Iridium-Stabilized π-Selenocyclohexadienyls: Synthesis, Molecular Structure, and Cytotoxicity

A series of iridium-stabilized selenocyclohexadienyls of general formula [Cp*Ir(η 5 -C 6 H 5–n Me n Se)][BF 4 ] {Cp* = η 5 -C 5 Me 5 , n = 0, n = 1, and n = 3} is described, with the selenocyclohexadienyl unit being isolated for the first time by π-coordination to a Cp*Ir moiety. The solid-state structure of one of [Cp*Ir(η 5 -C 6 H 2 Me 3 Se)][BF 4 ] was determined by single-crystal X-ray diffraction analysis. These compounds are obtained in good yields as orange-red microcrystalline solids by halogen displacement from the related π-bonded arene-chlorinated starting materials using Na 2 Se as the selenium source. Furthermore, these new compounds display relevant cytotoxic properties towards human ovarian cancer cells.