A novel palladium complex with a coumarin-thiosemicarbazone hybrid ligand inhibits Trypanosoma cruzi release from host cells and lowers the parasitemia in vivo.

In this work, two analogous coumarin-thio and semicarbazone hybrid compounds were prepared and evaluated as a potential antichagasic agents. Furthermore, palladium and platinum complexes with the thiosemicarbazone derivative as ligand (L1) were obtained in order to establish the effect of metal complexation on the antiparasitic activity. All compounds were fully characterized both in solution and in solid state including the resolution of the crystal structure of the palladium complex by X-ray diffraction methods. Unexpectedly, all experimental and theoretical characterizations in the solid state, demonstrated that the obtained palladium and platinum complexes are structurally different: [PdCl(L1)] and [PtCl2(HL1)]. All the studied compounds lower the proliferation of the amastigote form of Trypanosoma cruzi while some of them also have an effect on the trypomastigote stage. Additionally, the compounds inhibit T. cruzi release from host cells in variable extents. The Pd compound presented a remarkable profile in all the in vitro experiments, and it showed no toxicity for mammalian cells in the assayed concentrations. In this sense, in vivo experiments were performed for this compound using an acute model of Chagas disease. Results showed that the complex significantly lowered the parasite count in the mice blood with no significant toxicity.

Synthesis and Biological Evaluation of Novel (thio)semicarbazone-Based Benzimidazoles as Antiviral Agents against Human Respiratory Viruses.

Respiratory RNA viruses are responsible for recurrent acute respiratory illnesses that still represent a major medical need. Previously we developed a large variety of benzimidazole derivatives able to inhibit these viruses. Herein, two series of (thio)semicarbazone- and hydrazone-based benzimidazoles have been explored, by derivatizing 5-acetyl benzimidazoles previously reported by us, thereby evaluating the influence of the modification on the antiviral activity. Compounds 6, 8, 16 and 17, bearing the 5-(thio)semicarbazone and 5-hydrazone functionalities in combination with the 2-benzyl ring on the benzimidazole core structure, acted as dual inhibitors of influenza A virus and human coronavirus. For respiratory syncytial virus (RSV), activity is limited to the 5-thiosemicarbazone (25) and 5-hydrazone (22) compounds carrying the 2-[(benzotriazol-1/2-yl)methyl]benzimidazole scaffold. These molecules proved to be the most effective antiviral agents, able to reach the potency profile of the licensed drug ribavirin. The molecular docking analysis explained the SAR of these compounds around their binding mode to the target RSV F protein, revealing the key contacts for further assessment. The herein-investigated benzimidazole-based derivatives may represent valuable hit compounds, deserving subsequent structural improvements towards more efficient antiviral agents for the treatment of pathologies caused by these human respiratory viruses.

Design, synthesis and biological evaluation of novel semicarbazone-selenochroman-4-ones hybrids as potent antifungal agents.

A series of novel 2,3-dihydro-4H-1-benzoselenin-4-one (thio)semicarbazone derivatives were designed and synthesized by using molecular hybridization approach. All the target compounds were characterized by HRMS and NMR and evaluated in vitro antifungal activity against five pathogenic strains. In comparison with precursor selenochroman-4-ones, the hybrid molecules in this study showed significant improvement in antifungal activities. Notably, compound B8 showed significant antifungal activity against other strains excluding Aspergillus fumigatus (0.25 µg/mL on Candida albicans, 2 µg/mL on Cryptococcus neoformans, 8 µg/mL on Candida zeylanoides and 2 µg/mL on fluconazole-sensitive strains of Candida albicans). Moreover, compounds B8, B9 and C2 also displayed most potent activities against four fluconazole-resistance strains. Especially the MIC values of the hybrid molecule B8 against fluconazole-resistant strains were in the range of 0.5-2 µg/mL. Therefore, the molecular hybridization approach in this study provided new ideas for the development of antifungal drug.

Design, synthesis and biological evaluation of novel 4-phenoxy-6,7-disubstituted quinolines possessing (thio)semicarbazones as c-Met kinase inhibitors.

In continuing our efforts to identify small molecules able to inhibit c-Met kinase, three series of novel 6,7-disubstituted-4-phenoxyquinoline derivatives (23a-w, 26a-d and 30a-d) bearing (thio)semicarbazone scaffold were designed, synthesized and evaluated for their cytotoxicity. The biological data revealed that most compounds exhibited moderate-to-excellent activity against HT-29, MKN-45, A549 cancer cell lines and relative poor potency toward MDA-MB-231 cell as well as hardly any cytotoxicity in normal PBL cell. Eleven compounds were further examined for their inhibitory activity against c-Met kinase and three compounds (23h, 23n and 26a) demonstrated good inhibitory activity. This work resulted in the discovery of a potent c-Met inhibitor 23n, bearing 2-hydroxy-3-allylphenyl group at R(2) moiety, as a valuable lead molecule, which possessed remarkable cytotoxicity and high selectivity against A549 and HT-29 cell lines with IC50 values of 11 nM and 27 nM. Besides, it displayed excellent c-Met kinase inhibition on a single-digital nanomolar level (IC50=1.54 nM). Meanwhile, the results from preliminarily in vivo study reflected that compound 23n showed promising overall PK profiles, consistent with the efficacy in both MKN-45 and HT-29 tumor xenograft mice model. These results clearly indicated that compound 23n is a potent and highly selective c-Met inhibitor and its favorable in vitro and in vivo profiles warrant further investigation.

Crystal structure of 1-(4-formyl-benzyl-idene)thio-semicarbazone.

The asymmetric unit of the title compound, C9H9N3OS, contains two approximately planar mol-ecules (r.m.s. deviations for 14 non-H atoms = 0.094 and 0.045 Å), with different conformations. In one of them, the C=O group is syn to the S atom and in the other it is anti. Each mol-ecule features an intra-molecular N-H⋯N hydrogen bond, which generates an S(5) ring. In the crystal, mol-ecules are linked by N-H⋯O and N-H⋯S hydrogen bonds, generating discrete networks; the syn mol-ecules form [010] chains and the anti mol-ecules form (100) sheets.

Crystal structure of cis-bis-[4-phenyl-2-(1,2,3,4-tetra-hydro-naphthalen-1-yl-idene)hydrazinecarbo-thio-amidato-κ(2) N (1),S]nickel(II) monohydrate tetra-hydro-furan disolvate.

The reaction of Ni(II) acetate tetra-hydrate with the ligand 4-phenyl-2-(1,2,3,4-tetra-hydro-naphthalen-1-yl-idene)hydrazinecarbo-thio-amide in a 2:1 molar ratio yielded the title compound, [Ni(C16H16N3S)2]·2C4H8O·H2O. The deprotonated ligands act as N,S-donors, forming five-membered metallacycles with the metal ion exhibiting a cis coordination mode unusual for thio-semicarbazone complexes. The Ni(II) ion is four-coordinated in a tetra-hedrally distorted square-planar geometry. Trans-arranged anagostic C-H⋯Ni inter-actions are observed. In the crystal, the complex mol-ecules are linked by water mol-ecules through N-H⋯O and O-H⋯S hydrogen-bonding inter-actions into centrosymmetric dimers stacked along the c axis, forming rings of graph-set R 4 (4)(12). Classical O-H⋯O hydrogen bonds involving the water and tetra-hydro-furan solvent mol-ecules as well as weak C-H⋯π inter-actions are also present.

Crystal structure of 1-(4-formyl-benzyl-idene)-4-methyl-thio-semicarbazone.

The structure of the title compound, C10H11N3OS, comprises an approximately planar mol-ecule, with the r.m.s. deviation for the 15 non-H atoms being 0.089 Å. The conformation about the imine bond is E and an intra-molecular N-H⋯N hydrogen bond is evident. Mol-ecules are linked into a supra-molecular chain along the b axis by N-H⋯S hydrogen bonds.

Crystal structure of the charge-transfer complex 2-(1,2,3,4-tetra-hydro-naph-thal-en-1-yl-idene)hydrazinecarbo-thio-amide-pyrazine-2,3,5,6-tetra-carbo-nitrile (2/1).

The reaction of 2-(1,2,3,4-tetra-hydro-napthalen-1-yl-idene)hydrazinecarbo-thio-amide (TTSC) with pyrazine-2,3,5,6-tetra-carbo-nitrile (tetra-cyano-pyrazine, TCNP) yields the title 2:1 charge-transfer adduct, 2C11H12N3S·C6N8. The complete TCNP mol-ecule is generated by a crystallographic inversion centre and the non-aromatic ring in the TTSC mol-ecule adopts an envelope conformation with a methyl-ene C atom as the flap. In the crystal, the thio-semicarbazone mol-ecules are connected through inversion-related pairs of N-H⋯S inter-actions, building a polymeric chain along the b-axis direction. The TCNP mol-ecules are embedded in the structure, forming TTSC-TCNP-TTSC stacks with the aromatic rings of TTSC and the mol-ecular plane of TCNP in a parallel arrangement [centroid-centroid distance = 3.5558 (14) Å]. Charge-transfer (CT) via π-stacking is indicated by a CT band around 550 cm(-1) in the single-crystal absorption spectrum.

5-Hy-droxy-2-nitro-benzaldehyde thio-semicarbazone (HNBATSC).

The asymmetric unit of the title compound, C8H8N4O3S, consists of two independent mol-ecules. Each mol-ecule is approximately planar with dihedral angles of 8.71 (3) and 1.50 (2)° between the aromatic ring and the thio-semicarbazide moiety while the NO2 group makes dihedral angles of 29.27 (3) and 17.78 (3)° with the benzene ring. In the crystal, the molecules are linked by N-H⋯S, O-H⋯O and N-H⋯O hydrogen bonds, forming two-dimensional networks parallel to (100).

Synthesis, crystal structure and Hirshfeld analysis of N-ethyl-2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclo-pent-2-en-1-yl-idene}hydrazinecarbo-thio-amide.

The title compound (C14H23N3S, common name: cis-jasmone 4-ethyl-thio-semicarbazone) was synthesized by the equimolar reaction of cis-jasmone and 4-ethyl-thio-semicarbazide in ethanol facilitated by acid catalysis. There is one crystallographically independent mol-ecule 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 thio-semicarbazone 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) Å, while the maximum deviation of the mean plane through the five-membered ring of the jasmone fragment amounts to -0.0337 (8) Å. The dihedral angle between the two planes is 4.98 (7)°. The mol-ecule is not planar due to this structural feature and the sp 3-hybridized atoms of the jasmone carbon chain. Additionally, one H⋯N intra-molecular inter-action is observed, with graph-set motif S(5). In the crystal, the mol-ecules are connected through pairs of H⋯S inter-actions with R 2 2(8) and R 2 1(7) graph-set motifs into centrosymmetric dimers. The dimers are further connected by H⋯N inter-actions 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 supra-molecular assembly of the title compound are compared with four known cis-jasmone thio-semicarbazone 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⋯H (70.7%), H⋯S/S⋯H (13.5%), H⋯C/C⋯H (8.8%), and H⋯N/N⋯H (6.6%) inter-faces (only the disordered atoms with the highest s.o.f. were considered for the evaluation).

N-Methyl-2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclo-pent-2-en-1-yl-idene}hydrazinecarbo-thio-amide.

The equimolar and hydro-chloric acid-catalysed reaction between cis-jasmone and 4-methyl-thio-semicarbazide in ethano-lic solution yields the title compound, C13H21N3S (common name: cis-jasmone 4-methyl-thio-semicarbazone). Two mol-ecules with all atoms in general positions are present in the asymmetric unit. In one of them, the carbon chain is disordered [site occupancy ratio = 0.821 (3):0.179 (3)]. The thio-semicarbazone entities [N-N-C(=S)-N] are approximately planar, with the maximum deviation from the mean plane through the selected atoms being -0.0115 (16) Š(r.m.s.d. = 0.0078 Å) for the non-disordered mol-ecule and 0.0052 (14) Š(r.m.s.d. = 0.0031 Å) for the disordered one. The mol-ecules are not planar, since the jasmone groups have a chain with sp 3-hybridized carbon atoms and, in addition, the thio-semicarbazone fragments are attached to the respective carbon five-membered rings and the dihedral angles between them for each mol-ecule amount to 8.9 (1) and 6.3 (1)°. In the crystal, the mol-ecules are connected through pairs of N-H⋯S and C-H⋯S inter-actions into crystallographically independent centrosymmetric dimers, in which rings of graph-set motifs R 2 2(8) and R 2 1(7) are observed. A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are from H⋯H (70.6%), H⋯S/S⋯H (16.7%), H⋯C/C⋯H (7.5%) and H⋯N/N⋯H (4.9%) inter-actions [considering the two crystallographically independent mol-ecules and only the disordered atoms with the highest s.o.f. for the evaluation].

{[(E)-(1,3-Benzodioxol-5-yl)methyl-idene]amino}thio-urea.

The synthesis and crystallographic analysis of the title compound, C9H9N3O2S, are reported. The compound crystallizes in the monoclinic space group P21/c, revealing characteristic bond lengths and angles typical of thio-semicarbazone groups. The supra-molecular organization primarily arises from hydrogen bonding and π-π stacking inter-actions, leading to distinctive dimeric formations.

Synthesis, crystal structure and Hirshfeld surface analysis of 4-{(1E)-1-[(car-bamo-thioyl-amino)-imino]-eth-yl}phenyl propano-ate.

The title compound, C12H15N3O2S, adopts an E configuration with respect to the C=N bond. The propionate group adopts an anti-periplanar (ap) conformation. There are short intra-molecular N-H⋯N and C-H⋯O contacts, forming S(5) and S(6) ring motifs, respectively. In the crystal, mol-ecules are connected into ribbons extending parallel to [010] by pairs of N-H⋯S inter-actions, forming rings with R 2 2(8) graph-set motifs, and by pairs of C-H⋯S inter-actions, where rings with the graph-set motif R 2 1(7) are observed. The O atom of the carbonyl group is disordered over two positions, with a refined occupancy ratio of 0.27 (2):0.73 (2). The studied crystal consisted of two domains.

2-{1-[(6R,S)-3,5,5,6,8,8-Hexamethyl-5,6,7,8-tetra-hydro-naphthalen-2-yl]ethyl-idene}-N-methyl-hydrazinecarbo-thioamide.

The reaction between a racemic mixture of (R,S)-fixolide and 4-methyl-thio-semicarbazide in ethanol with a 1:1 stoichiometric ratio and catalysed with HCl, yielded the title compound, C20H31N3S [common name: (R,S)-fixolide 4-methyl-thio-semicarbazone]. There is one crystallographically independent mol-ecule in the asymmetric unit, which is disordered over the aliphatic ring [site-occupancy ratio = 0.667 (13):0.333 (13)]. The disorder includes the chiral C atom, the neighbouring methyl-ene group and the methyl H atoms of the methyl group bonded to the chiral C atom. The maximum deviations from the mean plane through the disordered aliphatic ring amount to 0.328 (6) and -0.334 (6) Š[r.m.s.d. = 0.2061 Å], and -0.3677 (12) and 0.3380 (12) Š[r.m.s.d. = 0.2198 Å] for the two different sites. Both fragments show a half-chair conformation. Additionally, the N-N-C(=S)-N entity is approximately planar, with the maximum deviation from the mean plane through the selected atoms being 0.0135 (18) Š[r.m.s.d. = 0.0100 Å]. The mol-ecule is not planar due to the dihedral angle between the thio-semicarbazone entity and the aromatic ring, which amounts to 51.8 (1)°, and due to the sp 3-hybridized carbon atoms of the fixolide fragment. In the crystal, the mol-ecules are connected by H⋯S inter-actions with graph-set motif C(4), forming a mono-periodic hydrogen-bonded ribbon along [100]. The Hirshfeld surface analysis suggests that the major contributions for the crystal cohesion are [(R,S)-isomers considered separately] H⋯H (75.7%), H⋯S/S⋯H (11.6%), H⋯C/C⋯H (8.3% and H⋯N/N⋯H (4.4% for both of them).

A second crystalline modification of 2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclo-pent-2-en-1-yl-idene}hydrazinecarbo-thio-amide.

A second crystalline modification of the title compound, C12H19N3S [common name: cis-jasmone thio-semicarbazone] was crystallized from tetra-hydro-furane at room temperature. There is one crystallographic independent mol-ecule in the asymmetric unit, showing disorder in the cis-jasmone chain [site-occupancy ratio = 0.590 (14):0.410 (14)]. The thio-semicarbazone entity is approximately planar, with the maximum deviation from the mean plane through the N/N/C/S/N atoms being 0.0463 (14) Š[r.m.s.d. = 0.0324 Å], while for the five-membered ring of the jasmone fragment, the maximum deviation from the mean plane through the carbon atoms amounts to 0.0465 (15) Š[r.m.s.d. = 0.0338 Å]. The mol-ecule is not planar due to the dihedral angle between these two fragments, which is 8.93 (1)°, and due to the sp 3-hybridized carbon atoms in the jasmone fragment chain. In the crystal, the mol-ecules are connected by N-H⋯S and C-H⋯S inter-actions, with graph-set motifs R 2 2(8) and R 2 1(7), building mono-periodic hydrogen-bonded ribbons along [010]. A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are H⋯H (67.8%), H⋯S/S⋯H (15.0%), H⋯C/C⋯H (8.5%) and H⋯N/N⋯H (5.6%) [only non-disordered atoms and those with the highest s.o.f. were considered]. This work reports the second crystalline modification of the cis-jasmone thio-semicarbazone structure, the first one being published recently [Orsoni et al. (2020 ▸). Int. J. Mol. Sci. 21, 8681-8697] with the crystals obtained in ethanol at 273 K.

Synthesis, crystal structure and Hirshfeld analysis of trans-bis-{(2E)-N-phenyl-2-[(2E)-3-phenyl-2-propen-1-yl-idene]hydrazinecarbo-thio-amidato-κ2N1,S}palladium(II).

The reaction of (2E)-N-phenyl-2-[(2E)-3-phenyl-2-propen-1-yl-idene]hydra-zine-carbo-thio-amide (common name: cinnamaldehyde-4-phenyl-thio-semi-carbazone) deprotonated with NaOH in ethanol with an ethano-lic suspension of PdII chloride in a 2:1 molar ratio yielded the title compound, [Pd(C16H14N3S)2]. The anionic ligands act as metal chelators, κ2 N 1 S-donors, forming five-membered rings with a trans-configuration. The PdII ion is fourfold coordinated in a slightly distorted square-planar geometry. For each ligand, one H⋯S and one H⋯N intra-molecular inter-actions are observed, with S(5) and S(6) graph-set motifs. Concerning the H⋯S inter-actions, the coordination sphere resembles a hydrogen-bonded macrocyclic environment-type. In the crystal, the complexes are linked via pairs of H⋯S inter-actions, with graph-set motif R 2 2(8), and building a mono-periodic hydrogen-bonded ribbon along [001]. The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are: H⋯H (45.3%), H⋯C/C⋯H (28.0%), H⋯S/S⋯H (8.0%) and H⋯N/N⋯H (7.4%).

2-{3-Methyl-2-[(2Z)-pent-2-en-1-yl]cyclo-pent-2-en-1-yl-idene}-N-phenylhydrazinecarbo-thio-amide.

The hydro-chloric acid-catalyzed equimolar reaction between cis-jasmone and 4-phenyl-thio-semicarbazide yielded the title compound, C18H23N3S (common name: cis-jasmone 4-phenyl-thio-semicarbazone). Concerning the hydrogen bonding, an N-H⋯N intra-molecular inter-action is observed, forming a ring with graph-set motif S(5). In the crystal, the mol-ecules are connected into centrosymmetric dimers by pairs of N-H⋯S and C-H⋯S inter-actions, forming rings of graph-set motifs R 2 2(8) and R 2 1(7), with the sulfur atoms acting as double acceptors. The thio-semicarbazone entity is approximately planar, with the maximum deviation from the mean plane through the N/N/C/S/N atoms being 0.0376 (9) Š(the r.m.s.d. amounts to 0.0234 Å). The mol-ecule is substantially twisted as indicated by the dihedral angle between the thio-semicarbazone 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%).

Synthesis, crystal structure and Hirshfeld analysis of trans-bis-(2-{1-[(6R,S)-3,5,5,6,8,8-hexa-methyl-5,6,7,8-tetra-hydronaphthalen-2-yl]ethyl-idene}-N-methyl-hydrazinecarbo-thio-amidato-κ2N2,S)palladium(II) ethanol monosolvate.

The reaction between the (R,S)-fixolide 4-methyl-thio-semicarbazone and PdII chloride yielded the title compound, [Pd(C20H30N3S)2]·C2H6O {common name: trans-bis-[(R,S)-fixolide 4-methyl-thio-semicarbazonato-κ2 N 2 S]palladium(II) ethanol monosolvate}. The asymmetric unit of the title compound consists of one bis-thio-semicarbazonato PdII complex and one ethanol solvent mol-ecule. The thio-semicarbazononato ligands act as metal chelators with a trans configuration in a distorted square-planar geometry. A C-H⋯S intra-molecular inter-action, with graph-set motif S(6), is observed and the coordination sphere resembles a hydrogen-bonded macrocyclic environment. Additionally, one C-H⋯Pd anagostic inter-action can be suggested. Each ligand is disordered over the aliphatic ring, which adopts a half-chair conformation, and two methyl groups [s.o.f. = 0.624 (2):0.376 (2)]. The disorder includes the chiral carbon atoms and, remarkably, one ligand has the (R)-isomer with the highest s.o.f. value atoms, while the other one shows the opposite, the atoms with the highest s.o.f. value are associated with the (S)-isomer. The N-N-C(=S)-N fragments of the ligands are approximately planar, with the maximum deviations from the mean plane through the selected atoms being 0.0567 (1) and -0.0307 (8) Š(r.m.s.d. = 0.0403 and 0.0269 Å) and the dihedral angle with the respective aromatic rings amount to 46.68 (5) and 50.66 (4)°. In the crystal, the complexes are linked via pairs of N-H⋯S inter-actions, with graph-set motif R 2 2(8), into centrosymmetric dimers. The dimers are further connected by centrosymmetric pairs of ethanol mol-ecules, building mono-periodic hydrogen-bonded ribbons along [011]. The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are [atoms with highest/lowest s.o.f.s considered separately]: H⋯H (81.6/82.0%), H⋯C/C⋯H (6.5/6.4%), H⋯N/N⋯H (5.2/5.0%) and H⋯S/S⋯H (5.0/4.9%).

Synthesis and crystal structure of a solvated CoIII complex with 2-hy-droxy-3-meth-oxy-benzaldehyde thio-semicarbazone ligands.

The title CoIII complex, bis-[bis-(2-hy-droxy-3-meth-oxy-benzaldehyde thio-semi-carbazonato)cobalt(III)] di-thio-nate-dimethylformamide-methanol (1/4/3), [Co(C9H10N3O2S)2]2(S2O6)·4C3H7NO·3CH3OH, with monodeprotonated 2-hy-droxy-3-meth-oxy-benzaldehyde thio-semicarbazone as ligands crystallizes in the space group P . The asymmetric unit consists of two mononuclear [CoL 2]+ cations, one di-thio-nate anion (S2O6)2- as counter-anion and seven solvate mol-ecules (four di-methyl-methanamide and three methanol). Each CoIII ion has a moderately distorted octa-hedral S2N2O2 geometry. In the crystal, the components are linked by numerous N-H⋯O and O-H⋯O contacts.

Bis{N'-[3-(4-nitro-phen-yl)-1-phenyl-prop-2-en-1-yl-idene]-N-phenyl-carbamimido-thio-ato}zinc(II): crystal structure, Hirshfeld surface analysis and computational study.

The title zinc bis-(thio-semicarbazone) complex, [Zn(C22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetra-hedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethyl-ene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitro-benzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitro-benzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supra-molecular chain along the b-axis direction features amine-N-H⋯O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C-H⋯O(nitro) and π(chelate ring)-π(phen-yl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C-H⋯O(nitro) and nitro-O⋯π(phen-yl) inter-actions.