We herein report the synthesis of nanostructured cyclopalladated complex and its nanosilver composite for the first time. The reaction between Schiff base ligand 4-methyl-N-(3,4-dimethoxybenzylidene)] benzenamine (L) and palladium acetate gave the cyclopalladted complex (Pd1) in nanoscale. Thermal treatment of silver oxalate with Pd1 resulted in the formation of novel nanostructured composite, silver nanoparticle-decorated palladacycle (Pd2). The synthesized compounds were characterized using spectroscopic analysis (FT-IR and ¹H NMR), thermal analysis (TGA), XRD and morphological analysis (SEM and TEM). The spectral analysis revealed that complex Pd1 has dimeric structure bridged with acetate ligands between two monomers. SEM images exhibited that Ag-NPs loaded on complex surface in decorated form. TEM photographs showed the particle sizes of composite ≈ 29 nm. Quantum chemical analysis of ligand and complex Pd1 has been carried out by DFT/B3LYP method. There are two suggested isomers for cyclopalladated complex named Pd1 and Pd1^* which are theoretically studied and correlated with practical results. HOMO, LUMO energy values, chemical hardness–softness, electronegativity and electrophilic index were calculated. The theoretical data obtained have been confirmed that the Pd1 isomer is more stable than Pd1^* isomer which correlated well with practical results. The ligand and complexes screened for antimicrobial activity against five medically important microorganisms, namely Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. The results showed that complex Pd2 displayed the highest activity against the tested microorganisms.

我们在此首次报道了纳米结构的环钯配合物及其纳米银复合物的合成。Schiff碱配体4-甲基-N-（3,4-二甲氧基亚苄基）苯甲醛（L）与乙酸钯之间的反应得到了纳米级的环钯配合物（Pd1）。用Pd1对草酸银进行热处理导致形成了新型的纳米结构复合材料，即装饰有银纳米颗粒的Palladacycle（Pd2）。使用光谱分析（FT-IR和¹1 H NMR），热分析（TGA），XRD和形态分析（SEM和TEM）。光谱分析表明，复合物Pd1具有在两个单体之间用乙酸酯配体桥接的二聚体结构。SEM图像表明，Ag-NP以修饰的形式负载在复杂表面上。TEM照片显示复合材料的粒径约为29 nm。配体和配合物Pd1的量子化学分析已通过DFT / B3LYP方法进行。有两种建议的环palpalated的异构体，称为Pd1和Pd1 ^*的异构体，经过理论研究并与实际结果相关。计算出HOMO，LUMO能量值，化学硬度-软度，电负性和亲电指数。获得的理论数据已证实，Pd1异构体比Pd1更稳定^*异构体与实际结果很好地相关。该配体和复合物针对五种医学上重要的微生物（即金黄色葡萄球菌，变形杆菌，铜绿假单胞菌，大肠杆菌和白色念珠菌）具有抗菌活性。结果表明，复合物Pd2对被测微生物表现出最高的活性。