2,6-Diiodo-4-nitrophenol, 2,6-diiodo-4-nitrophenyl acetate and 2,6-diiodo-4-nitroanisole: interplay of hydrogen bonds, iodo-nitro interactions and aromatic [pi]-[pi]-stacking interactions to give supramolecular structures in one, two and three dimensions

In 2,6-di­iodo-4-nitro­phenol, C₆H₃I₂NO₃, the mol­ecules are linked, by an O-H...O hydrogen bond and two iodo-nitro interactions, into sheets, which are further linked into a three-dimensional framework by aromatic [pi]-[pi]-stacking interactions. The mol­ecules of 2,6-di­iodo-4-nitro­phenyl acetate, C₈H₅I₂NO₄, lie across a mirror plane in space group Pnma, with the acetyl group on the mirror, and they are linked by a single iodo-nitro interaction to form isolated sheets. The mol­ecules of 2,6-di­iodo-4-nitro­anisole, C₇H₅I₂NO₃, are linked into isolated chains by a single two-centre iodo-nitro interaction.

S1. Comment

We have recently reported the molecular and supramolecular structures of several iodo-nitro anilines, unsubstituted at N (Garden et al., 2002). In these compounds, the supramolecular aggregation is dominated by a combination of N—H···O hydrogen bonds, iodo···nitro interactions and aromatic π···π stacking interactions, to give either two-dimensional or three-dimensional structures. The title compounds, 2,6-diiodo-4-nitrophenol, (I), 2,6-diiodo-4-nitrophenyl acetate, (II), and 2,6-diiodo-4-nitroanisole, (III), have been designed to reduce the scope for formation of hard (Braga et al., 1995) hydrogen bonds, while retaining the other potential intermolecular interactions, in that (I) has an OH group in place of the NH₂ group in simple anilines, allowing the molecule to act as only a single donor in such bonds, while (II) and (III) have no scope at all for the formation of hard hydrogen bonds. \sch

In compound (I) (Fig. 1), a combination of O—H···O hydrogen bonds and two independent iodo···nitro interactions links the molecules into sheets, and these sheets are weakly linked by aromatic π···π stacking interactions to form a continuous three-dimensional structure. The phenolic atom O1 acts as a hydrogen-bond donor to nitro atom O41 at (1 + x, y - 1, z) (Table 2), so generating by translation a C(8) chain (Bernstein et al., 1995) running parallel to the [110] direction. Chains of this type are linked into sheets by the iodo···nitro interactions, which involve both I atoms and both nitro O atoms. Atoms I2 and I6 participate in iodo···nitro interactions with nitro atoms O42 and O41, respectively [I2···O42ⁱ 3.326 (4) Å and C2—I2···O42ⁱ 152.2 (2)°, and I6···O41ⁱⁱ 3.552 (4) Å and C6—I6···O41ⁱⁱ 157.9 (2)°; symmetry codes: (i) 1 - x, 1 - y, -z; (ii) -x, 1 - y, 2 - z], so generating centrosymmetric R₂²(12) rings centred at (1/2,0,0) and (0,0,1), respectively. The combination of these two motifs generates a chain of fused rings running parallel to the [102] direction, while the combination of this chain with the hydrogen-bonded chain along [110] generates a (221) sheet in which there are four distinct types of ring, all centrosymmetric (Fig. 2).

The aromatic ring of (I) forms a close π···π contact with that at (1 - x, 1 - y, 1 - z) (Fig. 3); the interplanar spacing between parallel rings is 3.379 (4) Å, the centroid separation is 3.493 (4) Å and the centroid offset is 0.886 (4) Å. In this manner, each (221) sheet (Fig. 2) is linked to the two adjacent sheets, so generating a continuous framework in three dimensions.

Molecules of compound (II) lie across the mirror planes in space group Pnma (Fig. 4). The non-H atoms of the acetate group all lie on the mirror plane (chosen for the sake of convenience as that at y = 1/4 for the reference molecule), so that the plane of the acetate group is orthogonal to the aromatic ring. The methyl group was modelled using six H-atom sites, each with occupancy 0.5. The crystal structure exhibits neither C—H···O hydrogen bonds nor aromatic π···π stacking interactions. Instead, the single short iodo···nitro interaction generates a simple and elegant sheet structure (Fig. 5).

Each of the two symmetry-related I atoms in (II) participates in a two-centre iodo···nitro interaction with the O4 atoms at (1/2 - x, 1 - y, z - 1/2) and at (1/2 - x, y - 1/2, z - 1/2), respectively, with I2···O4 3.323 (3) Å and C—I···O4 140.8 (2)°. Propagation of these interactions produces two C(6) chain motifs running parallel to the [001] direction and generated by the 2₁ screw axes along (1/4,1/2,z) and (1/4,0,z). The combination of these two symmetry-related motifs and their propagation by the space group generates a (100) sheet in the form of a (4,4) net (Batten & Robson, 1998) built from a single type of R₄⁴(20) ring. The central space in each ring is occupied by an acetate group.

In compound (III) (Fig. 6), neither C—H···O hydrogen bonds nor aromatic π···π stacking interactions are present in the crystal structure. The molecules are linked into chains by an iodo···nitro interaction involving only one of the two I atoms and only one of the nitro O atoms. Atom I2 in the molecule at (x,y,z) forms a very short I···O contact with nitro atom O42 in the molecule at (1/2 + x, 1/2 - y, z - 1/2) [I2···O42^iv 2.992 (3) Å and C2—I2···O42^iv 171.3 (2)°; symmetry code: (iv) 1/2 + x, 1/2 - y, z - 1/2], and propagation of this interaction leads to the formation of a chain running parallel to the [101] direction, generated by the n glide plane at y = 1/4 (Fig. 7).

The intermolecular distances and angles in (I)-(III) present no unusual features. In each compound, the nitro group is almost coplanar with the adjacent aryl ring (Tables 1, 3 and 4).

S2. Experimental

Compound (I) was obtained by reaction of 4-nitrophenol with K[ICl₂] in aqueous solution (Garden et al., 2001). Compounds (II) and (III) were obtained from (I) by acetylation using acetic anhydride, and methylation using dimethylsulfate, respectively. Crystals of (I)-(III) suitable for single-crystal X-ray diffraction were grown by slow evaporation of solutions in ethanol [m.p. 439–441 K for (I), 409–411 K for (II) and 418–419 K for (III)].

S3. Refinement

Compound (I) is triclinic; space group P1 was selected and confirmed by the analysis. For compound (II), the systematic absences permitted Pnma and Pn2₁a (= Pna2₁) as possible space groups; Pnma was selected and confirmed by the structure analysis. For compound (III), the systematic absences permitted C2/c and Cc as possible space groups; C2/c was selected and confirmed by the analysis. All H atoms were located from difference maps and were treated as riding atoms, with O—H distances of 0.84 Å and C—H distances of 0.93–0.98 Å.

Computing details

Data collection: KappaCCD Server Software (Nonius, 1997) for (I), (III); SMART (Bruker, 1999) for (II). Cell refinement: DENZO-SMN (Otwinowski & Minor, 1997) for (I), (III); SAINT (Bruker, 1999) for (II). Data reduction: DENZO-SMN for (I), (III); SAINT for (II). For all compounds, program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2002); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).

Figures

	Fig. 1. The molecule of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. Part of the crystal structure of (I), showing formation of a (110) sheet containing four distinct centrosymmetric rings. For the sake of clarity, H atoms bonded to C atoms have been omitted. The atoms marked with an asterisk (*), hash (#), dollar sign (add) or ampersand (add) are at the symmetry positions (1 + x, y - 1, z), (1 - x, 1 - y, -z), (-x, 1 - y, 2 - z) and (x - 1, 1 + y, z), respectively.
	Fig. 3. Part of the crystal structure of (I), showing the π···π stacking interaction. The atoms marked with an asterisk (*) are at the symmetry position (1 - x, 1 - y, 1 - z).
	Fig. 4. The molecule of (II) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Atoms with the suffix A are at the symmetry position (x, 1 - y, z). For the sake of clarity, only one set of H atoms bonded to C12 is shown.
	Fig. 5. Part of the crystal structure of (II), showing formation of a (100) sheet of R4^4(20) rings. For the sake of clarity, H atoms bonded to C atoms have been omitted. The atoms marked with a plus sign (+), asterisk (*), hash (#), dollar sign (add) or ampersand (add) are at the symmetry positions (x, 1/2 - y, z), (1/2 - x, 1 - y, z - 1/2), (1/2 - x, y - 1/2, z - 1/2), (1/2 - x, y - 1/2, 1/2 + z) and (1/2 - x, 1 - y, 1/2 + z), respectively.
	Fig. 6. The molecule of (III) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 7. Part of the crystal structure of (III), showing formation of a chain along [101]. Atoms marked with an asterisk (*) or a hash (#) are at the symmetry positions (x - 1/2, 1/2 - y, 1/2 + z) and (1/2 + x, 1/2 - y, z - 1/2), respectively.

(I) 2,6-Diiodo-4-nitrophenol

Crystal data

C6H3I2NO3	Z = 2
Mr = 390.89	F(000) = 352
Triclinic, P1	Dx = 3.001 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.9749 (2) Å	Cell parameters from 1850 reflections
b = 8.0952 (3) Å	θ = 2.9–27.4°
c = 8.1395 (3) Å	µ = 7.24 mm^−1
α = 69.3082 (18)°	T = 120 K
β = 66.657 (2)°	Block, yellow
γ = 67.3547 (15)°	0.15 × 0.10 × 0.05 mm
V = 432.59 (3) Å^3

Data collection

Nonius KappaCCD diffractometer	1850 independent reflections
Radiation source: fine-focus sealed X-ray tube	1735 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.091
ϕ scans, and ω scans with κ offsets	θmax = 27.4°, θmin = 2.9°
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	h = −10→10
Tmin = 0.297, Tmax = 0.700	k = −10→10
4596 measured reflections	l = −10→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.115	H-atom parameters constrained
S = 1.17	w = 1/[σ^2(Fo^2) + (0.0584P)^2 + 0.3136P] where P = (Fo^2 + 2Fc^2)/3
1850 reflections	(Δ/σ)max < 0.001
110 parameters	Δρmax = 1.35 e Å^−3
0 restraints	Δρmin = −1.57 e Å^−3

Special details

Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm [Fox, G. C. & Holmes, K. C. (1966). Acta Cryst. 20, 886–891] which effectively corrects for absorption effects. High-redundancy data were used in the scaling program, hence the `multi-scan' code word was used.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4568 (7)	0.2563 (7)	0.5717 (7)	0.0151 (10)
O1	0.5878 (5)	0.1050 (5)	0.6302 (5)	0.0168 (7)
C2	0.4701 (7)	0.3379 (6)	0.3843 (7)	0.0165 (9)
I2	0.69997 (5)	0.21823 (4)	0.18496 (5)	0.01781 (17)
C3	0.3342 (7)	0.5005 (6)	0.3318 (7)	0.0153 (9)
C4	0.1880 (7)	0.5757 (7)	0.4659 (7)	0.0161 (10)
N4	0.0478 (6)	0.7482 (6)	0.4127 (6)	0.0188 (9)
O41	−0.0820 (6)	0.8178 (5)	0.5346 (6)	0.0265 (9)
O42	0.0673 (6)	0.8160 (5)	0.2483 (6)	0.0263 (9)
C5	0.1632 (7)	0.4974 (6)	0.6545 (7)	0.0166 (9)
C6	0.3004 (8)	0.3383 (7)	0.7039 (7)	0.0170 (10)
I6	0.27464 (5)	0.22289 (4)	0.98238 (5)	0.01917 (17)
H1	0.6626	0.0572	0.5414	0.025*
H3	0.3442	0.5567	0.2054	0.018*
H5	0.0564	0.5516	0.7449	0.020*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.012 (2)	0.015 (2)	0.018 (3)	−0.0026 (17)	−0.005 (2)	−0.0044 (19)
O1	0.0129 (16)	0.0158 (16)	0.0146 (18)	0.0056 (13)	−0.0064 (15)	−0.0039 (14)
C2	0.019 (2)	0.014 (2)	0.014 (2)	−0.002 (2)	−0.004 (2)	−0.0050 (19)
I2	0.0144 (3)	0.0183 (2)	0.0159 (3)	0.00020 (18)	−0.00123 (19)	−0.00785 (17)
C3	0.011 (2)	0.014 (2)	0.017 (2)	−0.0001 (17)	−0.006 (2)	−0.0018 (18)
C4	0.014 (2)	0.015 (2)	0.019 (3)	−0.0001 (18)	−0.009 (2)	−0.003 (2)
N4	0.0121 (18)	0.0175 (18)	0.023 (3)	0.0005 (16)	−0.0037 (18)	−0.0076 (18)
O41	0.023 (2)	0.0244 (19)	0.017 (2)	0.0041 (16)	0.0031 (17)	−0.0101 (17)
O42	0.024 (2)	0.0229 (19)	0.020 (2)	0.0076 (16)	−0.0129 (18)	−0.0002 (17)
C5	0.0074 (19)	0.022 (2)	0.019 (2)	−0.0034 (17)	0.004 (2)	−0.0134 (19)
C6	0.018 (2)	0.017 (2)	0.015 (2)	−0.008 (2)	0.002 (2)	−0.0073 (19)
I6	0.0178 (3)	0.0189 (2)	0.0137 (3)	0.00060 (17)	−0.00289 (19)	−0.00438 (17)

Geometric parameters (Å, º)

C1—O1	1.347 (6)	C4—C5	1.402 (7)
C1—C6	1.399 (7)	C4—N4	1.463 (6)
C1—C2	1.410 (7)	N4—O42	1.224 (6)
O1—H1	0.8400	N4—O41	1.227 (5)
C2—C3	1.400 (7)	C5—C6	1.384 (7)
C2—I2	2.078 (5)	C5—H5	0.9500
C3—C4	1.355 (7)	C6—I6	2.082 (5)
C3—H3	0.9500
O1—C1—C6	118.3 (5)	C3—C4—N4	118.7 (5)
O1—C1—C2	123.5 (5)	C5—C4—N4	117.7 (4)
C6—C1—C2	118.2 (5)	O42—N4—O41	123.4 (5)
C1—O1—H1	109.5	O42—N4—C4	118.0 (4)
C3—C2—C1	120.9 (5)	O41—N4—C4	118.5 (4)
C3—C2—I2	120.1 (4)	C6—C5—C4	117.4 (5)
C1—C2—I2	119.1 (4)	C6—C5—H5	121.3
C4—C3—C2	118.2 (5)	C4—C5—H5	121.3
C4—C3—H3	120.9	C5—C6—C1	121.7 (5)
C2—C3—H3	120.9	C5—C6—I6	118.7 (4)
C3—C4—C5	123.6 (4)	C1—C6—I6	119.6 (4)
C3—C4—N4—O41	−178.5 (6)	C5—C4—N4—O41	1.4 (8)
C3—C4—N4—O42	1.1 (8)	C5—C4—N4—O42	−179.1 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···I2	0.84	2.67	3.239 (4)	126
O1—H1···O41^i	0.84	2.20	2.808 (6)	129

Symmetry code: (i) x+1, y−1, z.

(II) 2,6-Diiodo-4-nitrophenyl acetate

Crystal data

C8H5I2NO4	F(000) = 792
Mr = 432.93	Dx = 2.453 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 2206 reflections
a = 8.0608 (9) Å	θ = 2.4–32.6°
b = 12.4501 (14) Å	µ = 5.36 mm^−1
c = 11.6790 (13) Å	T = 292 K
V = 1172.1 (2) Å^3	Block, colourless
Z = 4	0.50 × 0.23 × 0.12 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer	2206 independent reflections
Radiation source: fine-focus sealed X-ray tube	1555 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.044
ϕ and ω scans	θmax = 32.6°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −12→12
Tmin = 0.258, Tmax = 0.528	k = −17→18
11456 measured reflections	l = −17→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.041	H-atom parameters constrained
wR(F^2) = 0.112	w = 1/[σ^2(Fo^2) + (0.0513P)^2 + 0.8851P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
2206 reflections	Δρmax = 1.20 e Å^−3
81 parameters	Δρmin = −0.41 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0321 (13)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.1503 (5)	0.2500	0.1689 (3)	0.0376 (7)
O1	0.1962 (3)	0.2500	0.0539 (2)	0.0406 (6)
C11	0.0705 (6)	0.2500	−0.0268 (3)	0.0447 (9)
O12	−0.0711 (5)	0.2500	0.0010 (3)	0.0801 (14)
C12	0.1402 (6)	0.2500	−0.1442 (3)	0.0548 (12)
C2	0.1341 (3)	0.3471 (2)	0.2269 (2)	0.0407 (6)
I2	0.16877 (4)	0.49229 (2)	0.14194 (2)	0.06767 (17)
C3	0.1006 (4)	0.3473 (3)	0.3440 (2)	0.0444 (6)
C4	0.0833 (5)	0.2500	0.3985 (3)	0.0436 (9)
N4	0.0485 (5)	0.2500	0.5223 (3)	0.0540 (10)
O4	0.0328 (4)	0.3362 (3)	0.5705 (2)	0.0765 (9)
H12A	0.0605	0.2202	−0.1963	0.082*	0.50
H12B	0.2395	0.2075	−0.1457	0.082*	0.50
H12C	0.1657	0.3223	−0.1666	0.082*	0.50
H3	0.0903	0.4114	0.3842	0.053*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0379 (18)	0.048 (2)	0.0274 (15)	0.000	0.0006 (13)	0.000
O1	0.0390 (14)	0.0558 (17)	0.0270 (12)	0.000	0.0029 (10)	0.000
C11	0.052 (2)	0.051 (2)	0.0312 (17)	0.000	0.0005 (16)	0.000
O12	0.0437 (18)	0.150 (5)	0.0464 (19)	0.000	−0.0016 (15)	0.000
C12	0.064 (3)	0.072 (3)	0.0288 (18)	0.000	−0.0013 (17)	0.000
C2	0.0430 (14)	0.0448 (14)	0.0344 (12)	0.0022 (11)	−0.0010 (10)	0.0007 (10)
I2	0.1028 (3)	0.04586 (18)	0.0543 (2)	0.00141 (11)	0.00652 (12)	0.00583 (9)
C3	0.0461 (14)	0.0547 (17)	0.0323 (12)	0.0030 (13)	−0.0015 (11)	−0.0046 (11)
C4	0.0371 (19)	0.068 (3)	0.0255 (15)	0.000	−0.0045 (14)	0.000
N4	0.0471 (19)	0.089 (3)	0.0262 (15)	0.000	−0.0035 (13)	0.000
O4	0.088 (2)	0.103 (2)	0.0381 (12)	−0.0214 (16)	0.0074 (12)	−0.0237 (14)

Geometric parameters (Å, º)

C1—C2^i	1.392 (3)	C2—C3	1.394 (4)
C1—C2	1.392 (3)	C2—I2	2.080 (3)
C1—O1	1.393 (4)	C3—C4	1.375 (4)
O1—C11	1.385 (5)	C3—H3	0.9300
C11—O12	1.186 (6)	C4—C3^i	1.375 (4)
C11—C12	1.481 (6)	C4—N4	1.474 (5)
C12—H12A	0.9600	N4—O4	1.218 (3)
C12—H12B	0.9600	N4—O4^i	1.218 (3)
C12—H12C	0.9600
C2^i—C1—C2	120.6 (3)	C1—C2—C3	119.7 (3)
C2^i—C1—O1	119.58 (17)	C1—C2—I2	120.7 (2)
C2—C1—O1	119.58 (17)	C3—C2—I2	119.5 (2)
C11—O1—C1	117.5 (3)	C4—C3—C2	118.2 (3)
O12—C11—O1	121.2 (4)	C4—C3—H3	120.9
O12—C11—C12	128.2 (4)	C2—C3—H3	120.9
O1—C11—C12	110.6 (4)	C3^i—C4—C3	123.4 (4)
C11—C12—H12A	109.5	C3^i—C4—N4	118.27 (18)
C11—C12—H12B	109.5	C3—C4—N4	118.27 (18)
H12A—C12—H12B	109.5	O4—N4—O4^i	123.5 (4)
C11—C12—H12C	109.5	O4—N4—C4	118.2 (2)
H12A—C12—H12C	109.5	O4^i—N4—C4	118.2 (2)
H12B—C12—H12C	109.5
C2^i—C1—O1—C11	92.6 (3)	I2—C2—C3—C4	−178.0 (3)
C1—O1—C11—O12	0.0	C2—C3—C4—C3^i	1.4 (6)
C1—O1—C11—C12	180.0	C2—C3—C4—N4	179.8 (3)
C2^i—C1—C2—C3	−0.3 (5)	C3^i—C4—N4—O4	−179.9 (4)
O1—C1—C2—C3	−175.1 (3)	C3—C4—N4—O4	1.6 (6)
C2^i—C1—C2—I2	177.22 (18)	C3^i—C4—N4—O4^i	−1.6 (6)
O1—C1—C2—I2	2.4 (4)	C3—C4—N4—O4^i	179.9 (4)
C1—C2—C3—C4	−0.5 (5)	C2—C1—O1—C11	−92.6 (3)

Symmetry code: (i) x, −y+1/2, z.

(III) 2,6-Diiodo-4-nitroanisole

Crystal data

C7H5I2NO3	F(000) = 1472
Mr = 404.92	Dx = 2.640 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2312 reflections
a = 15.2372 (3) Å	θ = 2.9–27.5°
b = 16.2672 (4) Å	µ = 6.15 mm^−1
c = 8.3262 (2) Å	T = 120 K
β = 99.2039 (15)°	Block, yellow
V = 2037.22 (8) Å^3	0.10 × 0.05 × 0.03 mm
Z = 8

Data collection

Nonius KappaCCD diffractometer	2312 independent reflections
Radiation source: fine-focus sealed X-ray tube	2068 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
ϕ scans, and ω scans with κ offsets	θmax = 27.5°, θmin = 2.9°
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	h = −19→19
Tmin = 0.530, Tmax = 0.829	k = −21→18
7397 measured reflections	l = −10→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.077	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0371P)^2] where P = (Fo^2 + 2Fc^2)/3
2312 reflections	(Δ/σ)max < 0.001
119 parameters	Δρmax = 1.42 e Å^−3
0 restraints	Δρmin = −1.65 e Å^−3

Special details

Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm [Fox, G. C. & Holmes, K. C. (1966). Acta Cryst. 20, 886–891] which effectively corrects for absorption effects. High-redundancy data were used in the scaling program, hence the `multi-scan' code word was used.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.2503 (3)	0.0792 (3)	0.2707 (5)	0.0190 (8)
O1	0.30537 (18)	0.02160 (17)	0.2193 (3)	0.0222 (6)
C11	0.3802 (3)	−0.0013 (3)	0.3404 (6)	0.0297 (10)
C2	0.2648 (3)	0.1619 (3)	0.2520 (5)	0.0198 (8)
I2	0.371418 (17)	0.199410 (16)	0.13802 (3)	0.02086 (11)
C3	0.2082 (3)	0.2206 (3)	0.2988 (4)	0.0193 (8)
C4	0.1356 (3)	0.1926 (3)	0.3624 (5)	0.0209 (10)
N4	0.0728 (2)	0.2537 (2)	0.4084 (4)	0.0238 (8)
O41	0.0919 (2)	0.32653 (19)	0.4042 (4)	0.0314 (7)
O42	0.0042 (2)	0.2282 (2)	0.4497 (4)	0.0314 (7)
C5	0.1168 (3)	0.1110 (3)	0.3794 (4)	0.0211 (9)
C6	0.1750 (3)	0.0535 (3)	0.3330 (5)	0.0204 (8)
I6	0.146602 (18)	−0.071663 (18)	0.34506 (3)	0.02502 (12)
H11A	0.4198	0.0461	0.3647	0.045*
H11B	0.4127	−0.0465	0.2987	0.045*
H11C	0.3588	−0.0190	0.4398	0.045*
H3	0.2190	0.2776	0.2876	0.023*
H5	0.0653	0.0943	0.4218	0.025*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.017 (2)	0.025 (2)	0.0138 (18)	0.0011 (15)	−0.0008 (16)	0.0007 (15)
O1	0.0237 (15)	0.0216 (15)	0.0219 (14)	0.0020 (12)	0.0054 (12)	−0.0007 (11)
C11	0.026 (2)	0.031 (2)	0.032 (2)	0.0080 (18)	0.0048 (18)	0.0054 (18)
C2	0.0177 (19)	0.026 (2)	0.0160 (18)	0.0006 (16)	0.0027 (16)	0.0007 (16)
I2	0.01738 (17)	0.02245 (18)	0.02354 (18)	−0.00091 (10)	0.00564 (12)	0.00054 (9)
C3	0.020 (2)	0.023 (2)	0.0139 (18)	−0.0010 (17)	0.0014 (16)	0.0000 (16)
C4	0.017 (2)	0.029 (3)	0.017 (2)	0.0062 (16)	0.0027 (18)	−0.0036 (15)
N4	0.0214 (19)	0.030 (2)	0.0198 (18)	0.0017 (15)	0.0018 (15)	−0.0036 (15)
O41	0.0319 (18)	0.0261 (18)	0.0371 (19)	0.0035 (14)	0.0080 (15)	−0.0030 (14)
O42	0.0215 (16)	0.042 (2)	0.0325 (17)	−0.0003 (14)	0.0092 (14)	−0.0066 (15)
C5	0.016 (2)	0.033 (2)	0.0149 (18)	−0.0009 (17)	0.0029 (16)	−0.0002 (16)
C6	0.020 (2)	0.024 (2)	0.0161 (19)	−0.0026 (17)	0.0008 (16)	0.0010 (15)
I6	0.02599 (19)	0.0248 (2)	0.02382 (18)	−0.00485 (11)	0.00265 (13)	0.00228 (10)

Geometric parameters (Å, º)

C1—O1	1.372 (5)	C3—C4	1.378 (6)
C1—C2	1.376 (6)	C3—H3	0.9500
C1—C6	1.396 (6)	C4—C5	1.371 (6)
O1—C11	1.444 (5)	C4—N4	1.472 (5)
C11—H11A	0.9800	N4—O41	1.222 (5)
C11—H11B	0.9800	N4—O42	1.223 (5)
C11—H11C	0.9800	C5—C6	1.385 (6)
C2—C3	1.384 (6)	C5—H5	0.9500
C2—I2	2.099 (4)	C6—I6	2.087 (4)
O1—C1—C2	120.9 (4)	C4—C3—H3	121.4
O1—C1—C6	119.4 (4)	C2—C3—H3	121.4
C2—C1—C6	119.5 (4)	C5—C4—C3	123.6 (4)
C1—O1—C11	114.4 (3)	C5—C4—N4	118.1 (4)
O1—C11—H11A	109.5	C3—C4—N4	118.2 (4)
O1—C11—H11B	109.5	O41—N4—O42	123.7 (4)
H11A—C11—H11B	109.5	O41—N4—C4	118.6 (3)
O1—C11—H11C	109.5	O42—N4—C4	117.7 (4)
H11A—C11—H11C	109.5	C4—C5—C6	118.1 (4)
H11B—C11—H11C	109.5	C4—C5—H5	120.9
C1—C2—C3	121.5 (4)	C6—C5—H5	120.9
C1—C2—I2	119.1 (3)	C5—C6—C1	120.1 (4)
C3—C2—I2	119.3 (3)	C5—C6—I6	119.9 (3)
C4—C3—C2	117.1 (4)	C1—C6—I6	119.9 (3)
C3—C4—N4—O41	−7.4 (5)	C5—C4—N4—O42	−4.5 (5)
C3—C4—N4—O42	173.0 (4)	C2—C1—O1—C11	89.7 (5)
C5—C4—N4—O41	175.1 (4)	C6—C1—O1—C11	−94.7 (5)