Dinudear metal complexes have emerged as a promising class of anticancer compounds with the ability to cross-link biomolecular targets. Here, we describe two novel series of phosphine-linked dinudear ruthenium(II) p-cyrnene and gold(I) complexes, in which the length of the connecting poly(ethylene glycol) chain has been systematically modified. The impact,Of the multinuclearity, lipophilicity, and linker length on the antiproliferative activity of the compounds-on tumorigenic,(A2780 and A2780cisR) and nonturnorigenic (HEK-293) cell lines was assessed. The dinuclear ruthenium(II) complexes were considerably more cytotoxic than their mononuclear : counterparts, and a correlation between the lipophilicity of the linker and the cytotoxicity was observed, whereas the cytotoxicity of the gold(I) series, is independent of these factors.