To understand the stability, chelation behaviour, and biological activity of 4-Formylpyridinethiosemicarbazone (H4FPT), it is important to recognize its interactive geometry. Hence, computational studies on geometrically optimized structures of thione and thiol forms of H4FPT were performed. Binary metal complexes of the ligand, H4FPT (L) with the Ni(II) and Cu(II) metal ions (M), were synthesized and characterized by various spectroanalytical techniques as elemental analysis, molar conductance, magnetic susceptibility measurements, LC-MS, TGA, IR, UV-Visible, ESR, and powder XRD. Elemental analysis, LC-MS, and TGA studies indicate 1:2 (ML2) composition for mononuclear Ni(II) complex and 1:1 (ML) composition for dinuclear Cu(II) complex. Electronic absorption titrations, fluorescence quenching studies, and viscosity measurements suggest intercalative mode of binding of the complexes with calf thymus DNA (CT-DNA). These complexes also promote hydrolytic cleavage of plasmid pBR322. The ligand (H4FPT) and its complexes showed moderate-to-good activity against Gram-positive and Gram-negative bacterial strains. The DPPH radical scavenging studies showed antioxidant nature of both complexes.

中文翻译：

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4-甲酰基吡啶氨基硫脲的计算研究及其Ni(II)和Cu(II)配合物的结构和生物学研究

要了解 4-甲酰基吡啶氨基硫脲 (H4FPT) 的稳定性、螯合行为和生物活性，重要的是要了解其相互作用的几何形状。因此，对 H4FPT 的硫酮和硫醇形式的几何优化结构进行了计算研究。配体 H4FPT (L) 与 Ni(II) 和 Cu(II) 金属离子 (M) 的二元金属配合物被合成并通过各种光谱分析技术表征，如元素分析、摩尔电导、磁化率测量、LC-MS 、TGA、IR、UV-Visible、ESR 和粉末 XRD。元素分析、LC-MS 和 TGA 研究表明，单核 Ni(II) 配合物的组成为 1:2 (ML2)，双核 Cu(II) 配合物的组成为 1:1 (ML)。电子吸收滴定、荧光猝灭研究、和粘度测量表明复合物与小牛胸腺 DNA (CT-DNA) 结合的嵌入模式。这些复合物还促进质粒 pBR322 的水解裂解。配体 (H4FPT) 及其复合物对革兰氏阳性和革兰氏阴性细菌菌株显示出中等至良好的活性。DPPH 自由基清除研究表明这两种复合物都具有抗氧化性。