腙基席夫碱配体铜(Ⅱ)配合物的合成、结构表征、生物活性和密度泛函理论计算

以甲醇为介质，合成了3种新的席夫碱配体HL¹(2-hydroxybenzaldehyde2-(2-oxo-1，2-diphenylethylidene)hydrazone)、HL²(4-hydroxybenzaldehyde2-(2-oxo-1，2-diphenylethylidene)hydrazone)和 L³(2-methoxybenzaldehyde2-(2-oxo- 1，2-diphenylethylidene)hydrazone)的Cu(Ⅱ)配合物1~3。通过元素分析、光谱方法、磁化率测量和密度泛函理论(DFT)计算对配合物进行了表征。通过单晶X射线衍射研究对合成的配体进行了结构表征。通过DFT计算确定了配合物的优化结构。通过紫外可见吸收光谱和荧光发射光谱研究了配合物与小牛胸腺DNA(CT-DNA)的结合能力。吸收光谱研究揭示了增色效应，并提出了与CT-DNA相互作用的可能模式。溴化乙锭(EB)竞争结合研究表明，配合物可以取代 DNA-EB 加合物中的 DNA，且配合物可能以嵌入模式与 CT-DNA结合。配合物对革兰氏阴性肺炎克雷伯菌、大肠杆菌、鲍氏志贺菌和革兰氏阳性金黄色葡萄球菌的体外抗菌活性研究表明，配合物2对肺炎克雷伯菌和鲍氏志贺菌具有明显抗菌活性，但配合物1和3没有表现出任何显著的抗菌活性。

Synthesis, structural characterization, bio-activity, and density functional theory calculation on Cu(Ⅱ) complexes with hydrazone-based Schiff base ligands

Three new copper(Ⅱ) complexes 1-3 of Schiff base ligands HL¹ (2-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone), HL² (4-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone) and L³ (2-methoxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone) were synthesized from methanolic medium. The complexes were characterized by elemental analyses, spectroscopic methods, magnetic susceptibility measurements, and density functional theory (DFT) studies. The synthesized ligands were characterized structurally by single-crystal X-ray diffraction studies. The optimized structure of the complexes was ascertained by DFT studies. The DNA binding ability of the complexes with calf thymus DNA (CT-DNA) was studied by UV-Vis absorption and fluorescence emission spectral studies. Absorption spectral studies revealed a hyperchromic effect and suggested the possible mode of interaction with CT-DNA. The competitive binding studies using ethidium bromide (EB) show that the complexes can replace DNA from DNA-EB adduct and suggests that the complexes probably bind to CT-DNA in intercalative mode. In vitro antibacterial activity of the complexes against Gram-negative bacteria Klebsiella pneumoniae (K. pneumoniae), Escherichia coli(E. coli), and Shigella boydii (S. boydii), and gram-positive bacteria Staphylococcus aureus (S. aureus) exhibited an appreciable antibacterial activity of complex 2 against K. pneumoniae and S. boydii, but complexes 1 and 3 did not show any significant antibacterial activity.