A new tetradentate Schiff base ligand entitled as (L = (N²E, N^2′E)‐N¹, N^1′‐(ethane‐1,2‐diyl)bis(N2‐((E)‐3‐(2‐nitrophenyl)allylidene)ethane‐1,2‐diamine) and its six cadmium(II) complexes formulated as CdLX₂ in which X is Cl, Br, I, NO₃, NCS, or N₃ were synthesized under ultrasound irradiation and characterized by various physical and spectral techniques. Moreover, some complexes were also prepared in nanostructured dimensions confirmed by scanning electron microscopy (SEM), energy dispersive X‐ray analysis (EDXA), and X‐ray powder diffraction (XRPD) techniques and then were used as precursor for preparation of CdO nanoparticles via direct calcination at 600°C. As typical, the crystal structure of cadmium(II) nitrate complex was determined using single crystal X‐ray diffraction. Accordingly, it was found that [Cd(L)(NO₃)₂] complex crystallizes in the monoclinic space group P2₁/n with two independent molecules in the asymmetric unit with two coordination modes of nitrate anions. This complex has zero‐dimensional (0D) coordination supramolecular structure. Hirshfeld surface analyses suggested that H … O (49.5%), H … H (30.3%), and H … C (11.8%) intermolecular interactions are most considerable in the crystal packing. Computational studies of ligand structure leading to electrostatic potentials of the solid state geometry and some occupied molecular orbitals (HOMO, HOMO‐1, HOMO‐2, and HOMO‐5) prevailing the contribution of nitrogen lone pairs are also reported. Thermal behavior studies of the compounds under nitrogen atmosphere from room temperature to 900°C revealed that the ligand is completely decomposed without any residual whereas the complexes are decomposed via two to four thermal steps with trace amount of metallic cadmium as residue. Moreover, antibacterial and antifungal screening well showed that the complexes inhibit from the growth of the various bacteria and fungi more efficient than free ligand especially against Gram‐positive bacteria. DNA cleavage potentials of the compounds may be one of the reasons for their antimicrobial activity.

A new N₂O₂‐tetradentate Schiff base ligand entitled as N,N′‐((ethane‐1,2‐diybis [oxy])bis (ethan‐2,1‐diyl))bis(3‐(4‐methoxyphenyl)prop‐2‐en‐1‐imine was prepared by direct reaction between 3‐(4‐methoxyphenyl)‐2‐propenal and 1,8‐diamino‐3,6‐dioxaoctane. After characterization of the ligand, some novel cadmium coordination compounds formulated as CdLX₂ (X: Cl⁻, Br⁻, I⁻, N₃⁻, SCN⁻and NO₃⁻) were synthesized and characterized by physical and spectral techniques. Typically crystal structure of cadmium nitrate coordination compound was determined suggesting crystallization in monoclinic system (with space group of I_2/a) and a coordination geometry of square anti‐prism around the Cd (II) ion. Moreover, CdLBr₂ and CdLI₂ compounds were prepared in nanostructured dimensions by sonochemical method confirmed by SEM, EDX, and XRD techniques. In continuation, thermal behavior investigation of the compounds including thermal stabilities, thermal decomposition steps, and thermo‐kinetic parameters was performed based on Coats‐Redfern equations from room temperature to 900 °C. Furthermore, all the compounds were subjected to bioassay against two Gram‐positive bacteria of Staphylococcus aureus and Bacillus subtilis, two Gram‐negative bacteria of Pseudomonas aeruginosa and Escherichia coli, and two fungal strains of Aspergillus oryzae and Candida albicans. The results showed that all the synthesized compounds act well as antimicrobial agents. DNA cleavage power of the materials was also evaluated using extracted DNA from E. coli bacterium. The cytotoxic activities of some compounds were investigated against the prostate cancer cell lines (PC3) and human umbilical vein endothelial cells (HUVEC) (as normal cells) by MTT assay and nitric oxide level evaluation method as compared with cis‐platin confirming anti‐cancer effects of them. Finally, the antioxidant properties of the N₂O₂‐ligand and its cadmium coordination compounds were examined by DPPH and FRAP methods suggesting all the compounds have good antioxidant activity as compared with standard samples.