Crystal structures of two bis-(iodo-meth-yl)benzene derivatives: similarities and differences in the crystal packing.

The isomeric derivatives 1,2-bis-(iodo-meth-yl)benzene, (I), and 1,3-bis-(iodo-meth-yl)benzene (II), both C8H8I2, were prepared by metathesis from their di-bromo analogues. The ortho-derivative, (I), lies about a crystallographic twofold axis that bis-ects the C-C bond between the two iodo-methyl substituents. The packing in (I) relies solely on C-H⋯I hydrogen bonds supported by weak parallel slipped π-π stacking inter-actions [inter-centroid distance = 4.0569 (11) Å, inter-planar distance = 3.3789 (8) Å and slippage = 2.245 Å]. While C-H⋯I hydrogen bonds are also found in the packing of (II), type II, I⋯I halogen bonds [I⋯I = 3.8662 (2) Å] and C-H⋯π contacts feature prominently in stabilizing the three-dimensional structure.

Chemical context

The isomeric xylene derivatives reported here, 1,2-bis­(iodo­meth­yl)benzene, (I), and 1,3-bis­(iodo­meth­yl)benzene (II), are useful synthons for the preparation of a range of organic compounds. (I) is used particularly in the synthesis of polycyclic aromatic systems (see for example: Takahashi et al. 2006 ▸; Abreu et al., 2010 ▸; Wang et al., 2012 ▸). Similarly (II) has been used in polymer formation (Pandya & Gibson, 1991 ▸), in the synthesis of meta­cyclo­phanes (Ramming & Gleiter, 1997 ▸) and to provide aromatic spacers in organic synthesis (Kida et al., 2005 ▸). Our inter­est in such compounds is as components of ionene polymers. The compounds were readily prepared by metathesis from the bis­(bromo­meth­yl)benzene derivatives.

Structural commentary

The mol­ecular structures of 1,2-bis­(iodo­meth­yl)benzene, (I), and 1,3-bis­(iodo­meth­yl)benzene, (II), are shown in Figs. 1 ▸ and 2 ▸ and are sufficiently similar to be discussed together. Each comprises a benzene ring with two iodo­methyl substituents in the 1,2- and 1,3-positions for (I) and (II) respectively. The mol­ecule of (I) lies about a twofold axis that bis­ects the C—C bond between the two iodo­methyl substituents. For each mol­ecule the C—I bonds of the substituents point away from opposite faces of the benzene rings with the C—C—I planes almost orthogonal to the ring planes; dihedral angles = 87.99 (14)° for (I) and 82.23 (14) and 83.61 (15)° for (II). The C1—C11 and C11—I1 bond lengths in (I) and C1—C11, C11—I1, C3—C31 and C31—I3 in (II) are reasonably self-consistent and also compare well with those found in the isomeric 1,4-bis­(iodo­meth­yl)benzene (McAdam et al. 2009 ▸).

Figure 1

The mol­ecular structure of compound (I), with displacement ellipsoids drawn at the 50% probability level. The unlabelled atoms are related to labelled atoms by the symmetry operation (−x + 1, y, −z + ).

Figure 2

The mol­ecular structure of compound (II), with displacement ellipsoids drawn at the 50% probability level.

Supra­molecular features

Crystal packing for (I)

In the crystal of (I), weak parallel slipped π–π stacking inter­actions [inter-centroid distance = 4.0569 (11) Å, inter-planar distance = 3.3789 (8) Å, slippage = 2.245 Å], between the benzene rings of inversion-related mol­ecules are supported by C3—H3⋯I1 hydrogen bonds, Table 1 ▸, to link mol­ecules in a head-to tail-fashion, stacking them along c, Fig. 3 ▸. In addition, the iodine atoms act as bifurcated acceptors, forming weak C2—H2⋯I1 and C11—H112⋯I1 hydrogen bonds generating (6) ring motifs (Bernstein et al., 1995 ▸). These contacts link the mol­ecules into zigzag chains along [101], Fig. 4 ▸. These contacts combine to link stacked columns of mol­ecules through weak C—H⋯I hydrogen bonds and generate a three dimensional network structure, Fig. 5 ▸.

Table 1

Hydrogen-bond geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯I1i	0.95	3.38	4.046 (2)	129
C11—H112⋯I1ii	0.99	3.33	4.179 (2)	145
C2—H2⋯I1ii	0.95	3.36	4.257 (2)	158

Symmetry codes: (i) ; (ii) .

Figure 3

π–π stacking inter­actions (green dotted lines) supported by C—H⋯I hydrogen bonds for (I). Hydrogen bonds in this and subsequent figures are drawn as blue dashed lines.

Figure 4

Chains of mol­ecules of (I) in [101].

Figure 5

Overall packing for (I) viewed along the c-axis direction.

Crystal packing for (II)

In the crystal of (II), C11—H11B⋯I1 hydrogen bonds, Table 2 ▸, form a column supported by a series of C31—H31B⋯Cg1 contacts. C31—H31A⋯I3 hydrogen bonds link these in an obverse fashion, forming double chains along b, Fig. 6 ▸. C5—H5⋯I1 hydrogen bonds, Fig. 7 ▸, link the double chains into sheets in the ab plane. An extensive series of I1⋯I3 halogen bonds Fig. 8 ▸, I1⋯I3v,vi = 3.8662 (2) Å; symmetry codes: (v) = − + x,  − y,  + z; (vi) =  + x,  − y, − + z (Desiraju et al., 2013 ▸; Metrangolo et al., 2008 ▸), extend the structure in the third dimension, Fig. 9 ▸. The angles C11—I1—I3 = 117° and C31—I3—I1 = 165° characterize this halogen bond as type II (Pedireddi et al., 1994 ▸).

Table 2

Hydrogen-bond geometry (Å, °) for (II)

Cg is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11B⋯I1i	0.99	3.22	4.060 (3)	144
C5—H5⋯I1ii	0.95	3.25	4.078 (3)	147
C31—H31A⋯I3iii	0.99	3.27	4.224 (3)	162
C31—H31A⋯Cg iv	0.99	2.84	3.453 (3)	121

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

Figure 6

Double chains of mol­ecules of (II) formed by a series of C31—H31B⋯Cg1 contacts (green dotted lines) linked by C—H⋯I hydrogen bonds.

Figure 7

Sheets of mol­ecules of (II) in the ab plane formed by C—H⋯I. hydrogen bonds.

Figure 8

Sheets of mol­ecules of (II) in the (101) plane formed by I⋯I halogen bonds, blue dashed lines, supported by C—H⋯I hydrogen bonds.

Figure 9

Overall packing for (II) viewed along the b-axis direction.

Database survey

A search of the Cambridge Structural Database (Version 5.36 with three updates; Groom & Allen, 2014 ▸) for mol­ecules incorporating a C6CH2I fragment surprisingly generated only five hits for iodo­methyl­benzene derivatives. One of these is the isomeric 1,4-bis­(iodo­meth­yl)benzene reported by us previously (McAdam et al., 2009 ▸), while two others are the organic compounds 2-(iodo­meth­yl)-1,3,5-tri­methyl­benzene (Bats, 2014 ▸) and 3′-iodo-5′-(iodo­meth­yl)biphenyl-4-carbo­nitrile (He et al., 2013 ▸). The other two entries are metal complexes (Martínez-García et al., 2010 ▸; Rivada-Wheelaghan et al., 2012 ▸). In one of these, the iodine atom of the iodo­methyl unit was found to act as a ligand to a platinum(II) nucleus (Rivada-Wheelaghan et al., 2012 ▸). The structures of both the chloro- and bromo-analogues of 1,2-bis­(iodo­meth­yl)benzene (Basaran et al., 1992 ▸; Jones & Kus, 2007 ▸) and 1,3-bis­(iodo­meth­yl)benzene (Sanders et al., 2013 ▸; Li et al., 2006 ▸; Jones & Kus, 2007 ▸) have also been reported. Inter­estingly, 1,3-bis(bromo­meth­yl)benzene is isostructural with (II) and the packing features for the two compounds are identical, apart from somewhat increased distances for the iodo compound. For example I1⋯I3 = 3.8662 (2) Å for (II) but the equivalent Br⋯Br distance is 3.6742 (3) Å for the meta-di­bromo analogue (Jones & Kus, 2007 ▸). Similar isostructural behaviour is observed for para-bis­(iodo­meth­yl)benzene (McAdam et al., 2009 ▸) and its di­bromo analogue (Jones & Kus, 2007 ▸). However, in contrast, despite (I) and the ortho-di­bromo analogue both displaying twofold symmetry, compound (I) crystallizes in the monoclinic space group C2/c while that for the di­bromo counterpart is found to be ortho­rhom­bic, Fdd2 (Jones & Kus, 2007 ▸).

Synthesis and crystallization

Preparation of the title compounds was based on literature methods (Moore & Stupp, 1986 ▸; Kida et al., 2005 ▸). The appropriate bis­(bromo­meth­yl)benzene (1.32 g, 5 mmol) was refluxed for 7 h with sodium iodide (2.25 g, 15 mmol) in acetone (25 ml). The solution was allowed to cool overnight, the crystals that developed were rinsed gently with water to remove sodium bromide and air dried. The product was recrystallized a second time from acetone to give X-ray quality crystals. Confirmation of the metathesised (iodo) product was by microanalysis and mass spectroscopy. 13C NMR spectra of the di­iodo compounds are distinct from those of their di­bromo precursors.

Compound (I): Analysis calculated for C8H8I2: C, 26.84; H, 2.25%. Found: C, 26.86; H, 2.14%. 13C NMR (δ p.p.m.): 137.4, 130.8, 129.0, 1.8.

Compound (II): Analysis calculated for C8H8I2: C, 26.84; H, 2.25%. Found: C, 26.63; H, 2.19%. 13C NMR (δ p.p.m.): 140.0, 129.4, 129.0, 128.4, 4.9.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. All H atoms were refined using a riding model with d(C—H) = 0.95 Å, U iso = 1.2U eq(C) for aromatic and 0.99 Å, U iso = 1.2U eq(C) for CH2 H atoms. For (I), a low-angle reflection with F o << F c, that may have been affected by the beam-stop, was omitted from the final refinement cycles.

Table 3

Experimental details

	(I)	(II)
Crystal data
Chemical formula	C8H8I2	C8H8I2
M r	357.94	357.94
Crystal system, space group	Monoclinic, C2/c	Monoclinic, P21/n
Temperature (K)	90	90
a, b, c (Å)	14.5485 (5), 8.0461 (3), 8.0582 (3)	13.5323 (3), 4.5464 (1), 15.6269 (4)
β (°)	101.637 (2)	95.203 (1)
V (Å3)	923.89 (6)	957.46 (4)
Z	4	4
Radiation type	Mo Kα	Mo Kα
μ (mm−1)	6.74	6.50
Crystal size (mm)	0.31 × 0.17 × 0.15	0.45 × 0.06 × 0.05
Data collection
Diffractometer	Bruker APEXII CCD area detector	Bruker APEXII CCD area detector
Absorption correction	Multi-scan (SADABS; Bruker, 2013 ▸)	Multi-scan (SADABS; Bruker, 2013 ▸)
T min, T max	0.534, 1.000	0.569, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	8422, 1667, 1552	16804, 3435, 2826
R int	0.030	0.033
(sin θ/λ)max (Å−1)	0.775	0.775
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.018, 0.044, 1.15	0.024, 0.048, 1.06
No. of reflections	1667	3435
No. of parameters	46	91
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.52, −1.23	1.24, −0.77

Computer programs: APEX2 and SAINT (Bruker, 2013 ▸), SHELXT (Sheldrick, 2015a ▸), SHELXL2014 (Sheldrick, 2015b ▸), TITAN2000 (Hunter & Simpson, 1999 ▸), Mercury (Macrae et al., 2008 ▸), enCIFer (Allen et al., 2004 ▸), PLATON (Spek, 2009 ▸), WinGX (Farrugia, 2012 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) global, I, II. DOI: 10.1107/S2056989015021295/su5235sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015021295/su5235Isup2.hkl

Structure factors: contains datablock(s) II. DOI: 10.1107/S2056989015021295/su5235IIsup3.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015021295/su5235Isup4.cml

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015021295/su5235IIsup5.cml

CCDC references: 1436014, 1436013

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

C8H8I2	F(000) = 648
Mr = 357.94	Dx = 2.573 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 14.5485 (5) Å	Cell parameters from 5091 reflections
b = 8.0461 (3) Å	θ = 2.6–32.9°
c = 8.0582 (3) Å	µ = 6.74 mm−1
β = 101.637 (2)°	T = 90 K
V = 923.89 (6) Å3	Block, colourless
Z = 4	0.31 × 0.17 × 0.15 mm

Bruker APEXII CCD area-detector diffractometer	1552 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.030
ω scans	θmax = 33.4°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Bruker, 2013)	h = −21→21
Tmin = 0.534, Tmax = 1.000	k = −11→12
8422 measured reflections	l = −12→10
1667 independent reflections

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.018	H-atom parameters constrained
wR(F2) = 0.044	w = 1/[σ2(Fo2) + (0.0175P)2 + 1.2212P] where P = (Fo2 + 2Fc2)/3
S = 1.15	(Δ/σ)max = 0.002
1667 reflections	Δρmax = 0.52 e Å−3
46 parameters	Δρmin = −1.23 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. One low angle reflection with Fo << Fc was omitted from the final refinement cycles.

	x	y	z	Uiso*/Ueq
I1	0.31503 (2)	0.11885 (2)	0.75250 (2)	0.01529 (5)
C11	0.41526 (13)	0.2215 (2)	0.6102 (3)	0.0142 (3)
H111	0.4651	0.1386	0.6070	0.017*
H112	0.3826	0.2433	0.4921	0.017*
C1	0.45886 (13)	0.3782 (2)	0.6864 (2)	0.0111 (3)
C2	0.41839 (13)	0.5301 (2)	0.6268 (3)	0.0136 (3)
H2	0.3623	0.5307	0.5427	0.016*
C3	0.45882 (14)	0.6802 (2)	0.6886 (3)	0.0156 (4)
H3	0.4304	0.7823	0.6470	0.019*

	U11	U22	U33	U12	U13	U23
I1	0.01370 (7)	0.01474 (7)	0.01747 (8)	−0.00335 (4)	0.00325 (5)	0.00078 (4)
C11	0.0139 (8)	0.0163 (8)	0.0132 (9)	−0.0016 (6)	0.0044 (7)	−0.0027 (7)
C1	0.0115 (8)	0.0123 (8)	0.0102 (8)	−0.0008 (5)	0.0039 (6)	−0.0001 (6)
C2	0.0131 (8)	0.0158 (8)	0.0122 (9)	0.0026 (6)	0.0035 (7)	0.0011 (7)
C3	0.0212 (9)	0.0122 (8)	0.0153 (9)	0.0026 (7)	0.0085 (7)	0.0031 (7)

I1—C11	2.1902 (19)	C1—C1i	1.410 (4)
C11—C1	1.487 (3)	C2—C3	1.391 (3)
C11—H111	0.9900	C2—H2	0.9500
C11—H112	0.9900	C3—C3i	1.392 (4)
C1—C2	1.399 (3)	C3—H3	0.9500
C1—C11—I1	112.15 (13)	C1i—C1—C11	121.93 (11)
C1—C11—H111	109.2	C3—C2—C1	121.16 (18)
I1—C11—H111	109.2	C3—C2—H2	119.4
C1—C11—H112	109.2	C1—C2—H2	119.4
I1—C11—H112	109.2	C2—C3—C3i	119.72 (12)
H111—C11—H112	107.9	C2—C3—H3	120.1
C2—C1—C1i	119.10 (11)	C3i—C3—H3	120.1
C2—C1—C11	118.94 (18)
I1—C11—C1—C2	−93.41 (19)	C11—C1—C2—C3	−177.12 (17)
I1—C11—C1—C1i	88.3 (2)	C1—C2—C3—C3i	0.2 (3)
C1i—C1—C2—C3	1.2 (3)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···I1ii	0.95	3.38	4.046 (2)	129
C11—H112···I1iii	0.99	3.33	4.179 (2)	145
C2—H2···I1iii	0.95	3.36	4.257 (2)	158

C8H8I2	F(000) = 648
Mr = 357.94	Dx = 2.483 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 13.5323 (3) Å	θ = 2.6–33.0°
b = 4.5464 (1) Å	µ = 6.50 mm−1
c = 15.6269 (4) Å	T = 90 K
β = 95.203 (1)°	Needle, colourless
V = 957.46 (4) Å3	0.45 × 0.06 × 0.05 mm
Z = 4

Bruker APEXII CCD area-detector diffractometer	2826 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.033
ω scans	θmax = 33.4°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2013)	h = −20→20
Tmin = 0.569, Tmax = 1.000	k = −6→5
16804 measured reflections	l = −23→24
3435 independent reflections

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.024	H-atom parameters constrained
wR(F2) = 0.048	w = 1/[σ2(Fo2) + (0.0109P)2 + 1.4343P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max = 0.002
3435 reflections	Δρmax = 1.24 e Å−3
91 parameters	Δρmin = −0.77 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.

	x	y	z	Uiso*/Ueq
I1	0.35561 (2)	0.36401 (4)	0.46514 (2)	0.01445 (4)
C11	0.4498 (2)	0.1469 (6)	0.37746 (17)	0.0197 (5)
H11A	0.5193	0.1461	0.4034	0.024*
H11B	0.4282	−0.0599	0.3690	0.024*
C1	0.44471 (19)	0.2984 (6)	0.29275 (16)	0.0152 (5)
C2	0.51858 (18)	0.4993 (5)	0.27547 (16)	0.0138 (5)
H2	0.5707	0.5419	0.3185	0.017*
C3	0.51650 (18)	0.6379 (5)	0.19574 (16)	0.0128 (4)
C31	0.59593 (19)	0.8514 (6)	0.17788 (17)	0.0175 (5)
H31A	0.6261	0.9352	0.2326	0.021*
H31B	0.5667	1.0148	0.1421	0.021*
I3	0.71036 (2)	0.63230 (4)	0.11079 (2)	0.01692 (5)
C4	0.43920 (19)	0.5755 (6)	0.13244 (16)	0.0171 (5)
H4	0.4369	0.6696	0.0780	0.021*
C5	0.36591 (19)	0.3753 (6)	0.14961 (17)	0.0179 (5)
H5	0.3138	0.3322	0.1066	0.022*
C6	0.36832 (19)	0.2379 (6)	0.22919 (18)	0.0178 (5)
H6	0.3177	0.1021	0.2404	0.021*

	U11	U22	U33	U12	U13	U23
I1	0.01484 (7)	0.01475 (9)	0.01451 (8)	0.00033 (6)	0.00534 (5)	0.00083 (6)
C11	0.0223 (12)	0.0167 (13)	0.0216 (12)	0.0064 (11)	0.0091 (10)	0.0020 (11)
C1	0.0174 (11)	0.0125 (12)	0.0167 (11)	0.0032 (10)	0.0065 (9)	0.0003 (9)
C2	0.0149 (11)	0.0112 (12)	0.0155 (11)	0.0011 (9)	0.0035 (9)	−0.0025 (9)
C3	0.0139 (10)	0.0097 (11)	0.0153 (10)	0.0010 (9)	0.0044 (8)	−0.0013 (9)
C31	0.0191 (12)	0.0131 (13)	0.0215 (12)	−0.0020 (10)	0.0083 (10)	−0.0037 (10)
I3	0.01582 (8)	0.01765 (9)	0.01833 (8)	−0.00134 (6)	0.00728 (6)	−0.00027 (6)
C4	0.0184 (11)	0.0182 (13)	0.0148 (11)	0.0024 (10)	0.0016 (9)	0.0005 (10)
C5	0.0152 (11)	0.0191 (13)	0.0190 (12)	0.0004 (10)	−0.0012 (9)	−0.0044 (10)
C6	0.0153 (11)	0.0147 (13)	0.0243 (13)	−0.0029 (10)	0.0057 (10)	−0.0010 (11)

I1—C11	2.189 (3)	C3—C31	1.493 (3)
I1—I3i	3.8662 (2)	C31—I3	2.187 (2)
C11—C1	1.488 (4)	C31—H31A	0.9900
C11—H11A	0.9900	C31—H31B	0.9900
C11—H11B	0.9900	C4—C5	1.390 (4)
C1—C6	1.394 (4)	C4—H4	0.9500
C1—C2	1.399 (3)	C5—C6	1.390 (4)
C2—C3	1.394 (3)	C5—H5	0.9500
C2—H2	0.9500	C6—H6	0.9500
C3—C4	1.402 (3)
C11—I1—I3i	117.47 (7)	C3—C31—I3	110.27 (16)
C1—C11—I1	111.45 (17)	C3—C31—H31A	109.6
C1—C11—H11A	109.3	I3—C31—H31A	109.6
I1—C11—H11A	109.3	C3—C31—H31B	109.6
C1—C11—H11B	109.3	I3—C31—H31B	109.6
I1—C11—H11B	109.3	H31A—C31—H31B	108.1
H11A—C11—H11B	108.0	C5—C4—C3	119.7 (2)
C6—C1—C2	119.2 (2)	C5—C4—H4	120.1
C6—C1—C11	120.9 (2)	C3—C4—H4	120.1
C2—C1—C11	119.9 (2)	C6—C5—C4	120.5 (2)
C3—C2—C1	120.7 (2)	C6—C5—H5	119.7
C3—C2—H2	119.6	C4—C5—H5	119.7
C1—C2—H2	119.6	C5—C6—C1	120.3 (2)
C2—C3—C4	119.5 (2)	C5—C6—H6	119.9
C2—C3—C31	120.3 (2)	C1—C6—H6	119.9
C4—C3—C31	120.2 (2)
I1—C11—C1—C6	−83.6 (3)	C4—C3—C31—I3	−83.7 (3)
I1—C11—C1—C2	97.9 (2)	C2—C3—C4—C5	−0.3 (4)
C6—C1—C2—C3	−0.1 (4)	C31—C3—C4—C5	179.7 (2)
C11—C1—C2—C3	178.4 (2)	C3—C4—C5—C6	0.4 (4)
C1—C2—C3—C4	0.2 (4)	C4—C5—C6—C1	−0.3 (4)
C1—C2—C3—C31	−179.8 (2)	C2—C1—C6—C5	0.2 (4)
C2—C3—C31—I3	96.4 (2)	C11—C1—C6—C5	−178.4 (2)

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11B···I1ii	0.99	3.22	4.060 (3)	144
C5—H5···I1iii	0.95	3.25	4.078 (3)	147
C31—H31A···I3iv	0.99	3.27	4.224 (3)	162
C31—H31A···Cgv	0.99	2.84	3.453 (3)	121