Bilayers in 4-iodo-N-(2-iodo-4-nitrophenyl)benzamide generated by a combination of an N-H...O=C hydrogen bond and two independent iodo-nitro interactions

Molecules of the title compound, C₁₃H₈I₂N₂O₃, are linked into C(4) chains by a single N-H...O=C hydrogen bond [H...O = 2.10 Å, N...O = 2.832 (5) Å and N-H...O = 140°]. Two independent two-centre iodo-nitro interactions, both involving the same O atom but different I atoms [I...O = 3.205 (3) and 3.400 (3) Å, and C-I...O = 160.4 (2) and 155.7 (2)°], link the hydrogen-bonded chains into bilayers.

S1. Comment

As part of a general study of the interplay of hydrogen bonds, iodo···nitro interactions and aromatic π–π stacking interactions in aromatic systems containing both iodo and nitro substituents, we have recently reported the molecular and supramolecular structures of a range of diaryl species containing a variety of spacer units, namely arenesulfonamides (Kelly et al., 2002), Schiff base imines (Wardell et al., 2002; Glidewell, Howie et al., 2002), benzylanilines (Glidewell, Low et al., 2002) and phenylhydrazones (Glidewell et al., 2003). Here, we report the structure of an analogous compound containing an amide linker unit, N-(2-iodo-4-nitrophenyl)-4-iodobenzamide, (I), where there is an excess of iodo substituents over nitro substituents. \sch

The central C—C(O)—NH—C unit of (I) adopts a nearly planar trans configuration, and the dihedral angles between the mean plane of the spacer unit and the two aryl rings, C11—C16 and C21—C26, are 26.8 (2) and 29.2 (2)°, respectively. The dihedral angle between the nitro group and the adjacent aryl ring is 120.0 (2)° (see also Table 1). The bond distances and inter-bond angles are all normal.

There are two short non-bonded contacts within the molecule of (I), between atoms H1 and I22 and between atoms H26 and O13 (Fig.1, Table 2). While neither of these contacts can be regarded as a hydrogen bond, both involve a positively polarized H atom and a negatively polarized atom, I or O, and so are weakly attractive. These attractive interactions may contribute to the conformation of the molecular skeleton.

The molecules of (I) are linked into bilayers by a combination of one hydrogen bond and two iodo···nitro interactions. The formation of the supramolecular structure is most readily analysed by first considering each of the intermolecular interactions in turn, and then the effects of combining these interactions.

The amido atom N1 in the molecule at (x, y, z) acts as hydrogen-bond donor to carbonyl atom O17 in the molecule at (x, y − 1, z), so generating by translation a chain running parallel to the [010] direction (Fig. 2) which is characterized by the C(4) motif (Bernstein et al., 1995) typical of simple carboxylic amides.

The shorter of the two iodo···nitro interactions, between atom I14 in the molecule at (x, y, z) and nitro atom O24 in the molecule at (1 + x, 1/2 − y, 1/2 + z) [I···O 3.205 (3) Å, C—I···O 160.4 (2)° and I···O—N 135.0 (3)°] generates a C(13) chain (Starbuck et al., 1999) running parallel to the [201] direction (Fig. 2) and generated by the c-glide plane at y = 1/4. The longer of the iodo···nitro interactions, between atom I22 and nitro atom O24 in the molecules at (x, y, z) and (-x, −y, −z), respectively [I···O 3.400 (3) Å, C—I····O 155.7 (2)° and I···O—N 146.6 (3)°], generates an R₂²(12) ring centred at the origin (Fig. 3).

The combination of the two chain motifs together generates a (102) sheet in the form of a (4,4) net (Batten & Robson, 1998) built from a single type of R₄⁴(32) ring (Fig. 2), and pairs of these sheets, related by inversion, are linked by the R₂²(12) (Fig. 3) motif into bilayers, within which the two iodo···nitro interactions together form a C(13)[R₂²(12)] chain of rings (Fig. 3).

Table 2. Hydrogen bonds and short intramolecular contacts (Å, °) for compound (I).

S2. Experimental

A sample of (I) was prepared from 4-iodobenzoyl chloride and 2-iodo-4-nitroaniline according to the general procedure of Furniss et al. (1989). Crystals of (I) suitable for single-crystal X-ray diffraction were grown by slow evaporation of a solution in ethanol-acetone (1/1 v/v). Analysis: m.p. 512–513 K; IR (KBr): 3277 cm⁻¹ ν(NH), 1660 cm⁻¹ ν(CO).

S3. Refinement

Space group P2₁/c was uniquely assigned from the systematic absences. All H atoms were located from difference maps and they were then treated as riding atoms, with C—H distances of 0.95 Å and N—H distances of 0.88 Å.

Computing details

Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS86 (Sheldrick, 1985); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).

Figures

	Fig. 1. A view of 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. A stereoview of part of the crystal structure of (I) showing the formation of a (102) sheet of R4^4(32) rings by combination of C(4) and C(13) chains. For the sake of clarity, H atoms bonded to C atoms have been omitted.
	Fig. 3. A view of part of the crystal structure of (I) showing the combination of the two independent iodo···nitro interactions. For the sake of clarity, H atoms bonded to C atoms have been omitted.

N-(2-Iodo-4-nitrophenyl)-4-iodobenzamide

Crystal data

C13H8I2N2O3	F(000) = 920
Mr = 494.01	Dx = 2.319 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3217 reflections
a = 15.6188 (5) Å	θ = 3.0–27.5°
b = 4.7253 (1) Å	µ = 4.45 mm^−1
c = 19.7669 (7) Å	T = 120 K
β = 104.0822 (12)°	Needle, colourless
V = 1415.02 (7) Å^3	0.60 × 0.03 × 0.02 mm
Z = 4

Data collection

Nonius KappaCCD area-detector diffractometer	3217 independent reflections
Radiation source: fine-focus sealed X-ray tube	2733 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.079
ϕ scans, and ω scans with κ offsets	θmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	h = −20→18
Tmin = 0.677, Tmax = 0.912	k = −6→5
15901 measured reflections	l = −25→25

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.074	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.016P)^2 + 3.8598P] where P = (Fo^2 + 2Fc^2)/3
3217 reflections	(Δ/σ)max = 0.001
181 parameters	Δρmax = 0.71 e Å^−3
0 restraints	Δρmin = −1.22 e Å^−3

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

	x	y	z	Uiso*/Ueq
C11	0.4434 (3)	0.5630 (9)	0.0826 (2)	0.0144 (9)
C12	0.5253 (3)	0.6883 (9)	0.0844 (2)	0.0163 (9)
C13	0.6003 (3)	0.6032 (9)	0.1336 (2)	0.0158 (9)
C14	0.5936 (3)	0.3927 (9)	0.1814 (2)	0.0180 (9)
C15	0.5128 (3)	0.2681 (9)	0.1811 (2)	0.0166 (9)
C16	0.4380 (3)	0.3539 (9)	0.1314 (2)	0.0147 (9)
I14	0.70731 (2)	0.25316 (7)	0.254279 (15)	0.02303 (10)
C17	0.3641 (3)	0.6640 (9)	0.0289 (2)	0.0142 (9)
O17	0.3595 (2)	0.9044 (6)	0.00465 (16)	0.0178 (7)
N1	0.2990 (2)	0.4671 (8)	0.00990 (18)	0.0144 (7)
C21	0.2153 (3)	0.5039 (9)	−0.0358 (2)	0.0135 (9)
C22	0.1441 (3)	0.3480 (9)	−0.0245 (2)	0.0140 (9)
C23	0.0618 (3)	0.3607 (9)	−0.0718 (2)	0.0173 (9)
C24	0.0514 (3)	0.5397 (10)	−0.1286 (2)	0.0157 (9)
C25	0.1205 (3)	0.7044 (9)	−0.1400 (2)	0.0169 (9)
C26	0.2023 (3)	0.6833 (9)	−0.0938 (2)	0.0161 (9)
I22	0.15670 (2)	0.10085 (6)	0.065587 (14)	0.01839 (9)
N24	−0.0351 (3)	0.5466 (8)	−0.17893 (19)	0.0193 (8)
O24	−0.0889 (2)	0.3638 (7)	−0.17319 (18)	0.0274 (8)
O25	−0.0490 (2)	0.7302 (7)	−0.22304 (17)	0.0259 (8)
H12	0.5295	0.8322	0.0518	0.020*
H13	0.6558	0.6878	0.1348	0.019*
H15	0.5088	0.1266	0.2144	0.020*
H16	0.3825	0.2695	0.1307	0.018*
H1	0.3106	0.2976	0.0283	0.017*
H23	0.0139	0.2491	−0.0651	0.021*
H25	0.1115	0.8291	−0.1788	0.020*
H26	0.2503	0.7918	−0.1015	0.019*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C11	0.013 (2)	0.014 (2)	0.016 (2)	0.0011 (17)	0.0024 (17)	−0.0018 (16)
C12	0.018 (2)	0.012 (2)	0.020 (2)	0.0014 (17)	0.0063 (18)	0.0003 (17)
C13	0.012 (2)	0.019 (2)	0.017 (2)	−0.0027 (17)	0.0034 (17)	−0.0034 (17)
C14	0.019 (2)	0.020 (2)	0.013 (2)	0.0010 (18)	0.0003 (18)	−0.0029 (17)
C15	0.017 (2)	0.019 (2)	0.013 (2)	0.0025 (18)	0.0020 (18)	0.0017 (16)
C16	0.013 (2)	0.019 (2)	0.013 (2)	−0.0016 (17)	0.0037 (17)	−0.0021 (16)
I14	0.01636 (17)	0.0340 (2)	0.01466 (16)	0.00316 (13)	−0.00401 (12)	0.00051 (12)
C17	0.012 (2)	0.018 (2)	0.012 (2)	−0.0026 (17)	0.0021 (17)	−0.0033 (17)
O17	0.0155 (16)	0.0122 (15)	0.0241 (16)	−0.0007 (12)	0.0017 (13)	0.0031 (12)
N1	0.0135 (19)	0.0115 (17)	0.0165 (18)	0.0005 (14)	0.0003 (14)	0.0036 (14)
C21	0.015 (2)	0.012 (2)	0.013 (2)	0.0001 (17)	0.0032 (17)	−0.0015 (16)
C22	0.015 (2)	0.014 (2)	0.013 (2)	0.0003 (17)	0.0032 (17)	0.0007 (16)
C23	0.014 (2)	0.018 (2)	0.018 (2)	−0.0038 (18)	0.0002 (18)	−0.0004 (17)
C24	0.010 (2)	0.023 (2)	0.0103 (19)	0.0046 (18)	−0.0039 (16)	−0.0035 (17)
C25	0.018 (2)	0.018 (2)	0.013 (2)	−0.0029 (18)	0.0013 (18)	−0.0002 (17)
C26	0.014 (2)	0.017 (2)	0.017 (2)	0.0005 (18)	0.0031 (18)	0.0009 (17)
I22	0.01791 (16)	0.02143 (17)	0.01582 (15)	−0.00088 (12)	0.00405 (11)	0.00436 (11)
N24	0.018 (2)	0.022 (2)	0.0160 (19)	0.0000 (17)	−0.0004 (16)	−0.0030 (16)
O24	0.0170 (18)	0.034 (2)	0.0266 (18)	−0.0063 (15)	−0.0039 (14)	−0.0013 (15)
O25	0.0222 (19)	0.0277 (19)	0.0217 (18)	0.0049 (15)	−0.0065 (14)	0.0067 (14)

Geometric parameters (Å, º)

C11—C16	1.398 (6)	N1—H1	0.88
C11—C12	1.403 (6)	C21—C22	1.397 (6)
C11—C17	1.499 (6)	C21—C26	1.401 (6)
C12—C13	1.388 (6)	C22—C23	1.394 (6)
C12—H12	0.95	C22—I22	2.099 (4)
C13—C14	1.392 (6)	C23—C24	1.384 (6)
C13—H13	0.95	C23—H23	0.95
C14—C15	1.391 (6)	C24—C25	1.392 (6)
C14—I14	2.103 (4)	C24—N24	1.471 (5)
C15—C16	1.392 (6)	C25—C26	1.382 (6)
C15—H15	0.95	C25—H25	0.95
C16—H16	0.95	C26—H26	0.95
C17—O17	1.228 (5)	N24—O25	1.212 (5)
C17—N1	1.362 (5)	N24—O24	1.230 (5)
N1—C21	1.407 (5)
C16—C11—C12	119.2 (4)	C21—N1—H1	116.3
C16—C11—C17	122.4 (4)	C22—C21—C26	119.2 (4)
C12—C11—C17	118.4 (4)	C22—C21—N1	119.0 (4)
C13—C12—C11	120.3 (4)	C26—C21—N1	121.8 (4)
C13—C12—H12	119.8	C23—C22—C21	120.8 (4)
C11—C12—H12	119.8	C23—C22—I22	118.2 (3)
C12—C13—C14	119.5 (4)	C21—C22—I22	121.0 (3)
C12—C13—H13	120.3	C24—C23—C22	118.5 (4)
C14—C13—H13	120.3	C24—C23—H23	120.8
C15—C14—C13	121.2 (4)	C22—C23—H23	120.8
C15—C14—I14	118.9 (3)	C23—C24—C25	122.0 (4)
C13—C14—I14	119.8 (3)	C23—C24—N24	118.0 (4)
C14—C15—C16	118.9 (4)	C25—C24—N24	120.0 (4)
C14—C15—H15	120.5	C26—C25—C24	118.8 (4)
C16—C15—H15	120.5	C26—C25—H25	120.6
C15—C16—C11	120.8 (4)	C24—C25—H25	120.6
C15—C16—H16	119.6	C25—C26—C21	120.7 (4)
C11—C16—H16	119.6	C25—C26—H26	119.6
O17—C17—N1	123.8 (4)	C21—C26—H26	119.6
O17—C17—C11	122.1 (4)	O25—N24—O24	124.2 (4)
N1—C17—C11	114.2 (4)	O25—N24—C24	118.5 (4)
C17—N1—C21	127.4 (4)	O24—N24—C24	117.3 (4)
C17—N1—H1	116.3
C12—C11—C17—N1	153.2 (4)	C26—C21—C22—C23	2.7 (6)
C11—C17—N1—C21	175.9 (4)	N1—C21—C22—C23	−174.7 (4)
C17—N1—C21—C22	−148.5 (4)	C26—C21—C22—I22	−175.0 (3)
C16—C11—C12—C13	0.8 (6)	N1—C21—C22—I22	7.6 (5)
C17—C11—C12—C13	179.4 (4)	C21—C22—C23—C24	−2.5 (6)
C11—C12—C13—C14	−0.2 (6)	I22—C22—C23—C24	175.3 (3)
C12—C13—C14—C15	−0.7 (6)	C22—C23—C24—C25	0.4 (7)
C12—C13—C14—I14	178.2 (3)	C22—C23—C24—N24	178.7 (4)
C13—C14—C15—C16	0.9 (7)	C23—C24—C25—C26	1.5 (7)
I14—C14—C15—C16	−177.9 (3)	N24—C24—C25—C26	−176.8 (4)
C14—C15—C16—C11	−0.3 (6)	C24—C25—C26—C21	−1.3 (7)
C12—C11—C16—C15	−0.6 (6)	C22—C21—C26—C25	−0.8 (6)
C17—C11—C16—C15	−179.1 (4)	N1—C21—C26—C25	176.5 (4)
C16—C11—C17—O17	151.8 (4)	C23—C24—N24—O24	−10.5 (6)
C12—C11—C17—O17	−26.8 (6)	C23—C24—N24—O25	169.5 (4)
C16—C11—C17—N1	−28.2 (6)	C25—C24—N24—O24	167.8 (4)
O17—C17—N1—C21	−4.1 (7)	C25—C24—N24—O25	−12.2 (6)
C17—N1—C21—C26	34.2 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···I22	0.88	2.84	3.215 (4)	108
N1—H1···O17^i	0.88	2.10	2.832 (5)	140
C26—H26···O17	0.95	2.42	2.929 (5)	113

Symmetry code: (i) x, y−1, z.