research communications
E)-3-(3-iodophenyl)-1-(4-iodophenyl)prop-2-en-1-one
and Hirshfeld surface analysis of (aSchool of Chemistry, University of Bristol, Cantock's Close, Bristol, England, BS8 1TS, England, and bDepartment of Chemistry & Biochemistry, Gonzaga University, 502 E Boone Ave, Spokane, WA 99258, USA
*Correspondence e-mail: simon.hall@bristol.ac.uk
The title compound, C15H10I2O, is a halogenated chalcone formed from two iodine substituted rings, one para-substituted and the other meta-substituted, linked through a prop-2-en-1-one spacer. In the molecule, the mean planes of the 3-iodophenyl and the 4-iodophenyl groups are twisted by 46.51 (15)°. The calculated electrostatic potential surfaces show the presence of σ-holes on both substituted iodines. In the crystal, the molecules are linked through type II halogen bonds, forming a sheet structure parallel to the bc plane. Between the sheets, weak intermolecular C—H⋯π interactions are observed. Hirshfeld surface analysis showed that the most significant contacts in the structure are C⋯H/H⋯C (31.9%), followed by H⋯H (21.4%), I⋯H/H⋯I (18.4%). I⋯I (14.5%) and O⋯H/H⋯O (8.1%).
Keywords: crystal structure; E configuration; iodophenyl ring; chalcone; (E)-3-(3-iodophenyl)-1-(4-iodophenyl)prop-2-en-1-one.
CCDC reference: 1970266
1. Chemical context
et al., 2011). These molecules are essential to the biosynthesis of through a conjugate ring-closure to form flavone and have also attracted attention for their potential use in opto- and organic electronics (Shetty et al., 2016, 2017). As a family of molecules, substituted can be readily synthesized via a Claisen–Schmidt condensation reaction between an appropriately functionalized acetophenone and benzaldehyde. Substitutions on each of the benzene rings are currently being investigated in order to interrogate how the electronic properties of the crystal are altered. The iodo-substituted rings present in the title compound allows for the formation of iodine channels in the crystal, a conformation which may afford a change in the crystal's electrical properties.
are aromatic which have shown potential as antibacterial, antifungal and anti-inflammatory agents (D'silva2. Structural commentary
The title compound comprises two aromatic rings, 4-iodophenyl (1-Ring) and 3-iodophenyl (3-Ring), which are connected, respectively, to atoms C1 and C3 of the –CO—CH=CH– enone bridge (Fig. 1). The backbone torsion angles are C5—C4—C1—C2 = 151.6 (4)°, C4—C1—C2—C3 = 171.9 (4)°, C1—C2—C3—C10 = 176.4 (4)° and C2—C3—C10—C11 = 170.4 (5)°. The mean planes of the 3-iodophenyl and 4-iodophenyl groups are twisted by 46.51 (15)° relative to each other. The H atoms of the propenone group are trans-configured.
3. Supramolecular features
Electrostatic potential surfaces [Fig. 2(a)–(c)] show the presence of σ-holes on both substituted iodines, I1 and I2, which allow for halogen bonding of a bifurcated type II. Partial packing diagrams are shown in Fig. 3(a)–(c). Interestingly, these halogen bonds form exclusively between equivalent iodine atoms, either para–para or meta–meta. The geometries of the halogen bonds are I1⋯I1iv = 4.0980 (9) Å, C7—I1⋯I1iv = 113.85 (13)°, I1⋯I1v =4.0980 (9) Å and C7—I⋯I1v = 154.47 (13)° for the para–para I⋯I bonds, and I2⋯I2vi = 3.9805 (8) Å, C12—I2⋯I2vi = 108.20 (13)°, I2⋯I2vii = 3.9805 (8) Å and C12—I2⋯I2vii = 157.30 (13)° for the meta–meta I⋯I bonds [symmetry codes: (iv) x, − y, − + z; (v) x, − y, + z; (vi) x, − y, + z; (vii) x, − y, − + z]. A sheet structure is formed parallel to the bc plane. There are also three weak C—H⋯π interactions (Table 1) between the sheets.
Hirshfeld surfaces, mapped over dnorm, shape-index and de, and two-dimensional fingerprint plots of the title compound were calculated using CrystalExplorer17.5 (Turner et al., 2017). Hirshfeld surfaces [Fig. 4(a) and (c)] highlight the relationship between the contact distance and the van der Waals radii (Venkatesan et al., 2016). The Hirshfeld surface mapped over the shape-index [Fig. 4(b)] shows depressions on both 1-Ring and 3-Ring, which is indicative of C—H⋯π interactions. Two-dimensional fingerprint plots are used to illustrate the intermolecular contacts between molecules within the The fingerprint plots of all significant interactions are shown in Fig. 5(a)–(f). C⋯H/H⋯C contacts [Fig. 5(b)] make the largest contribution (31.9%) and show a pair of spikes at de + di = ∼2.8 Å, representative of intermolecular C—H⋯π interactions. The O⋯H/H⋯O plot also contains a pair of spikes at de + di = ∼2.7 Å [Fig. 5(f)]. The negligible contributions from other contacts, not included in Fig. 5, are as follows: C⋯C (3.1%), C⋯O/O⋯C (2.1%) and C⋯I/I⋯C (0.5%).
4. Database survey
A survey of the Cambridge Structural Database (CSD; Groom et al., 2016) showed that existing similar structures include (2E)-1-(4-bromophenyl)-3-(4-fluorophenyl)prop-2-en-1-one (refcode NURCIN; Dutkiewicz et al., 2010), 1-(4-bromophenyl)-3-(4-chlorophenyl)prop-2-en-1-one (LEPYIP; Yang et al., 2006), 1,3-bis(4-bromophenyl)prop-2-en-1-one (LEHROG; Ng et al., 2006), (E)-1-(4-bromophenyl)-3-(4-iodophenyl)prop-2-en-1-one (IWALAV; Zainuri et al., 2017) and 3-(3-bromophenyl)-1-(4-bromophenyl)prop-2-en-1-one (ODEDEH; Teh et al., 2006). Four compounds (NURCIN, LEPYIP, LEHROG and IWALAV) contain only para-substituted rings. Within these structures, halogen bonds exist only between bromine and iodine species, and never between equivalent halogens. 3-(3-Bromophenyl)-1-(4-bromophenyl)prop-2-en-1-one contains one meta-substituted ring and one para-substituted ring: each halogen bond exists between rings with the same substitution, either para–para or meta–meta, as seen in the title compound.
5. Synthesis and crystallization
4′-Iodoacetophenone (0.773 g, 3.14 mmol), 3-iodobenzaldehyde (0.697 g, 3.00), anhydrous zinc chloride (0.615 g, 4.51 mmol) and absolute ethanol (1.5 ml) were added to a microwave vessel with a stir bar. Using a microwave reactor, the reaction mixture was heated to 468 K for 15 minutes. Upon cooling the reaction, yellowish solids were collected by vacuum filtration and washed with 95% ethanol. The resulting solid was recrystallized from 95% ethanol (0.603 g, 44% yield, yellow crystals, m.p. 442.5–443.7 K). 1H NMR (400 MHz, DMSO-d6, referenced to TMS): δ (ppm) 8.37 (1H, s), 8.0–7.94 (5H, m), 7.88 (1H, d, J = 8 Hz), 7.81 (1H, d, J = 8 Hz), 7.68 (1H, d, J = 16 Hz), 7.26 (1H, t, J = 8 Hz). 13C NMR (100 MHz, DMSO-d6, referenced to solvent, 39.52 ppm): δ (ppm) 188.44, 142.75, 139.04, 137.72, 136.95, 136.66, 136.61, 130.89, 130.38, 128.73, 122.81, 102.14, 95.57. Single crystals suitable for X-ray diffraction were obtained by the slow evaporation technique from an acetone solution at room temperature.
6. Refinement
Crystal data, data collection and structure . H atoms were positioned geometrically (C—H = 0.95 Å) and refined using a riding model with Uiso(H) = 1.2Ueq(C).
details are summarized in Table 2
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Supporting information
CCDC reference: 1970266
https://doi.org/10.1107/S2056989019016402/is5526sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989019016402/is5526Isup2.hkl
13C NMR of the synthesised product. DOI: https://doi.org/10.1107/S2056989019016402/is5526sup3.pdf
1H NMR of the synthesised product. DOI: https://doi.org/10.1107/S2056989019016402/is5526sup4.pdf
Supporting information file. DOI: https://doi.org/10.1107/S2056989019016402/is5526Isup5.mol
Supporting information file. DOI: https://doi.org/10.1107/S2056989019016402/is5526Isup6.cml
Data collection: SAINT (Bruker, 2016); cell
SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).C15H10I2O | F(000) = 856 |
Mr = 460.03 | Dx = 2.191 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 7.2650 (7) Å | Cell parameters from 8513 reflections |
b = 32.864 (3) Å | θ = 2.5–27.5° |
c = 5.8446 (6) Å | µ = 4.50 mm−1 |
β = 92.277 (2)° | T = 200 K |
V = 1394.3 (2) Å3 | Plate, clear colourless |
Z = 4 | 0.57 × 0.29 × 0.08 mm |
Bruker APEXII kappa CCD area detector diffractometer | 3215 independent reflections |
Radiation source: fine-focus sealed tube | 2960 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.021 |
φ and ω scans | θmax = 27.5°, θmin = 2.5° |
Absorption correction: numerical (SADABS; Bruker, 2016) | h = −9→9 |
Tmin = 0.065, Tmax = 0.189 | k = −42→37 |
18346 measured reflections | l = −7→7 |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.037 | w = 1/[σ2(Fo2) + (0.0034P)2 + 6.4729P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.073 | (Δ/σ)max = 0.001 |
S = 1.27 | Δρmax = 1.14 e Å−3 |
3215 reflections | Δρmin = −1.30 e Å−3 |
164 parameters | Extinction correction: SHELXL2018 (Sheldrick, 2015b), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.00062 (7) |
Primary atom site location: iterative |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | ||
C4 | 0.8336 (6) | 0.43230 (13) | 0.5707 (7) | 0.0250 (9) | |
C9 | 0.9114 (6) | 0.42521 (14) | 0.7892 (8) | 0.0278 (9) | |
H9 | 0.939830 | 0.447424 | 0.888449 | 0.033* | |
C8 | 0.9474 (6) | 0.38548 (14) | 0.8617 (8) | 0.0289 (9) | |
H8 | 1.003866 | 0.380553 | 1.008533 | 0.035* | |
C7 | 0.9004 (6) | 0.35322 (14) | 0.7183 (8) | 0.0292 (9) | |
C6 | 0.8265 (6) | 0.35974 (14) | 0.4992 (8) | 0.0298 (10) | |
H6 | 0.797488 | 0.337429 | 0.400879 | 0.036* | |
C5 | 0.7955 (6) | 0.39954 (14) | 0.4252 (8) | 0.0285 (9) | |
H5 | 0.747935 | 0.404397 | 0.273958 | 0.034* | |
C1 | 0.7892 (6) | 0.47421 (14) | 0.4874 (8) | 0.0284 (9) | |
C2 | 0.7447 (6) | 0.50560 (14) | 0.6605 (8) | 0.0294 (9) | |
H2 | 0.729579 | 0.497837 | 0.815221 | 0.035* | |
C3 | 0.7258 (6) | 0.54438 (13) | 0.5999 (8) | 0.0268 (9) | |
H3 | 0.749373 | 0.550781 | 0.445302 | 0.032* | |
C10 | 0.6729 (6) | 0.57825 (13) | 0.7450 (7) | 0.0251 (9) | |
C11 | 0.6878 (6) | 0.61791 (13) | 0.6589 (8) | 0.0273 (9) | |
H11 | 0.740192 | 0.622248 | 0.514565 | 0.033* | |
C12 | 0.6264 (6) | 0.65086 (13) | 0.7836 (8) | 0.0289 (9) | |
C13 | 0.5540 (6) | 0.64548 (15) | 0.9989 (8) | 0.0322 (10) | |
H13 | 0.513741 | 0.668101 | 1.084900 | 0.039* | |
C14 | 0.5424 (6) | 0.60607 (15) | 1.0845 (8) | 0.0311 (10) | |
H14 | 0.493446 | 0.601952 | 1.230991 | 0.037* | |
C15 | 0.6003 (6) | 0.57271 (14) | 0.9618 (8) | 0.0280 (9) | |
H15 | 0.590951 | 0.546131 | 1.024224 | 0.034* | |
I1 | 0.92866 (6) | 0.29371 (2) | 0.84509 (7) | 0.04484 (12) | |
I2 | 0.63173 (6) | 0.70888 (2) | 0.63477 (6) | 0.04434 (12) | |
O1 | 0.7830 (5) | 0.48192 (10) | 0.2821 (6) | 0.0376 (8) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C4 | 0.022 (2) | 0.027 (2) | 0.026 (2) | 0.0011 (17) | 0.0023 (16) | 0.0009 (17) |
C9 | 0.027 (2) | 0.028 (2) | 0.028 (2) | −0.0020 (18) | −0.0031 (18) | −0.0029 (17) |
C8 | 0.028 (2) | 0.034 (2) | 0.024 (2) | 0.0032 (19) | −0.0031 (17) | 0.0017 (18) |
C7 | 0.027 (2) | 0.026 (2) | 0.034 (2) | 0.0048 (18) | 0.0022 (18) | 0.0026 (18) |
C6 | 0.029 (2) | 0.029 (2) | 0.031 (2) | 0.0003 (18) | −0.0001 (18) | −0.0077 (18) |
C5 | 0.028 (2) | 0.033 (2) | 0.024 (2) | 0.0036 (18) | −0.0010 (17) | −0.0009 (17) |
C1 | 0.023 (2) | 0.031 (2) | 0.031 (2) | 0.0005 (17) | 0.0008 (18) | 0.0024 (18) |
C2 | 0.033 (2) | 0.028 (2) | 0.027 (2) | −0.0004 (18) | 0.0022 (18) | 0.0019 (17) |
C3 | 0.026 (2) | 0.029 (2) | 0.026 (2) | −0.0005 (18) | 0.0003 (17) | 0.0016 (17) |
C10 | 0.021 (2) | 0.030 (2) | 0.025 (2) | −0.0016 (17) | −0.0045 (16) | 0.0015 (17) |
C11 | 0.027 (2) | 0.029 (2) | 0.026 (2) | −0.0048 (18) | −0.0012 (17) | 0.0022 (17) |
C12 | 0.031 (2) | 0.024 (2) | 0.031 (2) | −0.0037 (18) | −0.0077 (18) | 0.0016 (17) |
C13 | 0.028 (2) | 0.035 (2) | 0.033 (2) | 0.0014 (19) | −0.0018 (19) | −0.0073 (19) |
C14 | 0.028 (2) | 0.041 (3) | 0.024 (2) | −0.002 (2) | −0.0003 (18) | −0.0015 (19) |
C15 | 0.025 (2) | 0.030 (2) | 0.028 (2) | 0.0001 (18) | −0.0048 (17) | 0.0043 (18) |
I1 | 0.0555 (2) | 0.02652 (17) | 0.0520 (2) | 0.00766 (15) | −0.00426 (16) | 0.00411 (14) |
I2 | 0.0618 (3) | 0.02421 (16) | 0.0466 (2) | −0.00405 (15) | −0.00256 (16) | 0.00229 (14) |
O1 | 0.051 (2) | 0.0340 (18) | 0.0278 (17) | 0.0045 (16) | 0.0029 (15) | 0.0051 (14) |
C4—C9 | 1.395 (6) | C2—C3 | 1.328 (6) |
C4—C5 | 1.393 (6) | C3—H3 | 0.9500 |
C4—C1 | 1.492 (6) | C3—C10 | 1.460 (6) |
C9—H9 | 0.9500 | C10—C11 | 1.403 (6) |
C9—C8 | 1.394 (6) | C10—C15 | 1.403 (6) |
C8—H8 | 0.9500 | C11—H11 | 0.9500 |
C8—C7 | 1.386 (6) | C11—C12 | 1.388 (6) |
C7—C6 | 1.386 (6) | C12—C13 | 1.394 (7) |
C7—I1 | 2.099 (4) | C12—I2 | 2.097 (4) |
C6—H6 | 0.9500 | C13—H13 | 0.9500 |
C6—C5 | 1.393 (6) | C13—C14 | 1.392 (7) |
C5—H5 | 0.9500 | C14—H14 | 0.9500 |
C1—C2 | 1.490 (6) | C14—C15 | 1.385 (7) |
C1—O1 | 1.225 (5) | C15—H15 | 0.9500 |
C2—H2 | 0.9500 | ||
C9—C4—C1 | 121.8 (4) | C3—C2—H2 | 119.8 |
C5—C4—C9 | 119.5 (4) | C2—C3—H3 | 116.4 |
C5—C4—C1 | 118.6 (4) | C2—C3—C10 | 127.1 (4) |
C4—C9—H9 | 120.0 | C10—C3—H3 | 116.4 |
C8—C9—C4 | 119.9 (4) | C11—C10—C3 | 118.3 (4) |
C8—C9—H9 | 120.0 | C11—C10—C15 | 118.8 (4) |
C9—C8—H8 | 120.2 | C15—C10—C3 | 122.8 (4) |
C7—C8—C9 | 119.6 (4) | C10—C11—H11 | 119.8 |
C7—C8—H8 | 120.2 | C12—C11—C10 | 120.4 (4) |
C8—C7—I1 | 118.8 (3) | C12—C11—H11 | 119.8 |
C6—C7—C8 | 121.2 (4) | C11—C12—C13 | 121.0 (4) |
C6—C7—I1 | 120.0 (3) | C11—C12—I2 | 118.7 (3) |
C7—C6—H6 | 120.5 | C13—C12—I2 | 120.2 (3) |
C7—C6—C5 | 118.9 (4) | C12—C13—H13 | 120.9 |
C5—C6—H6 | 120.5 | C14—C13—C12 | 118.2 (4) |
C4—C5—C6 | 120.7 (4) | C14—C13—H13 | 120.9 |
C4—C5—H5 | 119.6 | C13—C14—H14 | 119.1 |
C6—C5—H5 | 119.6 | C15—C14—C13 | 121.8 (4) |
C2—C1—C4 | 117.9 (4) | C15—C14—H14 | 119.1 |
O1—C1—C4 | 120.6 (4) | C10—C15—H15 | 120.1 |
O1—C1—C2 | 121.4 (4) | C14—C15—C10 | 119.8 (4) |
C1—C2—H2 | 119.8 | C14—C15—H15 | 120.1 |
C3—C2—C1 | 120.4 (4) | ||
C4—C9—C8—C7 | −1.9 (7) | C2—C3—C10—C11 | 170.4 (5) |
C4—C1—C2—C3 | 171.9 (4) | C2—C3—C10—C15 | −12.5 (7) |
C9—C4—C5—C6 | 2.9 (7) | C3—C10—C11—C12 | 175.2 (4) |
C9—C4—C1—C2 | −28.3 (6) | C3—C10—C15—C14 | −176.0 (4) |
C9—C4—C1—O1 | 154.5 (5) | C10—C11—C12—C13 | 1.9 (7) |
C9—C8—C7—C6 | 3.3 (7) | C10—C11—C12—I2 | −175.0 (3) |
C9—C8—C7—I1 | −173.2 (3) | C11—C10—C15—C14 | 1.0 (6) |
C8—C7—C6—C5 | −1.5 (7) | C11—C12—C13—C14 | −0.9 (7) |
C7—C6—C5—C4 | −1.6 (7) | C12—C13—C14—C15 | 0.0 (7) |
C5—C4—C9—C8 | −1.1 (7) | C13—C14—C15—C10 | 0.0 (7) |
C5—C4—C1—C2 | 151.6 (4) | C15—C10—C11—C12 | −1.9 (6) |
C5—C4—C1—O1 | −25.6 (7) | I1—C7—C6—C5 | 175.0 (3) |
C1—C4—C9—C8 | 178.8 (4) | I2—C12—C13—C14 | 175.9 (3) |
C1—C4—C5—C6 | −177.0 (4) | O1—C1—C2—C3 | −10.9 (7) |
C1—C2—C3—C10 | 176.4 (4) |
Cg1 and Cg2 are the centroids of the C10–C15 and C4–C9 rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···Cg1i | 0.95 | 2.78 | 3.406 (5) | 124 |
C8—H8···Cg1ii | 0.95 | 2.85 | 3.491 (5) | 126 |
C14—H14···Cg2iii | 0.95 | 2.77 | 3.440 (5) | 129 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+2; (iii) −x+1, −y+1, −z+2. |
Acknowledgements
GU co-authors thank E. Mermann-Jozwiak, J. Hazen, S. Economu, M. Fellin, B. Hendricks, R. Meehan, & G. Warren for their assistance, as well as the Howard Hughes Medical Institute through its Undergraduate Science Education Program for supporting equipment acquisition.
Funding information
UoB co-authors acknowledge the Engineering and Physical Sciences Research Council UK (grant EP/G036780/1) and the Centre for Doctoral Training in Condensed Matter Physics for project funding. SRH and JP acknowledge MagnaPharm, a collaborative research project funded by the European Union's Horizon 2020 Research and Innovation programme (grant No. 736899).
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