2-{3-Methyl-2-[(2Z)-pent-2-en-1-yl]cyclopent-2-en-1-ylidene}-N-phenylhydrazinecarbothioamide

The synthesis, crystal structure and Hirshfeld analysis of the cis-jasmone 4-phenylthiosemicarbazone is reported. The molecules are linked into centrosymmetric dimers via pairs of N—H⋯S and C—H⋯S interactions, with graph-set motifs (8) and (7). In addition, one N—H⋯N intramolecular interaction is observed, with graph-set motif S(5). The crystal structure resembles a zigzag motif when viewed along [010].

The hydrochloric acid-catalyzed equimolar reaction between cis-jasmone and 4-phenylthiosemicarbazide yielded the title compound, C 18 H 23 N 3 S (common name: cis-jasmone 4-phenylthiosemicarbazone).Concerning the hydrogen bonding, an N-H� � �N intramolecular interaction is observed, forming a ring with graph-set motif S(5).In the crystal, the molecules are connected into centrosymmetric dimers by pairs of N-H� � �S and C-H� � �S interactions, forming rings of graph-set motifs R 2 2 (8) and R 2 1 (7), with the sulfur atoms acting as double acceptors.The thiosemicarbazone entity is approximately planar, with the maximum deviation from the mean plane through the N/N/C/S/N atoms being 0.0376 (9) A ˚(the r.m.s.d.amounts to 0.0234 A ˚).The molecule is substantially twisted as indicated by the dihedral angle between the thiosemicarbazone fragment and the phenyl ring, which amounts to 56.1 (5) � , and because of the jasmone fragment, which bears a chain with sp 3 -hybridized carbon atoms in the structure.The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are: H� � �H (65.3%),H� � �C/C� � �H (16.2%),H� � �S/S� � �H (10.9%) and H� � �N/N� � �H (5.5%).

Structure description
Thiosemicarbazone derivatives (TSCs), which are characterized by the [R 1 R 2 C N-N(H)-C( S)-NR 3 R 4 ] functional group, were reported more than a century ago (Freund & Schander, 1902), while the synthesis of jasmone derivatives can be traced back to the early 1930s (Ruzicka & Pfeiffer, 1933).Concerning TSC chemistry, thiosemicarbazone molecules are the major product of the reaction between thiosemicarbazide derivatives [H 2 N-N(H)-C( S)-NR 3 R 4 ] and aldehydes or ketones [R 1 R 2 C O]. Thiosemicarbazides have been employed as analytical reagents in organic chemistry for the detection of the [R 1 R 2 C O] functional group by a condensation reaction through nucleophilic attack of the [H 2 N-] thiosemicarbazide fragment on the carbonyl group.Thiosemicarbazone chemistry gained new perspectives in the mid-1940s when some derivatives were pointed out in in vitro essays to be tuberculostatic agents (Domagk et al., 1946).From these early times, this chemistry evolved into a large class of compounds with a wide range of applications across several scientific disciplines.The facile experimental procedure for the synthesis, combined with the vast structural diversity of the starting materials, i.e., aldehydes and ketones, lead to a large number of TSCs.As a result of their molecular structure and the respective Lewis basicity (nitrogen atoms, with some more hard character, and the soft sulfur atom), allowing for chemical bonding with different metal centers in diverse modes, e.g., bridging, chelating or terminal, thiosemicarbazones found several applications in coordination chemistry.For the synergetic effect of thiosemicarbazones and metal centers, see: Lobana et al. (2009).For the application on diagnostic medical imaging of TSC complexes, see : Dilworth & Hueting (2012) and for the application of TSC coordination compounds on theranostics, see: Parrilha et al. (2022).For electrocatalytic hydrogen production using a Pd II complex with the 4-{bis[4-(p-methoxyphenyl)thiosemicarbazone]}-2,3butane derivative, which is relevant for the energy research today, see: Straistari et al. (2018).For biological applications of TSCs and their complexes, see: Singh et al. (2023).For the antifungal activity and the crystal structure of the nonsubstituted cis-jasmone thiosemicarbazone, see: Orsoni et al., (2020) and for another report concerning the fungistatic effect of this TSC derivative, see: Jamiołkowska et al. (2022).For the application of thiosemicarbazones complexes as single-molecule precursors in the synthesis of nanostructured metal sulfides, see: Palve & Garje (2011) for ZnS, Pawar et al. (2016) for CdS and Pawar & Garje (2015) for CoS nanocrystalline materials.Regarding the use of a TSC on the formation of palladium nanoparticles for the Suzuki-Miyaura crosscoupling catalytic application, see: Kovala-Demertzi et al. (2008).Finally, to cite another example of their applications, thiosemicarbazones are employed as corrosion inhibitors.For an experimental and theoretical study regarding the corro-sion-inhibitory property of TSCs applied for carbon steel AISI 1020 in a hydrochloric acid medium, see: Goulart et al. (2013).For a theoretical approach of TSC dimers as corrosion inhibitors, see: Silva & Martı ´nez-Huitle (2021).
As part of our interest in this chemistry, we report herein the synthesis, crystal structure and Hirshfeld analysis of the cis-jasmone 4-phenylthiosemicarbazone.
For the title compound, the molecular structure matches the asymmetric unit, with all atoms being located in general positions (Fig. 1).The thiosemicarbazone fragment is almost planar, with the maximum deviation from the mean plane through the N1/N2/C12/S1/N3 group being 0.0376 (9) A ˚for N2 and the r.m.s.d. for the selected atoms amounting to 0.0234 A ˚.The torsion angles of the N1-N2-C12-S1 and N1-N2-C12-N3 chains amount to 176.3 (1) and À 5.2 (2) � .The C1-C5 pentagonal ring is almost planar, as the maximum deviation from the mean plane through the carbon atoms is 0.0117 (1) A ˚for C5 and the respective r.m.s.d.amounts to 0.0080 A ˚.The molecule is not planar because of the dihedral angle between the thiosemicarbazone entity and the phenyl ring, which is 56.1 (5) � , and due to the sp 3 -hybridized carbon atoms, e.g., C6 and C9 in the jasmone fragment.In addition, an N3-H3� � �N1 intramolecular hydrogen bond is observed (Fig. 2, Table 1), with graph-set motif S( 5), which contributes to stabilize the molecular structure.
In the crystal, the molecules are connected into centrosymmetric dimers by pairs of N2-H2� � �S1 i interactions, which form rings of graph-set motif R 2 2 (8) and pairs of N2-H2� � �S1 i /C2-H2B� � �S1 i interactions, where rings of graph-set motif R 1 2 (7) are observed (Fig. 2, Table 1).As a data reports Figure 1 The molecular structure of the title compound, showing the atom labeling and displacement ellipsoids drawn at the 40% probability level.

Figure 2
The molecular structure of the cis-jasmone 4-phenylthiosemicarbazone showing the intra-and intermolecular hydrogen-bond interactions as dashed lines.The molecules are linked into centrosymmetric dimers via pairs of N-H� � �S and C-H� � �S interactions, forming graph-set motifs R 2  2 (8) and R 1  2 (7).The N-H� � �N intramolecular interactions form rings with graph-set motif S( 5).[Symmetry code: feature of the dimeric structure, the sulfur atoms act as double acceptors and three rings with intermolecular hydrogen bonding are observed.No other strong intermolecular interactions can be suggested for the title compound due to the non-polar organic periphery and the steric effects of the phenyl ring and of the cis-jasmone fragment.Only weak interactions, i.e., London dispersion forces, can be proposed.The crystal packing resembles a zigzag motif when viewed along [010] (Fig. 3).
For the title compound, the Hirshfeld surface analysis (Hirshfeld, 1977), the graphical representations and the twodimensional Hirshfeld surface fingerprint (HSFP) were evaluated with the Crystal Explorer software (Wolff et al., 2012).The graphical representation of the Hirshfeld surface (d norm ) is represented using a ball-and-stick model with transparency.In red, the locations of the strongest intermolecular contacts, i.e, the regions around the H2 and S1 atoms (Fig. 4 To the best of our knowledge and from using database tools such as SciFinder (Chemical Abstracts Service, 2023) and the Cambridge Structural Database (CSD; Groom et al., 2016), only the crystal structure of the non-substituted cis-jasmone thiosemicarbazone has been reported (Orsoni et al., 2020).The terminal group of the thiosemicarbazones plays an essential role in the intermolecular interactions and the supramolecular arrangement, e.g., the non-substituted form, which shows the NH 2 terminal group, leads to the building of mono-periodic hydrogen-bonded ribbons, while a phenyl ring attached to the terminal nitrogen atom leads to the formation of discrete dimeric units (Oliveira et al., 2017).This molecular architecture is specially observed for compounds with a nonpolar organic periphery and therefore, the tetralone 4-phenylthiosemicarbazone derivative (Oliveira et al., 2014) was chosen for comparison with the title compound.As for the structure of the cis-jasmone 4-phenylthiosemicarbazone, an N3-H2N� � �N2 intramolecular interaction is observed, with  graph-set motif S( 5), and the thiosemicarbazone molecules are linked into centrosymmetric dimers via pairs of N1-H1N� � �S1 #1 and C3-H3A� � �S1 #1 interactions, forming hydrogen-bonded rings with graph-set motifs of R 2 2 (8) and R 1 2 (7).The sulfur atoms also act as double acceptors and, indeed, the intra and intermolecular hydrogen bonding in the structure of the tetralone 4-phenylthiosemicarbazone are quite similar to those of the title compound (for the dimeric structure and the symmetry code, see Fig. 6; for a structural comparison with the compound of this work, see: Fig. 2).In the crystal, viewed along [001], the tetralone 4-phenylthiosemicarbazone shows a also zigzag motif, resembling the packing structure of the title compound (Fig. 7).

Synthesis and crystallization
The starting materials are commercially available and were used without further purification.The synthesis was adapted from previously reported procedures (Freund & Schander, 1902;Oliveira et al., 2014).The hydrochloric acid-catalyzed reaction between cis-jasmone (8 mmol) and 4-phenylthiosemicarbazide (8 mmol) in ethanol (80 ml) was refluxed for 6 h.After cooling and filtering, the title compound was obtained as precipitate, filtered off and washed with cold ethanol.Colorless single crystals suitable for X-ray diffraction were obtained in tetrahydrofuran by slow evaporation of the solvent.

Figure 7
Crystal structure section of the comparison compound, tetralone 4phenylthiosemicarbazone (Oliveira et al., 2014), viewed along [001].For this view, a zigzag motif of the discrete dimeric units can be suggested.It resembles the packing structure of the title compound (Fig. 3).Only the intermolecular N-H� � �S interactions are shown for clarity, drawn as dashed lines.

Figure 6
The molecular structure of the reference compound, tetralone 4phenylthiosemicarbazone (Oliveira et al., 2014), showing the intra-and intermolecular hydrogen-bond interactions drawn as dashed lines, which are quite similar to the title compound (Fig. 2).The molecules are linked into centrosymmetric dimers via pairs of N-H� � �S and C-H� � �S interactions, forming graph-set motifs of R 2 2 (8) and R 1 2 ( 7).The N-H� � �N intramolecular interactions, which form rings with graph-set motif S( 5

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.
Refinement.An absorption correction was not performed, as the crystal data analysis suggested that the absorption effects were not significant for the structure refinement.Hydrogen atoms were located in a difference-Fourier map, but were positioned with idealized geometry and refined isotropically using a riding model (HFIX command).Methyl H atoms were allowed to rotate but not to tip to best fit the experimental electron density.Thus, for the methyl H atoms [U iso (H) = 1.5 U eq (C)], the C-H bond lengths were set to 0.96 Å.The other C-H bond lengths were also set according to the H atom neighbourhood [U iso (H) = 1.2 U eq (C)].For the phenyl H atoms and for the other H atoms attached to sp 2hybridized carbon atoms (C7 and C8), the C-H bond lengths were set 0.93 Å.For the H atoms of the -CH 2fragments (C2, C3, C6 and C9), the C-H bond lengths were set to 0.97 Å.Finally, the N-H bond lengths [U iso (H) = 1.2 U eq (N)] were set to 0.86 Å.

Fractional atomic coordinates and isotropic
) are indicated.These atoms are those involved in the H� � �S interactions showed in the previous figures (Figs. 2 and 3).The contributions to the crystal packing are shown as twodimensional Hirshfeld surface fingerprint plots (HSFP) with cyan dots.The d i (x-axis) and the d e (y-axis) values are the closest internal and external distances from given points on the Hirshfeld surface contacts (in A ˚).The major contributions to the crystal packing amount to (a) H� � �H = 65.3%,(b) H� � �C/C� � �H = 16.2%,(c) H� � �S/S� � �H = 10.9% and (d) H � � �N/N� � �H = 5.5% (Fig. 5).
Figure 3 Crystal structure section of the title compound viewed along [010].The hydrogen-bonding intermolecular interactions are drawn as dashed lines.The crystal structure resembles a zigzag motif when viewed from this direction.

Table 2
Experimental details.