Anti-cancer activities based on ZnII complex of potassium 5-thiophen-2-yl-[1,3,4]-oxadiazole-2-thiolate: Synthesis, crystal structure, photoluminescence study and Hirshfeld analysis

•A zinc complex of potassium 5-thiophen-2-yl-[1,3,4]-oxadiazole-2-thiolate (Kthot) was synthesized and characterized.•Kthot was obtained via cyclization of potassium N'-(thiophene-2-carbonyl)-hydrazine carbodithioate.•The anti-cancer activity of both compounds was examined against MDA-MB-231 cells.•MTT test was used to assess the cytotoxicity of Kthot and zinc complex.•The viability of MDA-MB-231 cells was more effectively inhibited by complex than Kthot. Recent advancements in developing the most suitable drug for humankind to cure cancer have paved the way to synthesize an alternative to platinum-based drugs. Herein, the synthesis of novel polymeric complex [Zn(thot)2]n (1) derived from potassium 5-thiophen-2-yl-[1,3,4]-oxadiazole-2-thiolate (Kthot) is reported. The synthesized ligand and complex were characterized by infrared, NMR, Mass and UV–vis. spectrometry. Moreover, single-crystal X-ray analysis revealed the polymeric nature of the [Zn(thot)2]n (1). Complex 1 is stabilized via various types of intermolecular interactions. The intermolecular interaction found in complex 1 was further investigated through Hirshfeld surface analysis. Emission spectra data showed that complex [Zn(thot)2]n (1) exhibits higher fluorescent intensity than Kthot. The cytotoxicity of complex 1 and Kthot was evaluated against MDA-MB-231 breast cancer cells, which was determined by measuring mitochondrial dehydrogenase activity using MTT as substrate. The result showed that they both suppressed the viability of cancer cells. Moreover, complex 1 was found to be more effective than ligand salt Kthot. The IC50 value for complex 1 was found around 37.43 μM whereas for Kthot it is 69.24 μM which suggests that complex 1 reduces the cell viability more effectively in comparison to the ligand salt. [Display omitted]