Crystal structure of 2-[12-methyl-14-phenyl-10,13,14,16-tetra­aza­tetra­cyclo[7.7.0.02,7.011,15]hexa­deca-1(16),2,4,6,9,11(15),12-heptaen-8-yl­idene]propandi­nitrile

Joel T Mague; Shaaban K Mohamed; Mehmet Akkurt; Hussein M S El-Kashef; Mustafa R Albayati

doi:10.1107/S1600536814024167

. 2014 Nov 8;70(Pt 12):o1244–o1245. doi: 10.1107/S1600536814024167

Crystal structure of 2-[12-methyl-14-phenyl-10,13,14,16-tetraazatetracyclo[7.7.0.0^2,7.0^11,15]hexadeca-1(16),2,4,6,9,11(15),12-heptaen-8-ylidene]propandinitrile

Joel T Mague ^a, Shaaban K Mohamed ^b,^c, Mehmet Akkurt ^d, Hussein M S El-Kashef ^e, Mustafa R Albayati ^f,^*

PMCID: PMC4257392 PMID: 25553023

Abstract

In the title molecule, C₂₂H₁₂N₆, the fused tetracyclic core shows a small lengthwise twist as indicated by the dihedral of 2.7 (2)° between the outer rings. In the crystal, molecules stack along the b-axis direction via offset π-stacking [centroid–centroid distances = 3.5282 (13) and 3.5597 (14) Å] with the stacks weakly associated through C—H⋯N hydrogen bonds. The phenyl ring is rotationally disordered over two orientations with an occupancy ratio of 0.516 (4):0.484 (4).

Keywords: crystal structure, heptaene, propandinitrile, pyrazine scaffold compound, fused tetracyclic core

Related literature

For the biological properties of pyrazine scaffold compounds, see: Kaliszan et al. (1985 ▶); Makino et al. (1990 ▶); Emary & Ibrahim (2006 ▶); Silva et al. (2010 ▶); Rusinov et al. (2005 ▶); Johnston & Kau (1993 ▶); Myadaraboina et al. (2010 ▶); Metobo et al. (2006 ▶). For use of pyrazines in industrial chemistry see: Rangnekar & Dhamnaskar, 1990 ▶). For the preparation of the title compound, see: El-Emary & El-Kashef (2013 ▶)

Experimental

Crystal data

C₂₂H₁₂N₆
M _r = 360.38
Monoclinic,
a = 35.968 (5) Å
b = 4.6483 (6) Å
c = 26.596 (3) Å
β = 129.6130 (12)°
V = 3425.5 (8) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 150 K
0.21 × 0.13 × 0.07 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2014 ▶) T _min = 0.77, T _max = 0.99
15751 measured reflections
3921 independent reflections
2489 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.136
S = 1.03
3921 reflections
249 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2014 ▶); cell refinement: SAINT (Bruker, 2014 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXT (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2012 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814024167/su5012sup1.cif

e-70-o1244-sup1.cif^{(509.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814024167/su5012Isup2.hkl

e-70-o1244-Isup2.hkl^{(215.2KB, hkl)}

Click here for additional data file.^{(6.8KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814024167/su5012Isup3.cml

Click here for additional data file.^{(1.5MB, tif)}

. DOI: 10.1107/S1600536814024167/su5012fig1.tif

The molecular structure of the title molecule, showing the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

Click here for additional data file.^{(1.2MB, tif)}

. DOI: 10.1107/S1600536814024167/su5012fig2.tif

Portions of two neighboring stacks showing the offset π-stacking and C—H⋯N interactions (Table 1) as green and blue dotted line, respectively.

Click here for additional data file.^{(1.4MB, tif)}

b . DOI: 10.1107/S1600536814024167/su5012fig3.tif

Crystal packing viewed along the b axis showing stacks of molecules connected by the weak C—H⋯N interactions (blue dotted lines; see Table 1 for details).

CCDC reference: 1032263

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

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C10H10AN5ⁱ	0.98	2.69	3.362(3)	126

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Symmetry code: (i) Inline graphic .

Acknowledgments

JTM thanks Tulane University for support of the Tulane Crystallography Laboratory. SKM and HMSE would like to thank Professor T. El-Emary, Assiut University, for his contribution to this study.

supplementary crystallographic information

S1. Comment

Over recent years there has been an increasing interest in the chemistry of pyrazine scaffold compounds due to their biological significance. Pyrazine ring is found in numerous pharmaceutically active compounds such as analgesic (Kaliszan et al., 1985), antiallergic (Makino et al., 1990), antibacterial (Emary & Ibrahim 2006), anti-inflammatory (Silva et al., 2010), antiviral (Rusinov et al., 2005), diuretic (Johnston & Kau, 1993), anticancer (Myadaraboina et al., 2010), and anti-HIV (Metobo et al., 2006) medications. Other pyrazine derivatives are also used as fluorescent dyes or dispersed dyes for polyester fibers (Rangnekar & Dhamnaskar, 1990). As part of our investigations of pyrazine derivatives to compare their chemical and biological activities, we have undertaken the X-ray crystal structure analysis of the title compound.

In the title compound, Fig. 1, the fused 4-ring core of the title molecule is nearly planar with only a slight lengthwise twist as indicated by the dihedral angle between the N1/N2/C7/C8/C9 and C12–C17 rings of 2.7 (2)°.

In the crystal, molecules pack in columns along [010] which involve offset π-stacking in which atom N2 is 3.36 (4) Å from the centroid of the N3/C11/C19/N4/C8/C7 ring one unit cell translation in b above it while C17 is 3.41 (4) Å from the centroid of the N3/C11/C19/N4/C8/C7 ring one unit cell translation in b below it (Fig. 2). Adjacent stacks are weakly associated via C—H···N hydrogen bonds (Fig. 3 and Table 1) and are inclined at ca 43.5° in opposite directions from (010).

S2. Experimental

The title compound was prepared according to the reported procedure (El-Emary & El-Kashef, 2013). Orange crystals suitable for X-ray diffraction were obtained by recrystallization of the reaction product from dimethylformamide (m.p. 587–589 K).