Crystal structures of the dimethyl sulfoxide solvate of 3,6-bis­(indol-3-yl)-1,4-di­methyl­piperazine-2,5-dione and of the dimethyl sulfoxide and tetra­hydro­furan solvates of 1,4-dimethyl-3,6-bis­(2-methyl­indol-3-yl)piperazine-2,5-dione

Padgett, C.W.; Lynch, W.E.; Crooke, S.N.; Whitlock, C.R.

doi:10.1107/S205698902500920X

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ISSN: 2056-9890

Volume 81| Part 11| November 2025| Pages 1071-1075

https://doi.org/10.1107/S205698902500920X

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Crystal structures of the dimethyl sulfoxide solvate of 3,6-bis(indol-3-yl)-1,4-dimethylpiperazine-2,5-dione and of the dimethyl sulfoxide and tetrahydrofuran solvates of 1,4-dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione

Clifford W. Padgett,^a ^* Will E. Lynch,^b Stephen N. Crooke ^c and Christine R. Whitlock ^c

^aDepartment of Biochemistry, Chemistry and Physics, Georgia Southern University, Armstrong Campus, 11935 Abercorn Street Savannah GA 31419, USA, ^bCenter for Advanced Materials Science, Department of Biochemistry, Chemistry and Physics, Georgia Southern University, 11935 Abercorn Street, Savannah, GA 31419, USA, and ^cDepartment of Biochemistry, Chemistry and Physics, Georgia Southern University, Statesboro Campus, 1332 Southern Drive Statesboro, GA 30458, USA
^*Correspondence e-mail: [email protected]

Edited by W. T. A. Harrison, University of Aberdeen, United Kingdom (Received 23 September 2025; accepted 20 October 2025; online 28 October 2025)

The syntheses and structures of the dimethyl sulfoxide (DMSO) solvate of 3,6-bis(indol-3-yl)-1,4-dimethylpiperazine-2,5-dione, C₁₁H₁₀N₂O (I), and of the dimethyl sulfoxide and tetrahydrofuran (THF) solvates of 1,4-dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione, C₁₂H₁₂N₂O, (II) and (III), respectively, are reported. The asymmetric units of (I) and (II) each contain two crystallographically independent half-molecules that are completed by inversion symmetry, whereas (III) contains one independent half-molecule. In all three structures, the piperazine-2,5-dione core is essentially planar and the overall molecular non-planarity arises from rotations of the indole substituents: ranging between 58 and 63° in (I), approximately 72° for both independent molecules in (II) and approximately 62° in (III). In the crystal of (I), molecules are linked by two N—H⋯O hydrogen bonds to form C(18) chains; (II) features a single N—H⋯O contact giving C(8) chains; and (III) exhibits N—H⋯O interactions that generate C(7) chains assembling into sheets lying parallel to (100). No significant π–π stacking is present in any of these structures. All three structures contain regions of disordered solvent (DMSO or THF) that were treated with a solvent mask during refinement.

Keywords: crystal structure; diketopiperazine; dimethyl sulfoxide (DMSO) solvate; tetrahydrofuran (THF) solvate.

CCDC references: 2496708; 2496707; 2496706

1. Chemical context

The bisindolyl piperazine-2,5-dione motif has attracted considerable interest as a precursor to the dragmacidin family of marine natural products (Garg et al., 2002 ). These alkaloids, isolated from deep-sea sponges and tunicates, are distinguished by a piperazine core bearing indole units at the 3- and 6-positions (Kawasaki et al., 2002 , 2003 ). Members of the dragmacidin series have been reported to display anticancer, antiviral, anti-inflammatory and antibacterial activity (Cutignano et al., 2000 ; Feldman & Ngernmeesri, 2011 ; Morris & Andersen, 1990 ; Wright et al., 1992 ). Notably, dragmacidin, the first reported member, exhibits in vitro cytotoxic activity in A-549 (human lung), HCT-8 (human colon), P388 (murine leukemia) and MDA-MB (human mammary) cell lines (Kohmoto et al., 1988 ).

3,6-Bis(indol-3-yl)-1,4-dimethylpiperazine-2,5-dione and 1,4-dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione were prepared during efforts to access new dragmacidin derivatives (Crooke & Whitlock, 2012 ). In addition to a one-pot route, a reproducible two-step procedure was used: sarcosine anhydride was brominated, and the resulting precipitate was reacted with the appropriate indole in dimethylformamide (DMF) to afford the bisindolyl products. As part of our work in this area, we now describe the syntheses and structures of the title compounds, each of which contain disordered solvent regions.

2. Structural commentary

Compound (I) crystallizes in the monoclinic space group C2/c and its molecular structure is shown in Fig. 1. The asymmetric unit contains two independent molecular halves with each complete C₂₂H₂₀N₄O₂ molecule generated by crystallographic inversion symmetry. Each indole ring shows an r.m.s. deviation of 0.004 Å. The indole ring containing N1 is rotated by 57.9 (2)° (C10—C9—C7—C6) relative to the piperazine-2,5-dione ring (r.m.s. deviation = 0.037 Å). Similarly, the indole ring containing N3 is rotated by 63.3 (3)° (C21—C20—C18—C17) relative to the piperazine-2,5-dione ring (r.m.s. deviation = 0.072 Å). These rotations are the principal contributors to the overall nonplanarity of the molecule. The carbonyl C=O distances are normal at 1.234 (2) Å for C10=O1 and 1.230 (4) Å for C21=O2.

Figure 1
The molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level. The unlabelled atoms in the C1 molecule are generated by the symmetry operation −x + $[{3\over 2}]$ , −y + $[{3\over 2}]$ , −z + 1 and those in the C12 molecule by −x + 1, −y, −z + 1.

The molecular structure of compound (II) (triclinic, space group P $[\overline{1}]$ ) is shown in Fig. 2. The asymmetric unit also contains two independent molecular halves completed by inversion symmetry to form C₂₄H₂₄N₄O₂ molecules. The indole rings show r.m.s. deviations of 0.019 and 0.021 Å for the rings containing N1 and N3, respectively. The indole ring containing N1 is rotated by 71.4 (2)° (C10—C9—C7—C6) relative to the piperazine-2,5-dione ring (r.m.s. deviation = 0.037 Å). Similarly, the indole ring containing N3 is rotated by −72.7 (3)° (C22—C21—C19—C18) relative to the piperazine-2,5-dione ring (r.m.s. deviation = 0.046 Å). These rotations are the principal contributors to the overall nonplanarity of the molecule. The carbonyl C=O distances are 1.232 (3) Å (C10=O1) and 1.226 (3) Å (C22=O2).

Figure 2
The molecular structure of (II) with displacement ellipsoids drawn at the 50% probability level. The unlabelled atoms in the C1 molecule are generated by the symmetry operation −x + 2, −y + 1, −z + 1 and those in the C13 molecule by −x, −y, −z.

Compound (III) crystallizes in the monoclinic space group P2₁/c and its molecular structure is shown in Fig. 3. The asymmetric unit contains a half molecule, which is completed by inversion symmetry to generate a C₂₄H₂₄N₄O₂ molecule. The indole ring shows an r.m.s. deviation of 0.010 Å. The indole ring is rotated by −62.4 (3)° (C1—C2—C3—C4) relative to the piperazine-2,5-dione ring (r.m.s. deviation = 0.031 Å) and the carbonyl C1=O1 distance is 1.231 (2) Å.

Figure 3
The molecular structure of (III) with displacement ellipsoids drawn at the 50% probability level. The unlabelled atoms are generated by the symmetry operation –x + 1, –y + 1, –z + 1.

All three structures contain disordered solvent regions that were masked (see Refinement).

3. Supramolecular features

In the crystal of (I), the molecules are linked by two N—H⋯O hydrogen bonds (Table 1, Fig. 4): N1—H1⋯O2, which generates chains parallel to [1 $[\overline{1}]$ 0] with graph-set motif C₂²(18), and N3—H3⋯O1, forming chains along [130] with graph-set motif C₂²(18). Together, the hydrogen bonds generate (001) sheets. No significant aromatic π–π stacking is observed.

Table 1
Hydrogen-bond geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O2ⁱ	0.89 (3)	2.10 (3)	2.828 (2)	138 (2)
N3—H3A⋯O1	0.95 (3)	1.86 (3)	2.730 (2)	151 (3)
Symmetry code: (i) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+1]$ .

Figure 4
A view along the b-axis direction of the crystal packing of (I) with close contacts shown as red dashed lines.

In the crystal of (II), molecules are linked by an N1—H1⋯O2 hydrogen bond (Table 2, Fig. 5), which generates chains running parallel to [100] with graph-set motif C₁¹(8). The second molecule (containing N3) is not involved in hydrogen bonding. No significant π–π stacking is observed.

Table 2
Hydrogen-bond geometry (Å, °) for (II)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1ⁱ	0.85 (3)	2.11 (3)	2.950 (2)	168 (3)
Symmetry code: (i) .

Figure 5
A view along the c-axis direction of the crystal packing of (II) with close contacts shown as red dashed lines.

In the crystal of (III), molecules are linked by an N2—H2⋯O1 hydrogen bond (Table 3, Fig. 6), which generates chains of N—H⋯O hydrogen bonds [graph-set motif C₁¹(7)] that form sheets parallel to the (100) plane. No significant π–π stacking is observed.

Table 3
Hydrogen-bond geometry (Å, °) for (III)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯O1ⁱ	0.91 (3)	1.89 (3)	2.787 (2)	168 (3)
Symmetry code: (i) $[x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ .

Figure 6
A view along the a-axis direction of the crystal packing of (III) with close contacts shown as red dashed lines.

4. Database survey

A search of the Cambridge Structural Database ((CSD; website, accessed on August, 2025; Groom et al., 2016 ) for 1,4-dimethyl-3,6-dioxopiperazine (diketopiperazine) frameworks bearing 2,6-substitution returned 13 structures. Seven entries feature simple alkyl groups; methyl (CSD refcode RMNALA10; Benedetti et al., 1976 ) and isopropyl (NMLVAL10; Benedetti et al., 1976), a mixed methyl/isopropyl pair (MOJTUB; Wang et al., 2008 ), and 1,1,1-trifluoroisopropyl (LAKGAF; Su et al., 1993 ). Five entries carry benzylic/aromatic groups, including benzyl (NMLPHE11; Ge et al., 2019 ) and (4-hydroxyphenyl)methyl (NIPBIB; Croft et al., 2004 ). One structure bears a carboxylate protecting group, tert-butoxycarbonyl (EZESIO; Yang, 2021 ).

5. Synthesis and crystallization

To prepare compound (I), 0.0117 g of 3,6-bis(indol-3-yl)-1,4-dimethylpiperazine-2,5-dione (Miles & Whitlock, 2009 ) were dissolved in ∼10 ml of dimethylsulfoxide (DMSO) and heated to ∼423 K in a 50 ml beaker. The beaker was placed in a fume hood to allow slow evaporation for approximately 1 week, after which X-ray quality crystals began to form.

Compound (II): a 0.0079-g sample of 1,4-dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione (Miles & Whitlock, 2009) was dissolved in ∼5 ml of DMSO and heated to near boiling (∼423 K) in a 50 ml beaker. The beaker was placed in a fume hood to allow slow evaporation for approximately 1 week, after which X-ray quality crystals began to form.

Compound (III) was prepared by the same procedure as (II) except that 0.050 g of 1,4-dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione (0.05 g) (Miles & Whitlock, 2009) was dissolved in ∼50 ml of tetrahydrofuran (THF) in a 100 ml beaker. The solution was allowed to slowly evaporate for approximately 1 week, after which X-ray quality crystals began to form.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4. In all three structures, disordered solvent regions were treated using the built-in solvent-mask routine in OLEX2. Solvent-accessible voids were located in each unit cell with the following characteristics: for compound (I), a total cavity volume of 520 Å³ per unit cell containing 172 electrons (consistent with one C₂H₆OS molecule per asymmetric unit, 168 electrons per cell); for compound (II), a 312 Å³ void with 85 electrons (one C₂H₆OS per asymmetric unit, 84 electrons per cell); and for compound (III), a 404 Å³ cavity holding 90 electrons (one C₄H₈O per asymmetric unit, 80 electrons per cell). All disordered solvent electron density was subsequently removed via the solvent-mask procedure.

Table 4
Experimental details

	(I)	(II)	(III)
Crystal data
Chemical formula	C₂₂H₂₀N₄O₂·0.5C₂H₆OS	C₂₄H₂₄N₄O₂·C₂H₆SO	C₂₄H₂₄N₄O₂·C₄H₈O
M_r	411.48	478.60	472.57
Crystal system, space group	Monoclinic, C2/c	Triclinic, P $[\overline{1}]$	Monoclinic, P2₁/c
Temperature (K)	100	298	293
a, b, c (Å)	31.2994 (4), 7.3881 (1), 17.9817 (2)	9.3137 (2), 12.3332 (2), 12.3873 (2)	8.5276 (9), 8.9357 (7), 17.4883 (13)
α, β, γ (°)	90, 102.023 (1), 90	117.110 (2), 93.520 (1), 97.399 (2)	90, 96.731 (8), 90
V (Å³)	4066.93 (9)	1244.35 (4)	1323.4 (2)
Z	8	2	2
Radiation type	Cu Kα	Cu Kα	Mo Kα
μ (mm⁻¹)	1.18	1.44	0.08
Crystal size (mm)	0.10 × 0.06 × 0.04	0.36 × 0.11 × 0.07	0.4 × 0.4 × 0.3

Data collection
Diffractometer	XtaLAB Synergy, Single source at home/near, HyPix3000	XtaLAB Synergy, Single source at home/near, HyPix3000	XtaLAB Mini (ROW)
Absorption correction	Gaussian (CrysAlis PRO; Rigaku OD, 2023 )	Multi-scan (CrysAlis PRO; Rigaku OD, 2023)	Multi-scan (CrysAlis PRO; Rigaku OD, 2023)
T_min, T_max	0.927, 1.000	0.436, 1.000	0.968, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	12151, 3716, 3134	25135, 4560, 4029	6423, 2420, 1519
R_int	0.027	0.039	0.031
(sin θ/λ)_max (Å⁻¹)	0.602	0.602	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.120, 1.05	0.058, 0.177, 1.06	0.053, 0.178, 1.02
No. of reflections	3716	4560	2420
No. of parameters	263	283	143
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement	H atoms treated by a mixture of independent and constrained refinement	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.36	0.60, −0.21	0.26, −0.15
Computer programs: CrysAlis PRO (Rigaku OD, 2023), SHELXT2018/2 (Sheldrick, 2015a ), SHELXL2018/3 (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Supporting information

CCDC references: 2496708; 2496707; 2496706

Crystal structure: contains datablocks I, II, III. DOI: https://doi.org/10.1107/S205698902500920X/hb8160sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S205698902500920X/hb8160Isup2.hkl

Structure factors: contains datablock II. DOI: https://doi.org/10.1107/S205698902500920X/hb8160IIsup3.hkl

Structure factors: contains datablock III. DOI: https://doi.org/10.1107/S205698902500920X/hb8160IIIsup4.hkl

Supporting information file. DOI: https://doi.org/10.1107/S205698902500920X/hb8160Isup5.cml

Supporting information file. DOI: https://doi.org/10.1107/S205698902500920X/hb8160IIsup6.cml

Supporting information file. DOI: https://doi.org/10.1107/S205698902500920X/hb8160IIIsup7.cml

checkCIF report

Computing details top

3,6-Bis(indol-3-yl)-1,4-dimethylpiperazine-2,5-dione dimethyl sulfoxide hemihydrate (I) top

Crystal data top

C₂₂H₂₀N₄O₂·0.5C₂H₆OS	F(000) = 1736
M_r = 411.48	D_x = 1.344 Mg m⁻³
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54184 Å
a = 31.2994 (4) Å	Cell parameters from 6717 reflections
b = 7.3881 (1) Å	θ = 2.9–69.6°
c = 17.9817 (2) Å	µ = 1.18 mm⁻¹
β = 102.023 (1)°	T = 100 K
V = 4066.93 (9) Å³	Block, clear colourless
Z = 8	0.10 × 0.06 × 0.04 mm

Data collection top

XtaLAB Synergy, Single source at home/near, HyPix3000 diffractometer	3716 independent reflections
Radiation source: micro-focus sealed X-ray tube, PhotonJet (Cu) X-ray Source	3134 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.027
Detector resolution: 10.0000 pixels mm^-1	θ_max = 68.3°, θ_min = 2.9°
ω scans	h = −37→37
Absorption correction: gaussian (CrysAlisPro; Rigaku OD, 2023)	k = −8→8
T_min = 0.927, T_max = 1.000	l = −21→19
12151 measured reflections

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.046	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.120	w = 1/[σ²(F_o²) + (0.0451P)² + 5.8441P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
3716 reflections	Δρ_max = 0.21 e Å⁻³
263 parameters	Δρ_min = −0.36 e Å⁻³
0 restraints

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
O1	0.69198 (5)	0.5128 (2)	0.42587 (8)	0.0444 (4)
N2	0.76249 (5)	0.5922 (2)	0.46638 (8)	0.0308 (4)
N1	0.87085 (5)	0.8346 (3)	0.37106 (9)	0.0344 (4)
O2	0.53832 (5)	−0.2656 (3)	0.59204 (13)	0.0703 (6)
C6	0.80197 (6)	0.9116 (2)	0.37659 (9)	0.0220 (4)
N3	0.61216 (6)	0.3788 (3)	0.43637 (13)	0.0474 (5)
N4	0.53359 (5)	0.0338 (3)	0.56374 (12)	0.0489 (5)
C1	0.83537 (6)	0.9333 (3)	0.33524 (10)	0.0264 (4)
C5	0.76208 (6)	1.0008 (2)	0.35093 (9)	0.0250 (4)
H5	0.739130	0.989127	0.377837	0.030*
C7	0.81931 (6)	0.7946 (3)	0.43927 (9)	0.0258 (4)
C9	0.79628 (6)	0.7240 (3)	0.49886 (10)	0.0296 (4)
H9	0.818533	0.658316	0.537430	0.035*
C10	0.71973 (7)	0.6176 (3)	0.46083 (10)	0.0314 (4)
C4	0.75654 (6)	1.1058 (3)	0.28604 (10)	0.0299 (4)
H4	0.729678	1.167259	0.268447	0.036*
C16	0.56976 (6)	−0.0656 (3)	0.39021 (11)	0.0303 (4)
H16	0.546853	−0.137952	0.401555	0.036*
C8	0.86087 (6)	0.7530 (3)	0.43377 (10)	0.0329 (4)
H8	0.880200	0.678246	0.468420	0.040*
C3	0.79030 (7)	1.1224 (3)	0.24595 (10)	0.0325 (4)
H3	0.785603	1.193938	0.201093	0.039*
C17	0.57703 (6)	0.1098 (3)	0.42017 (12)	0.0334 (4)
C15	0.59634 (6)	−0.1316 (3)	0.34402 (11)	0.0315 (4)
H15	0.591717	−0.250734	0.324046	0.038*
C2	0.82979 (6)	1.0385 (3)	0.26952 (10)	0.0315 (4)
H2	0.852523	1.051494	0.242183	0.038*
C14	0.63015 (6)	−0.0256 (3)	0.32604 (11)	0.0324 (4)
H14	0.647679	−0.074018	0.293596	0.039*
C12	0.61152 (6)	0.2127 (3)	0.40155 (12)	0.0346 (5)
C13	0.63833 (6)	0.1467 (3)	0.35452 (11)	0.0338 (4)
H13	0.661286	0.217965	0.342668	0.041*
C11	0.77761 (8)	0.4289 (3)	0.43354 (12)	0.0408 (5)
H11A	0.783541	0.457243	0.383422	0.061*
H11B	0.755010	0.335199	0.428275	0.061*
H11C	0.804409	0.384838	0.466972	0.061*
C18	0.55721 (6)	0.2240 (3)	0.46845 (14)	0.0447 (6)
C21	0.52059 (7)	−0.1388 (4)	0.55313 (16)	0.0543 (7)
C20	0.52044 (7)	0.1779 (4)	0.50718 (15)	0.0515 (7)
H20	0.514382	0.288344	0.535425	0.062*
C19	0.57983 (7)	0.3831 (3)	0.47672 (16)	0.0540 (7)
H19	0.573892	0.482684	0.506405	0.065*
C22	0.56984 (7)	0.0801 (4)	0.62727 (16)	0.0614 (8)
H22A	0.570409	−0.005583	0.669088	0.092*
H22B	0.565694	0.203079	0.644882	0.092*
H22C	0.597536	0.073426	0.610121	0.092*
H1	0.8970 (9)	0.837 (4)	0.3587 (14)	0.054 (7)*
H3A	0.6357 (10)	0.461 (4)	0.4377 (17)	0.076 (9)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0531 (9)	0.0501 (9)	0.0362 (7)	−0.0279 (8)	0.0232 (7)	−0.0200 (7)
N2	0.0444 (10)	0.0248 (8)	0.0255 (8)	−0.0095 (7)	0.0124 (7)	−0.0039 (6)
N1	0.0252 (8)	0.0467 (10)	0.0321 (8)	0.0051 (8)	0.0080 (7)	−0.0045 (8)
O2	0.0217 (8)	0.0698 (13)	0.1167 (17)	0.0058 (9)	0.0079 (9)	−0.0323 (12)
C6	0.0252 (8)	0.0206 (8)	0.0209 (8)	−0.0030 (7)	0.0067 (6)	−0.0032 (7)
N3	0.0293 (9)	0.0349 (10)	0.0782 (14)	−0.0068 (8)	0.0118 (9)	−0.0178 (10)
N4	0.0218 (8)	0.0628 (14)	0.0636 (12)	−0.0095 (9)	0.0121 (8)	−0.0367 (11)
C1	0.0258 (9)	0.0288 (10)	0.0253 (9)	−0.0001 (8)	0.0065 (7)	−0.0057 (7)
C5	0.0263 (9)	0.0259 (9)	0.0243 (8)	−0.0006 (7)	0.0088 (7)	−0.0022 (7)
C7	0.0292 (9)	0.0256 (9)	0.0218 (8)	−0.0011 (8)	0.0037 (7)	−0.0022 (7)
C9	0.0392 (10)	0.0282 (10)	0.0203 (8)	−0.0052 (8)	0.0039 (7)	0.0005 (7)
C10	0.0474 (11)	0.0303 (10)	0.0194 (8)	−0.0143 (9)	0.0139 (8)	−0.0034 (7)
C4	0.0338 (10)	0.0279 (10)	0.0276 (9)	0.0063 (8)	0.0056 (7)	−0.0005 (8)
C16	0.0225 (9)	0.0314 (10)	0.0364 (10)	−0.0024 (8)	0.0052 (7)	−0.0047 (8)
C8	0.0328 (10)	0.0354 (11)	0.0282 (9)	0.0062 (9)	0.0006 (7)	−0.0025 (8)
C3	0.0440 (11)	0.0303 (10)	0.0250 (9)	0.0000 (9)	0.0108 (8)	0.0038 (8)
C17	0.0186 (8)	0.0348 (11)	0.0453 (11)	−0.0003 (8)	0.0031 (8)	−0.0109 (9)
C15	0.0301 (9)	0.0308 (10)	0.0325 (10)	0.0011 (8)	0.0042 (8)	−0.0048 (8)
C2	0.0358 (10)	0.0354 (11)	0.0275 (9)	−0.0046 (9)	0.0164 (8)	−0.0011 (8)
C14	0.0265 (9)	0.0398 (11)	0.0309 (9)	0.0049 (8)	0.0058 (7)	−0.0010 (9)
C12	0.0220 (9)	0.0316 (11)	0.0478 (11)	−0.0011 (8)	0.0015 (8)	−0.0056 (9)
C13	0.0230 (9)	0.0381 (11)	0.0397 (10)	−0.0015 (8)	0.0048 (8)	0.0036 (9)
C11	0.0601 (14)	0.0277 (11)	0.0393 (11)	−0.0066 (10)	0.0208 (10)	−0.0081 (9)
C18	0.0201 (9)	0.0458 (13)	0.0677 (15)	−0.0031 (9)	0.0082 (9)	−0.0293 (12)
C21	0.0170 (10)	0.0634 (17)	0.0854 (18)	−0.0041 (11)	0.0175 (11)	−0.0408 (15)
C20	0.0218 (10)	0.0555 (15)	0.0787 (17)	−0.0048 (10)	0.0141 (10)	−0.0425 (14)
C19	0.0269 (10)	0.0444 (14)	0.0899 (19)	−0.0028 (10)	0.0104 (11)	−0.0347 (13)
C22	0.0233 (10)	0.081 (2)	0.0773 (17)	−0.0086 (12)	0.0056 (11)	−0.0446 (16)

Geometric parameters (Å, º) top

O1—C10	1.234 (2)	C16—H16	0.9500
N2—C9	1.466 (2)	C16—C17	1.404 (3)
N2—C10	1.335 (3)	C16—C15	1.381 (3)
N2—C11	1.465 (3)	C8—H8	0.9500
N1—C1	1.372 (2)	C3—H3	0.9500
N1—C8	1.371 (3)	C3—C2	1.369 (3)
N1—H1	0.89 (3)	C17—C12	1.417 (3)
O2—C21	1.230 (4)	C17—C18	1.440 (3)
C6—C1	1.413 (2)	C15—H15	0.9500
C6—C5	1.402 (2)	C15—C14	1.407 (3)
C6—C7	1.434 (2)	C2—H2	0.9500
N3—C12	1.376 (3)	C14—H14	0.9500
N3—C19	1.363 (3)	C14—C13	1.377 (3)
N3—H3A	0.95 (3)	C12—C13	1.397 (3)
N4—C21	1.340 (3)	C13—H13	0.9500
N4—C20	1.471 (4)	C11—H11A	0.9800
N4—C22	1.473 (3)	C11—H11B	0.9800
C1—C2	1.395 (3)	C11—H11C	0.9800
C5—H5	0.9500	C18—C20	1.503 (3)
C5—C4	1.382 (3)	C18—C19	1.364 (3)
C7—C9	1.504 (2)	C21—C20ⁱⁱ	1.526 (3)
C7—C8	1.360 (3)	C20—H20	1.0000
C9—H9	1.0000	C19—H19	0.9500
C9—C10ⁱ	1.516 (3)	C22—H22A	0.9800
C4—H4	0.9500	C22—H22B	0.9800
C4—C3	1.403 (3)	C22—H22C	0.9800

C10—N2—C9	124.44 (17)	C16—C17—C12	118.38 (18)
C10—N2—C11	119.27 (17)	C16—C17—C18	135.76 (19)
C11—N2—C9	116.15 (17)	C12—C17—C18	105.86 (18)
C1—N1—H1	124.6 (17)	C16—C15—H15	119.4
C8—N1—C1	108.59 (16)	C16—C15—C14	121.16 (19)
C8—N1—H1	126.3 (17)	C14—C15—H15	119.4
C1—C6—C7	106.35 (15)	C1—C2—H2	121.3
C5—C6—C1	118.65 (16)	C3—C2—C1	117.39 (17)
C5—C6—C7	135.01 (16)	C3—C2—H2	121.3
C12—N3—H3A	121.3 (19)	C15—C14—H14	119.3
C19—N3—C12	108.71 (19)	C13—C14—C15	121.33 (18)
C19—N3—H3A	129.0 (19)	C13—C14—H14	119.3
C21—N4—C20	123.9 (2)	N3—C12—C17	108.09 (18)
C21—N4—C22	119.5 (3)	N3—C12—C13	129.3 (2)
C20—N4—C22	115.3 (2)	C13—C12—C17	122.63 (19)
N1—C1—C6	107.95 (16)	C14—C13—C12	117.34 (18)
N1—C1—C2	129.81 (17)	C14—C13—H13	121.3
C2—C1—C6	122.24 (17)	C12—C13—H13	121.3
C6—C5—H5	120.4	N2—C11—H11A	109.5
C4—C5—C6	119.23 (16)	N2—C11—H11B	109.5
C4—C5—H5	120.4	N2—C11—H11C	109.5
C6—C7—C9	127.58 (16)	H11A—C11—H11B	109.5
C8—C7—C6	106.87 (16)	H11A—C11—H11C	109.5
C8—C7—C9	125.51 (17)	H11B—C11—H11C	109.5
N2—C9—C7	111.08 (14)	C17—C18—C20	127.9 (2)
N2—C9—H9	107.1	C19—C18—C17	106.9 (2)
N2—C9—C10ⁱ	114.85 (16)	C19—C18—C20	125.1 (2)
C7—C9—H9	107.1	O2—C21—N4	123.8 (2)
C7—C9—C10ⁱ	109.13 (15)	O2—C21—C20ⁱⁱ	118.3 (2)
C10ⁱ—C9—H9	107.1	N4—C21—C20ⁱⁱ	117.8 (3)
O1—C10—N2	122.59 (19)	N4—C20—C18	110.70 (18)
O1—C10—C9ⁱ	117.43 (18)	N4—C20—C21ⁱⁱ	115.3 (2)
N2—C10—C9ⁱ	119.93 (17)	N4—C20—H20	107.1
C5—C4—H4	119.8	C18—C20—C21ⁱⁱ	109.0 (2)
C5—C4—C3	120.49 (17)	C18—C20—H20	107.1
C3—C4—H4	119.8	C21ⁱⁱ—C20—H20	107.1
C17—C16—H16	120.4	N3—C19—C18	110.4 (2)
C15—C16—H16	120.4	N3—C19—H19	124.8
C15—C16—C17	119.16 (18)	C18—C19—H19	124.8
N1—C8—H8	124.9	N4—C22—H22A	109.5
C7—C8—N1	110.24 (17)	N4—C22—H22B	109.5
C7—C8—H8	124.9	N4—C22—H22C	109.5
C4—C3—H3	119.0	H22A—C22—H22B	109.5
C2—C3—C4	121.99 (17)	H22A—C22—H22C	109.5
C2—C3—H3	119.0	H22B—C22—H22C	109.5

N1—C1—C2—C3	179.52 (19)	C8—C7—C9—N2	−107.9 (2)
C6—C1—C2—C3	0.2 (3)	C8—C7—C9—C10ⁱ	124.5 (2)
C6—C5—C4—C3	0.4 (3)	C17—C16—C15—C14	−0.6 (3)
C6—C7—C9—N2	69.8 (2)	C17—C12—C13—C14	−0.1 (3)
C6—C7—C9—C10ⁱ	−57.9 (2)	C17—C18—C20—N4	64.5 (3)
C6—C7—C8—N1	−0.7 (2)	C17—C18—C20—C21ⁱⁱ	−63.3 (3)
N3—C12—C13—C14	−179.1 (2)	C17—C18—C19—N3	0.8 (3)
C1—N1—C8—C7	0.7 (2)	C15—C16—C17—C12	0.1 (3)
C1—C6—C5—C4	0.4 (3)	C15—C16—C17—C18	179.7 (2)
C1—C6—C7—C9	−177.64 (17)	C15—C14—C13—C12	−0.4 (3)
C1—C6—C7—C8	0.4 (2)	C12—N3—C19—C18	−1.0 (3)
C5—C6—C1—N1	179.87 (16)	C12—C17—C18—C20	−176.9 (2)
C5—C6—C1—C2	−0.7 (3)	C12—C17—C18—C19	−0.3 (3)
C5—C6—C7—C9	2.6 (3)	C11—N2—C9—C7	61.3 (2)
C5—C6—C7—C8	−179.4 (2)	C11—N2—C9—C10ⁱ	−174.29 (16)
C5—C4—C3—C2	−0.9 (3)	C11—N2—C10—O1	−3.5 (3)
C7—C6—C1—N1	0.1 (2)	C11—N2—C10—C9ⁱ	173.93 (16)
C7—C6—C1—C2	179.48 (17)	C18—C17—C12—N3	−0.2 (2)
C7—C6—C5—C4	−179.87 (19)	C18—C17—C12—C13	−179.45 (19)
C9—N2—C10—O1	171.94 (17)	C21—N4—C20—C18	−104.3 (2)
C9—N2—C10—C9ⁱ	−10.6 (3)	C21—N4—C20—C21ⁱⁱ	20.0 (3)
C9—C7—C8—N1	177.38 (17)	C20—N4—C21—O2	163.8 (2)
C10—N2—C9—C7	−114.30 (19)	C20—N4—C21—C20ⁱⁱ	−20.5 (3)
C10—N2—C9—C10ⁱ	10.1 (3)	C20—C18—C19—N3	177.5 (2)
C4—C3—C2—C1	0.6 (3)	C19—N3—C12—C17	0.7 (3)
C16—C17—C12—N3	179.44 (18)	C19—N3—C12—C13	179.9 (2)
C16—C17—C12—C13	0.2 (3)	C19—C18—C20—N4	−111.5 (3)
C16—C17—C18—C20	3.5 (4)	C19—C18—C20—C21ⁱⁱ	120.6 (3)
C16—C17—C18—C19	−179.9 (2)	C22—N4—C21—O2	−2.9 (3)
C16—C15—C14—C13	0.8 (3)	C22—N4—C21—C20ⁱⁱ	172.8 (2)
C8—N1—C1—C6	−0.5 (2)	C22—N4—C20—C18	62.9 (2)
C8—N1—C1—C2	−179.8 (2)	C22—N4—C20—C21ⁱⁱ	−172.75 (18)

Symmetry codes: (i) −x+3/2, −y+3/2, −z+1; (ii) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2ⁱⁱⁱ	0.89 (3)	2.10 (3)	2.828 (2)	138 (2)
N3—H3A···O1	0.95 (3)	1.86 (3)	2.730 (2)	151 (3)

Symmetry code: (iii) −x+3/2, −y+1/2, −z+1.

1,4-Dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione dimethyl sulfoxide monosolvate (II) top

Crystal data top

C₂₄H₂₄N₄O₂·C₂H₆SO	Z = 2
M_r = 478.60	F(000) = 508
Triclinic, P1	D_x = 1.277 Mg m⁻³
a = 9.3137 (2) Å	Cu Kα radiation, λ = 1.54184 Å
b = 12.3332 (2) Å	Cell parameters from 17902 reflections
c = 12.3873 (2) Å	θ = 4.0–69.7°
α = 117.110 (2)°	µ = 1.44 mm⁻¹
β = 93.520 (1)°	T = 298 K
γ = 97.399 (2)°	Block, clear colourless
V = 1244.35 (4) Å³	0.36 × 0.11 × 0.07 mm

Data collection top

XtaLAB Synergy, Single source at home/near, HyPix3000 diffractometer	4560 independent reflections
Radiation source: micro-focus sealed X-ray tube, PhotonJet (Cu) X-ray Source	4029 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.039
Detector resolution: 10.0000 pixels mm^-1	θ_max = 68.2°, θ_min = 4.1°
ω scans	h = −11→11
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2023)	k = −14→14
T_min = 0.436, T_max = 1.000	l = −14→14
25135 measured reflections

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.058	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.177	w = 1/[σ²(F_o²) + (0.0886P)² + 0.6913P] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
4560 reflections	Δρ_max = 0.60 e Å⁻³
283 parameters	Δρ_min = −0.21 e Å⁻³
0 restraints

Special details top

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	1.20329 (17)	0.40135 (17)	0.56994 (18)	0.0588 (5)
O2	0.1008 (2)	0.24272 (15)	0.12756 (17)	0.0649 (5)
N2	0.99719 (17)	0.48117 (16)	0.60324 (16)	0.0397 (4)
N4	0.14924 (19)	0.05031 (16)	0.02277 (16)	0.0428 (4)
N1	0.50383 (19)	0.35296 (18)	0.53767 (18)	0.0472 (5)
C6	0.7058 (2)	0.30236 (18)	0.44973 (18)	0.0358 (4)
C10	1.1103 (2)	0.44957 (18)	0.5413 (2)	0.0398 (5)
C7	0.7330 (2)	0.43181 (18)	0.53668 (18)	0.0372 (4)
N3	0.2971 (3)	−0.2443 (2)	0.1043 (2)	0.0638 (6)
C9	0.87168 (19)	0.52304 (18)	0.56525 (19)	0.0373 (4)
H9	0.859990	0.600449	0.635377	0.045*
C1	0.5593 (2)	0.2567 (2)	0.4515 (2)	0.0411 (5)
C8	0.6080 (2)	0.4585 (2)	0.58912 (19)	0.0416 (5)
C5	0.7883 (2)	0.21910 (19)	0.37191 (19)	0.0419 (5)
H5	0.885399	0.245795	0.369211	0.050*
C19	0.1706 (2)	−0.1339 (2)	0.04553 (19)	0.0421 (5)
C22	0.0582 (2)	0.13100 (19)	0.06521 (19)	0.0430 (5)
C18	0.1568 (2)	−0.0974 (2)	0.1717 (2)	0.0465 (5)
C21	0.1057 (2)	−0.08458 (19)	−0.03270 (18)	0.0403 (4)
H21	0.147604	−0.119704	−0.109616	0.048*
C4	0.7237 (2)	0.0973 (2)	0.2995 (2)	0.0486 (5)
H4	0.778644	0.041646	0.248834	0.058*
C20	0.2590 (2)	−0.2212 (2)	0.0089 (2)	0.0511 (5)
C2	0.4933 (2)	0.1344 (2)	0.3766 (2)	0.0519 (6)
H2	0.395996	0.106783	0.377810	0.062*
C3	0.5770 (3)	0.0556 (2)	0.3007 (2)	0.0546 (6)
H3	0.535511	−0.026734	0.249262	0.065*
C13	0.2377 (3)	−0.1687 (2)	0.2053 (3)	0.0569 (6)
C23	0.3070 (2)	0.0969 (2)	0.0516 (3)	0.0577 (6)
H23A	0.327020	0.174278	0.049641	0.087*
H23B	0.356563	0.038075	−0.007708	0.087*
H23C	0.340683	0.108909	0.131721	0.087*
C12	0.5754 (3)	0.5746 (2)	0.6888 (2)	0.0556 (6)
H12A	0.565830	0.564851	0.760764	0.083*
H12B	0.485780	0.592162	0.663120	0.083*
H12C	0.653563	0.641771	0.706880	0.083*
C17	0.0903 (3)	−0.0086 (3)	0.2608 (2)	0.0586 (6)
H17	0.037260	0.040576	0.241326	0.070*
C11	0.9833 (3)	0.4598 (3)	0.7088 (2)	0.0563 (6)
H11A	1.078464	0.462640	0.745463	0.084*
H11B	0.924690	0.380024	0.683006	0.084*
H11C	0.937461	0.522671	0.767542	0.084*
C16	0.1048 (3)	0.0049 (4)	0.3782 (3)	0.0756 (9)
H16	0.061535	0.064059	0.438113	0.091*
C24	0.3164 (3)	−0.2864 (3)	−0.1101 (3)	0.0691 (8)
H24A	0.409581	−0.306274	−0.095669	0.104*
H24B	0.327194	−0.233579	−0.147959	0.104*
H24C	0.249199	−0.361111	−0.163052	0.104*
C14	0.2508 (3)	−0.1543 (3)	0.3241 (3)	0.0760 (9)
H14	0.304350	−0.202074	0.345346	0.091*
C15	0.1829 (4)	−0.0684 (4)	0.4080 (3)	0.0858 (11)
H15	0.189089	−0.058611	0.487213	0.103*
H1	0.414 (4)	0.357 (3)	0.548 (3)	0.073 (9)*
H3A	0.375 (4)	−0.280 (3)	0.111 (3)	0.095 (11)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0336 (8)	0.0773 (12)	0.0873 (12)	0.0219 (8)	0.0136 (8)	0.0533 (10)
O2	0.0573 (10)	0.0392 (9)	0.0720 (12)	0.0033 (7)	−0.0119 (9)	0.0077 (8)
N2	0.0262 (8)	0.0467 (9)	0.0451 (9)	0.0066 (7)	0.0039 (7)	0.0205 (8)
N4	0.0352 (9)	0.0410 (9)	0.0461 (10)	0.0036 (7)	0.0004 (7)	0.0165 (8)
N1	0.0245 (8)	0.0544 (11)	0.0559 (11)	0.0062 (7)	0.0117 (7)	0.0194 (9)
C6	0.0272 (9)	0.0402 (10)	0.0395 (10)	0.0052 (7)	0.0041 (7)	0.0185 (8)
C10	0.0227 (9)	0.0392 (10)	0.0544 (12)	0.0045 (7)	0.0017 (8)	0.0200 (9)
C7	0.0243 (9)	0.0418 (10)	0.0408 (10)	0.0060 (7)	0.0050 (7)	0.0153 (9)
N3	0.0533 (12)	0.0568 (13)	0.0852 (16)	0.0139 (10)	−0.0035 (11)	0.0370 (12)
C9	0.0247 (9)	0.0357 (10)	0.0441 (10)	0.0069 (7)	0.0048 (7)	0.0121 (8)
C1	0.0293 (9)	0.0456 (11)	0.0474 (11)	0.0055 (8)	0.0061 (8)	0.0212 (9)
C8	0.0287 (9)	0.0475 (11)	0.0436 (11)	0.0082 (8)	0.0068 (8)	0.0165 (9)
C5	0.0325 (10)	0.0434 (11)	0.0480 (12)	0.0080 (8)	0.0093 (8)	0.0189 (9)
C19	0.0359 (10)	0.0442 (11)	0.0437 (11)	0.0075 (8)	0.0044 (8)	0.0185 (9)
C22	0.0432 (11)	0.0401 (11)	0.0371 (10)	0.0048 (9)	−0.0028 (8)	0.0123 (9)
C18	0.0331 (10)	0.0582 (13)	0.0500 (12)	0.0017 (9)	0.0023 (9)	0.0289 (11)
C21	0.0404 (11)	0.0399 (11)	0.0342 (10)	0.0091 (8)	0.0059 (8)	0.0112 (8)
C4	0.0473 (12)	0.0426 (11)	0.0514 (13)	0.0120 (9)	0.0115 (10)	0.0166 (10)
C20	0.0419 (12)	0.0436 (12)	0.0617 (14)	0.0084 (9)	0.0021 (10)	0.0197 (11)
C2	0.0343 (11)	0.0515 (13)	0.0618 (14)	−0.0041 (9)	0.0031 (10)	0.0229 (11)
C3	0.0509 (13)	0.0411 (12)	0.0599 (14)	−0.0003 (10)	0.0036 (11)	0.0163 (11)
C13	0.0442 (12)	0.0642 (15)	0.0688 (16)	−0.0034 (11)	−0.0046 (11)	0.0415 (13)
C23	0.0367 (12)	0.0583 (14)	0.0704 (16)	0.0011 (10)	−0.0013 (11)	0.0266 (13)
C12	0.0387 (11)	0.0606 (14)	0.0535 (13)	0.0165 (10)	0.0133 (10)	0.0121 (11)
C17	0.0415 (12)	0.0866 (18)	0.0497 (13)	0.0120 (12)	0.0113 (10)	0.0327 (13)
C11	0.0424 (12)	0.0770 (17)	0.0587 (14)	0.0101 (11)	0.0062 (10)	0.0399 (13)
C16	0.0521 (15)	0.123 (3)	0.0509 (15)	0.0039 (16)	0.0127 (12)	0.0420 (17)
C24	0.0587 (15)	0.0563 (15)	0.0728 (18)	0.0226 (12)	0.0116 (13)	0.0102 (13)
C14	0.0594 (16)	0.101 (2)	0.087 (2)	−0.0105 (16)	−0.0146 (15)	0.071 (2)
C15	0.0646 (18)	0.140 (3)	0.0644 (18)	−0.014 (2)	0.0007 (15)	0.067 (2)

Geometric parameters (Å, º) top

O1—C10	1.232 (3)	C18—C13	1.407 (3)
O2—C22	1.226 (3)	C18—C17	1.400 (4)
N2—C10	1.336 (3)	C21—H21	0.9800
N2—C9	1.471 (2)	C4—H4	0.9300
N2—C11	1.457 (3)	C4—C3	1.400 (3)
N4—C22	1.334 (3)	C20—C24	1.494 (4)
N4—C21	1.468 (3)	C2—H2	0.9300
N4—C23	1.465 (3)	C2—C3	1.374 (3)
N1—C1	1.373 (3)	C3—H3	0.9300
N1—C8	1.373 (3)	C13—C14	1.395 (4)
N1—H1	0.85 (3)	C23—H23A	0.9600
C6—C7	1.438 (3)	C23—H23B	0.9600
C6—C1	1.414 (3)	C23—H23C	0.9600
C6—C5	1.402 (3)	C12—H12A	0.9600
C10—C9ⁱ	1.517 (3)	C12—H12B	0.9600
C7—C9	1.506 (3)	C12—H12C	0.9600
C7—C8	1.371 (3)	C17—H17	0.9300
N3—C20	1.372 (3)	C17—C16	1.382 (4)
N3—C13	1.377 (4)	C11—H11A	0.9600
N3—H3A	0.92 (4)	C11—H11B	0.9600
C9—H9	0.9800	C11—H11C	0.9600
C1—C2	1.389 (3)	C16—H16	0.9300
C8—C12	1.488 (3)	C16—C15	1.387 (5)
C5—H5	0.9300	C24—H24A	0.9600
C5—C4	1.377 (3)	C24—H24B	0.9600
C19—C18	1.435 (3)	C24—H24C	0.9600
C19—C21	1.495 (3)	C14—H14	0.9300
C19—C20	1.368 (3)	C14—C15	1.361 (5)
C22—C21ⁱⁱ	1.520 (3)	C15—H15	0.9300

C10—N2—C9	125.04 (18)	C5—C4—H4	119.3
C10—N2—C11	119.54 (18)	C5—C4—C3	121.4 (2)
C11—N2—C9	114.98 (17)	C3—C4—H4	119.3
C22—N4—C21	124.73 (18)	N3—C20—C24	120.2 (2)
C22—N4—C23	118.72 (19)	C19—C20—N3	109.0 (2)
C23—N4—C21	115.63 (18)	C19—C20—C24	130.7 (2)
C1—N1—C8	109.87 (17)	C1—C2—H2	121.2
C1—N1—H1	128 (2)	C3—C2—C1	117.7 (2)
C8—N1—H1	121 (2)	C3—C2—H2	121.2
C1—C6—C7	106.30 (17)	C4—C3—H3	119.5
C5—C6—C7	135.52 (18)	C2—C3—C4	121.0 (2)
C5—C6—C1	118.17 (18)	C2—C3—H3	119.5
O1—C10—N2	121.9 (2)	N3—C13—C18	107.6 (2)
O1—C10—C9ⁱ	118.61 (18)	N3—C13—C14	130.6 (3)
N2—C10—C9ⁱ	119.49 (17)	C14—C13—C18	121.7 (3)
C6—C7—C9	126.94 (17)	N4—C23—H23A	109.5
C8—C7—C6	107.46 (17)	N4—C23—H23B	109.5
C8—C7—C9	125.59 (18)	N4—C23—H23C	109.5
C20—N3—C13	109.4 (2)	H23A—C23—H23B	109.5
C20—N3—H3A	125 (2)	H23A—C23—H23C	109.5
C13—N3—H3A	122 (2)	H23B—C23—H23C	109.5
N2—C9—C10ⁱ	114.68 (16)	C8—C12—H12A	109.5
N2—C9—C7	110.94 (16)	C8—C12—H12B	109.5
N2—C9—H9	107.0	C8—C12—H12C	109.5
C10ⁱ—C9—H9	107.0	H12A—C12—H12B	109.5
C7—C9—C10ⁱ	109.76 (16)	H12A—C12—H12C	109.5
C7—C9—H9	107.0	H12B—C12—H12C	109.5
N1—C1—C6	107.51 (18)	C18—C17—H17	120.6
N1—C1—C2	129.92 (19)	C16—C17—C18	118.9 (3)
C2—C1—C6	122.56 (19)	C16—C17—H17	120.6
N1—C8—C12	119.88 (18)	N2—C11—H11A	109.5
C7—C8—N1	108.82 (18)	N2—C11—H11B	109.5
C7—C8—C12	131.2 (2)	N2—C11—H11C	109.5
C6—C5—H5	120.4	H11A—C11—H11B	109.5
C4—C5—C6	119.18 (19)	H11A—C11—H11C	109.5
C4—C5—H5	120.4	H11B—C11—H11C	109.5
C18—C19—C21	127.36 (19)	C17—C16—H16	119.5
C20—C19—C18	107.4 (2)	C17—C16—C15	121.0 (3)
C20—C19—C21	125.2 (2)	C15—C16—H16	119.5
O2—C22—N4	122.9 (2)	C20—C24—H24A	109.5
O2—C22—C21ⁱⁱ	117.74 (19)	C20—C24—H24B	109.5
N4—C22—C21ⁱⁱ	119.35 (18)	C20—C24—H24C	109.5
C13—C18—C19	106.5 (2)	H24A—C24—H24B	109.5
C17—C18—C19	134.7 (2)	H24A—C24—H24C	109.5
C17—C18—C13	118.8 (2)	H24B—C24—H24C	109.5
N4—C21—C19	111.20 (17)	C13—C14—H14	121.0
N4—C21—C22ⁱⁱ	114.68 (17)	C15—C14—C13	118.0 (3)
N4—C21—H21	106.7	C15—C14—H14	121.0
C19—C21—C22ⁱⁱ	110.40 (17)	C16—C15—H15	119.2
C19—C21—H21	106.7	C14—C15—C16	121.6 (3)
C22ⁱⁱ—C21—H21	106.7	C14—C15—H15	119.2

N1—C1—C2—C3	−177.7 (2)	C22—N4—C21—C19	−113.3 (2)
C6—C7—C9—N2	−56.4 (3)	C22—N4—C21—C22ⁱⁱ	12.9 (3)
C6—C7—C9—C10ⁱ	71.4 (2)	C18—C19—C21—N4	55.7 (3)
C6—C7—C8—N1	−1.1 (2)	C18—C19—C21—C22ⁱⁱ	−72.7 (3)
C6—C7—C8—C12	176.2 (2)	C18—C19—C20—N3	2.1 (3)
C6—C1—C2—C3	1.6 (4)	C18—C19—C20—C24	−176.6 (2)
C6—C5—C4—C3	1.1 (3)	C18—C13—C14—C15	−0.1 (4)
C10—N2—C9—C10ⁱ	−10.2 (3)	C18—C17—C16—C15	−0.4 (4)
C10—N2—C9—C7	114.8 (2)	C21—N4—C22—O2	168.4 (2)
C7—C6—C1—N1	−1.8 (2)	C21—N4—C22—C21ⁱⁱ	−13.4 (3)
C7—C6—C1—C2	178.7 (2)	C21—C19—C18—C13	−179.5 (2)
C7—C6—C5—C4	179.5 (2)	C21—C19—C18—C17	−2.8 (4)
N3—C13—C14—C15	177.8 (3)	C21—C19—C20—N3	−179.7 (2)
C9—N2—C10—O1	−171.18 (19)	C21—C19—C20—C24	1.6 (4)
C9—N2—C10—C9ⁱ	10.7 (3)	C20—N3—C13—C18	1.3 (3)
C9—C7—C8—N1	178.31 (19)	C20—N3—C13—C14	−176.9 (3)
C9—C7—C8—C12	−4.3 (4)	C20—C19—C18—C13	−1.3 (2)
C1—N1—C8—C7	0.0 (3)	C20—C19—C18—C17	175.3 (3)
C1—N1—C8—C12	−177.7 (2)	C20—C19—C21—N4	−122.1 (2)
C1—C6—C7—C9	−177.62 (19)	C20—C19—C21—C22ⁱⁱ	109.4 (2)
C1—C6—C7—C8	1.8 (2)	C13—N3—C20—C19	−2.1 (3)
C1—C6—C5—C4	0.8 (3)	C13—N3—C20—C24	176.7 (2)
C1—C2—C3—C4	0.3 (4)	C13—C18—C17—C16	−0.8 (4)
C8—N1—C1—C6	1.2 (2)	C13—C14—C15—C16	−1.1 (4)
C8—N1—C1—C2	−179.4 (2)	C23—N4—C22—O2	−0.1 (3)
C8—C7—C9—N2	124.3 (2)	C23—N4—C22—C21ⁱⁱ	178.1 (2)
C8—C7—C9—C10ⁱ	−108.0 (2)	C23—N4—C21—C19	55.6 (2)
C5—C6—C7—C9	3.5 (4)	C23—N4—C21—C22ⁱⁱ	−178.29 (19)
C5—C6—C7—C8	−177.0 (2)	C17—C18—C13—N3	−177.2 (2)
C5—C6—C1—N1	177.29 (19)	C17—C18—C13—C14	1.1 (4)
C5—C6—C1—C2	−2.2 (3)	C17—C16—C15—C14	1.4 (5)
C5—C4—C3—C2	−1.6 (4)	C11—N2—C10—O1	0.8 (3)
C19—C18—C13—N3	0.0 (2)	C11—N2—C10—C9ⁱ	−177.35 (19)
C19—C18—C13—C14	178.4 (2)	C11—N2—C9—C10ⁱ	177.48 (18)
C19—C18—C17—C16	−177.1 (3)	C11—N2—C9—C7	−57.5 (2)

Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x, −y, −z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱⁱⁱ	0.85 (3)	2.11 (3)	2.950 (2)	168 (3)

Symmetry code: (iii) x−1, y, z.

1,4-Dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione tetrahydrofuran monosolvate (III) top

Crystal data top

C₂₄H₂₄N₄O₂·C₄H₈O	F(000) = 504
M_r = 472.57	D_x = 1.186 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.5276 (9) Å	Cell parameters from 1124 reflections
b = 8.9357 (7) Å	θ = 2.4–21.3°
c = 17.4883 (13) Å	µ = 0.08 mm⁻¹
β = 96.731 (8)°	T = 293 K
V = 1323.4 (2) Å³	Irregular, clear light red
Z = 2	0.4 × 0.4 × 0.3 mm

Data collection top

XtaLAB Mini (ROW) diffractometer	2420 independent reflections
Radiation source: fine-focus sealed X-ray tube, Rigaku (Mo) X-ray Source	1519 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
ω scans	θ_max = 25.4°, θ_min = 2.4°
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2023)	h = −9→10
T_min = 0.968, T_max = 1.000	k = −10→9
6423 measured reflections	l = −21→20

Refinement top

Refinement on F²	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.053	w = 1/[σ²(F_o²) + (0.0989P)²] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.178	(Δ/σ)_max < 0.001
S = 1.02	Δρ_max = 0.26 e Å⁻³
2420 reflections	Δρ_min = −0.15 e Å⁻³
143 parameters	Extinction correction: SHELXL-2018/3 (Sheldrick 2015b), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.019 (4)
Primary atom site location: dual

Special details top

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.6513 (2)	0.59725 (19)	0.63282 (8)	0.0738 (6)
N1	0.5240 (2)	0.65140 (17)	0.51655 (9)	0.0552 (5)
N2	0.6285 (3)	0.7814 (2)	0.27788 (12)	0.0705 (6)
C1	0.5781 (3)	0.5565 (2)	0.57146 (10)	0.0493 (6)
C4	0.7086 (3)	0.6138 (2)	0.36953 (11)	0.0516 (6)
C2	0.4530 (3)	0.6105 (2)	0.43922 (10)	0.0499 (6)
H2A	0.350921	0.661728	0.430019	0.060*
C3	0.5519 (3)	0.6631 (2)	0.37871 (11)	0.0550 (6)
C9	0.7526 (3)	0.6901 (2)	0.30495 (11)	0.0587 (6)
C10	0.5065 (3)	0.7634 (3)	0.32147 (12)	0.0648 (7)
C5	0.8164 (3)	0.5138 (3)	0.40716 (12)	0.0623 (6)
H5	0.791463	0.462054	0.450270	0.075*
C8	0.8974 (3)	0.6686 (3)	0.27802 (14)	0.0700 (7)
H8	0.924270	0.720385	0.235309	0.084*
C7	0.9994 (3)	0.5686 (3)	0.31634 (15)	0.0779 (8)
H7	1.097093	0.551645	0.299209	0.094*
C6	0.9599 (3)	0.4919 (3)	0.38035 (15)	0.0759 (7)
H6	1.031507	0.424606	0.405495	0.091*
C12	0.5442 (5)	0.8121 (3)	0.53101 (16)	0.0991 (11)
H12A	0.465945	0.866466	0.498128	0.149*
H12B	0.647594	0.842222	0.520525	0.149*
H12C	0.532183	0.833018	0.583857	0.149*
C11	0.3572 (4)	0.8489 (3)	0.30298 (16)	0.0923 (10)
H11A	0.379818	0.954165	0.304557	0.138*
H11B	0.286236	0.825603	0.340035	0.138*
H11C	0.309282	0.822071	0.252427	0.138*
H2	0.622 (3)	0.825 (3)	0.2308 (16)	0.092 (9)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0805 (12)	0.0974 (13)	0.0430 (8)	−0.0108 (10)	0.0060 (8)	−0.0230 (8)
N1	0.0905 (15)	0.0337 (9)	0.0431 (9)	−0.0042 (9)	0.0150 (9)	−0.0044 (7)
N2	0.0864 (16)	0.0763 (13)	0.0498 (11)	−0.0047 (12)	0.0129 (11)	0.0245 (10)
C1	0.0623 (14)	0.0549 (12)	0.0330 (10)	−0.0011 (10)	0.0157 (9)	−0.0048 (9)
C4	0.0645 (15)	0.0517 (12)	0.0394 (11)	−0.0034 (10)	0.0100 (10)	0.0024 (9)
C2	0.0643 (14)	0.0462 (12)	0.0406 (11)	0.0089 (10)	0.0117 (10)	0.0061 (9)
C3	0.0722 (16)	0.0516 (12)	0.0423 (11)	0.0043 (11)	0.0115 (10)	0.0119 (9)
C9	0.0748 (17)	0.0593 (13)	0.0430 (11)	−0.0088 (12)	0.0111 (11)	0.0041 (10)
C10	0.0811 (18)	0.0644 (14)	0.0491 (12)	0.0045 (13)	0.0083 (12)	0.0189 (10)
C5	0.0703 (17)	0.0625 (14)	0.0560 (12)	0.0033 (12)	0.0144 (12)	0.0089 (11)
C8	0.0795 (19)	0.0754 (16)	0.0594 (14)	−0.0175 (14)	0.0261 (13)	0.0032 (12)
C7	0.0702 (18)	0.0842 (18)	0.0833 (18)	−0.0055 (15)	0.0254 (15)	−0.0084 (15)
C6	0.0714 (19)	0.0778 (17)	0.0798 (16)	0.0058 (14)	0.0143 (14)	0.0063 (14)
C12	0.168 (3)	0.0423 (13)	0.093 (2)	−0.0147 (16)	0.038 (2)	−0.0148 (13)
C11	0.098 (2)	0.092 (2)	0.0856 (19)	0.0211 (17)	0.0080 (17)	0.0409 (16)

Geometric parameters (Å, º) top

O1—C1	1.231 (2)	C10—C11	1.487 (4)
N1—C1	1.323 (3)	C5—H5	0.9300
N1—C2	1.462 (3)	C5—C6	1.375 (3)
N1—C12	1.465 (3)	C8—H8	0.9300
N2—C9	1.376 (3)	C8—C7	1.366 (4)
N2—C10	1.369 (3)	C7—H7	0.9300
N2—H2	0.91 (3)	C7—C6	1.387 (3)
C1—C2ⁱ	1.524 (3)	C6—H6	0.9300
C4—C3	1.434 (3)	C12—H12A	0.9600
C4—C9	1.408 (3)	C12—H12B	0.9600
C4—C5	1.391 (3)	C12—H12C	0.9600
C2—H2A	0.9800	C11—H11A	0.9600
C2—C3	1.504 (3)	C11—H11B	0.9600
C3—C10	1.365 (3)	C11—H11C	0.9600
C9—C8	1.386 (4)

C1—N1—C2	125.65 (16)	C3—C10—C11	131.2 (2)
C1—N1—C12	118.62 (19)	C4—C5—H5	120.2
C2—N1—C12	115.62 (18)	C6—C5—C4	119.7 (2)
C9—N2—H2	122.0 (18)	C6—C5—H5	120.2
C10—N2—C9	110.06 (18)	C9—C8—H8	121.1
C10—N2—H2	125.8 (18)	C7—C8—C9	117.8 (2)
O1—C1—N1	122.78 (19)	C7—C8—H8	121.1
O1—C1—C2ⁱ	117.35 (19)	C8—C7—H7	119.4
N1—C1—C2ⁱ	119.85 (18)	C8—C7—C6	121.2 (2)
C9—C4—C3	106.31 (19)	C6—C7—H7	119.4
C5—C4—C3	135.82 (19)	C5—C6—C7	121.0 (3)
C5—C4—C9	117.9 (2)	C5—C6—H6	119.5
N1—C2—C1ⁱ	113.94 (15)	C7—C6—H6	119.5
N1—C2—H2A	107.4	N1—C12—H12A	109.5
N1—C2—C3	111.53 (18)	N1—C12—H12B	109.5
C1ⁱ—C2—H2A	107.4	N1—C12—H12C	109.5
C3—C2—C1ⁱ	108.90 (15)	H12A—C12—H12B	109.5
C3—C2—H2A	107.4	H12A—C12—H12C	109.5
C4—C3—C2	126.14 (17)	H12B—C12—H12C	109.5
C10—C3—C4	107.89 (19)	C10—C11—H11A	109.5
C10—C3—C2	126.0 (2)	C10—C11—H11B	109.5
N2—C9—C4	107.2 (2)	C10—C11—H11C	109.5
N2—C9—C8	130.2 (2)	H11A—C11—H11B	109.5
C8—C9—C4	122.5 (2)	H11A—C11—H11C	109.5
N2—C10—C11	120.36 (19)	H11B—C11—H11C	109.5
C3—C10—N2	108.5 (2)

N1—C2—C3—C4	64.2 (3)	C9—N2—C10—C3	1.6 (3)
N1—C2—C3—C10	−117.7 (2)	C9—N2—C10—C11	−179.2 (2)
N2—C9—C8—C7	−179.5 (2)	C9—C4—C3—C2	178.71 (19)
C1—N1—C2—C1ⁱ	8.7 (3)	C9—C4—C3—C10	0.3 (2)
C1—N1—C2—C3	−115.1 (2)	C9—C4—C5—C6	−0.5 (3)
C1ⁱ—C2—C3—C4	−62.4 (3)	C9—C8—C7—C6	−0.4 (4)
C1ⁱ—C2—C3—C10	115.7 (2)	C10—N2—C9—C4	−1.4 (3)
C4—C3—C10—N2	−1.2 (3)	C10—N2—C9—C8	178.3 (2)
C4—C3—C10—C11	179.8 (3)	C5—C4—C3—C2	−0.4 (4)
C4—C9—C8—C7	0.2 (4)	C5—C4—C3—C10	−178.8 (2)
C4—C5—C6—C7	0.3 (4)	C5—C4—C9—N2	180.0 (2)
C2—N1—C1—O1	172.4 (2)	C5—C4—C9—C8	0.3 (3)
C2—N1—C1—C2ⁱ	−9.1 (4)	C8—C7—C6—C5	0.2 (4)
C2—C3—C10—N2	−179.6 (2)	C12—N1—C1—O1	−3.5 (3)
C2—C3—C10—C11	1.4 (4)	C12—N1—C1—C2ⁱ	174.9 (2)
C3—C4—C9—N2	0.7 (2)	C12—N1—C2—C1ⁱ	−175.3 (2)
C3—C4—C9—C8	−179.1 (2)	C12—N1—C2—C3	60.9 (3)
C3—C4—C5—C6	178.6 (2)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O1ⁱⁱ	0.91 (3)	1.89 (3)	2.787 (2)	168 (3)

Symmetry code: (ii) x, −y+3/2, z−1/2.

Acknowledgements

The authors thank the Center for Advanced Materials Science, located within 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: National Science Foundation, Directorate for Mathematical and Physical Sciences, MRI (grant No. 2215812).

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research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Crystal structures of the di­methyl sulfoxide solvate of 3,6-bis­­(indol-3-yl)-1,4-di­methyl­piperazine-2,5-dione and of the di­methyl sulfoxide and tetra­hydro­furan solvates of 1,4-di­methyl-3,6-bis­­(2-methyl­indol-3-yl)piperazine-2,5-dione

1. Chemical context

2. Structural commentary

3. Supra­molecular features

4. Database survey

5. Synthesis and crystallization

6. Refinement

Supporting information

Acknowledgements

Funding information

References

research communications

Crystal structures of the dimethyl sulfoxide solvate of 3,6-bis(indol-3-yl)-1,4-dimethylpiperazine-2,5-dione and of the dimethyl sulfoxide and tetrahydrofuran solvates of 1,4-dimethyl-3,6-bis(2-methylindol-3-yl)piperazine-2,5-dione

3. Supramolecular features