Designing the host-guest properties of tetranuclear arene ruthenium metalla-rectangles to accommodate a pyrene molecule
Author(s)
Barry, Nicolas P. E.
Furrer, Julien
Date issued
2010
In
Eur. J. Inorg. Chem.
Vol
5
From page
725
To page
728
Subjects
ruthenium arene naphthoquinone semiquinone bipyridine pyrazine self assembly macrocyclic complex tetranuclear rectangular areneruthenium semiquinone bipyridine pyrazine bridged hydrophobic cavity macrocyclic tetranuclear rectangular areneruthenium pyrene inclusion diffusion ordered NMR ROESY inclusion pyrene hydrophobic areneruthenium metallamacrocycle
Abstract
Cationic tetranuclear rectangular macrocyclic arene ruthenium complexes [Ru4(p-cymene)4(?-N-N)2(?-dhnq)2](CF3SO3)4 [1-3, dhnq = 5,8-dihydroxy-1,4-naphthoquinonato(2-); N-N = pyrazine, 4,4'-bipyridine, 1,2-bis(4-pyridyl)ethene], featuring Ru-dhnq-Ru-N-N-Ru-dhnq-Ru rectangle structures with adjustable Ru-Ru distances (7.0 Å, 11.2 Å, 13.6 Å, resp.), are obtained in methanol from the reaction of the dinuclear arene ruthenium precursor [Ru2(p-cymene)2(dhnq)2Cl2] with pyrazine or bipyridine linkers in the presence of AgCF3SO3. All complexes 1-3, isolated in good yield as triflate salts, have been characterized by NMR and IR spectroscopy. The interaction of these rectangular complexes with pyrene as a guest mol. has been studied in soln. by various NMR techniques (1D, DOSY, ROESY). In CD3CN, the pyrazine-contg. metalla-rectangle 1 shows no meaningful interactions with pyrene. On the other hand, the 4,4'-bipyridine- and 1,2-bis(4-pyridyl)ethylene-contg. metalla-rectangles 2 and 3 clearly interact with pyrene. DOSY measurements suggest that, in the case of the 4,4'-bipyridine complex 2, the interactions occur on the outside of the rectangular assembly, while in the case of dipyridylethylene complex 3 the pyrene mol. is found inside the hydrophobic cavity of the metalla-rectangle, thus giving rise to a host-guest system. [on SciFinder(R)]
Publication type
journal article