Encapsulation of inorganic and organic guest molecules into an organometallic hexacationic arene osmium metalla-prism: Synthesis, characterization and anticancer activity

The arene Os metalla-prism [(p-cymene)6Os6(donq)3(tpt)2]6+ ([2]6+) (donq = 5,8-dioxydo-1,4-naphthoquinonato, tpt = 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine) was prepd. from the dinuclear arene Os precursor [(p-cymene)2Os2(donq)Cl2] (1) in the presence of the tridentate panel tpt and Ag triflate. The assembly of the arene Os metalla-prism also was achieved in the presence of one equiv. of planar guest mols., Pt(acac)2 (acac = acetylacetonato) and 1-(4,6-dichloro-1,3,5-triazin-2-yl)pyrene (pyrene-R), to give the corresponding guest-encapsulated systems, [Pt(acac)2?2]6+ and [pyrene-R?2]6+. All complexes were isolated as triflate salts and characterized by IR, UV-visible, NMR and by elemental anal. The empty metalla-prism also was characterized by mass spectrometry. The cytotoxicities of the dinuclear and hexanuclear Os complexes were established using ovarian A2780 and A2780cisR cancer cell lines and compared with the cytotoxicities of their Ru analogs. [on SciFinder(R)]