Encapsulation of Pyrene-Functionalized Poly(benzyl ether) Dendrons into a Water-Soluble Organometallic Cage

Two generations of lipophilic pyrenyl functionalized poly(benzyl ether) dendrimers (P₁ and P₂) have been synthesized. The thermal properties of the two functionalized dendrimers have been investigated, and the pyrenyl group of the dendritic molecules encapsulated in the arene–ruthenium metalla-cage, [Ru₆(<i>p</i>-cymene)₆(tpt)₂(donq)₃]⁶⁺ ([<b>1</b>]⁶⁺) (tpt=2,4,6-tri(pyridin-4-yl)-1,3,5-triazine; donq=5,8-dioxydo-1,4-naphthoquinonato). The host–guest properties of [P1⊂<b>1</b>]⁶⁺ and [P2⊂<b>1</b>]⁶⁺ were studied in solution by NMR and UV/Vis spectroscopic methods, thus allowing the determination of the affinity constants. Moreover, the cytotoxicity of these water-soluble host–guest systems was evaluated on human ovarian cancer cells.