| Summary: | Mixed ligand complexes of Pd(II) and Cd(II) with <i>N</i>-picolyl-amine dithiocarbamate (PAC-dtc) as primary ligand and tertiary phosphine ligand as secondary ligands have been synthesized and characterized via elemental analysis, molar conductance, NMR (<sup>1</sup>H and <sup>31</sup>P), and IR techniques. The PAC-dtc ligand displayed in a monodentate fashion via sulfur atom whereas diphosphine ligands coordinated as a bidentate mode to afford a square planner around the Pd(II) ion or tetrahedral around the Cd(II) ion. Except for complexes [Cd(PAC-dtc)<sub>2</sub>(dppe)] and [Cd(PAC-dtc)<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>], the prepared complexes showed significant antimicrobial activity when evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Moreover, DFT calculations were performed to investigate three complexes {[Pd(PAC-dtc)<sub>2</sub>(dppe)](1), [Cd(PAC-dtc)<sub>2</sub>(dppe)](2), [Cd(PAC-dtc)<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>](7)}, and their quantum parameters were evaluated using the Gaussian 09 program at the B3LYP/Lanl2dz theoretical level. The optimized structures of the three complexes were square planar and tetrahedral geometry. The calculated bond lengths and bond angles showed a slightly distorted tetrahedral geometry for [Cd(PAC-dtc)<sub>2</sub>(dppe)](2) compared to [Cd(PAC-dtc)<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>](7) due to the ring constrain in the dppe ligand. Moreover, the [Pd(PAC-dtc)<sub>2</sub>(dppe)](1) complex showed higher stability compared to <b>Cd(2)</b> and <b>Cd(7)</b> complexes which can be attributed to the higher back-donation of Pd(1) complex.
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