1,4-Bis(iodo-meth-yl)benzene.

The centrosymmetric title compound, C(8)H(8)I(2), was prepared by metathesis from the dibromo analogue. In the crystal structure, weak C-H⋯I inter-actions link the mol-ecules into stacks down the b axis. The structure is further stabilized by short I⋯I contacts [3.8433 (2) Å], forming undulating sheets in the (101) plane.

Related literature

For the synthesis, see: Moore & Stupp (1986 ▶); Kida et al. (2005 ▶). For related structures, see: Basaran et al. (1992 ▶); Fun et al. (2009 ▶); Jones & Kus (2007 ▶); Zhang et al. (2007 ▶). For applications of dihalo-p-xylenes in living radical polymerization processes, see: Samakande et al., (2007 ▶); Asandei et al. (2008 ▶). For other polymer applications, see: Leir & Stark (1989 ▶); Hochberg & Schulz (1993 ▶). For additional applications of dihalo-p-xylenes, see: Le Baccon et al. (2001 ▶); Sobransingh & Kaifer (2006 ▶); Song et al. (2008 ▶); Au et al. (2009 ▶). For details of halogen⋯halogen inter­actions, see: Pedireddi et al. (1994 ▶) and for reference structural data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C8H8I2

M = 357.94

Monoclinic,

a = 9.0978 (3) Å

b = 4.5982 (2) Å

c = 11.2793 (3) Å

β = 99.808 (1)°

V = 464.96 (3) Å3

Z = 2

Mo Kα radiation

μ = 6.69 mm−1

T = 89 K

0.21 × 0.15 × 0.03 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2006 ▶) T min = 0.410, T max = 0.818

8198 measured reflections

1674 independent reflections

1538 reflections with I > 2σ(I)

R int = 0.026

Refinement

R[F 2 > 2σ(F 2)] = 0.013

wR(F 2) = 0.033

S = 1.06

1674 reflections

62 parameters

All H-atom parameters refined

Δρmax = 0.51 e Å−3

Δρmin = −0.51 e Å−3

Data collection: APEX2 (Bruker 2006 ▶); cell refinement: APEX2 and SAINT (Bruker 2006 ▶); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) and TITAN (Hunter & Simpson, 1999 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004 ▶), PLATON (Spek, 2009 ▶) and publCIF (Westrip, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809021151/hb2998sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809021151/hb2998Isup2.hkl

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

C8H8I2	F(000) = 324
Mr = 357.94	Dx = 2.557 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5590 reflections
a = 9.0978 (3) Å	θ = 2.3–33.0°
b = 4.5982 (2) Å	µ = 6.69 mm−1
c = 11.2793 (3) Å	T = 89 K
β = 99.808 (1)°	Rectangular plate, pale yellow
V = 464.96 (3) Å3	0.21 × 0.15 × 0.03 mm
Z = 2

Bruker APEXII CCD area-detector diffractometer	1674 independent reflections
Radiation source: fine-focus sealed tube	1538 reflections with I > 2σ(I)
graphite	Rint = 0.026
ω scans	θmax = 33.4°, θmin = 3.7°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −13→13
Tmin = 0.410, Tmax = 0.818	k = −5→7
8198 measured reflections	l = −16→16

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)] = 0.013	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.033	All H-atom parameters refined
S = 1.06	w = 1/[σ2(Fo2) + (0.0145P)2 + 0.1407P] where P = (Fo2 + 2Fc2)/3
1674 reflections	(Δ/σ)max = 0.001
62 parameters	Δρmax = 0.51 e Å−3
0 restraints	Δρmin = −0.51 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
C1	0.62504 (16)	0.1521 (3)	0.47504 (13)	0.0138 (2)
C2	0.63784 (17)	−0.0405 (3)	0.57245 (14)	0.0154 (3)
C3	0.51429 (17)	−0.1903 (3)	0.59710 (14)	0.0154 (3)
C4	0.75717 (18)	0.3189 (4)	0.45106 (15)	0.0190 (3)
I1	0.880515 (9)	0.07951 (2)	0.331669 (8)	0.01438 (4)
H2	0.729 (3)	−0.073 (4)	0.620 (2)	0.021 (6)*
H41	0.841 (3)	0.354 (5)	0.524 (2)	0.031 (6)*
H3	0.523 (2)	−0.330 (5)	0.6678 (19)	0.022 (5)*
H42	0.733 (3)	0.509 (5)	0.405 (2)	0.021 (5)*

	U11	U22	U33	U12	U13	U23
C1	0.0142 (6)	0.0109 (6)	0.0180 (6)	−0.0017 (5)	0.0078 (5)	−0.0032 (5)
C2	0.0133 (6)	0.0159 (7)	0.0174 (7)	0.0007 (5)	0.0038 (5)	−0.0010 (5)
C3	0.0175 (6)	0.0126 (6)	0.0175 (6)	0.0006 (5)	0.0070 (5)	0.0012 (5)
C4	0.0191 (7)	0.0150 (7)	0.0258 (8)	−0.0039 (5)	0.0124 (6)	−0.0051 (6)
I1	0.01367 (5)	0.01628 (6)	0.01473 (5)	−0.00037 (3)	0.00680 (3)	0.00092 (3)

C1—C3i	1.396 (2)	C3—C1i	1.396 (2)
C1—C2	1.401 (2)	C3—H3	1.01 (2)
C1—C4	1.489 (2)	C4—I1	2.1907 (15)
C2—C3	1.386 (2)	C4—H41	1.04 (2)
C2—H2	0.92 (2)	C4—H42	1.02 (2)
C3i—C1—C2	118.88 (13)	C1i—C3—H3	118.7 (12)
C3i—C1—C4	120.68 (14)	C1—C4—I1	111.52 (10)
C2—C1—C4	120.42 (14)	C1—C4—H41	116.4 (13)
C3—C2—C1	120.64 (14)	I1—C4—H41	100.5 (13)
C3—C2—H2	119.1 (14)	C1—C4—H42	114.9 (13)
C1—C2—H2	120.3 (14)	I1—C4—H42	101.8 (13)
C2—C3—C1i	120.48 (14)	H41—C4—H42	109.8 (19)
C2—C3—H3	120.9 (12)
C3i—C1—C2—C3	−0.1 (2)	C3i—C1—C4—I1	−91.95 (15)
C4—C1—C2—C3	178.24 (14)	C2—C1—C4—I1	89.71 (15)
C1—C2—C3—C1i	0.1 (2)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H42···I1ii	1.02 (2)	3.12 (2)	3.9774 (16)	141.8 (16)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H42⋯I1i	1.02 (2)	3.12 (2)	3.9774 (16)	141.8 (16)

Symmetry code: (i) .