A centrosymmetric monoclinic polymorph of N,N-bis-(pyridin-3-yl-methyl-idene)benzene-1,4-diamine.

The complete molecule of the title compound, C(18)H(14)N(4), is generated by the application of a centre of inversion. The dihedral angle between the central benzene ring and the pyridine ring is 31.88 (7)°. In the crystal, mol-ecules are stacked in columns along the c axis and several inter-molecular π-π inter-actions are present between the six-membered rings, the shortest centroid-centroid distance being 3.937 (2) Å. The structure reported herein represents a centrosymmetric polymorph of the previously reported non-centrosymmetric (P2(1)) form [Kim et al. (2005 ▶). Bull. Korean Chem. Soc.26, 892-898].

Related literature

For the crystal structure of N 1,N 4-bis­(pyridin-3-yl­methyl­ene)benzene-1,4-diamine, see: Kim et al. (2005 ▶). For the crystal structure of N 1,N 4-bis­(pyridin-2-yl­methyl­ene)benzene-1,4-diamine, see: Chanda et al. (2002 ▶); Ball et al. (2004 ▶).

Experimental

Crystal data

C18H14N4

M = 286.33

Monoclinic,

a = 16.622 (6) Å

b = 6.171 (2) Å

c = 7.159 (2) Å

β = 95.732 (8)°

V = 730.6 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 200 K

0.22 × 0.14 × 0.11 mm

Data collection

Bruker SMART 1000 CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T min = 0.825, T max = 1.000

5128 measured reflections

1790 independent reflections

1027 reflections with I > 2σ(I)

R int = 0.049

Refinement

R[F 2 > 2σ(F 2)] = 0.053

wR(F 2) = 0.152

S = 1.03

1790 reflections

100 parameters

H-atom parameters constrained

Δρmax = 0.21 e Å−3

Δρmin = −0.24 e Å−3

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811030789/tk2772sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811030789/tk2772Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811030789/tk2772Isup3.cml

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

C18H14N4	F(000) = 300
Mr = 286.33	Dx = 1.301 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1327 reflections
a = 16.622 (6) Å	θ = 2.5–28.2°
b = 6.171 (2) Å	µ = 0.08 mm−1
c = 7.159 (2) Å	T = 200 K
β = 95.732 (8)°	Plate, yellow
V = 730.6 (4) Å3	0.22 × 0.14 × 0.11 mm
Z = 2

Bruker SMART 1000 CCD diffractometer	1790 independent reflections
Radiation source: fine-focus sealed tube	1027 reflections with I > 2σ(I)
graphite	Rint = 0.049
φ and ω scans	θmax = 28.3°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −22→19
Tmin = 0.825, Tmax = 1.000	k = −8→8
5128 measured reflections	l = −8→9

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.152	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.064P)2 + 0.0036P] where P = (Fo2 + 2Fc2)/3
1790 reflections	(Δ/σ)max < 0.001
100 parameters	Δρmax = 0.21 e Å−3
0 restraints	Δρmin = −0.24 e Å−3

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.

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 > σ(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.

	x	y	z	Uiso*/Ueq
N1	0.40327 (10)	0.2126 (3)	0.3182 (2)	0.0434 (5)
N2	0.16109 (9)	0.0893 (2)	0.4230 (2)	0.0296 (4)
C1	0.32643 (12)	0.1772 (3)	0.3548 (3)	0.0374 (5)
H1	0.3091	0.0310	0.3622	0.045*
C2	0.27031 (11)	0.3394 (3)	0.3825 (3)	0.0298 (5)
C3	0.29604 (12)	0.5530 (3)	0.3732 (3)	0.0426 (6)
H3	0.2602	0.6690	0.3922	0.051*
C4	0.37490 (13)	0.5940 (3)	0.3356 (3)	0.0501 (6)
H4	0.3938	0.7387	0.3282	0.060*
C5	0.42572 (13)	0.4208 (3)	0.3092 (3)	0.0439 (6)
H5	0.4795	0.4514	0.2831	0.053*
C6	0.18734 (11)	0.2849 (3)	0.4232 (3)	0.0300 (5)
H6	0.1520	0.3990	0.4507	0.036*
C7	0.07963 (11)	0.0508 (3)	0.4617 (2)	0.0264 (4)
C8	0.06382 (11)	−0.1381 (3)	0.5601 (2)	0.0293 (5)
H8	0.1070	−0.2333	0.6006	0.035*
C9	0.01465 (11)	0.1882 (3)	0.4004 (2)	0.0286 (4)
H9	0.0243	0.3158	0.3318	0.034*

	U11	U22	U33	U12	U13	U23
N1	0.0308 (10)	0.0441 (11)	0.0568 (12)	0.0014 (8)	0.0123 (8)	0.0005 (8)
N2	0.0263 (9)	0.0297 (9)	0.0338 (8)	−0.0027 (7)	0.0080 (6)	0.0001 (7)
C1	0.0320 (12)	0.0327 (11)	0.0488 (12)	−0.0006 (8)	0.0108 (9)	0.0010 (9)
C2	0.0266 (10)	0.0296 (10)	0.0337 (10)	−0.0018 (8)	0.0057 (8)	−0.0005 (8)
C3	0.0331 (12)	0.0279 (11)	0.0688 (14)	0.0000 (9)	0.0149 (10)	−0.0012 (10)
C4	0.0388 (13)	0.0348 (12)	0.0790 (17)	−0.0103 (10)	0.0176 (11)	0.0000 (11)
C5	0.0288 (11)	0.0456 (13)	0.0586 (13)	−0.0069 (10)	0.0113 (10)	0.0003 (10)
C6	0.0261 (10)	0.0307 (11)	0.0338 (10)	0.0001 (8)	0.0060 (8)	−0.0016 (8)
C7	0.0248 (10)	0.0278 (10)	0.0274 (9)	−0.0017 (7)	0.0063 (7)	−0.0026 (7)
C8	0.0273 (10)	0.0284 (10)	0.0325 (10)	0.0003 (8)	0.0038 (8)	0.0007 (8)
C9	0.0310 (11)	0.0264 (10)	0.0288 (9)	−0.0011 (8)	0.0048 (8)	0.0018 (7)

N1—C5	1.341 (3)	C4—C5	1.387 (3)
N1—C1	1.347 (2)	C4—H4	0.9500
N2—C6	1.283 (2)	C5—H5	0.9500
N2—C7	1.429 (2)	C6—H6	0.9500
C1—C2	1.396 (3)	C7—C8	1.401 (2)
C1—H1	0.9500	C7—C9	1.408 (3)
C2—C3	1.389 (3)	C8—C9i	1.396 (3)
C2—C6	1.476 (3)	C8—H8	0.9500
C3—C4	1.387 (3)	C9—C8i	1.396 (3)
C3—H3	0.9500	C9—H9	0.9500
C5—N1—C1	116.01 (18)	N1—C5—H5	118.1
C6—N2—C7	118.98 (16)	C4—C5—H5	118.1
N1—C1—C2	124.86 (18)	N2—C6—C2	122.54 (17)
N1—C1—H1	117.6	N2—C6—H6	118.7
C2—C1—H1	117.6	C2—C6—H6	118.7
C3—C2—C1	117.39 (18)	C8—C7—C9	118.75 (16)
C3—C2—C6	121.57 (17)	C8—C7—N2	117.70 (16)
C1—C2—C6	121.03 (17)	C9—C7—N2	123.50 (16)
C4—C3—C2	118.94 (19)	C9i—C8—C7	120.79 (16)
C4—C3—H3	120.5	C9i—C8—H8	119.6
C2—C3—H3	120.5	C7—C8—H8	119.6
C5—C4—C3	119.1 (2)	C8i—C9—C7	120.45 (17)
C5—C4—H4	120.5	C8i—C9—H9	119.8
C3—C4—H4	120.5	C7—C9—H9	119.8
N1—C5—C4	123.7 (2)
C5—N1—C1—C2	0.2 (3)	C3—C2—C6—N2	176.31 (18)
N1—C1—C2—C3	−0.5 (3)	C1—C2—C6—N2	−4.7 (3)
N1—C1—C2—C6	−179.58 (18)	C6—N2—C7—C8	−145.41 (17)
C1—C2—C3—C4	0.5 (3)	C6—N2—C7—C9	37.0 (2)
C6—C2—C3—C4	179.57 (19)	C9—C7—C8—C9i	−1.0 (3)
C2—C3—C4—C5	−0.2 (3)	N2—C7—C8—C9i	−178.72 (16)
C1—N1—C5—C4	0.2 (3)	C8—C7—C9—C8i	1.0 (3)
C3—C4—C5—N1	−0.2 (4)	N2—C7—C9—C8i	178.58 (16)
C7—N2—C6—C2	−179.26 (16)