Crystal structure and Hirshfeld surface analysis of 3,3′-(sulfanedi­yl)bis­(2-iodo-1-methyl-1H-indole)

Ayobami, A.; Shaikh, A.; Padgett, C.W.

doi:10.1107/S2056989026002872

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 82| Part 4| April 2026| Pages 418-421

https://doi.org/10.1107/S2056989026002872

Open

access

Crystal structure and Hirshfeld surface analysis of 3,3′-(sulfanediyl)bis(2-iodo-1-methyl-1H-indole)

Adisa Ayobami,^a Abid Shaikh ^a and Clifford W. Padgett ^b ^*

^aGeorgia Southern University, 521 College of Education Dr., Department of Chemistry, Biochemistry and Physics, Statesboro, GA 30458, USA, and ^bGeorgia Southern University, 11935 Abercorn St., Department of Chemistry, Biochemistry and Physics, Savannah, GA 31419, USA
^*Correspondence e-mail: [email protected]

Edited by F. F. Ferreira, Universidade Federal do ABC, Brazil (Received 16 January 2026; accepted 18 March 2026; online 27 March 2026)

The title compound, C₁₈H₁₄I₂N₂S, comprises two N-methyl-2-iodoindole fragments linked at the 3-positions by a thioether bridge. The sulfur atom adopts a typical thioether geometry, and the C—S—C linkage is gauche on both sides, with C—S—C—C torsion angles of −64.1 (11) and −48.3 (10)°. The indole units are essentially planar and are strongly inclined to one another, with an interplanar angle of 103.3 (3)°. The compound crystallizes in the orthorhombic space group Fdd2; the molecule lacks classical hydrogen-bond donors, and no significant hydrogen bonding or π–π stacking is observed. The packing is dominated by van der Waals interactions together with short I⋯C and I⋯π contacts, giving a herringbone arrangement and forming chains along the b axis. Hirshfeld surface analysis indicates that H⋯H (33.1%), H⋯C/C⋯H (25.5%) and H⋯I/I⋯H (24.4%) contacts make the largest contributions to the crystal packing.

Keywords: bis(indolyl)sulfane; synthesis; crystal structure.

CCDC reference: 2539020

1. Chemical context

Sulfur-bridged indolyl compounds have attracted interest because of their relevance to medicinal chemistry (Xalxo et al., 2023 ; Silveira et al., 2013 ) and materials science (Yuan et al., 2022 ), as well as their ability to serve as versatile synthons in organic chemistry (Wang, 2024 ). Diarylated thioethers (aryl–S–aryl motifs) are used in functional materials; for example, thioether-linked polymeric systems have been developed for adsorption/capture applications such as iodine uptake (Shetty et al., 2022 ), and porous poly(aryl thioether) frameworks have also been explored for metal capture, sensing, and heterogeneous catalysis (Rivero-Crespo et al., 2021 ). Thienoindole-based π-systems have also been incorporated into conjugated polymers for organic electronic applications (Jeong et al., 2016 ). The motivation for studying these motifs comes from the central role of indole scaffolds in drug discovery (Mo et al., 2024 ) and from literature reports that indole-based aryl sulfides can exhibit potent antibacterial activity against Staphylococcus aureus (Lavekar et al., 2024 ). Organosulfur compounds containing thioether (sulfane) linkages are known to influence molecular conformation, electronic properties, and intermolecular interactions in the solid state (Gundermann, 1963 ). Incorporation of a sulfide bridge between two indole moieties can enhance structural rigidity while allowing conformational flexibility about the C–S–C linkage (Mohanty et al., 2025 ). The presence of iodine atoms at the 2-position of the indole rings provides opportunities for specific intermolecular contacts, while N-methylation suppresses classical N—H hydrogen bonding, allowing a clearer assessment of the roles played by halogen⋯halogen, halogen⋯π, and sulfur-involved interactions in the crystal structure (Bergman & Janosik, 2002 ). 3,3′-Sulfanediylbis(2-iodo-1-methyl-1H-indole) serves as a model system for assessing I⋯I, I⋯π and sulfur-involving contacts in the absence of classical hydrogen-bond donors, providing guidance for the crystal engineering of closely related derivatives. Herein, we report its synthesis and single-crystal X-ray diffraction analysis.

2. Structural commentary

The molecular structure of 3,3′-sulfanediylbis(2-iodo-1-methyl-1H-indole), (I), consists of two N-methyl-2-iodoindole fragments linked through a thioether bridge at the 3-position (Fig. 1). The C—I bond lengths are similar [I1—C1 = 2.079 (12) Å and I2—C10 = 2.080 (9) Å]. The sulfur atom adopts a typical thioether geometry with S1—C2 = 1.761 (11) Å and S1—C11 = 1.770 (11) Å, and a C2—S1—C11 angle of 100.6 (5)°. The conformation about the S bridge is gauche on both sides, as shown by the torsion angles C11—S1—C2—C1 = −64.1 (11)° and C2—S1—C11—C12 = −48.3 (10)°. Both indole ring systems are essentially planar, with r.m.s. deviations of 0.012 Å for the N1/C1–C8 system and 0.017 Å for the N2/C10–C17 system. The two indole mean planes are strongly inclined, with an interplanar angle (normal-to-normal) of 76.3 (3)°.

Figure 1
The molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level.

3. Supramolecular features

Compound (I) crystallizes in the orthorhombic space group Fdd2. In the crystal, the molecule lacks classical hydrogen-bond donors and no significant hydrogen-bonding interactions are observed; likewise, no π–π stacking between indole rings is evident. The packing (Fig. 2) is dominated primarily by van der Waals contacts, but with shorter than van der Waals intermolecular I⋯C contacts, C14⋯I1ⁱ = 3.341 (12) Å and C5⋯I2ⁱ = 3.433 (14) Å [symmetry code: (i) $[{3\over 4}]$ − x, $[{1\over 4}]$ + y, − $[{1\over 4}]$ + z]. The molecules pack in a herringbone pattern with each iodine substituent oriented toward the six-membered π-system of an indole ring in a neighbouring, symmetry-related molecule, giving rise to I⋯π contacts. For I1, the perpendicular separation from the plane of the C12–C17 ring is 3.217 (13) Å and the iodine-to-centroid distance is I1⋯Cg(C12–C17)ⁱ = 3.906 (5) Å; the C1—I1 vector makes an angle of 152.7 (4)° with the ring-plane normal and the C1—I1⋯Cgⁱ angle is 166.8 (3)°. Similarly, I2 lies 3.323 (14) Å from the plane of the C3–C8 ring with I2⋯Cg(C3–C8)ⁱ = 3.999 (5) Å; the C10–I2 vector makes an angle of 25.0 (4)° with the ring-plane normal and the C10—I2⋯Cgⁱ angle is 171.2 (3)°. These I⋯π contacts link the molecules into chains running parallel to the b axis.

Figure 2
A view along the c-axis direction of the crystal packing of (I)

4. Hirshfeld surface analysis

The intermolecular interactions were further investigated by quantitative analysis of the Hirshfeld surface, and visualized with Crystal Explorer 21.5 (Spackman et al., 2021 ) and the two-dimensional fingerprint plots (McKinnon et al., 2007 ). The shorter and longer contacts are indicated as red and blue spots, respectively, on the Hirshfeld surfaces, and contacts with distances approximately equal to the sum of the van der Waals radii are colored white. The function d_norm is a ratio enclosing the distances of any surface point to the nearest interior (d_i) and exterior (d_e) atom and the van der Waals (vdW) radii of the atoms. The d_norm plots were mapped with a color scale between −0.19 a.u. (red) and +1.2 a.u. (blue).

Fig. 3 shows the d_norm Hirshfeld surface of the title compound. The most intense red regions on the surface correspond to short intermolecular contacts involving H⋯I and H⋯C interactions, indicating their importance in the crystal packing. No pronounced red–blue triangular features are observed on the shape-index surface, suggesting the absence of significant π–π stacking interactions. Analysis of the two-dimensional fingerprint plots reveals that H⋯H contacts make the largest contribution to the Hirshfeld surface (33.1%), highlighting the dominant role of van der Waals interactions in the packing. This is followed by H⋯C/C⋯H (25.5%) and H⋯I/I⋯H (24.4%) interactions, which together account for a substantial fraction of the intermolecular contacts. Smaller contributions arise from C⋯I/I⋯C (5.2%), H⋯S/S⋯H (4.9%), and H⋯N/N⋯H (2.6%) contacts, while all remaining interactions contribute less than 2% individually, see Table 1.

Table 1
Contributions of selected intermolecular contacts (%) to the Hirshfeld surfaces of (I)

Contact	(%)
H⋯H	33.1
H⋯C/C⋯H	25.5
H⋯I/I⋯H	24.4
C⋯I/I⋯C	5.2
H⋯S/S⋯H	4.9
H⋯N/N⋯H	2.6
I⋯S/S⋯I	1.7
C⋯S/S⋯C	1.4
S⋯N/N⋯S	0.9
I⋯I	0.2

Figure 3
Hirshfeld surface for (I) mapped over d_norm.

5. Database survey

A search of the Cambridge Structural Database (CSD; website, accessed on 6 January 2026; Groom et al., 2016 ) for structures related to the title compound, 3,3′-sulfanediylbis(2-iodo-1-methyl-1H-indole), returned nine relevant entries. Three structures feature the 3,3′-thioether-linked bis(indole) motif: GETCAK, 1,1′-bis(t-butyldimethylsilyl)-3,3′-bis(1H-indol-3-yl)sulfide (Shirani et al., 2006 ), LOJTOX, 3,3′-sulfanediylbis(2-methyl-1H-indole) (Sharma et al., 2024 ), and YIQPEV, 3,3′-sulfanediylbis(1-methyl-1H-indole) (Shibahara et al., 2014 ); among these, YIQPEV is the closest analogue in terms of N-methylation, but it lacks the 2-iodo substitution present in the title compound. The remaining entries comprise iodinated indole derivatives with differing substitution patterns and functionalization, including JEVQOR, 2,3-diiodo-1-(phenylsulfonyl)-1H-indole (Rinderspacher et al., 2007 ), KAGQIV, 2-iodo-1-phenyl-1H-indole (Messaoud et al., 2015 ), iodoindole benzamide derivatives KAGGEJ and KAGGIN (Kim et al., 2025 ), and 2-iodo-3-[(trifluoromethyl)selanyl]indole derivatives KOYFAJ and KOYFIR (Huang et al., 2024 ).

6. Synthesis and crystallization

Di-tert-butyl disulfide (200 mg, 1.12 mmol) and N-methyl indole (147 mg, 1.12 mmol) were placed in a round-bottomed flask along with 2 mL of DMSO. The mixture was flushed with argon and iodine (710 mg, 2.8 mmol) and one drop of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) were added successively. The reaction mixture was then allowed to stir at room temperature for 12 h. After satisfactory conversion as indicated on TLC (10% ethyl acetate: hexane), the reaction mixture was washed with dilute sodium thiosulfate and the product was extracted in ethyl acetate. The crude product was subjected to purification using column chromatography to obtain a white solid (200 mg, 66%). Crystals for X-ray analysis were obtained by slow evaporation from ethyl acetate solution at room temperature.

Spectroscopic data: ¹H NMR (400 MHz, CDCl₃) δ = 7.75 (d, J = 6.3 Hz, 2H), 7.27 (m, 2H), 7.15 (m, 4H), 3.78 (s, 6H). ¹³C NMR (101 MHz, CDCl₃) δ = 138.8, 129.6, 122.2, 120.1, 119.9, 112.6, 109.7, 97.12, 35.1.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. H atoms were positioned geometrically (C—H = 0.93–0.96 Å) and refined as riding with U_iso(H) = 1.2U_eq(C) or 1.5U_eq(Cmethyl).

Table 2
Experimental details

Crystal data
Chemical formula	C₁₈H₁₄I₂N₂S
M_r	544.17
Crystal system, space group	Orthorhombic, Fdd2
Temperature (K)	298
a, b, c (Å)	37.8416 (4), 31.6009 (3), 5.94404 (5)
V (Å³)	7108.05 (11)
Z	16
Radiation type	Cu Kα
μ (mm⁻¹)	28.89
Crystal size (mm)	0.15 × 0.05 × 0.02

Data collection
Diffractometer	XtaLAB Synergy, Single source at home/near, HyPix3000
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2023 )
T_min, T_max	0.401, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	9127, 2434, 2352
R_int	0.099
(sin θ/λ)_max (Å⁻¹)	0.608

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.146, 1.18
No. of reflections	2434
No. of parameters	210
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.90, −1.60
Absolute structure	Flack x determined using 558 quotients [(I⁺)−(I⁻)]/[(I⁺)+(I⁻)] (Parsons et al., 2013 )
Absolute structure parameter	−0.034 (16)
Computer programs: CrysAlis PRO (Rigaku OD, 2023), SHELXL2018/3 (Sheldrick, 2015 ) and OLEX2 (Dolomanov et al., 2009 ).

Supporting information

CCDC reference: 2539020

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989026002872/ee2026sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989026002872/ee2026Isup2.hkl

checkCIF report

Computing details top

2-Iodo-3-[(2-iodo-1-methyl-1H-indol-3-yl)sulfanyl]-1-methyl-1H-indole top

Crystal data top

C₁₈H₁₄I₂N₂S	D_x = 2.034 Mg m⁻³
M_r = 544.17	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, Fdd2	Cell parameters from 7695 reflections
a = 37.8416 (4) Å	θ = 2.8–69.4°
b = 31.6009 (3) Å	µ = 28.89 mm⁻¹
c = 5.94404 (5) Å	T = 298 K
V = 7108.05 (11) Å³	Needle, clear colourless
Z = 16	0.15 × 0.05 × 0.02 mm
F(000) = 4128

Data collection top

XtaLAB Synergy, Single source at home/near, HyPix3000 diffractometer	2434 independent reflections
Radiation source: micro-focus sealed X-ray tube, PhotonJet (Cu) X-ray Source	2352 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.099
Detector resolution: 10.0000 pixels mm^-1	θ_max = 69.6°, θ_min = 3.7°
ω scans	h = −45→39
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2023)	k = −38→38
T_min = 0.401, T_max = 1.000	l = −7→5
9127 measured reflections

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.052	w = 1/[σ²(F_o²) + (0.1145P)²] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.146	(Δ/σ)_max = 0.001
S = 1.18	Δρ_max = 0.90 e Å⁻³
2434 reflections	Δρ_min = −1.60 e Å⁻³
210 parameters	Absolute structure: Flack x determined using 558 quotients [(I⁺)-(I^-)]/[(I⁺)+(I^-)] (Parsons et al., 2013)
1 restraint	Absolute structure parameter: −0.034 (16)

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

	x	y	z	U_iso*/U_eq
I1	0.32692 (2)	0.48490 (2)	0.93756 (14)	0.0508 (3)
I2	0.43892 (2)	0.47566 (2)	0.71981 (17)	0.0578 (3)
S1	0.36946 (6)	0.53925 (8)	0.4606 (5)	0.0439 (6)
C5	0.2780 (3)	0.6351 (4)	0.230 (3)	0.061 (3)
H5	0.279642	0.654130	0.111082	0.073*
C14	0.3706 (3)	0.6641 (3)	0.938 (3)	0.055 (3)
H14	0.356860	0.688280	0.920913	0.066*
C7	0.2432 (3)	0.6070 (4)	0.538 (3)	0.052 (3)
H7	0.222570	0.606600	0.622775	0.062*
C16	0.4158 (3)	0.6273 (4)	1.158 (2)	0.052 (3)
H16	0.431069	0.625179	1.280030	0.063*
C9	0.2490 (3)	0.5395 (4)	0.926 (2)	0.047 (2)
H9A	0.245021	0.509541	0.927082	0.071*
H9B	0.227240	0.553922	0.894335	0.071*
H9C	0.257864	0.548363	1.069472	0.071*
C6	0.2476 (4)	0.6347 (4)	0.360 (3)	0.061 (3)
H6	0.229574	0.653719	0.326893	0.073*
C12	0.3896 (2)	0.5966 (3)	0.815 (2)	0.037 (2)
C13	0.3671 (3)	0.6333 (4)	0.786 (2)	0.050 (3)
H13	0.351147	0.635244	0.667507	0.060*
C18	0.4594 (4)	0.5450 (5)	1.140 (3)	0.067 (4)
H18A	0.480997	0.540454	1.058117	0.101*
H18B	0.452750	0.519378	1.215169	0.101*
H18C	0.462896	0.567063	1.248555	0.101*
N1	0.2752 (2)	0.5500 (3)	0.7496 (16)	0.0410 (18)
C17	0.4136 (3)	0.5951 (4)	0.998 (2)	0.043 (2)
C15	0.3947 (3)	0.6622 (4)	1.128 (2)	0.055 (3)
H15	0.395848	0.684538	1.229133	0.066*
C10	0.4193 (2)	0.5350 (3)	0.805 (2)	0.039 (2)
C11	0.3936 (2)	0.5572 (3)	0.697 (2)	0.039 (2)
C4	0.3058 (3)	0.6082 (3)	0.272 (2)	0.047 (3)
H4	0.326016	0.608604	0.182858	0.057*
C1	0.3086 (2)	0.5320 (3)	0.723 (2)	0.040 (2)
N2	0.4320 (2)	0.5572 (3)	0.986 (2)	0.047 (2)
C3	0.3025 (3)	0.5800 (3)	0.454 (2)	0.042 (2)
C2	0.3259 (2)	0.5495 (3)	0.550 (2)	0.039 (2)
C8	0.2712 (3)	0.5797 (3)	0.5853 (19)	0.039 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
I1	0.0529 (4)	0.0460 (4)	0.0535 (5)	0.0002 (3)	−0.0029 (3)	0.0119 (3)
I2	0.0527 (4)	0.0459 (4)	0.0748 (6)	0.0076 (3)	0.0014 (4)	−0.0028 (4)
S1	0.0357 (10)	0.0523 (13)	0.0437 (14)	−0.0027 (10)	−0.0002 (10)	−0.0062 (12)
C5	0.067 (7)	0.046 (5)	0.069 (8)	−0.012 (5)	−0.021 (7)	0.020 (6)
C14	0.044 (5)	0.041 (5)	0.079 (9)	−0.008 (4)	0.023 (7)	0.002 (6)
C7	0.041 (5)	0.054 (6)	0.061 (7)	−0.001 (5)	−0.006 (5)	−0.009 (6)
C16	0.045 (5)	0.060 (6)	0.052 (7)	−0.012 (5)	0.001 (5)	−0.010 (6)
C9	0.040 (4)	0.060 (6)	0.042 (6)	−0.007 (5)	0.005 (5)	−0.003 (5)
C6	0.059 (6)	0.045 (6)	0.080 (10)	0.004 (5)	−0.028 (7)	−0.002 (6)
C12	0.031 (4)	0.037 (4)	0.043 (5)	−0.002 (3)	0.003 (4)	−0.006 (4)
C13	0.047 (6)	0.053 (6)	0.051 (7)	−0.023 (5)	0.017 (5)	−0.011 (5)
C18	0.067 (8)	0.064 (8)	0.071 (9)	0.014 (6)	−0.018 (8)	−0.009 (7)
N1	0.037 (4)	0.043 (4)	0.043 (5)	0.001 (3)	0.004 (4)	−0.001 (4)
C17	0.042 (4)	0.045 (5)	0.043 (6)	−0.006 (4)	0.000 (5)	0.001 (5)
C15	0.058 (6)	0.051 (6)	0.057 (8)	−0.012 (5)	0.004 (6)	−0.016 (6)
C10	0.033 (4)	0.031 (4)	0.054 (7)	0.002 (4)	0.007 (4)	0.001 (4)
C11	0.037 (4)	0.033 (4)	0.046 (6)	−0.002 (4)	0.002 (5)	−0.004 (4)
C4	0.048 (5)	0.042 (5)	0.051 (7)	−0.008 (5)	−0.004 (5)	0.007 (5)
C1	0.033 (4)	0.033 (4)	0.053 (6)	−0.007 (3)	−0.001 (5)	−0.004 (5)
N2	0.037 (4)	0.044 (4)	0.059 (6)	0.005 (4)	−0.006 (4)	0.001 (5)
C3	0.040 (4)	0.037 (4)	0.048 (6)	0.000 (4)	−0.001 (5)	0.000 (5)
C2	0.033 (4)	0.037 (5)	0.047 (6)	−0.012 (4)	−0.010 (4)	0.005 (5)
C8	0.038 (4)	0.031 (4)	0.047 (5)	0.002 (4)	−0.006 (4)	−0.004 (4)

Geometric parameters (Å, º) top

I1—C1	2.079 (12)	C6—H6	0.9300
I2—C10	2.080 (9)	C12—C13	1.448 (17)
S1—C11	1.770 (11)	C12—C17	1.418 (16)
S1—C2	1.761 (11)	C12—C11	1.436 (13)
C5—H5	0.9300	C13—H13	0.9300
C5—C6	1.39 (2)	C18—H18A	0.9600
C5—C4	1.375 (18)	C18—H18B	0.9600
C14—H14	0.9300	C18—H18C	0.9600
C14—C13	1.336 (17)	C18—N2	1.435 (17)
C14—C15	1.452 (19)	N1—C1	1.393 (12)
C7—H7	0.9300	N1—C8	1.364 (14)
C7—C6	1.38 (2)	C17—N2	1.390 (14)
C7—C8	1.394 (15)	C15—H15	0.9300
C16—H16	0.9300	C10—C11	1.361 (14)
C16—C17	1.392 (16)	C10—N2	1.369 (16)
C16—C15	1.373 (19)	C4—H4	0.9300
C9—H9A	0.9600	C4—C3	1.409 (16)
C9—H9B	0.9600	C1—C2	1.342 (17)
C9—H9C	0.9600	C3—C2	1.428 (14)
C9—N1	1.476 (14)	C3—C8	1.417 (15)

C2—S1—C11	100.6 (5)	C1—N1—C9	126.6 (9)
C6—C5—H5	119.0	C8—N1—C9	126.0 (9)
C4—C5—H5	119.0	C8—N1—C1	107.4 (9)
C4—C5—C6	121.9 (12)	C16—C17—C12	122.7 (10)
C13—C14—H14	118.1	N2—C17—C16	129.3 (11)
C13—C14—C15	123.8 (12)	N2—C17—C12	108.0 (10)
C15—C14—H14	118.1	C14—C15—H15	120.0
C6—C7—H7	121.5	C16—C15—C14	120.0 (11)
C6—C7—C8	117.0 (12)	C16—C15—H15	120.0
C8—C7—H7	121.5	C11—C10—I2	127.2 (9)
C17—C16—H16	121.3	C11—C10—N2	111.0 (9)
C15—C16—H16	121.3	N2—C10—I2	121.9 (7)
C15—C16—C17	117.5 (12)	C12—C11—S1	127.6 (8)
H9A—C9—H9B	109.5	C10—C11—S1	125.4 (8)
H9A—C9—H9C	109.5	C10—C11—C12	107.0 (10)
H9B—C9—H9C	109.5	C5—C4—H4	121.2
N1—C9—H9A	109.5	C5—C4—C3	117.5 (12)
N1—C9—H9B	109.5	C3—C4—H4	121.2
N1—C9—H9C	109.5	N1—C1—I1	121.7 (8)
C5—C6—H6	119.0	C2—C1—I1	127.0 (7)
C7—C6—C5	122.1 (11)	C2—C1—N1	111.3 (10)
C7—C6—H6	119.0	C17—N2—C18	124.2 (11)
C17—C12—C13	119.5 (10)	C10—N2—C18	128.0 (9)
C17—C12—C11	106.2 (9)	C10—N2—C17	107.8 (9)
C11—C12—C13	134.3 (10)	C4—C3—C2	132.7 (11)
C14—C13—C12	116.5 (13)	C4—C3—C8	120.1 (10)
C14—C13—H13	121.8	C8—C3—C2	107.2 (10)
C12—C13—H13	121.8	C1—C2—S1	127.9 (8)
H18A—C18—H18B	109.5	C1—C2—C3	106.3 (9)
H18A—C18—H18C	109.5	C3—C2—S1	125.8 (9)
H18B—C18—H18C	109.5	C7—C8—C3	121.4 (10)
N2—C18—H18A	109.5	N1—C8—C7	130.8 (11)
N2—C18—H18B	109.5	N1—C8—C3	107.8 (9)
N2—C18—H18C	109.5

I1—C1—C2—S1	−2.6 (15)	C17—C12—C11—C10	−1.5 (12)
I1—C1—C2—C3	179.6 (8)	C15—C14—C13—C12	−1.3 (16)
I2—C10—C11—S1	2.4 (15)	C15—C16—C17—C12	−2.7 (17)
I2—C10—C11—C12	−179.0 (7)	C15—C16—C17—N2	179.0 (11)
I2—C10—N2—C18	0.6 (18)	C11—S1—C2—C1	−64.1 (11)
I2—C10—N2—C17	−179.7 (7)	C11—S1—C2—C3	113.3 (10)
C5—C4—C3—C2	−177.0 (12)	C11—C12—C13—C14	178.3 (11)
C5—C4—C3—C8	0.6 (16)	C11—C12—C17—C16	−176.7 (10)
C16—C17—N2—C18	−3 (2)	C11—C12—C17—N2	1.9 (12)
C16—C17—N2—C10	176.9 (11)	C11—C10—N2—C18	−179.0 (13)
C9—N1—C1—I1	0.9 (14)	C11—C10—N2—C17	0.7 (13)
C9—N1—C1—C2	−178.3 (10)	C4—C5—C6—C7	−1 (2)
C9—N1—C8—C7	−0.2 (18)	C4—C3—C2—S1	1.5 (18)
C9—N1—C8—C3	179.3 (10)	C4—C3—C2—C1	179.4 (11)
C6—C5—C4—C3	−0.3 (19)	C4—C3—C8—C7	0.1 (16)
C6—C7—C8—N1	178.5 (11)	C4—C3—C8—N1	−179.5 (10)
C6—C7—C8—C3	−1.0 (17)	C1—N1—C8—C7	−179.0 (11)
C12—C17—N2—C18	178.1 (12)	C1—N1—C8—C3	0.6 (11)
C12—C17—N2—C10	−1.6 (12)	N2—C10—C11—S1	−178.0 (8)
C13—C14—C15—C16	0.7 (18)	N2—C10—C11—C12	0.6 (12)
C13—C12—C17—C16	2.1 (16)	C2—S1—C11—C12	−48.3 (10)
C13—C12—C17—N2	−179.3 (9)	C2—S1—C11—C10	130.0 (10)
C13—C12—C11—S1	−1.5 (18)	C2—C3—C8—C7	178.3 (10)
C13—C12—C11—C10	180.0 (11)	C2—C3—C8—N1	−1.3 (12)
N1—C1—C2—S1	176.6 (8)	C8—C7—C6—C5	1.3 (19)
N1—C1—C2—C3	−1.3 (13)	C8—N1—C1—I1	179.7 (7)
C17—C16—C15—C14	1.3 (17)	C8—N1—C1—C2	0.5 (12)
C17—C12—C13—C14	−0.1 (15)	C8—C3—C2—S1	−176.3 (8)
C17—C12—C11—S1	177.0 (8)	C8—C3—C2—C1	1.6 (12)

Contributions of selected intermolecular contacts (%) to the Hirshfeld surfaces of (I) top

Contact	(%)
H···H	33.1
H···C/C···H	25.5
H···I/I···H	24.4
C···I/I···C	5.2
H···S/S···H	4.9
H···N/N···H	2.6
I···S/S···I	1.7
C···S/S···C	1.4
S···N/N···S	0.9
I···I	0.2

Acknowledgements

The authors thank the Department of Biochemistry, Chemistry, and Physics at Georgia Southern University for the financial support of this work and the National Science Foundation Major Research Instrumentation fund for the purchase of the X-ray diffractometer.

Funding information

Funding for this research was provided by: NSF Major Research Instrumentation (MRI) program (grant No. 2215812).

References

Bergman, J. & Janosik, T. (2002). Prog. Heterocycl. Chem. 14, 1–18. CrossRef CAS Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CrossRef IUCr Journals Google Scholar
Gundermann, K. D. (1963). Angew. Chem. Int. Ed. Engl. 2, 674–683. CrossRef Google Scholar
Huang, Y., Zhang, Z., Wang, H. & Weng, Z. (2024). Org. Chem. Front. 11, 3968–3973. CrossRef CAS Google Scholar
Jeong, I., Kim, J., Kim, J., Lee, J., Lee, D. Y., Kim, I., Park, S. H. & Suh, H. (2016). Synth. Met. 213, 25–33. CrossRef CAS Google Scholar
Kim, A., Cho, H.-A., Oh, B., Song, J. & Kwon, Y. (2025). Commun. Chem. 8, 190. CrossRef PubMed Google Scholar
Lavekar, A. G., Thakare, R., Saima, Equbal, D., Chopra, S. & Sinha, A. K. (2024). Drug Dev. Res. 85, e22123. CrossRef PubMed Google Scholar
McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). Chem. Commun. pp. 3814–3816. Web of Science CrossRef Google Scholar
Messaoud, M. Y. A., Bentabed-Ababsa, G., Hedidi, M., Derdour, A., Chevallier, F., Halauko, Y. S., Ivashkevich, O. A., Matulis, V. E., Picot, L., Thiéry, V., Roisnel, T., Dorcet, V. & Mongin, F. (2015). Beilstein J. Org. Chem. 11, 1475–1485. Web of Science CSD CrossRef CAS PubMed Google Scholar
Mo, X., Rao, D. P., Kaur, K., Hassan, R., Abdel-Samea, A. S., Farhan, S. M., Bräse, S. & Hashem, H. (2024). Molecules 29, 4770. CrossRef PubMed Google Scholar
Mohanty, B. & Munshi, P. (2025). Sci. Rep. 15, 45462. CrossRef PubMed Google Scholar
Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249–259. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Rigaku OD (2023). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, Oxfordshire, England. Google Scholar
Rinderspacher, A., Gribble, G. W., Butcher, R. J. & Jasinski, J. P. (2007). Acta Cryst. E63, o671–o672. CrossRef IUCr Journals Google Scholar
Rivero-Crespo, M. A., Toupalas, G. & Morandi, B. (2021). J. Am. Chem. Soc. 143, 21331–21339. CAS PubMed Google Scholar
Sharma, S., Kumar, A. & Erande, R. D. (2024). ChemistrySelect 9 e202303476. Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Shetty, S., Baig, N. & Alameddine, B. (2022). Polymers 14, 4818. CrossRef PubMed Google Scholar
Shibahara, F., Kanai, T., Yamaguchi, E., Kamei, A., Yamauchi, T. & Murai, T. (2014). Chem. Asian J. 9, 237–244. CrossRef CAS PubMed Google Scholar
Shirani, H., Stensland, B., Bergman, J. & Janosik, T. (2006). Synlett 2459–2463. Google Scholar
Silveira, C. C., Mendes, S. R., Soares, J. R., Victoria, F. N., Martinez, D. M. & Savegnago, L. (2013). Tetrahedron Lett. 54, 4926–4929. CrossRef CAS Google Scholar
Spackman, P. R., Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Jayatilaka, D. & Spackman, M. A. (2021). J. Appl. Cryst. 54, 1006–1011. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wang, M. (2024). Molecules 29, 5523. CrossRef PubMed Google Scholar
Xalxo, A., Jyoti Goswami, U., Sarkar, S., Kandasamy, T., Mehta, K., Ghosh, S. S., Bharatam, P. V. & Khan, A. T. (2023). Bioorg. Chem. 141, 106900. CrossRef PubMed Google Scholar
Yuan, J., Xu, Z. & Wolf, M. O. (2022). Chem. Sci. 13, 5447–5464. CrossRef CAS PubMed Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.