organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

9,10-Bis(iodo­ethyn­yl)anthracene

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aDepartment of Chemistry and Physics, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA, and bDepartment of Chemistry, Clemson University, Clemson, SC 29634, USA
*Correspondence e-mail: jared-pienkos@utc.edu

Edited by W. T. A. Harrison, University of Aberdeen, United Kingdom (Received 12 June 2023; accepted 22 June 2023; online 4 July 2023)

The title compound, C18H8I2, is an ethynyl-substituted anthracene. The C—C—I bond angles deviate from 180°, being affected by inter­molecular I⋯π inter­actions. These inter­actions form a two-dimensional supra­molecular structure further supported by offset ππ stacking of neighboring anthracene moieties.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

The flat, stable, and conjugated composition of anthracene derivatives makes them good candidates for two-dimensional mol­ecular crystals. Two-dimensional crystals can have unique properties with applications in electronics, biomedicine, and sensors (Yan et al., 2023[Yan, X., Zhao, Y., Cao, G., Li, X., Gao, C., Liu, L., Ahmed, S., Altaf, F., Tan, H., Ma, X., Xie, Z. & Zhang, H. (2023). Adv. Sci. 10, 2203889.]). The title compound is an iodoethynyl-substituted anthracene. The iodine functional groups provide the opportunity for halogen-bonding inter­actions. The synthesis and structure of the title compound are reported here.

The crystal stucture represents the first example of an ethynyl–anthracene halogenated with iodine (Fig. 1[link]). The C—I bonds have an average length of 1.996 (4) Å, similar to that found in 1,4-bis­(iodo­ethyn­yl)benzene [2.007 (7) Å; Barrès et al., 2008[Barrès, A.-L., El-Ghayoury, A., Zorina, L. V., Canadell, E., Auban-Senzier, P. & Batail, P. (2008). Chem. Commun. pp. 2194-2196.]], 4-iodo­ethnynylanisole [1.990 (3) Å; Dumele et al., 2014[Dumele, O., Wu, D., Trapp, N., Goroff, N. & Diederich, F. (2014). Org. Lett. 16, 4722-4725.]], and other iodo­ethynyl derivatives (Lehnherr et al., 2015[Lehnherr, D., Alzola, J. M., Lobkovsky, E. B. & Dichtel, W. R. (2015). Chem. Eur. J. 21, 18122-18127.]). The 180° bond angle expected from the alkynyl C atoms and iodine, C15—C16—I1 and C17—C18—I2, are slightly bent to 177.4 (3) and 178.0 (3)°, respectively. This may be attributed to halogen bonding between C(sp)—I moieties and the π-electrons of the adjacent anthracene rings (Fig. 2[link]), where I1 maintains its shortest I⋯centroid contact to the centroid of the C2–C7 ring (Cg1) [I1⋯Cg1 = 3.528 (4) Å and C16—I1⋯Cg1 = 151.2 (3)°] and I2 has a short contact to the centroid of the C9–C14 ring (Cg2) [I2⋯Cg2 = 3.767 (4) Å and C18—I2⋯Cg2 = 150.1 (3)°]. The bent nature of the C—I⋯centroid inter­actions leads to short I⋯C contacts ranging from 3.352 (4) to 3.655 (4) Å. The shorter contact between I1 and Cg1 appears to influence more significantly the bending of the entire alkynyl substituent [C1—C15—I1 = 173.8 (3)° versus C8—C17—I2 = 178.7 (3)°], notably pulling the I1 atom away from the central ring of the neighboring anthracene mol­ecule and toward its C2–C7 centroid.

[Figure 1]
Figure 1
The title mol­ecule, showing the atom-labeling scheme and with displacement ellipsoids drawn at the 50% probability level.
[Figure 2]
Figure 2
I⋯π inter­actions (blue dashed lines) occurring to and from a central mol­ecule of the title compound.

Propagation of the I⋯π inter­actions results in a two-dimensional supra­molecular structure in the (101) plane (Fig. 3[link]). Inter­estingly, in 1,4-bis­(iodo­ethyn­yl)benzene, 4-iodo­ethnynylanisole, and 1-chloro-4-(iodo­ethyn­yl)benzene, the I⋯π inter­actions occur at a similar distance [for example, the shortest I⋯C contact is 3.427 (7) Å in 1,4-bis­(iodo­ethyn­yl)benzene, 3.392 (3) Å in 4-iodo­ethnynylanisole, and 3.417 (4) Å in 1-chloro-4-(iodo­ethyn­yl)benzene], but occur to the alkynyl C atoms rather than to the aromatic rings as in the title compound (Barrès et al., 2008[Barrès, A.-L., El-Ghayoury, A., Zorina, L. V., Canadell, E., Auban-Senzier, P. & Batail, P. (2008). Chem. Commun. pp. 2194-2196.]; Dumele et al., 2014[Dumele, O., Wu, D., Trapp, N., Goroff, N. & Diederich, F. (2014). Org. Lett. 16, 4722-4725.]; Lehnherr et al., 2015[Lehnherr, D., Alzola, J. M., Lobkovsky, E. B. & Dichtel, W. R. (2015). Chem. Eur. J. 21, 18122-18127.]). The I atom in (tert-but­yl)[4-(iodo­ethyn­yl)phen­yl]carbamate (Kahlfuss et al., 2016[Kahlfuss, C., Denis-Quanquin, S., Calin, N., Dumont, E., Garavelli, M., Royal, G., Cobo, S., Saint-Aman, E. & Bucher, C. (2016). J. Am. Chem. Soc. 138, 15234-15242.]) does appear to inter­act with the aromatic system of a neighboring mol­ecule to form a one-dimensional I⋯π motif of similar C—I⋯centroid geometries to the title anthracene derivative. Anthracene portions of adjacent mol­ecules are arranged in an offset stacking arrangement (Fig. 4[link]), with an inter­planar separation of 3.377 Å, a shortest C⋯C distance of 3.436 (5) Å, and a shortest centroid–centroid distance of 3.692 (5) Å. The inter­planar spacing of the anthracene scaffold in the title compound is shorter than in the offset stacking in 9,10-di­iodo­anthracene (3.602 Å; Peters et al., 1996[Peters, K., Peters, E.-M. & Syassen, K. (1996). Z. Kristallogr. 211, 360.]) and similar to that of the offset stacking in monoclinic 9,10-bis­(phenyl­ethyn­yl)anthracene (3.405 Å; Batsanov et al., 2013[Batsanov, A. S., Collings, J. C. & Marder, T. B. (2013). Private communication (deposition number 855467). CCDC, Cambridge, England.]).

[Figure 3]
Figure 3
The two-dimensional supra­molecular motif formed via I⋯π inter­actions in the title compound.
[Figure 4]
Figure 4
Top (left) and side (right) views of the offset stacking of neighboring mol­ecules in the title compound.

Synthesis and crystallization

The procedure was modeled after an analogous functionalization of an alkynylsilane (Tse et al., 2021[Tse, Y. C., Docker, A., Zhang, Z. & Beer, P. D. (2021). Chem. Commun. 57, 4950-4953.]). 9,10-Bis(tri­methyl­silylethyn­yl)anthracene (0.0325 g, 0.0878 mmol), N-iodo­suc­cinimide (0.0531 g, 0.236 mmol) and AgNO3 (0.0022 g, 0.0129 mmol) were added to dry di­methyl­formamide (5 ml), and the resulting mixture was stirred under nitro­gen. After 5 h, the reaction mixture was diluted with EtOAc (30 ml) and washed with H2O (5 × 30 ml). The organic layer was dried in vacuo, resulting in an orange solid. The product was crystallized from the orange solid using vapor–vapor diffusion (CH2Cl2/hexa­nes).

1H NMR key spectroscopic features as determined from the crude product (400 MHz, chloro­form-d): δ 8.33 (d, J = 9.2 Hz, 4H), 7.82 (m, 4H).

Refinement

Crystal data, data collection, and structural refinement details are summarized in Table 1[link].

Table 1
Experimental details

Crystal data
Chemical formula C18H8I2
Mr 478.04
Crystal system, space group Monoclinic, P21/n
Temperature (K) 100
a, b, c (Å) 8.0022 (3), 15.0735 (7), 12.2506 (5)
β (°) 96.2749 (17)
V3) 1468.83 (11)
Z 4
Radiation type Mo Kα
μ (mm−1) 4.27
Crystal size (mm) 0.17 × 0.15 × 0.13
 
Data collection
Diffractometer Bruker D8 Venture Photon 2
Absorption correction Multi-scan (SADABS; Krause et al., 2015[Krause, L., Herbst-Irmer, R., Sheldrick, G. M. & Stalke, D. (2015). J. Appl. Cryst. 48, 3-10.])
Tmin, Tmax 0.774, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections 37187, 3373, 3084
Rint 0.037
(sin θ/λ)max−1) 0.650
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.026, 0.063, 1.13
No. of reflections 3373
No. of parameters 181
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 1.41, −0.90
Computer programs: APEX3 (Bruker, 2017[Bruker (2017). APEX3. Bruker AXS Inc., Madison, Wisconsin, USA.]), SAINT (Bruker, 2016[Bruker (2016). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXT2014 (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2016 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]), Mercury (Macrae et al., 2020[Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226-235.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Structural data


Computing details top

Data collection: APEX3 (Bruker, 2017); cell refinement: SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015b); molecular graphics: Mercury (Macrae et al., 2020); software used to prepare material for publication: publCIF (Westrip, 2010).

9,10-Bis(iodoethynyl)anthracene top
Crystal data top
C18H8I2F(000) = 888
Mr = 478.04Dx = 2.162 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 8.0022 (3) ÅCell parameters from 9890 reflections
b = 15.0735 (7) Åθ = 2.7–30.6°
c = 12.2506 (5) ŵ = 4.27 mm1
β = 96.2749 (17)°T = 100 K
V = 1468.83 (11) Å3Column, red
Z = 40.17 × 0.14 × 0.13 mm
Data collection top
Bruker D8 Venture Photon 2
diffractometer
3084 reflections with I > 2σ(I)
Radiation source: Incoatec IµSRint = 0.037
φ and ω scansθmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Krause et al., 2015)
h = 1010
Tmin = 0.774, Tmax = 1.000k = 1919
37187 measured reflectionsl = 1515
3373 independent reflections
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.026Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.063H-atom parameters constrained
S = 1.13 w = 1/[σ2(Fo2) + (0.0142P)2 + 7.1388P]
where P = (Fo2 + 2Fc2)/3
3373 reflections(Δ/σ)max = 0.001
181 parametersΔρmax = 1.41 e Å3
0 restraintsΔρmin = 0.90 e Å3
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I10.82384 (3)0.70341 (2)0.18275 (2)0.02740 (8)
I20.03465 (3)0.12055 (2)0.56404 (2)0.02483 (8)
C10.5433 (5)0.4778 (2)0.3413 (3)0.0183 (7)
C20.6141 (5)0.4243 (2)0.4292 (3)0.0178 (7)
C30.7841 (5)0.4348 (3)0.4760 (3)0.0207 (7)
H30.8532570.4778160.4464220.025*
C40.8486 (5)0.3842 (3)0.5624 (3)0.0223 (8)
H40.9619590.3923640.5927760.027*
C50.7470 (5)0.3190 (3)0.6078 (3)0.0230 (8)
H50.7924900.2846320.6689720.028*
C60.5867 (5)0.3059 (2)0.5643 (3)0.0196 (7)
H60.5209360.2618460.5948400.024*
C70.5139 (5)0.3572 (2)0.4729 (3)0.0178 (7)
C80.3466 (5)0.3430 (2)0.4245 (3)0.0190 (7)
C90.2770 (5)0.3953 (2)0.3353 (3)0.0192 (7)
C100.1094 (5)0.3826 (3)0.2846 (3)0.0266 (8)
H100.0420070.3372850.3112300.032*
C110.0440 (5)0.4340 (3)0.1990 (4)0.0297 (9)
H110.0676950.4240740.1664170.036*
C120.1413 (6)0.5018 (3)0.1588 (3)0.0282 (9)
H120.0948350.5370290.0987120.034*
C130.3010 (5)0.5178 (3)0.2048 (3)0.0234 (8)
H130.3636880.5647850.1773260.028*
C140.3761 (5)0.4645 (2)0.2943 (3)0.0190 (7)
C150.6415 (5)0.5464 (2)0.2976 (3)0.0201 (7)
C160.7133 (5)0.6047 (3)0.2564 (3)0.0226 (8)
C170.2484 (5)0.2737 (3)0.4661 (3)0.0224 (8)
C180.1684 (5)0.2157 (2)0.5008 (3)0.0227 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.02902 (14)0.02681 (14)0.02568 (14)0.00824 (10)0.00015 (10)0.01045 (10)
I20.03161 (14)0.01874 (12)0.02455 (13)0.00641 (10)0.00495 (10)0.00300 (9)
C10.0253 (18)0.0140 (16)0.0175 (16)0.0007 (14)0.0104 (14)0.0041 (13)
C20.0229 (18)0.0134 (16)0.0180 (16)0.0009 (13)0.0067 (14)0.0033 (13)
C30.0209 (18)0.0204 (18)0.0216 (18)0.0032 (14)0.0061 (14)0.0020 (14)
C40.0230 (18)0.0224 (19)0.0211 (18)0.0003 (15)0.0007 (15)0.0044 (15)
C50.030 (2)0.0184 (18)0.0208 (18)0.0028 (15)0.0031 (15)0.0004 (14)
C60.0267 (19)0.0137 (16)0.0193 (17)0.0010 (14)0.0066 (14)0.0018 (13)
C70.0238 (18)0.0136 (16)0.0171 (16)0.0001 (13)0.0066 (14)0.0057 (13)
C80.0231 (18)0.0151 (16)0.0203 (17)0.0009 (14)0.0094 (14)0.0038 (13)
C90.0209 (17)0.0172 (17)0.0200 (17)0.0009 (14)0.0052 (14)0.0049 (14)
C100.026 (2)0.028 (2)0.027 (2)0.0051 (16)0.0061 (16)0.0027 (16)
C110.0226 (19)0.034 (2)0.032 (2)0.0005 (17)0.0016 (16)0.0029 (18)
C120.033 (2)0.028 (2)0.0241 (19)0.0056 (17)0.0021 (16)0.0009 (16)
C130.0274 (19)0.0222 (19)0.0216 (18)0.0009 (15)0.0078 (15)0.0011 (15)
C140.0268 (18)0.0157 (16)0.0158 (16)0.0012 (14)0.0086 (14)0.0034 (13)
C150.0234 (18)0.0189 (18)0.0188 (17)0.0020 (14)0.0055 (14)0.0018 (14)
C160.0266 (19)0.0221 (18)0.0197 (17)0.0043 (15)0.0055 (15)0.0016 (14)
C170.0251 (19)0.0199 (18)0.0225 (18)0.0003 (15)0.0046 (15)0.0029 (14)
C180.0274 (19)0.0185 (18)0.0228 (18)0.0048 (15)0.0046 (15)0.0012 (14)
Geometric parameters (Å, º) top
I1—C161.996 (4)C7—C81.420 (5)
I2—C181.996 (4)C8—C91.412 (5)
C1—C141.413 (5)C8—C171.433 (5)
C1—C21.413 (5)C9—C101.428 (6)
C1—C151.437 (5)C9—C141.434 (5)
C2—C31.426 (5)C10—C111.362 (6)
C2—C71.431 (5)C10—H100.9500
C3—C41.360 (5)C11—C121.406 (6)
C3—H30.9500C11—H110.9500
C4—C51.426 (5)C12—C131.360 (6)
C4—H40.9500C12—H120.9500
C5—C61.349 (6)C13—C141.437 (5)
C5—H50.9500C13—H130.9500
C6—C71.430 (5)C15—C161.192 (5)
C6—H60.9500C17—C181.190 (5)
C14—C1—C2120.9 (3)C7—C8—C17119.3 (3)
C14—C1—C15118.8 (3)C8—C9—C10122.3 (3)
C2—C1—C15120.3 (3)C8—C9—C14119.4 (3)
C1—C2—C3121.9 (3)C10—C9—C14118.3 (3)
C1—C2—C7119.6 (3)C11—C10—C9121.5 (4)
C3—C2—C7118.5 (3)C11—C10—H10119.3
C4—C3—C2121.0 (3)C9—C10—H10119.3
C4—C3—H3119.5C10—C11—C12120.1 (4)
C2—C3—H3119.5C10—C11—H11119.9
C3—C4—C5120.4 (4)C12—C11—H11119.9
C3—C4—H4119.8C13—C12—C11121.0 (4)
C5—C4—H4119.8C13—C12—H12119.5
C6—C5—C4120.3 (4)C11—C12—H12119.5
C6—C5—H5119.9C12—C13—C14120.8 (4)
C4—C5—H5119.9C12—C13—H13119.6
C5—C6—C7121.3 (3)C14—C13—H13119.6
C5—C6—H6119.4C1—C14—C9119.7 (3)
C7—C6—H6119.4C1—C14—C13122.0 (3)
C8—C7—C6122.1 (3)C9—C14—C13118.2 (3)
C8—C7—C2119.4 (3)C16—C15—C1175.4 (4)
C6—C7—C2118.5 (3)C15—C16—I1177.4 (4)
C9—C8—C7120.9 (3)C18—C17—C8179.3 (4)
C9—C8—C17119.8 (3)C17—C18—I2178.0 (3)
C14—C1—C2—C3178.2 (3)C7—C8—C9—C10179.9 (3)
C15—C1—C2—C31.1 (5)C17—C8—C9—C100.7 (5)
C14—C1—C2—C71.6 (5)C7—C8—C9—C140.9 (5)
C15—C1—C2—C7179.0 (3)C17—C8—C9—C14180.0 (3)
C1—C2—C3—C4178.2 (3)C8—C9—C10—C11179.7 (4)
C7—C2—C3—C41.9 (5)C14—C9—C10—C110.4 (6)
C2—C3—C4—C50.3 (6)C9—C10—C11—C120.4 (6)
C3—C4—C5—C61.1 (6)C10—C11—C12—C130.5 (6)
C4—C5—C6—C70.6 (5)C11—C12—C13—C141.3 (6)
C5—C6—C7—C8178.6 (3)C2—C1—C14—C90.5 (5)
C5—C6—C7—C21.0 (5)C15—C1—C14—C9178.8 (3)
C1—C2—C7—C82.5 (5)C2—C1—C14—C13179.9 (3)
C3—C2—C7—C8177.3 (3)C15—C1—C14—C130.5 (5)
C1—C2—C7—C6177.9 (3)C8—C9—C14—C11.8 (5)
C3—C2—C7—C62.3 (5)C10—C9—C14—C1178.9 (3)
C6—C7—C8—C9179.1 (3)C8—C9—C14—C13178.9 (3)
C2—C7—C8—C91.3 (5)C10—C9—C14—C130.4 (5)
C6—C7—C8—C171.7 (5)C12—C13—C14—C1178.0 (4)
C2—C7—C8—C17177.9 (3)C12—C13—C14—C91.3 (5)
 

Footnotes

Both authors contributed equally.

§Both authors contributed equally

Acknowledgements

The authors thank John Lee for his advice on preparing this report. Funding for this research was provided by the UTC Irvine and Nita Grote Fund. Nehemiah Antoine was supported by the Tom Rybolt and Richard X. Zhang Endowed Undergraduate Research in Chemistry Scholarship. Marisa James was supported by the William H. Wheeler Center for Odor Research.

References

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