: (ii)y;x;zþ1

2.

Data collection:SMART(Siemens, 1995); cell refinement:SAINT

(Siemens, 1995); data reduction:SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL (Sheldrick, 2001) andPLATON(Spek, 2003); software used to prepare material for publication:SHELXTL.

References

Boubekeur, K., Fourmigue, M., Batail, P. & Bechgaard. K. (1989).Acta Cryst.

C45, 1636–1637.

Enkelmann, V. Morra, B. S., Kro¨hnke, C., Wegner, G. & Heinze, J. (1982).

Chem. Phys.66, 303–313.

Eskildsen, J. & Christensen, J. (2004).Molbank, 2004, M386.

Sheldrick, G. M. (2001).SHELXTL. Version 6.12. Bruker AXS Inc., Madison, Wisconsin, USA.

Sheldrick, G. M. (2003).SADABS. Version 2.10. Bruker AXS Inc., Madison, Wisconsin, USA.

Siemens (1995). SMART and SAINT. Versions 4.05. Siemens AXS Inc., Madison, Wisconsin, USA.

Spek, A. L. (2003).J. Appl. Cryst.36, 7–13.

Figure 2

supporting information

sup-1

Acta Cryst. (2006). E62, o1291–o1292

supporting information

Acta Cryst. (2006). E62, o1291–o1292 [https://doi.org/10.1107/S1600536806007823]

Acenaphtho[1,2-

b

]pyrazine

Niels Thorup, J

ø

rgen Eskildsen and J

ø

rn B. Christensen

Acenaphtho[1,2-b]pyrazine

Crystal data

C14H8N2

Mr = 204.22

Tetragonal, P42/mbc

Hall symbol: -P 4c 2ab

a = 11.9243 (2) Å

c = 14.4040 (3) Å

V = 2048.09 (6) Å3

Z = 8

F(000) = 848

Dx = 1.325 Mg m−3

Melting point: 419 K

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 7188 reflections

θ = 2.4–26.4°

µ = 0.08 mm−1

T = 120 K Prism, yellow

0.30 × 0.09 × 0.06 mm

Data collection

Bruker SMART 1K CCD area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

ω scan, frame data integration Absorption correction: multi-scan

(SADABS; Sheldrick, 2003)

Tmin = 0.900, Tmax = 0.995

17778 measured reflections 1088 independent reflections 910 reflections with I > 2σ(I)

Rint = 0.052

θmax = 26.4°, θmin = 2.4°

h = −14→14

k = −14→14

l = −17→17

Refinement

Refinement on F2

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.043}

wR(F2_{) = 0.099}

S = 1.14 1088 reflections 93 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

All H-atom parameters refined

w = 1/[σ2_(F

o2) + (0.041P)2 + 0.8729P]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001

Δρmax = 0.27 e Å−3

Δρmin = −0.20 e Å−3

Extinction correction: SHELXTL, Fc*_{=kFc[1+0.001xFc}2_λ3_/sin(2θ)]-1/4

Special details

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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 6.5712 (0.0024) x - 9.9501 (0.0016) y - 0.0666 (0.0102) z = 1.7028 (0.0010)

* -0.0046 (0.0012) C1 * -0.0123 (0.0013) C2 * -0.0064 (0.0012) C3 * 0.0020 (0.0012) C4 * 0.0105 (0.0014) C5 * 0.0056 (0.0014) C6 * -0.0084 (0.0015) C7 * 0.0063 (0.0010) C8 * 0.0074 (0.0011) N1

Rms deviation of fitted atoms = 0.0076

6.5712 (0.0024) x - 9.9501 (0.0016) y + 0.0666 (0.0102) z = 1.7028 (0.0010) Angle to previous plane (with approximate e.s.d.) = 0.53 (0.03)

* -0.0046 (0.0012) C1_$2 * -0.0123 (0.0013) C2_$2 * -0.0064 (0.0012) C3_$2 * 0.0020 (0.0012) C4_$2 * 0.0105 (0.0014) C5_$2 * 0.0056 (0.0014) C6_$2 * -0.0084 (0.0015) C7_$2 * 0.0063 (0.0010) C8_$2 * 0.0074 (0.0011) N1_$2 Rms deviation of fitted atoms = 0.0076

6.5674 (0.0023) x - 9.9528 (0.0015) y - 0.0000 (0.0000) z = 1.7086 (0.0005) Angle to previous plane (with approximate e.s.d.) = 0.27 (0.03)

* -0.0069 (0.0012) C1 * -0.0130 (0.0013) C2 * -0.0016 (0.0014) C3 * 0.0063 (0.0014) C4 * 0.0093 (0.0013) C5 * -0.0013 (0.0019) C6 * -0.0148 (0.0018) C7 * 0.0049 (0.0010) C8 * 0.0090 (0.0011) N1 * -0.0069 (0.0012) C1_$2 * -0.0130 (0.0013) C2_$2 * -0.0016 (0.0014) C3_$2 * 0.0063 (0.0014) C4_$2 * 0.0093 (0.0013) C5_$2 * 0.0049 (0.0010) C8_$2 * 0.0090 (0.0011) N1_$2

Rms deviation of fitted atoms = 0.0083

- 6.5674 (0.0023) x + 9.9528 (0.0015) y + 0.0000 (0.0000) z = 1.7086 (0.0005) Angle to previous plane (with approximate e.s.d.) = 0.00 (0.03)

* -0.0069 (0.0012) C1_$3 * -0.0130 (0.0013) C2_$3 * -0.0016 (0.0014) C3_$3 * 0.0063 (0.0014) C4_$3 * 0.0093 (0.0013) C5_$3 * -0.0013 (0.0019) C6_$3 * -0.0148 (0.0018) C7_$3 * 0.0049 (0.0010) C8_$3 * 0.0090 (0.0011) N1_$3 * -0.0069 (0.0012) C1_$4 * -0.0130 (0.0013) C2_$4 * -0.0016 (0.0014) C3_$4 * 0.0063 (0.0014) C4_$4 * 0.0093 (0.0013) C5_$4 * 0.0049 (0.0010) C8_$4 * 0.0090 (0.0011) N1_$4 - 3.4042 (0.0016) C2 - 3.4024 (0.0021) C7 Rms deviation of fitted atoms = 0.0083

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_,

conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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₎

x y z Uiso*/Ueq

N1 −0.03065 (10) −0.19279 (10) 0.09972 (8) 0.0204 (3) C1 0.04718 (11) −0.13985 (11) 0.04957 (9) 0.0174 (3) C2 0.14477 (11) −0.07484 (11) 0.08179 (9) 0.0183 (3) C3 0.18878 (13) −0.04694 (12) 0.16699 (10) 0.0236 (4) H3 0.1536 (13) −0.0705 (13) 0.2255 (12) 0.030 (5)* C4 0.28878 (13) 0.01825 (13) 0.16870 (11) 0.0290 (4) H4 0.3209 (15) 0.0372 (13) 0.2305 (12) 0.034 (5)* C5 0.34289 (13) 0.05366 (13) 0.08905 (11) 0.0285 (4) H5 0.4118 (16) 0.0982 (16) 0.0926 (11) 0.036 (5)*

C6 0.29894 (17) 0.02572 (17) 0.0000 0.0230 (5)

C7 0.19992 (17) −0.03826 (16) 0.0000 0.0185 (4)

supporting information

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Acta Cryst. (2006). E62, o1291–o1292 Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

N1 0.0210 (6) 0.0210 (6) 0.0193 (6) 0.0002 (5) 0.0027 (5) 0.0012 (5) C1 0.0198 (7) 0.0163 (7) 0.0160 (7) 0.0031 (5) 0.0005 (5) −0.0003 (5) C2 0.0201 (7) 0.0170 (7) 0.0179 (7) 0.0021 (5) 0.0002 (6) −0.0013 (5) C3 0.0268 (8) 0.0255 (8) 0.0183 (8) 0.0005 (6) −0.0010 (6) −0.0025 (6) C4 0.0304 (9) 0.0317 (9) 0.0248 (8) −0.0032 (7) −0.0077 (7) −0.0073 (7) C5 0.0254 (8) 0.0269 (8) 0.0333 (9) −0.0065 (6) −0.0040 (7) −0.0045 (7) C6 0.0229 (11) 0.0194 (10) 0.0265 (11) −0.0022 (8) 0.000 0.000 C7 0.0213 (10) 0.0165 (9) 0.0177 (10) 0.0022 (8) 0.000 0.000 C8 0.0202 (7) 0.0228 (7) 0.0250 (8) −0.0030 (6) 0.0022 (6) 0.0010 (6)

Geometric parameters (Å, º)

N1—C1 1.3347 (17) C4—C5 1.382 (2)

N1—C8 1.3489 (18) C4—H4 0.996 (18)

C1—C1i _{1.428 (3) C5—C6 1.4251 (18)}

C1—C2 1.4734 (19) C5—H5 0.98 (2)

C2—C3 1.376 (2) C6—C7 1.406 (3)

C2—C7 1.4179 (17) C8—C8i _{1.392 (3)}

C3—C4 1.424 (2) C8—H8 0.982 (17)

C3—H3 0.982 (17)

C1—N1—C8 113.94 (12) C3—C4—H4 117.5 (10)

N1—C1—C1i _{122.76 (8) C4—C5—C6 120.27 (15)}

N1—C1—C2 128.87 (12) C4—C5—H5 120.9 (10)

C1i_{—C1—C2 108.36 (8) C6}i_{—C5—H5 118.9 (10)}

C3—C2—C7 119.34 (13) C6—C5—H5 118.9 (10)

C3—C2—C1 135.20 (13) C7—C6—C5 115.83 (10)

C7—C2—C1 105.45 (12) C5—C6—C5i _{128.3 (2)}

C2—C3—C4 117.84 (14) C6—C7—C2 123.81 (9)

C2—C3—H3 122.2 (9) C2i_{—C7—C2 112.38 (17)}

C4—C3—H3 119.9 (9) N1—C8—C8i _{123.29 (8)}

C5—C4—C3 122.91 (14) N1—C8—H8 116.4 (9)

C5—C4—H4 119.6 (10) C8i_{—C8—H8 120.3 (9)}

C8—N1—C1—C1i _{−0.93 (14) C5—C6—C7—C7}i _{0.00 (4)}

C8—N1—C1—C2 179.75 (13) C5i_{—C6—C7—C7}i _{0.00 (4)}

N1—C1—C2—C3 0.2 (3) C6i_{—C6—C7—C2}i _{0.00 (6)}

C1i_{—C1—C2—C3 −179.17 (15) C5—C6—C7—C2}i _{−179.34 (17)}

N1—C1—C2—C7i _{179.33 (14) C5}i_{—C6—C7—C2}i _{0.2 (3)}

C1i_{—C1—C2—C7}i _{−0.07 (12) C6}i_{—C6—C7—C2 0.00 (6)}

N1—C1—C2—C7 179.33 (14) C5—C6—C7—C2 −0.2 (3)

C1i_{—C1—C2—C7 −0.07 (12) C5}i_{—C6—C7—C2 179.34 (17)}

C7i_{—C2—C3—C4 0.1 (2) C3—C2—C7—C7}i _{0.00 (4)}

C7—C2—C3—C4 0.1 (2) C1—C2—C7—C7i _{0.00 (2)}

C2—C3—C4—C5 −0.3 (2) C1—C2—C7—C6i _{−179.06 (17)}

C3—C4—C5—C6i _{0.3 (3) C3—C2—C7—C6 0.2 (3)}

C3—C4—C5—C6 0.3 (3) C1—C2—C7—C6 −179.06 (17)

C4—C5—C6—C6i _{0.00 (5) C3—C2—C7—C2}i _{179.39 (10)}

C4—C5—C6—C7i _{0.0 (3) C1—C2—C7—C2}i _{0.1 (2)}

C4—C5—C6—C7 0.0 (3) C1—N1—C8—C8i _{0.94 (14)}

C4—C5—C6—C5i _{−179.51 (15)}

Symmetry code: (i) x, y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A

C3—H3···N1ii _{0.982 (17) 2.605 (16) 3.3663 (19) 134.5 (12)}