1H-Indole-3-carbaldehyde azine.

The molecule of the title compound, C(18)H(14)N(4), lies on a center of inversion such that there is one half-mol-ecule in the asymmetric unit. The N-N single bond adopts a trans configuration and the indole fused-ring system is nearly coplanar with the -CH=N-N=CH- fragment [dihedral angle = 9.8 (2)°]. Adjacent mol-ecules are linked by indole-azine N-H⋯N hydrogen bonds into a layer motif.

Related literature

For the synthesis, see: Alemany et al. (1970 ▶); Swaminathan & Narasimhan (1964 ▶). For the crystal structures of some aromatic azines, for example, benzalazine, see: Burke-Laing & Laing (1976 ▶); Mom & de With (1978 ▶); Sinha, 1970 ▶). For other heterocyclic aldehyde azines, see: Lin et al. (2001a ▶,b ▶); Wu et al. (2006 ▶).

Experimental

Crystal data

C18H14N4

M = 286.33

Monoclinic,

a = 5.0849 (2) Å

b = 10.6708 (4) Å

c = 13.4435 (5) Å

β = 94.366 (3)°

V = 727.33 (5) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 295 (2) K

0.33 × 0.27 × 0.17 mm

Data collection

Bruker APEX2 diffractometer

Absorption correction: none

5388 measured reflections

1659 independent reflections

1085 reflections with I > 2σ(I)

R int = 0.038

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.121

S = 1.01

1659 reflections

105 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.17 e Å−3

Δρmin = −0.16 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808003164/fl2186sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808003164/fl2186Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C18H14N4	F000 = 300
Mr = 286.33	Dx = 1.307 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1012 reflections
a = 5.0849 (2) Å	θ = 2.3–23.6º
b = 10.6708 (4) Å	µ = 0.08 mm−1
c = 13.4435 (5) Å	T = 295 (2) K
β = 94.366 (3)º	Irregular block, green–yellow
V = 727.33 (5) Å3	0.33 × 0.27 × 0.17 mm
Z = 2

Bruker APEX2 diffractometer	1085 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.038
Monochromator: graphite	θmax = 27.5º
T = 295(2) K	θmin = 2.4º
φ and ω scans	h = −6→6
Absorption correction: none	k = −9→13
5388 measured reflections	l = −17→17
1659 independent reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.042	w = 1/[σ2(Fo2) + (0.0645P)2 + ] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.121	(Δ/σ)max = 0.001
S = 1.01	Δρmax = 0.17 e Å−3
1659 reflections	Δρmin = −0.16 e Å−3
105 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.016 (6)
Secondary atom site location: difference Fourier map

	x	y	z	Uiso*/Ueq
N1	0.4730 (3)	0.8059 (1)	0.1978 (1)	0.0484 (4)
N2	0.4464 (2)	0.5165 (1)	0.4519 (1)	0.0422 (4)
C1	0.2718 (3)	0.7222 (1)	0.1726 (1)	0.0425 (4)
C2	0.1064 (3)	0.7130 (2)	0.0860 (1)	0.0538 (5)
C3	−0.0787 (3)	0.6201 (2)	0.0817 (1)	0.0579 (5)
C4	−0.1034 (4)	0.5384 (2)	0.1612 (1)	0.0546 (4)
C5	0.0606 (3)	0.5473 (1)	0.2473 (1)	0.0454 (4)
C6	0.2548 (3)	0.6396 (1)	0.2540 (1)	0.0388 (4)
C7	0.4578 (3)	0.6773 (1)	0.3285 (1)	0.0400 (4)
C8	0.5819 (3)	0.7783 (1)	0.2901 (1)	0.0466 (4)
C9	0.5376 (3)	0.6213 (1)	0.4228 (1)	0.0411 (4)
H1	0.524 (3)	0.865 (2)	0.159 (1)	0.062 (5)*
H2	0.1210	0.7680	0.0330	0.065*
H3	−0.1911	0.6111	0.0243	0.070*
H4	−0.2329	0.4767	0.1561	0.065*
H5	0.0419	0.4926	0.3002	0.054*
H8	0.7215	0.8217	0.3228	0.056*
H9	0.6619	0.6629	0.4650	0.049*

	U11	U22	U33	U12	U13	U23
N1	0.061 (1)	0.041 (1)	0.043 (1)	−0.002 (1)	0.005 (1)	0.012 (1)
N2	0.063 (1)	0.036 (1)	0.027 (1)	−0.001 (1)	−0.003 (1)	0.001 (1)
C1	0.049 (1)	0.039 (1)	0.039 (1)	0.006 (1)	0.006 (1)	0.005 (1)
C2	0.062 (1)	0.058 (1)	0.040 (1)	0.007 (1)	−0.001 (1)	0.014 (1)
C3	0.060 (1)	0.065 (1)	0.047 (1)	0.005 (1)	−0.008 (1)	0.003 (1)
C4	0.054 (1)	0.050 (1)	0.059 (1)	−0.003 (1)	−0.001 (1)	0.000 (1)
C5	0.052 (1)	0.040 (1)	0.045 (1)	0.003 (1)	0.006 (1)	0.004 (1)
C6	0.046 (1)	0.035 (1)	0.036 (1)	0.007 (1)	0.007 (1)	0.003 (1)
C7	0.052 (1)	0.034 (1)	0.034 (1)	0.004 (1)	0.004 (1)	0.001 (1)
C8	0.059 (1)	0.040 (1)	0.041 (1)	−0.002 (1)	0.001 (1)	0.003 (1)
C9	0.056 (1)	0.036 (1)	0.032 (1)	−0.003 (1)	−0.001 (1)	−0.003 (1)

N1—C8	1.351 (2)	C6—C7	1.440 (2)
N1—C1	1.381 (2)	C7—C8	1.370 (2)
N2—C9	1.283 (2)	C7—C9	1.432 (2)
N2—N2i	1.409 (2)	N1—H1	0.87 (2)
C1—C2	1.387 (2)	C2—H2	0.9300
C1—C6	1.412 (2)	C3—H3	0.9300
C2—C3	1.365 (2)	C4—H4	0.9300
C3—C4	1.393 (2)	C5—H5	0.9300
C4—C5	1.377 (2)	C8—H8	0.9300
C5—C6	1.393 (2)	C9—H9	0.9300
C8—N1—C1	109.2 (1)	N2—C9—C7	123.4 (1)
C9—N2—N2i	112.0 (1)	C8—N1—H1	126 (1)
N1—C1—C2	129.9 (1)	C1—N1—H1	125 (1)
N1—C1—C6	107.6 (1)	C3—C2—H2	121.4
C2—C1—C6	122.5 (2)	C1—C2—H2	121.4
C3—C2—C1	117.3 (2)	C2—C3—H3	119.2
C2—C3—C4	121.7 (2)	C4—C3—H3	119.2
C5—C4—C3	121.2 (2)	C5—C4—H4	119.4
C4—C5—C6	118.9 (1)	C3—C4—H4	119.4
C5—C6—C1	118.5 (1)	C4—C5—H5	120.5
C5—C6—C7	135.2 (1)	C6—C5—H5	120.5
C1—C6—C7	106.3 (1)	N1—C8—H8	124.8
C8—C7—C9	123.7 (1)	C7—C8—H8	124.8
C8—C7—C6	106.5 (1)	N2—C9—H9	118.3
C9—C7—C6	129.7 (1)	C7—C9—H9	118.3
N1—C8—C7	110.5 (1)
C8—N1—C1—C2	−179.5 (2)	C2—C1—C6—C7	179.4 (1)
C8—N1—C1—C6	0.5 (2)	C5—C6—C7—C8	−178.6 (2)
N1—C1—C2—C3	−179.6 (2)	C1—C6—C7—C8	0.5 (2)
C6—C1—C2—C3	0.4 (2)	C5—C6—C7—C9	5.1 (3)
C1—C2—C3—C4	0.7 (3)	C1—C6—C7—C9	−175.9 (2)
C2—C3—C4—C5	−0.7 (3)	C1—N1—C8—C7	−0.2 (2)
C3—C4—C5—C6	−0.3 (2)	C9—C7—C8—N1	176.5 (1)
C4—C5—C6—C1	1.3 (2)	C6—C7—C8—N1	−0.2 (2)
C4—C5—C6—C7	−179.7 (2)	N2i—N2—C9—C7	−178.9 (1)
N1—C1—C6—C5	178.6 (1)	C8—C7—C9—N2	−169.5 (1)
C2—C1—C6—C5	−1.4 (2)	C6—C7—C9—N2	6.3 (3)
N1—C1—C6—C7	−0.6 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N2ii	0.87 (2)	2.21 (2)	3.065 (2)	167 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N2i	0.87 (2)	2.21 (2)	3.065 (2)	167 (2)

Symmetry code: (i) .