Synthesis, crystal structure and Hirshfeld analysis of N-ethyl-2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclopent-2-en-1-ylidene}hydrazinecarbothioamide

The title compound (C14H23N3S, common name: cis-jasmone 4-ethylthiosemicarbazone) was synthesized by the equimolar reaction of cis-jasmone and 4-ethylthiosemicarbazide in ethanol facilitated by acid catalysis. There is one crystallographically independent molecule in the asymmetric unit, which shows disorder of the terminal ethyl group of the jasmone carbon chain [site-occupancy ratio = 0.911 (5):0.089 (5)]. The thiosemicarbazone entity [N-N-C(=S)-N] is approximately planar, with the maximum deviation of the mean plane through the N/N/C/S/N atoms being 0.0331 (8) angstrom, while the maximum deviation of the mean plane through the five-membered ring of the jasmone fragment amounts to 0.0337 (8) angstrom. The dihedral angle between the two planes is 4.98 (7)degrees. The molecule is not planar due to this structural feature and the sp(3)-hybridized atoms of the jasmone carbon chain. Additionally, one H center dot center dot center dot N intramolecular interaction is observed, with graph-set motif S(5). In the crystal, the molecules are connected through pairs of H center dot center dot center dot S interactions with R-2(2)(8) and R-2(1)(7) graph-set motifs into centrosymmetric dimers. The dimers are further connected by H center dot center dot center dot N interactions with graph-set motif R-2(2)(12), which are related by an inversion centre, forming a mono-periodic hydrogen-bonded ribbon parallel to the b-axis. The crystal structure and the supramolecular assembly of the title compound are compared with four known cis-jasmone thiosemicarbazone derivatives (two crystalline modifications of the non-substituted form, the 4-methyl and the 4-phenyl derivatives). A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are from H center dot center dot center dot H (70.7%), H center dot center dot center dot S/S center dot center dot center dot H (13.5%), H center dot center dot center dot C/C center dot center dot center dot H (8.8%), and H center dot center dot center dot N/N center dot center dot center dot H (6.6%) interfaces (only the disordered atoms with the highest s.o.f. were considered for the evaluation).