Host-Guest Chemistry in the Hexanuclear (Arene)ruthenium Metalla-Prismatic Cage [Ru6(p-cymene)6(tpt)2(dhnq)3]6+

A large cationic triangular metalla-prism, [Ru-6(p-cymene)(6)(tpt)(2)(dhnq)(3)](6+) ([1](6+)), incorporating (p-cymene)ruthenium building blocks, bridged by 5,8-dihydroxy-1,4-naphthoquinonato (dhnq) ligands, and connected by two 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine (tpt) subunits, allows encapsulation of various guest molecules. This cationic cage, isolated as its triflate salt, possesses a portal size smaller than its cavity, thus allowing both, permanent and temporary encapsulation of guest molecules. The host-guest proper-ties of [1](6+) have been studied in solution in the presence of planar molecules [phenanthrene, pyrene, (pyren-1-ylmethyl)amine, Pt(acac)(2), triphenylene], The stability constant of association (K-a) was estimated by NMR spectroscopy for the following host-guest systems: [pyrene subset of 1](6+), [phenanthrene subset of 1](6+) and [(pyren-1-ylmethyl)amine subset of 1](6+). All K-a values were found to be larger than 2.4 x 10(4) M-1 for these host-guest systems ([D-3]acetonitrile, 21 degrees C). The other two synthesised complexes, [Pt-(acac)(2)subset of 1](6+) and [triphenylene subset of 1](6+), were shown to act as carceplexes only. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)