Tuning In Vitro Cytotoxicity in Diruthenium(I) bis‐Cyclopentadienyl Complexes

ABSTRACT A series of diruthenium(I) aminocarbyne complexes of general formula [Ru 2 Cp 2 (CO)(L)(μ‐CO){μ‐CNMe (Cy)}] + (L = NH 3 , [ 2 ] + ; Py, [ 3 ] + , PPh 3 , [ 4 ] + ; DMSO, [ 5 ] + ; thiourea, [ 6 ] + ) and [Ru 2 Cp 2 (μ‐H)(CO) 2 {μ‐CNMe (Cy)}], 7 , were prepared from the tricarbonyl precursor [Ru 2 Cp 2 (CO) 2 (μ‐CO){μ‐CNMe (Cy)}] + . The reactivity of the diruthenium(I) vinyliminium complex [Ru 2 Cp 2 (CO)(μ‐CO){μ‐η 1 :η 3 ‐C (Ph)CHCNMe (Cy)}] + , was also investigated, providing access to piano stool Ru (II) cyclopentadienyl complexes with a five‐membered metallacyclic ligand containing sulfur. The new compounds were characterized by IR and multinuclear NMR spectroscopy and X‐ray diffraction (in three cases). The solubility in water, lipophilicity, and the speciation of [ 2 – 6 ]CF 3 SO 3 in water/DMSO and cell culture medium are regulated by different monodentate ligands. Subsequently, [ 1 , 3 – 6 ] + were tested in vitro against human ovarian cancer cells (A2780 and A2780cis) and embryonic kidney cells (HEK293), demonstrating moderate to potent cytotoxicity.