Permanent Encapsulation or Host-Guest Behavior of Aromatic Molecules in Hexanuclear Arene Ruthenium Prisms

Cationic arene Ru metallaprisms [Ru6(p-cymene)6(tpt)2(OO?OO)3]6+ {tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine; OO?OO = 9,10-dioxo-9,10-dihydroanthracene-1,4-diolato [1]6+, 6,11-dioxo-6,11-dihydronaphthacene-5,12-diolato [2]6+} were obtained from the corresponding dinuclear arene Ru complexes [Ru2(p-cymene)2(OO?OO)Cl2] by reaction with tpt and Ag trifluoromethanesulfonate. Arom. mols. (phenanthrene, pyrene, triphenylene, coronene) present during the synthesis of these metallaprisms are permanently encapsulated to give carceplex systems. All empty cages ([1]6+ and [2]6+) and carceplex systems ([guest?1]6+ and [guest?2]6+) were isolated in good yield as trifluoromethanesulfonate salts and characterized by NMR, UV, and IR spectroscopy. The host-guest properties of [1]6+ and [2]6+ were studied in soln. in the presence of small arom. mols. (phenanthrene and pyrene). The stability const. of assocn. (Ka) was estd. by NMR spectroscopy for the following host-guest systems: [phenanthrene?1]6+, [pyrene?1]6+ and [phenanthrene?2]6+, [pyrene?2]6+. All Ka values are larger than 2.0 × 104 M-1 for these host-guest systems ([D3]acetonitrile, 21°). [on SciFinder(R)]