6,8-Di­iodo-4-oxo-4H-chromene-3-carbalde­hyde

Yoshinobu Ishikawa

doi:10.1107/S1600536814006904

. 2014 Apr 12;70(Pt 5):o536. doi: 10.1107/S1600536814006904

6,8-Diiodo-4-oxo-4H-chromene-3-carbaldehyde

Yoshinobu Ishikawa ^a,^*

PMCID: PMC4011213 PMID: 24860346

Abstract

The title compound, C₁₀H₄I₂O₃, is an iodinated 3-formylchromone derivative, and the atoms are essentially coplanar [r.m.s. deviation = 0.049 Å, largest deviation from the least-squares plane = 0.111 (9) Å for the CH(=O) C atom]. In the crystal, molecules are linked into a three-dimensional network through halogen bonds [I⋯O = 3.352 (5) and 3.405 (7) Å, C—I⋯O = 144.2 (3) and 154.5 (3)°, and C=O⋯I = 134.9 (6) and 146.0 (6)°], and π–π stacking interactions [centroid–centroid distance = 3.527 (6) Å].

Related literature

For the preparation of the precursor of the title compound, see: Khansole et al. (2008 ▶). For related structures, see: Ishikawa & Motohashi (2013 ▶); Ishikawa (2014 ▶). For halogen bonding, see: Auffinger et al. (2004 ▶); Metrangolo et al. (2005 ▶); Wilcken et al. (2013) ▶; Sirimulla et al. (2013 ▶).

Experimental

Crystal data

C₁₀H₄I₂O₃
M _r = 425.95
Triclinic,
a = 7.290 (3) Å
b = 8.779 (5) Å
c = 9.767 (4) Å
α = 63.82 (3)°
β = 75.44 (3)°
γ = 68.05 (4)°
V = 517.5 (5) Å³
Z = 2
Mo Kα radiation
μ = 6.06 mm⁻¹
T = 100 K
0.48 × 0.30 × 0.25 mm

Data collection

Rigaku AFC-7R diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.152, T _max = 0.220
2933 measured reflections
2383 independent reflections
2361 reflections with F ² > 2σ(F ²)
R _int = 0.026
3 standard reflections every 150 reflections intensity decay: −1.1%

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.147
S = 1.23
2383 reflections
137 parameters
H-atom parameters constrained
Δρ_max = 3.56 e Å⁻³
Δρ_min = −3.01 e Å⁻³

Data collection: WinAFC Diffractometer Control Software (Rigaku, 1999 ▶); cell refinement: WinAFC Diffractometer Control Software; data reduction: WinAFC Diffractometer Control Software; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalStructure (Rigaku, 2010 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablock(s) General, I. DOI: 10.1107/S1600536814006904/zl2583sup1.cif

e-70-0o536-sup1.cif^{(22.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814006904/zl2583Isup2.hkl

e-70-0o536-Isup2.hkl^{(117.1KB, hkl)}

Click here for additional data file.^{(3.4KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814006904/zl2583Isup3.cml

CCDC reference: 994113

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

Acknowledgments

We acknowledge the University of Shizuoka for instrumental support.

supplementary crystallographic information

1. Comment

Halogen bonds have been found to occur in organic, inorganic, and biological systems, and have recently attracted much attention in medicinal chemistry, chemical biology and supramolecular chemistry (Auffinger et al., 2004, Metrangolo et al., 2005, Wilcken et al., 2013, Sirimulla et al., 2013). We have recently reported the crystal structures of halogenated 3-formylchromone derivatives, 6,8-dichloro-4-oxochromene-3-carbaldehyde and 6,8-dibromo-4-oxochromene-3-carbaldehyde (Ishikawa & Motohashi, 2013; Ishikawa, 2014). It was found that these molecules are linked through halogen bonds in a similar fashion in the crystals. As part of our interest in chemical bonding, we herein report the crystal structure of 6,8-diiodo-4-oxochromene-3-carbaldehyde, which was prepared by the Vilsmeier–Haack reaction of 2-hydroxy-3,5-diiodoacetophenone with N,N-dimethylformamide (DMF) in the presence of POCl₃ in good yield.

The mean deviation of the least-square planes for the non-hydrogen atoms is 0.0487 Å, and the largest deviations is 0.111 (9) Å for C10. These mean that the atoms are essentially coplanar.

In the crystal, the molecule is assembled through characteristic intermolecular interactions between the I1 atom at the 6-position and the O2 atom of the α,β-unsaturated carbonyl group of its inversion-symmetry equivalent [I1···O2; 3.405 (7) Å, C5–I1···O2ⁱ = 154.5 (3)°, I1···O2ⁱ–C3ⁱ = 134.9 (6)° (i): -x + 1, -y + 2, -z + 1, Fig. 1], and between the I2 atom at the 6-position and the O2 atom of the α,β-unsaturated carbonyl group of its translation-symmetry equivalent [I2···O2; 3.352 (5) Å, C7–I2···O2ⁱⁱ = 144.2 (3)°, I2···O2ⁱⁱ–C3ⁱⁱ = 146.0 (6)° (i): x, y - 1, z+1, Fig. 2]. The short contact and the geometry of the I···O interactions come within the range of halogen bonding (Auffinger et al., 2004). It is noted that the geometry of the I···O interactions for the title compound is different from that for 6,8-dichloro-4-oxochromene-3-carbaldehyde and 6,8-dibromo-4-oxochromene-3-carbaldehyde. The three-dimensional network via the halogen bonds in the crystal of the title compound is more extensive. This is probably due to the larger size of the positive σ-holes of the I1 and I2 atoms (Auffinger et al., 2004, Sirimulla et al., 2013). The intermolecular π-π stacking interaction of the benzene ring of the molecule with that of the inversion-symmetry equivalentⁱⁱⁱ is also observed [centroid–centroid distance = 3.527 (6) Å (iii): -x + 1, -y + 1, -z + 1], as shown in Fig. 2.

2. Experimental

2-Hydroxy-3,5-diiodoacetophenone was prepared according to the literature method (Khansole et al., 2008). To a solution of 2-hydroxy-3,5-diiodoacetophenone (134 mmol) in DMF (5 ml) was added dropwise POCl₃ (335 mmol) for 5 min at 0 °C. After the mixture was stirred for 15 h at room temperature, water (20 ml) was added. The precipitates were collected, washed with water and dried in vacuo (yield: 81.1%). ¹H NMR (400 MHz, DMSO-d₆): δ = 8.31 (d, 1H, J = 2.0 Hz), 8.63 (d, 1H, J = 2.0 Hz), 9.04 (s, 1H), 10.07 (s, 1H). DART-MS calcd for [C₁₀H₄I₂O₃ + H⁺]: 426.825, found 426.869. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of an ethyl acetate solution of the title compound at room temperature.