Crystal structure determination, Hirshfeld surface analysis and energy frameworks of 6-phenyl­sulfonyl-6H-thieno[3,2-c]carbazole

Mohamooda Sumaya, U.; Sankar, E.; Arasambattu MohanaKrishnan, K.; Biruntha, K.; Usha, G.

doi:10.1107/S2056989018007971

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ISSN: 2056-9890

Volume 74| Part 7| July 2018| Pages 878-883

https://doi.org/10.1107/S2056989018007971

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Crystal structure determination, Hirshfeld surface analysis and energy frameworks of 6-phenylsulfonyl-6H-thieno[3,2-c]carbazole

U. Mohamooda Sumaya,^a E. Sankar,^b K. Arasambattu MohanaKrishnan,^b K. Biruntha ^a and G. Usha ^c ^*

^aDepartment of Physics, Bharathi Women's College (A), Chennai-108, Tamilnadu, India, ^bDepartment of organic Chemistry, University of Madras, Chennai-25, Tamilnadu, India, and ^cPG and Research Department of Physics, Queen Mary's College (A), Chennai-4, Tamilnadu, India
^*Correspondence e-mail: guqmc@yahoo.com

Edited by L. Fabian, University of East Anglia, England (Received 16 April 2018; accepted 30 May 2018; online 5 June 2018)

In the title compound, C₂₀H₁₃NO₂S₂, the carbazole ring system forms a dihedral angle of 89.08 (1)° with the sulfonyl-substituted phenyl ring. Intramolecular C—H⋯O hydrogen bonds involving the sulfone O atoms and the carbazole moiety result in two S(6) rings. In the crystal, molecules are linked via pairs of C—H⋯O hydrogen bonds forming inversion dimers with an R₂²(12) graph-set motif. Analysis of the Hirshfeld surfaces and two-dimensional fingerprint plots was used to explore the distribution of weak intermolecular interactions in the crystal structure.

Keywords: crystal structure; carbazole; Hirshfeld surface analysis; two-dimensional fingerprint plot; energy frameworks.

CCDC reference: 1825258

1. Chemical context

Carbazole derivatives are among the most important and highly exploited heterocyclic compounds in the field of medicinal chemistry. They have been attractive to researchers because of their broad spectrum of biological activities, such as anti-oxidative (Tachibana et al., 2001 ), antitumor (Itoigawa et al., 2000 ), anti-inflammatory and antimutagenic (Ramsewak et al., 1999 ), antibiotic, antifungal and cytotoxic (Chakraborty et al., 1965 , 1978 ), pim kinase inhibitory (Giraud et al., 2014 ), antimicrobial (Gu et al., 2014 ) and anti-Alzheimer (Thiratmatrakul et al., 2014 ). Carbazole derivatives are also used as precursor compounds for the synthesis of pyridocarbazole alkaloids (Karmakar et al., 1991 ).

2. Structural commentary

The molecular structure of the title compound is illustrated in Fig.1. The title compound comprises a carbazole ring system, which is attached to a phenyl sulfonyl ring and a thiopene ring. The carbazole ring system forms a dihedral angle of 89.08 (1)° with the sulfonyl-substituted phenyl ring. The tetrahedral configuration is distorted around the atom S2. The increase in the O2—S2—O1 angle [120.14 (9)°], with a simultaneous decrease in the N1—S2—C15 angle [104.96 (9)°] from the ideal tetrahedral value (109.5°) are attributed to the Thorpe–Ingold effect (Bassindale, 1984 ). The N1—C6 [1.428 (2) Å] and N1—C7 [1.429 (2) Å] bond lengths in the molecule are longer than the mean Nsp²—Csp² bond length value of 1.355 (14) Å (Allen et al., 1987 ; Groom et al., 2016 ). The elongation observed may be due to the electron-withdrawing character of the phenylsulfonyl group. The molecular structure is stabilized by C1—H1⋯O2 and C9—H9⋯O1 intramolecular interactions involving the sulfone oxygen atoms, which generate two S(6) ring motifs (Fig. 1).

Figure 1
The molecular structure of the title compound with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level. Dashed lines indicate the intramolecular C—H⋯O hydrogen bonds, which generate S(6) ring motifs.

3. Supramolecular features

In the crystal packing (Fig. 2), the molecules are linked via pairs of C—H⋯O hydrogen bonds (Table 1), forming inversion dimers with an $[R_{2}^{2}]$ (12) graph-set motif. Each molecule is involved in the formation of two dimers that propagate as a ribbon in the c-axis direction.

Table 1
Hydrogen-bond geometry (Å, °)

Cg5 is the centroid of the C15–C20 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O2	0.93	2.34	2.935 (3)	121
C1—H1⋯O2ⁱ	0.93	2.62	3.443 (3)	148
C9—H9⋯O1	0.93	2.35	2.949 (3)	122
C9—H9⋯O1ⁱⁱ	0.93	2.57	3.382 (2)	146
C13—H13⋯Cg5ⁱⁱⁱ	0.93	2.82	3.604 (2)	143
Symmetry codes: (i) ; (ii) ; (iii) .

Figure 2
The crystal packing of the title compound, viewed along the a axis. Dashed lines indicate intermolecular hydrogen bonds. For clarity, only the H atoms involved in these interactions have been included.

4. Hirshfeld surface analysis, interaction energies and energy frameworks

In order to investigate the weak intermolecular interactions in the crystal, the Hirshfeld surfaces (d_norm, curvedness and shape index) and 2D fingerprint plots were generated using CrystalExplorer 17.5 (Turner et al., 2017 ). The d_norm mapping uses the normalized functions of d_i and d_e (Fig. 3a), with white, red and blue coloured surfaces where d_i (x axis) and d_e (y axis) are the closest internal and external distances from a given point on the Hirshfeld surface to the nearest atom. The white surface indicates those contacts with distances equal to the sum of van der Waals (vdW) radii, red indicates shorter contacts (< vdW radii) and blue longer contacts (> vdW radii). The electrostatic potential was also mapped on the Hirshfeld surface using a STO-3G basis set and the Hartee–Fock level of theory (Spackman et al., 2008 ; Jayatilaka et al., 2005 ). The C—H⋯O hydrogen-bond donors and acceptors are shown as blue and red regions around the atoms corresponding to positive and negative electrostatic potentials, respectively (Fig. 3b). The presence of π–π stacking interactions is indicated by red and blue triangles on the shape-index surface (Fig. 3c). Areas on the Hirshfeld surface with high curvedness tend to divide the surface into contact patches with each neighbouring molecule. The coordination number in the crystal is defined by the curvedness of the Hirshfeld surface (Fig. 3d). The nearest neighbour coordination environment of a molecule is identified from the colour patches on the Hirshfeld surface depending on their closeness to adjacent molecules (Fig. 3e).

Figure 3
Hirshfeld surfaces for visualizing the intermolecular contacts of the title compound: (a) d_norm highlighting the regions of C—H⋯O hydrogen bonds, (b) electrostatic potential, (c) shape index, (d) curvedness and (e) fragment patches.

Two-dimensional fingerprint plots showing the occurrence of all intermolecular contacts (McKinnon et al., 2007 ) are presented in Fig. 4a. The fingerprint plot of H⋯H contacts, which represent the largest contribution to the Hirshfeld surfaces (40%), shows a distinct pattern with a minimum value of d_e = d_i ≃ 1.2 Å (Fig. 4b). The C⋯H/H⋯C interactions appear as the next largest region of the fingerprint plot, highly concentrated at the edges, having almost the same d_e + d_i ≃ 2.7 Å (Fig. 4c), with an overall Hirshfeld surface contribution of 24.1%. The O⋯H/H⋯O interactions on the fingerprint plot, which contribute 15.1% of the total Hirshfeld surface with d_e + d_i ≃ 2.5 Å (Fig. 4d), are shown as two symmetrical narrow pointed wings. The H⋯S/S⋯H interactions cover only 3.5% (Fig. 4e) of the surface. The C⋯C contacts, which are the measure of π–π stacking interactions, occupy 8.7% of the Hirshfeld surface and appear as a unique triangle at d_e = d_i ≃ 1.8 Å (Fig. 4f). These are the weak interactions that contribute the most to the packing of the title compound.

Figure 4
Two-dimensional fingerprint plots for the title compound showing the contributions of different types of interactions: (a) all intermolecular contacts, (b) H⋯H contacts, (c) C⋯H/H⋯C contacts, (d) O⋯H/H⋯O contacts, (e) H⋯S/S⋯H contacts and (f) C⋯C contacts. The outline of the the full fingerprint is shown in gray. Surfaces to the right highlight the relevant surface patches associated with the specific contact type and are coloured as d_norm.

The interaction energy between the molecules is expressed in terms of four components: electrostatic, polarization, dispersion and exchange repulsion. These energies were obtained using monomer wavefunctions calculated at the B3LYP/6-31G(d,p) level. The total interaction energy, which is the sum of scaled components, was calculated for a 3.8 Å radius cluster of molecules around the selected molecule (Fig. 5a). The scale factors used in the CE-B3LYP benchmarked energy model (Mackenzie et al., 2017 ) are given in Table 2. The interaction energies calculated by the energy model reveal that the interactions in crystal have a significant contribution from dispersion components (Table 3). Using energy frameworks, the magnitudes of the intermolecular interaction energies are represented graphically and the supramolecular architecture of the crystal structure is visualized. Energies between molecular pairs are represented as cylinders joining the centroids of pairs of molecules, with the cylinder radius proportional to the magnitude of the interaction energy. Frameworks were constructed for E_elec as red cylinders, E_dis as green and E_tot as blue (Fig. 5b–5d) and these cylinders represent the relative strength of molecular packing in different directions.

Table 2
Scale factors for benchmarked energy model

Energy model	k_elec	k_pol	k_{energy-dispersive}	k_rep
CE-B3LYP⋯B3LYP/6–31G(d,p) electron densities	1.057	0.740	0.871	0.618

Table 3
Interaction energies (kJ mol⁻¹) between a reference molecule and its neighbours

N is the number of equivalent neighbours, R is the distance between molecular centroids (mean atomic position) in Å. The colours identify molecules in Fig. 5a, with the reference molecule shown in grey.

Colour	N	symmetry	R	E_elec	E_pol	E_{energy-dispersive}	E_rep	E_total
Red	1	inversion	9.29	−3.7	−1.5	−27.5	14.6	−20.0
Orange	1	inversion	8.65	0.9	−1.4	−23.3	10.3	−14.0
Yellow	1	inversion	6.18	−12.2	−2.6	−83.1	54.3	−53.7
Green	2	translation	12.53	1.7	−0.5	−7.3	2.4	−3.4
Lime	2	translation	9.88	−2.4	−0.6	−19.5	14.0	−11.3
Aqua	2	translation	7.65	−4.5	−2.1	−12.1	5.4	−13.5
Cyan	1	inversion	7.79	−17.5	−4.8	−23.5	16.7	−32.2
Blue	1	inversion	8.76	−19.3	−5.0	−26.9	22.3	−33.8
Indigo	1	inversion	5.84	−11.7	−2.7	−87.7	51.5	−58.9
Purple	2	translation	11.22	1.9	−0.4	−6.9	3.6	−2.0
Pink	1	inversion	10.79	−2.6	−0.4	−8.1	2.1	−8.8

Figure 5
(a) Interactions between the selected reference molecule (highlighted in yellow) and the molecules present in a 3.8 Å cluster around it, (b) Coulomb energy framework, (c) dispersion energy framework and (d) total energy framework.

5. Synthesis and crystallization

The first step was the alkylation of 2-bromo-3-(phenylsulfonylmethyl)thiophene (0.7 g, 2.21 mmol) with 2-bromomethyl-1-phenylsulfonylindol (0.85 g, 2.43 mmol) using t-BuOK (0.37 g, 3.32 mmol) in DMF (20 mL) at 278–283 K for 15 min. After completion of the reaction, the reaction mixture was poured into crushed ice. The solid obtained was filtered and dried to afford the alkylated sulfone (1.16 g) as a colourless solid. To a solution of the crude alkylated sulfone (1.16 g, 1.97 mmol) in DMF (15 mL), Pd(OAc)₂ (0.04 g, 0.19 mmol), PPh₃ (0.10 g, 0.39 mmol) and K₂CO₃ (0.55 g, 3.94 mmol) were added. Then the reaction mixture was heated at 353 K for 2 h. After that, the reaction mixture was filtered through a celite bed and washed with ethyl acetate (2 × 10 mL). The combined organic layer was washed with water (3 × 20 mL) and dried (Na₂SO₄). Removal of the solvent followed by column chromatographic purification (silica gel, 100% hexane) afforded 6-(phenylsulfonyl)-6H-thieno[3,2-c]carbazole (0.50 g, 70%) as a colourless solid (Fig. 6). Diffraction-quality crystals were obtained from the product by slow evaporation using chloroform as a solvent; m.p. 417–419 K.

Figure 6
Reaction scheme.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4. All H atoms were positioned geometrically (C—H = 0.93 Å) and refined using a riding model with U_iso(H) = 1.2U_eq(C). In the final refinement, reflection (001), which was obstructed by the beam stop, was omitted.

Table 4
Experimental details

Crystal data
Chemical formula	C₂₀H₁₃NO₂S₂
M_r	363.43
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	298
a, b, c (Å)	7.6461 (8), 9.8772 (9), 11.2191 (12)
α, β, γ (°)	72.571 (5), 88.496 (6), 86.144 (6)
V (Å³)	806.54 (14)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.34
Crystal size (mm)	0.25 × 0.20 × 0.20

Data collection
Diffractometer	Bruker Kappa APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2012 )
T_min, T_max	0.921, 0.934
No. of measured, independent and observed [I > 2σ(I)] reflections	16616, 3174, 2458
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.034, 0.091, 1.03
No. of reflections	3102
No. of parameters	226
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.41
Computer programs: APEX2, SAINT and XPREP (Bruker, 2012), SHELXS97 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ) and ORTEP-3 for Windows (Farrugia, 2012 ).

Supporting information

CCDC reference: 1825258

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989018007971/fy2128sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989018007971/fy2128Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989018007971/fy2128Isup3.cml

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2012); cell refinement: APEX2 and SAINT (Bruker, 2012); data reduction: SAINT and XPREP (Bruker, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).

6-Phenylsulfonyl-6H-thieno[3,2-c]carbazole top

Crystal data top

C₂₀H₁₃NO₂S₂	Z = 2
M_r = 363.43	F(000) = 376
Triclinic, P1	D_x = 1.497 Mg m⁻³
a = 7.6461 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.8772 (9) Å	Cell parameters from 3175 reflections
c = 11.2191 (12) Å	θ = 2.4–28.8°
α = 72.571 (5)°	µ = 0.34 mm⁻¹
β = 88.496 (6)°	T = 298 K
γ = 86.144 (6)°	Needle, colourless
V = 806.54 (14) Å³	0.25 × 0.20 × 0.20 mm

Data collection top

Bruker Kappa APEXII CCD diffractometer	2458 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.036
ω and φ scan	θ_max = 26.0°, θ_min = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2012)	h = −9→9
T_min = 0.921, T_max = 0.934	k = −12→12
16616 measured reflections	l = −13→13
3174 independent reflections

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.034	H-atom parameters constrained
wR(F²) = 0.091	w = 1/[σ²(F_o²) + (0.0389P)² + 0.3787P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
3102 reflections	Δρ_max = 0.24 e Å⁻³
226 parameters	Δρ_min = −0.41 e Å⁻³

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
C1	0.3947 (3)	0.2820 (2)	0.4004 (2)	0.0462 (5)
H1	0.4480	0.1960	0.4478	0.055*
C2	0.3350 (4)	0.3854 (3)	0.4540 (2)	0.0590 (7)
H2	0.3496	0.3685	0.5394	0.071*
C3	0.2541 (4)	0.5137 (3)	0.3848 (2)	0.0614 (7)
H3	0.2148	0.5806	0.4242	0.074*
C4	0.2317 (3)	0.5426 (2)	0.2583 (2)	0.0478 (6)
H4	0.1776	0.6287	0.2118	0.057*
C5	0.2909 (3)	0.44110 (19)	0.20083 (18)	0.0327 (4)
C6	0.3716 (3)	0.31203 (19)	0.27287 (18)	0.0331 (4)
C7	0.3683 (2)	0.30993 (19)	0.06791 (17)	0.0313 (4)
C8	0.2892 (2)	0.43910 (19)	0.07345 (17)	0.0300 (4)
C9	0.3877 (3)	0.2747 (2)	−0.04358 (19)	0.0395 (5)
H9	0.4417	0.1880	−0.0450	0.047*
C10	0.3247 (3)	0.3722 (2)	−0.1510 (2)	0.0432 (5)
H10	0.3350	0.3499	−0.2259	0.052*
C11	0.2454 (3)	0.5042 (2)	−0.15089 (19)	0.0378 (5)
C12	0.2289 (2)	0.53705 (19)	−0.03801 (19)	0.0335 (4)
C13	0.1126 (3)	0.7312 (2)	−0.2176 (2)	0.0526 (6)
H13	0.0633	0.8143	−0.2728	0.063*
C14	0.1762 (3)	0.6197 (2)	−0.2532 (2)	0.0499 (6)
H14	0.1756	0.6172	−0.3354	0.060*
C15	0.2718 (3)	−0.02095 (18)	0.26426 (18)	0.0318 (4)
C16	0.2018 (3)	−0.0612 (2)	0.38416 (19)	0.0392 (5)
H16	0.2624	−0.0493	0.4508	0.047*
C17	0.0401 (3)	−0.1193 (2)	0.4027 (2)	0.0458 (5)
H17	−0.0082	−0.1480	0.4826	0.055*
C18	−0.0494 (3)	−0.1347 (2)	0.3035 (2)	0.0482 (6)
H18	−0.1589	−0.1727	0.3166	0.058*
C19	0.0212 (3)	−0.0946 (2)	0.1843 (2)	0.0473 (5)
H19	−0.0408	−0.1052	0.1178	0.057*
C20	0.1835 (3)	−0.0388 (2)	0.1641 (2)	0.0405 (5)
H20	0.2332	−0.0135	0.0845	0.049*
O1	0.55980 (19)	0.02188 (14)	0.13545 (14)	0.0426 (4)
O2	0.56255 (19)	0.02622 (14)	0.35412 (13)	0.0423 (4)
S1	0.13085 (7)	0.70590 (5)	−0.05968 (6)	0.04557 (17)
S2	0.47505 (6)	0.05704 (5)	0.23770 (5)	0.03323 (14)
N1	0.4252 (2)	0.23071 (16)	0.19079 (14)	0.0332 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0662 (15)	0.0380 (12)	0.0332 (12)	−0.0017 (10)	−0.0041 (11)	−0.0091 (9)
C2	0.094 (2)	0.0533 (14)	0.0340 (12)	−0.0060 (13)	0.0035 (13)	−0.0189 (11)
C3	0.095 (2)	0.0454 (14)	0.0500 (15)	−0.0002 (13)	0.0092 (14)	−0.0256 (12)
C4	0.0623 (15)	0.0344 (11)	0.0468 (13)	0.0051 (10)	0.0037 (11)	−0.0143 (10)
C5	0.0353 (11)	0.0284 (9)	0.0352 (11)	−0.0037 (8)	0.0016 (8)	−0.0105 (8)
C6	0.0376 (11)	0.0299 (10)	0.0331 (10)	−0.0034 (8)	0.0006 (8)	−0.0111 (8)
C7	0.0332 (10)	0.0278 (9)	0.0313 (10)	−0.0025 (7)	−0.0018 (8)	−0.0060 (8)
C8	0.0289 (10)	0.0267 (9)	0.0345 (10)	−0.0039 (7)	0.0000 (8)	−0.0091 (8)
C9	0.0520 (13)	0.0321 (10)	0.0361 (11)	0.0008 (9)	0.0007 (10)	−0.0138 (9)
C10	0.0570 (14)	0.0434 (12)	0.0312 (11)	−0.0052 (10)	−0.0007 (10)	−0.0138 (9)
C11	0.0395 (12)	0.0363 (11)	0.0349 (11)	−0.0065 (9)	−0.0049 (9)	−0.0053 (9)
C12	0.0315 (10)	0.0274 (9)	0.0394 (11)	−0.0043 (8)	−0.0022 (8)	−0.0057 (8)
C13	0.0534 (15)	0.0415 (13)	0.0508 (14)	0.0009 (10)	−0.0151 (11)	0.0051 (11)
C14	0.0554 (15)	0.0509 (14)	0.0369 (12)	−0.0075 (11)	−0.0106 (11)	−0.0012 (10)
C15	0.0354 (11)	0.0243 (9)	0.0354 (11)	0.0050 (7)	−0.0050 (8)	−0.0095 (8)
C16	0.0436 (12)	0.0368 (11)	0.0365 (11)	0.0035 (9)	−0.0044 (9)	−0.0111 (9)
C17	0.0472 (13)	0.0432 (12)	0.0455 (13)	−0.0025 (10)	0.0070 (11)	−0.0116 (10)
C18	0.0366 (12)	0.0391 (12)	0.0694 (16)	−0.0011 (9)	0.0007 (11)	−0.0173 (11)
C19	0.0470 (13)	0.0443 (12)	0.0546 (14)	−0.0018 (10)	−0.0144 (11)	−0.0199 (11)
C20	0.0470 (13)	0.0366 (11)	0.0373 (11)	0.0013 (9)	−0.0045 (10)	−0.0106 (9)
O1	0.0446 (9)	0.0362 (8)	0.0472 (9)	0.0064 (6)	0.0048 (7)	−0.0150 (6)
O2	0.0417 (8)	0.0387 (8)	0.0427 (9)	0.0048 (6)	−0.0145 (7)	−0.0066 (6)
S1	0.0462 (3)	0.0317 (3)	0.0526 (4)	0.0048 (2)	−0.0053 (3)	−0.0043 (2)
S2	0.0342 (3)	0.0271 (2)	0.0365 (3)	0.00447 (18)	−0.0042 (2)	−0.0077 (2)
N1	0.0429 (10)	0.0271 (8)	0.0287 (8)	0.0026 (7)	−0.0039 (7)	−0.0077 (7)

Geometric parameters (Å, º) top

C1—C2	1.380 (3)	C11—C14	1.437 (3)
C1—C6	1.385 (3)	C12—S1	1.7323 (19)
C1—H1	0.9300	C13—C14	1.338 (3)
C2—C3	1.386 (4)	C13—S1	1.722 (3)
C2—H2	0.9300	C13—H13	0.9300
C3—C4	1.374 (3)	C14—H14	0.9300
C3—H3	0.9300	C15—C20	1.387 (3)
C4—C5	1.392 (3)	C15—C16	1.387 (3)
C4—H4	0.9300	C15—S2	1.760 (2)
C5—C6	1.401 (3)	C16—C17	1.382 (3)
C5—C8	1.435 (3)	C16—H16	0.9300
C6—N1	1.428 (2)	C17—C18	1.374 (3)
C7—C8	1.392 (3)	C17—H17	0.9300
C7—C9	1.397 (3)	C18—C19	1.382 (3)
C7—N1	1.429 (2)	C18—H18	0.9300
C8—C12	1.399 (3)	C19—C20	1.378 (3)
C9—C10	1.373 (3)	C19—H19	0.9300
C9—H9	0.9300	C20—H20	0.9300
C10—C11	1.401 (3)	O1—S2	1.4233 (15)
C10—H10	0.9300	O2—S2	1.4236 (15)
C11—C12	1.399 (3)	S2—N1	1.6572 (16)

C2—C1—C6	117.0 (2)	C8—C12—S1	128.08 (16)
C2—C1—H1	121.5	C14—C13—S1	113.43 (17)
C6—C1—H1	121.5	C14—C13—H13	123.3
C1—C2—C3	122.1 (2)	S1—C13—H13	123.3
C1—C2—H2	118.9	C13—C14—C11	112.8 (2)
C3—C2—H2	118.9	C13—C14—H14	123.6
C4—C3—C2	120.5 (2)	C11—C14—H14	123.6
C4—C3—H3	119.8	C20—C15—C16	121.34 (19)
C2—C3—H3	119.8	C20—C15—S2	119.11 (16)
C3—C4—C5	119.1 (2)	C16—C15—S2	119.55 (16)
C3—C4—H4	120.5	C17—C16—C15	118.7 (2)
C5—C4—H4	120.5	C17—C16—H16	120.6
C4—C5—C6	119.44 (19)	C15—C16—H16	120.6
C4—C5—C8	132.60 (19)	C18—C17—C16	120.2 (2)
C6—C5—C8	107.96 (16)	C18—C17—H17	119.9
C1—C6—C5	121.89 (18)	C16—C17—H17	119.9
C1—C6—N1	130.16 (18)	C17—C18—C19	120.8 (2)
C5—C6—N1	107.91 (17)	C17—C18—H18	119.6
C8—C7—C9	122.62 (18)	C19—C18—H18	119.6
C8—C7—N1	108.02 (16)	C20—C19—C18	120.0 (2)
C9—C7—N1	129.33 (17)	C20—C19—H19	120.0
C7—C8—C12	118.03 (17)	C18—C19—H19	120.0
C7—C8—C5	108.38 (16)	C19—C20—C15	119.0 (2)
C12—C8—C5	133.58 (18)	C19—C20—H20	120.5
C10—C9—C7	117.95 (19)	C15—C20—H20	120.5
C10—C9—H9	121.0	C13—S1—C12	91.09 (11)
C7—C9—H9	121.0	O1—S2—O2	120.14 (9)
C9—C10—C11	121.76 (19)	O1—S2—N1	106.94 (8)
C9—C10—H10	119.1	O2—S2—N1	106.82 (8)
C11—C10—H10	119.1	O1—S2—C15	108.46 (9)
C12—C11—C10	119.05 (18)	O2—S2—C15	108.51 (9)
C12—C11—C14	111.32 (19)	N1—S2—C15	104.96 (9)
C10—C11—C14	129.6 (2)	C6—N1—C7	107.66 (15)
C11—C12—C8	120.57 (18)	C6—N1—S2	124.02 (13)
C11—C12—S1	111.34 (15)	C7—N1—S2	124.80 (13)

C6—C1—C2—C3	0.5 (4)	C12—C11—C14—C13	0.1 (3)
C1—C2—C3—C4	−0.5 (4)	C10—C11—C14—C13	−178.9 (2)
C2—C3—C4—C5	0.2 (4)	C20—C15—C16—C17	−0.4 (3)
C3—C4—C5—C6	0.1 (3)	S2—C15—C16—C17	178.53 (15)
C3—C4—C5—C8	−179.2 (2)	C15—C16—C17—C18	−0.8 (3)
C2—C1—C6—C5	−0.2 (3)	C16—C17—C18—C19	0.9 (3)
C2—C1—C6—N1	176.9 (2)	C17—C18—C19—C20	0.2 (3)
C4—C5—C6—C1	−0.1 (3)	C18—C19—C20—C15	−1.4 (3)
C8—C5—C6—C1	179.39 (19)	C16—C15—C20—C19	1.6 (3)
C4—C5—C6—N1	−177.79 (18)	S2—C15—C20—C19	−177.40 (15)
C8—C5—C6—N1	1.7 (2)	C14—C13—S1—C12	0.00 (19)
C9—C7—C8—C12	−0.6 (3)	C11—C12—S1—C13	0.04 (16)
N1—C7—C8—C12	177.62 (16)	C8—C12—S1—C13	179.58 (19)
C9—C7—C8—C5	−179.87 (18)	C20—C15—S2—O1	−30.91 (17)
N1—C7—C8—C5	−1.6 (2)	C16—C15—S2—O1	150.12 (15)
C4—C5—C8—C7	179.3 (2)	C20—C15—S2—O2	−162.97 (15)
C6—C5—C8—C7	0.0 (2)	C16—C15—S2—O2	18.06 (18)
C4—C5—C8—C12	0.2 (4)	C20—C15—S2—N1	83.12 (16)
C6—C5—C8—C12	−179.1 (2)	C16—C15—S2—N1	−95.86 (16)
C8—C7—C9—C10	−0.4 (3)	C1—C6—N1—C7	179.9 (2)
N1—C7—C9—C10	−178.23 (19)	C5—C6—N1—C7	−2.7 (2)
C7—C9—C10—C11	0.9 (3)	C1—C6—N1—S2	20.2 (3)
C9—C10—C11—C12	−0.5 (3)	C5—C6—N1—S2	−162.32 (14)
C9—C10—C11—C14	178.4 (2)	C8—C7—N1—C6	2.7 (2)
C10—C11—C12—C8	−0.6 (3)	C9—C7—N1—C6	−179.27 (19)
C14—C11—C12—C8	−179.65 (18)	C8—C7—N1—S2	162.11 (14)
C10—C11—C12—S1	179.00 (16)	C9—C7—N1—S2	−19.8 (3)
C14—C11—C12—S1	−0.1 (2)	O1—S2—N1—C6	−166.71 (15)
C7—C8—C12—C11	1.1 (3)	O2—S2—N1—C6	−36.89 (18)
C5—C8—C12—C11	−179.87 (19)	C15—S2—N1—C6	78.21 (17)
C7—C8—C12—S1	−178.41 (14)	O1—S2—N1—C7	37.08 (18)
C5—C8—C12—S1	0.6 (3)	O2—S2—N1—C7	166.91 (15)
S1—C13—C14—C11	0.0 (3)	C15—S2—N1—C7	−78.00 (17)

Hydrogen-bond geometry (Å, º) top

Cg5 is the centroid of the C15–C20 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O2	0.93	2.34	2.935 (3)	121
C1—H1···O2ⁱ	0.93	2.62	3.443 (3)	148
C9—H9···O1	0.93	2.35	2.949 (3)	122
C9—H9···O1ⁱⁱ	0.93	2.57	3.382 (2)	146
C13—H13···Cg5ⁱⁱⁱ	0.93	2.82	3.604 (2)	143

Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+1, −y, −z; (iii) −x, −y+1, −z.

Scale factors for benchmarked energy model top

Energy model	k_elec	k_pol	k_disp	k_rep
CE-B3LYP···B3LYP/6-31G(d,p) electron densities	1.057	0.740	0.871	0.618

Interaction energies (kJ mol^-1) between a reference molecule and its neighbours top

Colour	N	symmetry	R	E_elec	E_pol	E_disp	E_rep	E_total
Red	1	inversion	9.29	-3.7	-1.5	-27.5	14.6	-20.0
Orange	1	inversion	8.65	0.9	-1.4	-23.3	10.3	-14.0
Yellow	1	inversion	6.18	-12.2	-2.6	-83.1	54.3	-53.7
Green	2	translation	12.53	1.7	-0.5	-7.3	2.4	-3.4
Lime	2	translation	9.88	-2.4	-0.6	-19.5	14.0	-11.3
Aqua	2	translation	7.65	-4.5	-2.1	-12.1	5.4	-13.5
cyan	1	inversion	7.79	-17.5	-4.8	-23.5	16.7	-32.2
Blue	1	inversion	8.76	-19.3	-5.0	-26.9	22.3	-33.8
Indigo	1	inversion	5.84	-11.7	-2.7	-87.7	51.5	-58.9
Purple	2	translation	11.22	1.9	-0.4	-6.9	3.6	-2.0
Pink	1	inversion	10.79	-2.6	-0.4	-8.1	2.1	-8.8

Acknowledgements

The authors thank the Central Instrumentation Facility (DST–FIST), Queen Mary's College (A), Chennai-4 for the computing facility and SAIF, IIT, Madras, for the X-ray data-collection facility.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Bassindale, A. (1984). The Third Dimension in Organic Chemistry, ch. 1, p. 11. New York: John Wiley and Sons. Google Scholar
Bruker (2012). APEX2, SAINT, XPREP and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chakraborty, D. P., Barman, B. K. & Bose, P. K. (1965). Tetrahedron, 21, 681–685. CrossRef CAS Web of Science Google Scholar
Chakraborty, D. P., Bhattacharyya, P., Roy, S., Bhattacharyya, S. P. & Biswas, A. K. (1978). Phytochemistry, 17, 834–835. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Giraud, F., Bourhis, M., Nauton, L., Théry, V., Herfindal, L., Døskeland, S. O., Anizon, F. & Moreau, P. (2014). Bioorg. Chem. 57, 108–115. Web of Science CrossRef CAS PubMed 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
Gu, W., Qiao, C., Wang, S. F., Hao, Y. & Miao, T. T. (2014). Bioorg. Med. Chem. Lett. 24, 328–331. Web of Science CrossRef CAS PubMed Google Scholar
Itoigawa, M., Kashiwada, Y., Ito, C., Furukawa, H., Tachibana, Y., Bastow, K. F. & Lee, K. H. (2000). J. Nat. Prod. 63, 893–897. Web of Science CrossRef PubMed CAS Google Scholar
Jayatilaka, D., Grimwood, D. J., Lee, A., Lemay, A., Russel, A. J., Taylor, C., Wolff, S. K., Cassam-Chenai, P. & Whitton, A. (2005). TONTO -- A System for Computational Chemistry. Available at: http://hirshfeldsurface.net/ Google Scholar
Karmakar, A. C., Kar, G. K. & Ray, J. K. (1991). J. Chem. Soc. Perkin Trans. 1, pp. 1997–2002. CrossRef Web of Science Google Scholar
Mackenzie, C. F., Spackman, P. R., Jayatilaka, D. & Spackman, M. A. (2017). IUCrJ, 4, 575–587. Web of Science CrossRef CAS PubMed IUCr Journals Google Scholar
McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). Chem. Commun. pp. 3814–3816. Web of Science CrossRef Google Scholar
Ramsewak, R. S., Nair, M. G., Strasburg, G. M., DeWitt, D. L. & Nitiss, J. L. (1999). J. Agric. Food Chem. 47, 444–447. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spackman, M. A., McKinnon, J. J. & Jayatilaka, D. (2008). CrystEngComm, 10, 377–388. CAS Google Scholar
Tachibana, Y., Kikuzaki, H., Lajis, N. H. & Nakatani, N. (2001). J. Agric. Food Chem. 49, 5589–5594. Web of Science CrossRef PubMed CAS Google Scholar
Thiratmatrakul, S., Yenjai, C., Waiwut, P., Vajragupta, O., Reubroycharoen, P., Tohda, M. & Boonyarat, C. (2014). Eur. J. Med. Chem. 75, 21–30. Web of Science CrossRef CAS PubMed Google Scholar
Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Spackman, P. R., Jayatilaka, D. & Spackman, M. A. (2017). CrystalExplorer. The University of Western Australia. Google Scholar

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