A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate and nicotinaldehyde. The metal complexes of Co⁺², Ni⁺², Cu⁺², and Zn⁺² were characterized and investigated by physical and spectral techniques, namely, elemental analysis, melting point, conductivity, ¹H NMR, IR, UV-Vis spectra, ESR, SEM, and mass spectrometry measurements. They were further analyzed by thermal technique (TGA/DTA) to gain better insight about the thermal stability and kinetic properties of the complexes. Thermal data revealed high thermal stability and nonspontaneous nature of the decomposition steps. The Coats-Redfern method was applied to extract thermodynamic parameters to explain the kinetic behavior. The molar conductance values were relatively low, showing their nonelectrolytic nature. The powder XRD pattern revealed amorphous nature except copper complex (1c) that crystallized in the triclinic crystal system. The EPR study strongly recommends the tetrahedral geometry of 1c. The structure optimization by MM force field calculation through ArgusLab 4.0.1 software program supports the concerned geometry of the complexes. The in vitro antibacterial activity of all the compounds, at their two different concentrations, was screened against four bacterial pathogens, namely, E. coli, P. vulgaris, K. pneumoniae, and S. aureus, and showed better activity compared to parent drug and control drug.

中文翻译：

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基于青霉素的新型席夫碱的金属配合物：表征，分子模型和抗菌活性研究。

通过阿莫西林三水合物和烟醛的缩合制备了新型的HL型席夫碱配体。通过物理和光谱技术对Co ⁺²，Ni ⁺²，Cu ⁺²和Zn ⁺²的金属配合物进行了表征和研究，即元素分析，熔点，电导率，¹1 H NMR，IR，UV-Vis光谱，ESR，SEM和质谱测量。通过热技术（TGA / DTA）对它们进行了进一步分析，以更好地了解配合物的热稳定性和动力学性质。热数据显示出高热稳定性和分解步骤的非自发性质。应用Coats-Redfern方法提取热力学参数以解释动力学行为。摩尔电导值相对较低，显示出它们的非电解性质。粉末XRD图谱显示出无定形性质，除了在三斜晶系中结晶的铜络合物（1c）。EPR研究强烈建议1c的四面体几何形状。通过ArgusLab 4.0.1软件程序通过MM力场计算进行的结构优化支持了配合物的相关几何形状。大肠杆菌，寻常型体育，肺炎克雷伯菌和金黄色葡萄球菌比母体药物和对照药物显示出更好的活性。