New symmetric palladacycle complexes including phosphorus ylide: synthesis, characterization, theoretical and cytotoxicity studies

The reaction between symmetric ylides RC₆H₄C(O)CH = PPh₂(CH₂)₂PPh₂ = CHC(O)C₆H₄R (Y) (R = OMe, F) and [PdCl₂(COD)] (COD = 1,5-cyclooctadiene) led to the formation of palladacycle complexes, whose structures were investigated using CHN, NMR, and IR identification methods. Additionally, the precise structure of Y was confirmed through X-ray diffraction analysis. The structures of these complexes were also examined theoretically using Density Functional Theory at the BP86/def2-SVP level. The nature of the bond between the Y and PdCl₂ moieties in the synthesized complexes was studied using Energy Decomposition Analysis, Natural Bond Orbital analysis, and their associated natural orbitals for chemical reactivity. The results obtained suggest the formation of palladacycles through the coordination of the ylide to the metal, mediated by ylidic carbon. Finally, the anticancer activity of these complexes as antiproliferative agents against breast carcinoma (MCF-7), Human cervix (HeLa), gastric carcinoma (AGS), and non-small lung carcinoma (A549) cell lines was investigated using the micro-culture (MTT) assay.