Anticancer Activity of Half-Sandwich RhIII and IrIII Metalla-Prisms Containing Lipophilic Side Chains

Two hexacationic pentamethylcyclopentadienyl rhodium(III) and iridium(III) metalla-prisms, [((5)-C5Me5)(6)M-6((3)-tpt-N)(2)((4)-C6HRO4-O)(3)](6+) (tpt=2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; R=(CH2)(10)CH3; M=Rh, [3](6+); M=Ir, [4](6+)) isolated as their triflate salts, have been synthesised from the dinuclear complexes ((5)-C5Me5)(2)M-2((4)-C6HRO4-O)Cl-2 (M=Rh, 1; M=Ir, 2) and AgCF3SO3. The antiproliferative activity of the neutral and cationic complexes has been evaluated invitro 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][CF3SO3](6) possesses excellent activities, not only invitro but also invivo in tumour-induced C57L6/J mice.