Reaction of C60 with [Pd/Pt(dba)2] (dba ¼ dibenzylideneacetone) and phosphorus ylides [Ph2P(CH2)nPPh2 ¼ C(H)C(O)C6H4-m-OMe] (n ¼ 1, (Y1); n ¼ 2, (Y2)) gave the new Pd/Pt-[60]fullerene complexes. The obtained [(h2-C60)Pd(k2-Y1)] (1), [(h2-C60)Pt(k2-Y1)] (2), [(h2-C60)Pd(Y2)2] (3) and [(h2- C60)Pt(Y2)2] (4) complexes were characterized successfully by cyclic voltammetry, elemental analysis, mass spectrometry, and IR, UV-Vis and multinuclear NMR (1H, 13C and 31P) spectroscopy. The results of spectroscopic characterization revealed the different coordination modes of phosphorus ylides Y1 and Y2 as a consequence of P,C-chelation in 1 and 2 and P-coordination in 3 and 4 complexes. Theoretical studies confirmed the P,C-chelation and P-coordination behaviors of ligands Y1 and Y2, respectively. The energy decomposition analysis (EDA) showed that both C60-metal and metal-ylide bonds were more electrostatic than covalent in character. Also, the cytotoxicity activity assays have demonstrated that these complexes could effectively inhibit specific cancer cells lines.
