The extended structure of a pyrazolo[3,4-a]carbazole features {N—H}2⋯N hydrogen bonds, which generate [010] chains.
Keywords: crystal structure, carbazole, Hirshfeld surface, N—H⋯N hydrogen bonding, C—H⋯π contact
Abstract
The title carbazole derivative, C14H11N3, was prepared by reacting 1-hydroxy-8-methyl-9H-carbazole-2-carbaldehyde with hydrazine hydrate. In the solid state, the fused-ring system is slightly puckered, the dihedral angle between the planes of the outer rings being 2.24 (7)°. In the crystal, molecules are linked by {N—H}2⋯N hydrogen bonds to generate [010] chains, and weak C—H⋯π contacts consolidate the structure. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (43.1%), C⋯H/H⋯C (36.8%) and N⋯H/H⋯N (15.3%) interactions.
1. Chemical context
Carbazoles are tricyclic aromatic heterocycles that have attracted significant attention due to their presence in natural products and their wide-ranging biological activities. Synthetic methodologies to access carbazoles and their fused-ring derivatives include direct annulation, cyclization reactions and transition-metal catalysis (Knölker & Reddy, 2002 ▸). Linear and angular fused carbazoles, such as pyrido-, pyrazolo-, pyrimido- and pyridazinocarbazoles, possess pharmacological applications, including antitumour and anti-HIV activities, as well as an ability to act as DNA intercalating agents (Kumar et al., 2023 ▸; El-Essawy & Odah, 2024 ▸). Among these, pyrazolo-annulated heterocycles like pyrazolopyridopyrimidines stand out for their structural complexity, containing five N atoms and three fused rings, which combine the properties of pyrazole, pyridine and pyrimidine (Iorkula et al., 2025 ▸). Beyond therapeutic applications, carbazole derivatives have emerged as versatile fluorescent chemosensors, enabling bioimaging of ionic species, reactive oxygen and sulfur species, biomacromolecules and microenvironments (Yin et al., 2020 ▸). Synthetic efforts often employ 2,3,4,9-tetrahydrocarbazol-1-ones as precursors, which provide easily accessible intermediates for the construction of diverse heteroannulated carbazoles (e.g. Suvarna et al., 2024 ▸). In particular, pyrazolo[3,4-a]carbazoles bridge the gap between natural carbazole alkaloids and synthetic medicinal chemistry, offering a scaffold of broad medical importance in oncology, infectious disease and neurology (Ramoba et al., 2025 ▸; Menezes & Bhat, 2025 ▸). As part of our studies in this area, we now describe the synthesis and structure of the title compound 9-methyl-1,10-dihydropyrazolo[3,4-a]carbazole, (I).
2. Structural commentary
In the solid state, compound (I) (Fig. 1 ▸) is slightly puckered, the dihedral angle between the outer C2–C7 and N1/N2/C13/C12/C14 rings being 2.24 (7)°. The dihedral angle between the inner C6–C9/N3 and C8–C13 rings is 1.79 (7)°. Alternately, the molecule may be regarded as almost planar, the r.m.s. deviation from planarity for all the C and N atoms being 0.022 Å. Significant bond lengths and angles include C6—C9 [1.447 (2) Å], C11—C12 [1.425 (2) Å], N1—N2 [1.3667 (19) Å], N3—C8—C13 [130.82 (13)°], C13—N2—N1 [111.40 (12)°] and N2—N1—C14 [105.60 (12)°].
Figure 1.
The molecular structure of (I), showing displacement ellipsoids drawn at the 50% probability level.
3. Supramolecular features
In the extended structure of (I), the molecules are linked by N—H⋯N hydrogen bonds, with atom N1 accepting two such bonds from both N2—H2 and N3—H3A (Table 1 ▸ and Fig. 2 ▸). This generates an [010] chain, with adjacent molecules in the chain related by a 21 screw axis. The packing also exhibits three weak C—H⋯π interactions that connect parallel chains (Fig. 3 ▸ and Table 1 ▸). The molecules exhibit some apparent offset π–π stacking interactions with an interplanar spacing of 3.491 Å between molecules related by a translation along the b axis. However, a quantitative analysis of these interactions (see Hirshfeld surface analysis section below) suggests that they make a very minor contribution to the overall packing of (I).
Table 1. Hydrogen-bond geometry (Å, °).
Cg1, Cg3 and Cg4 are the centroids of the N1/N2/C13/C12/C14, C2–C7 and C8–C13 rings, respectively.
| D—H⋯A | D—H | H⋯A | D⋯A | D—H⋯A |
|---|---|---|---|---|
| N2—H2⋯N1i | 0.80 (2) | 2.37 (2) | 3.097 (2) | 150.9 (19) |
| N3—H3A⋯N1i | 0.88 (2) | 2.24 (2) | 3.050 (2) | 152.8 (17) |
| C1—H1B⋯Cg1ii | 0.98 | 2.74 | 3.504 (3) | 135 |
| C5—H5⋯Cg3iii | 0.95 | 2.57 | 3.408 (3) | 147 |
| C14—H14⋯Cg4iv | 0.95 | 2.47 | 3.264 (3) | 142 |
Symmetry codes: (i) 
; (ii) 
; (iii) 
; (iv) 
.
Figure 2.
Partial packing view of (I), viewed down the b-axis direction, showing the hydrogen bonds. Black dashed lines represent N—H⋯N hydrogen bonds.
Figure 3.
Straw-style packing view of (I), viewed down the a-axis direction, showing the C—H⋯π contacts. Centroids are given as green spheres and black dashed lines are H⋯π contacts.
4. Database survey
A search of the Cambridge Structural Database (CSD, Version 6.01, updated to November 2025; Groom et al., 2016 ▸) using the core structure of (I) gave one hit, namely, 3,9-dimethyl-1,10-dihydropyrazolo[3,4-a]carbazole (CSD refcode TIGPIJ; Martin et al., 2007 ▸), in which a methyl group occurs additionally at the 3-position [atom C14 in (I)]. The only other compound sharing the same core tetracyclic structure as the title compound is 7-methyl-1-phenyl-1,10-dihydropyrazolo[3,4-a]carbazole (CSD refcode ZIJGIK), featuring a phenyl substituent at the pyrazole N atom [N2 in (I)] and a methyl group at the 7-position [C4 in (I)] (Archana et al., 2013 ▸).
5. Hirshfeld surface (HS) and 2D fingerprint plots
CrystalExplorer (Version 21.5; Spackman et al., 2021 ▸) was used to investigate and visualize further the intermolecular interactions of (I). The HS plotted over dnorm in the range from −0.39 to 1.20 a.u. is shown in Fig. 4 ▸(a). The electrostatic potential surface using the STO-3G basis set at the Hartree–Fock level of theory and mapped on the Hirshfeld surface over the range from −0.05 to 0.05 a.u. clearly shows the positions of the close intermolecular contacts in the compound [Fig. 4 ▸(b)]. The positive electrostatic potential (blue area) over the surface indicates hydrogen-donor potential, whereas the negative (red area) represents the hydrogen-bond acceptors.
Figure 4.
(a) View of the three-dimensional Hirshfeld surface of (I), plotted over dnorm in the range from −0.39 to 1.20 a.u. (b) View of the three-dimensional electrostatic potential surface of (I) plotted over the range from −0.05 to 0.05 a.u., using the STO-3G basis set at the Hartree–Fock method of theory.
The overall two-dimensional fingerprint plot is shown in Fig. 5 ▸(a), while those delineated into H⋯H, C⋯H/H⋯C, C⋯N/N⋯C, N⋯H/H⋯N and C⋯C contacts are illustrated in Figs. 5 ▸(b)–5(f), respectively, together with their relative contributions to the Hirshfeld surface. The most significant interaction type is H⋯H, contributing 43.1% to the Hirshfeld surface, which is reflected in Fig. 5 ▸(b) as widely scattered points of high density due to the large hydrogen content of the molecule. In the presence of C⋯H interactions, the pair of characteristic wings in the fingerprint plot is delineated into C⋯H/H⋯C contacts [36.8% contribution to the HS; Fig. 5 ▸(c)]. The C⋯N/N⋯C contacts contribute only 1.5% [Fig. 5 ▸(d)] and the N⋯H/H⋯N contacts contribute 15.3% [Fig. 5 ▸(e)]. Finally, the C⋯C contacts [Fig. 5 ▸(f)] contribute only 3.3%. The packing of (I) is thus dominated by van der Waals interactions, augmented by N—H⋯N hydrogen bonds and some C—H⋯π interactions, while π–π interactions play only a very minor role, despite the planar nature of the individual molecules.
Figure 5.
Two-dimensional fingerprint plots for (I), showing (a) all interactions, and delineated into (b) H⋯H, (c) C⋯H/H⋯C, (d) C⋯N/N⋯C, (e) N⋯H/H⋯N and (f) C⋯C interactions. The di and de values are the closest internal and external distances (in Å) from given points on the Hirshfeld surface.
For a DFT and molecular docking study of (I), see the supporting information.
6. Synthesis and crystallization
A solution of 1-hydroxy-8-methyl-9H-carbazole-2-carbaldehyde (0.001 mol) in glacial acetic acid (20 ml) was treated with hydrazine hydrate (0.1 ml, 0.002 mol) under continuous stirring. The reaction mixture was subjected to reflux in an oil bath for 2 h, and the progress of the transformation was monitored periodically by thin-layer chromatography (TLC) using petroleum ether–ethyl acetate (8:2 v/v) as the mobile phase. Upon completion, the hot reaction mixture was poured onto crushed ice, resulting in the immediate precipitation of a yellow solid. The solid was collected by vacuum filtration, washed thoroughly with distilled water to remove residual acetic acid and air-dried. The crude product was further purified by column chromatography over silica gel, employing petroleum ether–ethyl acetate (90:10 v/v) as the eluent. This afforded the title compound as a yellow crystalline solid (Fig. 6 ▸). Yellow prisms of (I) were recrystallized from ethanol solution.
Figure 6.
The synthesis of (I).
Pale-yellow solid (0.191 g, 86%); m.p. 474–476 K; IR: νmax 3393, 2919, 1619, 1570, 1480, 1228, 1056, 857 cm−1. 1H NMR: δ 12.48 (b s, 1H, pyrazole –NH), 11.16 (s, 1H, N10-H), 8.16 (s, 1H, C3-H), 7.96 (d, 1H, C6-H, J = 7.56 Hz), 7.82 (d, 1H, C4-H, J = 8.44 Hz), 7.48 (d, 1H, C5-H, J = 8.44 Hz), 7.20 (d, 1H, C8-H, J = 6.88 Hz), 7.12 (t, 1H, C7-H, J = 7.60 Hz), 2.48 (s, 3H, C9-CH3). MS: m/z (%) 221 (M+ = 100). Analysis calculated (%) for C14H11N3: C 76.00, H 5.01, N 18.99; found: C 75.89, H 4.92, N 18.76.
7. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. Atoms H2 and H3A bonded to N2 and N3 were located in a difference Fourier map and refined isotropically with Uiso(H) = 1.2Ueq(N). All the other H atoms were placed in calculated positions and were refined with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(methyl C).
Table 2. Experimental details.
| Crystal data | |
| Chemical formula | C14H11N3 |
| M r | 221.26 |
| Crystal system, space group | Orthorhombic, P212121 |
| Temperature (K) | 100 |
| a, b, c (Å) | 6.570 (4), 7.541 (5), 21.854 (14) |
| V (Å3) | 1082.8 (12) |
| Z | 4 |
| Radiation type | Mo Kα |
| μ (mm−1) | 0.08 |
| Crystal size (mm) | 0.45 × 0.28 × 0.25 |
| Data collection | |
| Diffractometer | Bruker SMART APEX CCD |
| Absorption correction | Multi-scan (SADABS2016; Krause et al., 2015 ▸) |
| Tmin, Tmax | 0.714, 0.746 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 13749, 3671, 3470 |
| R int | 0.024 |
| (sin θ/λ)max (Å−1) | 0.752 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.098, 1.05 |
| No. of reflections | 3671 |
| No. of parameters | 161 |
| H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
| Δρmax, Δρmin (e Å−3) | 0.37, −0.25 |
| Absolute structure | Flack x determined using 1366 quotients [(I+)−(I−)]/[(I+)+(I−)] (Parsons et al., 2013 ▸) |
| Absolute structure parameter | 0.5 (6) |
Supplementary Material
Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989026000502/hb8187sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989026000502/hb8187Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989026000502/hb8187Isup3.cdx
Density functional theory calculations and Molecular docking studies. DOI: 10.1107/S2056989026000502/hb8187sup4.pdf
Supporting information file. DOI: 10.1107/S2056989026000502/hb8187Isup5.cml
CCDC reference: 2524177
Additional supporting information: crystallographic information; 3D view; checkCIF report
Acknowledgments
The contributions of the authors are as follows: conceptualization, synthesis, methodology and writing original draft, MS; crystallographic analysis, Hirshfeld surface analysis, molecular docking, software, validation, review and editing, AAT; DFT, software and validation, BMR. MS thanks the academic and administrative authorities of RV College of Engineering for their support and encouragement. The authors thank Dr M. Zeller for the X-ray data collection. The X-ray diffractometer was funded by NSF Grant CHE 0087210, Ohio Board of Regents Grant CAP-491, and by Youngstown State University.
supplementary crystallographic information
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Crystal data
| C14H11N3 | Dx = 1.357 Mg m−3 |
| Mr = 221.26 | Melting point: 475(1) K |
| Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
| a = 6.570 (4) Å | Cell parameters from 5839 reflections |
| b = 7.541 (5) Å | θ = 2.9–32.2° |
| c = 21.854 (14) Å | µ = 0.08 mm−1 |
| V = 1082.8 (12) Å3 | T = 100 K |
| Z = 4 | Prism, yellow |
| F(000) = 464 | 0.45 × 0.28 × 0.25 mm |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Data collection
| Bruker SMART APEX CCD diffractometer | 3671 independent reflections |
| Radiation source: fine-focus sealed tube | 3470 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.024 |
| ω scans | θmax = 32.3°, θmin = 1.9° |
| Absorption correction: multi-scan (SADABS2016; Krause et al., 2015) | h = −9→9 |
| Tmin = 0.714, Tmax = 0.746 | k = −11→10 |
| 13749 measured reflections | l = −32→31 |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Refinement
| Refinement on F2 | Secondary atom site location: difference Fourier map |
| Least-squares matrix: full | Hydrogen site location: mixed |
| R[F2 > 2σ(F2)] = 0.037 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.098 | w = 1/[σ2(Fo2) + (0.0582P)2 + 0.1706P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.05 | (Δ/σ)max < 0.001 |
| 3671 reflections | Δρmax = 0.37 e Å−3 |
| 161 parameters | Δρmin = −0.25 e Å−3 |
| 0 restraints | Absolute structure: Flack x determined using 1366 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013) |
| Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.5 (6) |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Special details
| 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. |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| C1 | 0.0602 (2) | 0.5882 (2) | 0.09586 (7) | 0.0194 (3) | |
| H1A | 0.056164 | 0.706817 | 0.077613 | 0.029* | |
| H1B | 0.057787 | 0.598395 | 0.140561 | 0.029* | |
| H1C | −0.058266 | 0.519946 | 0.082146 | 0.029* | |
| C2 | 0.2520 (2) | 0.49503 (19) | 0.07631 (6) | 0.0153 (2) | |
| C3 | 0.3868 (2) | 0.56427 (19) | 0.03354 (6) | 0.0176 (3) | |
| H3 | 0.358181 | 0.676651 | 0.015884 | 0.021* | |
| C4 | 0.5644 (2) | 0.47378 (19) | 0.01542 (7) | 0.0181 (3) | |
| H4 | 0.651095 | 0.525425 | −0.014452 | 0.022* | |
| C5 | 0.6148 (2) | 0.31070 (19) | 0.04042 (6) | 0.0163 (3) | |
| H5 | 0.735680 | 0.250830 | 0.028457 | 0.020* | |
| C6 | 0.4828 (2) | 0.23636 (18) | 0.08385 (6) | 0.0139 (2) | |
| C7 | 0.3035 (2) | 0.32869 (18) | 0.10041 (6) | 0.0141 (2) | |
| C8 | 0.3057 (2) | 0.07438 (18) | 0.15330 (6) | 0.0135 (2) | |
| C9 | 0.4842 (2) | 0.07220 (17) | 0.11814 (6) | 0.0138 (2) | |
| C10 | 0.6257 (2) | −0.07029 (19) | 0.12205 (6) | 0.0162 (2) | |
| H10 | 0.745464 | −0.068954 | 0.097703 | 0.019* | |
| C11 | 0.5891 (2) | −0.21041 (18) | 0.16118 (6) | 0.0165 (3) | |
| H11 | 0.682735 | −0.306001 | 0.164139 | 0.020* | |
| C12 | 0.4079 (2) | −0.20876 (18) | 0.19703 (6) | 0.0144 (2) | |
| C13 | 0.26791 (19) | −0.06831 (18) | 0.19293 (6) | 0.0140 (2) | |
| C14 | 0.3203 (2) | −0.32329 (19) | 0.24136 (6) | 0.0173 (3) | |
| H14 | 0.379954 | −0.431679 | 0.254346 | 0.021* | |
| N1 | 0.14434 (18) | −0.26063 (18) | 0.26256 (6) | 0.0195 (2) | |
| N2 | 0.11285 (18) | −0.10440 (17) | 0.23232 (6) | 0.0173 (2) | |
| N3 | 0.19676 (18) | 0.22779 (16) | 0.14285 (5) | 0.0152 (2) | |
| H2 | 0.017 (3) | −0.042 (3) | 0.2393 (9) | 0.018* | |
| H3A | 0.077 (3) | 0.250 (3) | 0.1598 (9) | 0.018* |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0191 (6) | 0.0179 (6) | 0.0212 (6) | 0.0043 (5) | −0.0022 (5) | 0.0003 (5) |
| C2 | 0.0175 (6) | 0.0139 (6) | 0.0146 (5) | 0.0009 (5) | −0.0018 (4) | −0.0007 (5) |
| C3 | 0.0221 (6) | 0.0143 (6) | 0.0163 (6) | −0.0018 (5) | −0.0012 (5) | 0.0014 (5) |
| C4 | 0.0209 (6) | 0.0175 (6) | 0.0160 (6) | −0.0042 (5) | 0.0013 (5) | 0.0017 (5) |
| C5 | 0.0174 (6) | 0.0176 (6) | 0.0140 (5) | −0.0013 (5) | 0.0017 (5) | 0.0001 (5) |
| C6 | 0.0145 (5) | 0.0144 (5) | 0.0129 (5) | 0.0000 (4) | 0.0009 (4) | −0.0006 (4) |
| C7 | 0.0155 (5) | 0.0146 (5) | 0.0121 (5) | −0.0001 (5) | 0.0001 (4) | 0.0001 (4) |
| C8 | 0.0129 (5) | 0.0142 (5) | 0.0133 (5) | 0.0008 (5) | 0.0006 (4) | 0.0012 (4) |
| C9 | 0.0138 (5) | 0.0149 (5) | 0.0126 (5) | 0.0005 (5) | 0.0015 (4) | −0.0003 (5) |
| C10 | 0.0150 (5) | 0.0166 (6) | 0.0168 (6) | 0.0019 (5) | 0.0025 (5) | −0.0004 (5) |
| C11 | 0.0160 (6) | 0.0156 (6) | 0.0179 (6) | 0.0019 (5) | 0.0010 (5) | −0.0006 (5) |
| C12 | 0.0143 (6) | 0.0140 (5) | 0.0149 (5) | 0.0003 (4) | −0.0008 (4) | −0.0004 (5) |
| C13 | 0.0128 (5) | 0.0156 (6) | 0.0137 (5) | −0.0003 (4) | 0.0005 (4) | 0.0012 (5) |
| C14 | 0.0155 (6) | 0.0173 (6) | 0.0191 (6) | 0.0000 (5) | −0.0012 (5) | 0.0042 (5) |
| N1 | 0.0170 (5) | 0.0205 (6) | 0.0210 (6) | −0.0008 (5) | 0.0013 (4) | 0.0074 (5) |
| N2 | 0.0143 (5) | 0.0188 (6) | 0.0189 (5) | 0.0016 (4) | 0.0039 (4) | 0.0058 (5) |
| N3 | 0.0141 (5) | 0.0156 (5) | 0.0158 (5) | 0.0024 (4) | 0.0024 (4) | 0.0017 (4) |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Geometric parameters (Å, º)
| C1—C2 | 1.505 (2) | C8—C9 | 1.4023 (19) |
| C1—H1A | 0.9800 | C8—C13 | 1.403 (2) |
| C1—H1B | 0.9800 | C9—C10 | 1.424 (2) |
| C1—H1C | 0.9800 | C10—C11 | 1.380 (2) |
| C2—C3 | 1.390 (2) | C10—H10 | 0.9500 |
| C2—C7 | 1.402 (2) | C11—C12 | 1.425 (2) |
| C3—C4 | 1.408 (2) | C11—H11 | 0.9500 |
| C3—H3 | 0.9500 | C12—C13 | 1.4058 (19) |
| C4—C5 | 1.386 (2) | C12—C14 | 1.420 (2) |
| C4—H4 | 0.9500 | C13—N2 | 1.3612 (18) |
| C5—C6 | 1.4027 (19) | C14—N1 | 1.3319 (19) |
| C5—H5 | 0.9500 | C14—H14 | 0.9500 |
| C6—C7 | 1.415 (2) | N1—N2 | 1.3667 (19) |
| C6—C9 | 1.447 (2) | N2—H2 | 0.80 (2) |
| C7—N3 | 1.3897 (18) | N3—H3A | 0.88 (2) |
| C8—N3 | 1.3794 (18) | ||
| C2—C1—H1A | 109.5 | C9—C8—C13 | 118.49 (12) |
| C2—C1—H1B | 109.5 | C8—C9—C10 | 121.49 (13) |
| H1A—C1—H1B | 109.5 | C8—C9—C6 | 105.57 (11) |
| C2—C1—H1C | 109.5 | C10—C9—C6 | 132.91 (12) |
| H1A—C1—H1C | 109.5 | C11—C10—C9 | 120.08 (13) |
| H1B—C1—H1C | 109.5 | C11—C10—H10 | 120.0 |
| C3—C2—C7 | 115.78 (13) | C9—C10—H10 | 120.0 |
| C3—C2—C1 | 123.33 (13) | C10—C11—C12 | 118.65 (12) |
| C7—C2—C1 | 120.88 (13) | C10—C11—H11 | 120.7 |
| C2—C3—C4 | 122.35 (14) | C12—C11—H11 | 120.7 |
| C2—C3—H3 | 118.8 | C13—C12—C14 | 103.67 (12) |
| C4—C3—H3 | 118.8 | C13—C12—C11 | 121.21 (12) |
| C5—C4—C3 | 121.15 (13) | C14—C12—C11 | 135.12 (13) |
| C5—C4—H4 | 119.4 | N2—C13—C8 | 132.52 (13) |
| C3—C4—H4 | 119.4 | N2—C13—C12 | 107.39 (12) |
| C4—C5—C6 | 118.25 (13) | C8—C13—C12 | 120.09 (12) |
| C4—C5—H5 | 120.9 | N1—C14—C12 | 111.94 (13) |
| C6—C5—H5 | 120.9 | N1—C14—H14 | 124.0 |
| C5—C6—C7 | 119.42 (13) | C12—C14—H14 | 124.0 |
| C5—C6—C9 | 133.50 (13) | C14—N1—N2 | 105.60 (12) |
| C7—C6—C9 | 107.07 (11) | C13—N2—N1 | 111.40 (12) |
| N3—C7—C2 | 128.21 (13) | C13—N2—H2 | 126.2 (14) |
| N3—C7—C6 | 108.76 (12) | N1—N2—H2 | 122.3 (14) |
| C2—C7—C6 | 123.03 (13) | C8—N3—C7 | 107.93 (12) |
| N3—C8—C9 | 110.67 (12) | C8—N3—H3A | 123.4 (13) |
| N3—C8—C13 | 130.82 (13) | C7—N3—H3A | 128.6 (13) |
| C7—C2—C3—C4 | −0.1 (2) | C6—C9—C10—C11 | 177.71 (14) |
| C1—C2—C3—C4 | −179.28 (13) | C9—C10—C11—C12 | 0.1 (2) |
| C2—C3—C4—C5 | −1.0 (2) | C10—C11—C12—C13 | 0.2 (2) |
| C3—C4—C5—C6 | 0.8 (2) | C10—C11—C12—C14 | −179.27 (15) |
| C4—C5—C6—C7 | 0.31 (19) | N3—C8—C13—N2 | 1.7 (3) |
| C4—C5—C6—C9 | 179.06 (14) | C9—C8—C13—N2 | 179.72 (14) |
| C3—C2—C7—N3 | −179.06 (14) | N3—C8—C13—C12 | −177.62 (14) |
| C1—C2—C7—N3 | 0.2 (2) | C9—C8—C13—C12 | 0.36 (19) |
| C3—C2—C7—C6 | 1.26 (19) | C14—C12—C13—N2 | −0.32 (15) |
| C1—C2—C7—C6 | −179.52 (13) | C11—C12—C13—N2 | −179.92 (13) |
| C5—C6—C7—N3 | 178.86 (12) | C14—C12—C13—C8 | 179.19 (12) |
| C9—C6—C7—N3 | −0.19 (15) | C11—C12—C13—C8 | −0.4 (2) |
| C5—C6—C7—C2 | −1.4 (2) | C13—C12—C14—N1 | 0.00 (16) |
| C9—C6—C7—C2 | 179.54 (12) | C11—C12—C14—N1 | 179.52 (15) |
| N3—C8—C9—C10 | 178.28 (12) | C12—C14—N1—N2 | 0.32 (16) |
| C13—C8—C9—C10 | −0.1 (2) | C8—C13—N2—N1 | −178.88 (14) |
| N3—C8—C9—C6 | −0.09 (15) | C12—C13—N2—N1 | 0.54 (16) |
| C13—C8—C9—C6 | −178.45 (12) | C14—N1—N2—C13 | −0.53 (16) |
| C5—C6—C9—C8 | −178.69 (15) | C9—C8—N3—C7 | −0.02 (15) |
| C7—C6—C9—C8 | 0.17 (14) | C13—C8—N3—C7 | 178.07 (14) |
| C5—C6—C9—C10 | 3.2 (3) | C2—C7—N3—C8 | −179.58 (13) |
| C7—C6—C9—C10 | −177.93 (14) | C6—C7—N3—C8 | 0.13 (15) |
| C8—C9—C10—C11 | −0.1 (2) |
9-Methyl-1,10-dihydropyrazolo[3,4-a]carbazole . Hydrogen-bond geometry (Å, º)
Cg1, Cg3 and Cg4 are the centroids of the N1/N2/C13/C12/C14, C2–C7 and C8–C13 rings respectively.
| D—H···A | D—H | H···A | D···A | D—H···A |
| N2—H2···N1i | 0.80 (2) | 2.37 (2) | 3.097 (2) | 150.9 (19) |
| N3—H3A···N1i | 0.88 (2) | 2.24 (2) | 3.050 (2) | 152.8 (17) |
| C1—H1B···Cg1ii | 0.98 | 2.74 | 3.504 (3) | 135 |
| C5—H5···Cg3iii | 0.95 | 2.57 | 3.408 (3) | 147 |
| C14—H14···Cg4iv | 0.95 | 2.47 | 3.264 (3) | 142 |
Symmetry codes: (i) −x, y+1/2, −z+1/2; (ii) x, y+1, z; (iii) x+1/2, −y+1/2, −z; (iv) −x+1, y−1/2, −z+1/2.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989026000502/hb8187sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989026000502/hb8187Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989026000502/hb8187Isup3.cdx
Density functional theory calculations and Molecular docking studies. DOI: 10.1107/S2056989026000502/hb8187sup4.pdf
Supporting information file. DOI: 10.1107/S2056989026000502/hb8187Isup5.cml
CCDC reference: 2524177
Additional supporting information: crystallographic information; 3D view; checkCIF report