N,N'-Bis(2-iodo-benzyl-idene)ethane-1,2-diamine.

The mol-ecule of the title Schiff base compound, C(16)H(14)I(2)N(2), lies across a crystallographic inversion centre. An intra-molecular C-H⋯I hydrogen bond forms a five-membered ring, producing an S(5) ring motif. The C=N bond is coplanar with the benzene ring and adopts a trans configuration. Within the mol-ecule, the planar units are parallel, but extend in opposite directions from the dimethyl-ene bridge. An inter-esting feature of the crystal structure is the short I⋯N [3.2096 (15) Å] inter-action, which is significantly shorter than the sum of the van der Waals radii of these atoms. In the crystal structure, mol-ecules are linked into one-dimensional extended chains along the c axis and also into one-dimensional extended chains along the b axis through short inter-molecular I⋯N inter-actions, forming two-dimensional networks parallel to the bc plane.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For the hydrogen bond capability of halogens, see: Brammer et al. (2001 ▶). For halogen–electronegative atom inter­actions, see: Lommerse et al. (1996 ▶). For related structures, see, for example: Fun, Kia & Kargar (2008 ▶); Fun, Kargar & Kia (2008 ▶); Fun, Mirkhani et al. (2008 ▶); Calligaris & Randaccio, (1987 ▶). For information on Schiff base ligands, their complexes and their applications, see, for example: Pal et al. (2005 ▶); Hou et al. (2001 ▶); Ren et al. (2002 ▶).

Experimental

Crystal data

C16H14I2N2

M = 488.09

Monoclinic,

a = 12.1820 (4) Å

b = 4.5978 (1) Å

c = 14.5664 (4) Å

β = 94.424 (2)°

V = 813.44 (4) Å3

Z = 2

Mo Kα radiation

μ = 3.86 mm−1

T = 100.0 (1) K

0.51 × 0.14 × 0.02 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.244, T max = 0.916

24819 measured reflections

4235 independent reflections

3466 reflections with I > 2σ(I)

R int = 0.044

Refinement

R[F 2 > 2σ(F 2)] = 0.030

wR(F 2) = 0.074

S = 1.16

4235 reflections

115 parameters

All H-atom parameters refined

Δρmax = 1.89 e Å−3

Δρmin = −1.74 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808027608/at2623sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808027608/at2623Isup2.hkl

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

C16H14I2N2	F(000) = 460
Mr = 488.09	Dx = 1.993 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7125 reflections
a = 12.1820 (4) Å	θ = 2.8–38.9°
b = 4.5978 (1) Å	µ = 3.86 mm−1
c = 14.5664 (4) Å	T = 100 K
β = 94.424 (2)°	Plate, colourless
V = 813.44 (4) Å3	0.51 × 0.14 × 0.02 mm
Z = 2

Bruker SMART APEXII CCD area-detector diffractometer	4235 independent reflections
Radiation source: fine-focus sealed tube	3466 reflections with I > 2σ(I)
graphite	Rint = 0.044
φ and ω scans	θmax = 37.5°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −19→20
Tmin = 0.244, Tmax = 0.917	k = −7→7
24819 measured reflections	l = −24→24

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.074	All H-atom parameters refined
S = 1.16	w = 1/[σ2(Fo2) + (0.0295P)2 + 0.1458P] where P = (Fo2 + 2Fc2)/3
4235 reflections	(Δ/σ)max = 0.001
115 parameters	Δρmax = 1.89 e Å−3
0 restraints	Δρmin = −1.74 e Å−3

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
I1	0.219874 (11)	0.02241 (3)	0.328844 (8)	0.01748 (5)
N1	0.14038 (12)	0.3597 (4)	0.03053 (10)	0.0158 (3)
C1	0.29294 (15)	−0.0875 (4)	0.20654 (12)	0.0146 (3)
C2	0.37697 (15)	−0.2923 (4)	0.21484 (12)	0.0167 (3)
C3	0.43327 (16)	−0.3648 (5)	0.13879 (12)	0.0178 (3)
C4	0.40419 (16)	−0.2345 (5)	0.05442 (13)	0.0185 (4)
C5	0.32010 (17)	−0.0341 (4)	0.04599 (13)	0.0160 (3)
H5	0.2813	−0.0060	−0.0162	0.019*
C6	0.26222 (16)	0.0456 (4)	0.12178 (13)	0.0135 (3)
C7	0.17398 (15)	0.2630 (4)	0.10940 (12)	0.0147 (3)
C8	0.05021 (16)	0.5681 (4)	0.02623 (13)	0.0160 (3)
H8B	0.0723 (18)	0.725 (5)	−0.0044 (15)	0.016 (6)*
H4	0.4465 (18)	−0.278 (5)	0.0004 (15)	0.017 (6)*
H8A	0.0293 (19)	0.629 (6)	0.0866 (16)	0.021 (6)*
H2	0.3998 (18)	−0.387 (6)	0.2766 (16)	0.015 (6)*
H7	0.144 (2)	0.323 (7)	0.1634 (18)	0.034 (7)*
H3	0.488 (3)	−0.507 (5)	0.148 (2)	0.031 (9)*

	U11	U22	U33	U12	U13	U23
I1	0.02070 (7)	0.01995 (7)	0.01214 (6)	0.00044 (4)	0.00353 (4)	0.00024 (4)
N1	0.0157 (7)	0.0154 (8)	0.0163 (6)	0.0034 (6)	0.0008 (5)	0.0003 (5)
C1	0.0162 (8)	0.0149 (8)	0.0127 (7)	−0.0002 (6)	0.0015 (6)	−0.0012 (6)
C2	0.0184 (8)	0.0151 (8)	0.0160 (7)	0.0003 (7)	−0.0026 (6)	0.0001 (6)
C3	0.0155 (8)	0.0175 (9)	0.0201 (8)	0.0046 (7)	−0.0003 (6)	−0.0004 (7)
C4	0.0192 (8)	0.0187 (9)	0.0178 (8)	0.0049 (7)	0.0033 (6)	−0.0019 (6)
C5	0.0188 (8)	0.0161 (8)	0.0132 (7)	0.0018 (6)	0.0028 (6)	−0.0030 (6)
C6	0.0151 (8)	0.0132 (8)	0.0123 (7)	0.0001 (6)	0.0011 (6)	−0.0011 (6)
C7	0.0147 (7)	0.0129 (8)	0.0168 (7)	0.0008 (6)	0.0021 (6)	−0.0011 (6)
C8	0.0151 (8)	0.0149 (8)	0.0178 (8)	0.0038 (6)	0.0009 (6)	0.0002 (6)

I1—C1	2.1133 (17)	C4—C5	1.376 (3)
N1—C7	1.270 (2)	C4—H4	0.99 (2)
N1—C8	1.455 (2)	C5—C6	1.404 (3)
C1—C2	1.389 (3)	C5—H5	0.9975
C1—C6	1.403 (3)	C6—C7	1.469 (3)
C2—C3	1.388 (3)	C7—H7	0.93 (3)
C2—H2	1.02 (2)	C8—C8i	1.526 (4)
C3—C4	1.388 (3)	C8—H8B	0.90 (2)
C3—H3	0.94 (3)	C8—H8A	0.98 (2)
C7—N1—C8	117.33 (16)	C4—C5—H5	117.7
C2—C1—C6	121.13 (17)	C6—C5—H5	116.7
C2—C1—I1	116.36 (13)	C1—C6—C5	117.54 (18)
C6—C1—I1	122.46 (14)	C1—C6—C7	123.23 (17)
C3—C2—C1	119.97 (17)	C5—C6—C7	119.23 (17)
C3—C2—H2	118.9 (13)	N1—C7—C6	122.09 (17)
C1—C2—H2	121.1 (13)	N1—C7—H7	122.8 (17)
C2—C3—C4	119.67 (18)	C6—C7—H7	115.1 (17)
C2—C3—H3	116 (2)	N1—C8—C8i	108.9 (2)
C4—C3—H3	124 (2)	N1—C8—H8B	107.1 (14)
C5—C4—C3	120.34 (18)	C8i—C8—H8B	109.9 (14)
C5—C4—H4	119.5 (13)	N1—C8—H8A	113.6 (15)
C3—C4—H4	120.1 (13)	C8i—C8—H8A	108.3 (14)
C4—C5—C6	121.35 (18)	H8B—C8—H8A	109 (2)
C6—C1—C2—C3	1.1 (3)	I1—C1—C6—C7	−2.6 (3)
I1—C1—C2—C3	−176.50 (15)	C4—C5—C6—C1	−0.2 (3)
C1—C2—C3—C4	−0.9 (3)	C4—C5—C6—C7	179.31 (18)
C2—C3—C4—C5	0.1 (3)	C8—N1—C7—C6	178.18 (17)
C3—C4—C5—C6	0.5 (3)	C1—C6—C7—N1	−173.04 (19)
C2—C1—C6—C5	−0.5 (3)	C5—C6—C7—N1	7.4 (3)
I1—C1—C6—C5	176.90 (13)	C7—N1—C8—C8i	−114.6 (2)
C2—C1—C6—C7	179.94 (17)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···I1	0.93 (3)	2.87 (3)	3.3880 (18)	116 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯I1	0.93 (3)	2.87 (3)	3.3880 (18)	116 (2)