Anticancer Activity of Half-Sandwich Rh and Ir Metalla-Prisms Containing Lipophilic Side Chains.

Two hexacationic pentamethylcyclopentadienyl rhodium(III) and iridium(III) metalla-prisms, [(η -C Me ) M (μ -tpt-κN) (μ -C HRO -κO) ] (tpt=2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; R=(CH ) CH ; M=Rh, [3] ; M=Ir, [4] ) isolated as their triflate salts, have been synthesised from the dinuclear complexes (η -C Me ) M (μ -C HRO -κO)Cl (M=Rh, 1; M=Ir, 2) and AgCF SO . The antiproliferative activity of the neutral and cationic complexes has been evaluated in vitro in human cancer cell lines. The positively charged metalla-prisms appear to target mitochondria, which ultimately induce apoptosis in cancer cells. All biological studies suggest that the rhodium derivative [3][CF SO ] possesses excellent activities, not only in vitro but also in vivo in tumour-induced C57L6/J mice.