A novel Schiff base (E)-N-(pyridine-2-yl)thiophen-2-ylmethylene)hydrazine carbothioamide (L), has been synthesised by the condensation of thiophen-2-carbaldehyde and 4-(pyridin-2-yl)-thiosemicarbazide, using solvent free microwave synthesis. The Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base are also prepared. They are characterised by elemental analysis, EI-mass spectrum, 1H &13C-NMR spectrum, FTIR, UV-vis spectra, magnetic, EPR spectra and thermal analysis. The “SNSN” donor ligand binds the metal ion in tetradentate mode through thiophenyl and thioenolic sulphur atoms and imino and pyridine nitrogen atoms. The electronic spectra along with magnetic measurements demonstrate tetrahedral geometry for Co(II), Ni(II) and Zn(II) complexes, and square planar geometry for Cu(II) complex. All the complexes are found to be thermally stable from thermogravimetric studies. The complexes show enhanced antibacterial activity than the ligand against various bacterial strains. The BSA binding activity of the complexes shows that the affinity for binding is greater towards copper complex. The cytotoxicity of the ligand and its complexes are tested on HT29 colon cancer cells using MTT assay.

中文翻译：

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具有新型SNSN供体席夫碱配体的过渡金属配合物的微波合成、表征和生物活性

通过噻吩-2-甲醛和4-(吡啶-2-基)缩合合成了一种新型席夫碱(E)-N-(吡啶-2-基)噻吩-2-基亚甲基)肼碳硫酰胺(L) )-氨基硫脲，使用无溶剂微波合成。还制备了席夫碱的 Co(II)、Ni(II)、Cu(II) 和 Zn(II) 配合物。它们的特征在于元素分析、EI 质谱、1H 和 13C-NMR 光谱、FTIR、UV-vis 光谱、磁性、EPR 光谱和热分析。“SNSN”供体配体通过噻吩和硫烯醇硫原子以及亚氨基和吡啶氮原子以四齿模式结合金属离子。电子光谱和磁性测量表明 Co(II)、Ni(II) 和 Zn(II) 配合物为四面体几何形状，Cu(II) 配合物为方形平面几何形状。从热重研究中发现所有配合物都是热稳定的。与配体相比，复合物对各种细菌菌株的抗菌活性增强。复合物的 BSA 结合活性表明对铜复合物的结合亲和力更大。使用 MTT 测定法在 HT29 结肠癌细胞上测试配体及其复合物的细胞毒性。