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In- and Out-of-Cavity Interactions by Modulating the Size of Ruthenium Metallarectangles
Auteur(s)
Date de parution
2010
In
Helvetica Chimica Acta, Wiley, 2010/93/7/1313-1328
Résumé
Cationic (arene)ruthenium-based tetranuclear complexes of the general formula [Ru<sub>4</sub>(<i>η</i><sup>6</sup>-<i>p</i>-cymene)<sub>4</sub>(<i>μ</i>-<i>N</i>∩<i>N</i>)<sub>2</sub>(<i>μ</i>-<i>OO</i>∩<i>OO</i>)<sub>2</sub>]<sup>4+</sup> were obtained from the dinuclear (arene)ruthenium complexes [Ru<sub>2</sub> (<i>η</i><sup>6</sup>-<i>p</i>-cymene)<sub>2</sub>(<i>μ</i>-<i>OO</i>∩<i>OO</i>)<sub>2</sub>Cl<sub>2</sub>] (<i>p</i>-cymene=1-methyl-4-(1-methylethyl)benzene, <i>OO</i>∩<i>OO</i>=5,8-dihydroxy-1,4-naphthoquinonato(2−), 9,10-dihydroxy-1,4-anthraquinonato(2−), or 6,11-dihydroxynaphthacene-5,12-dionato(2−)) by reaction with pyrazine or bipyridine linkers (<i>N</i>∩<i>N</i>=pyrazine, 4,4′-bipyridine, 4,4′-[(1<i>E</i>)-ethene-1,2-diyl]bis[pyridine]) in the presence of silver trifluoromethanesulfonate (CF<sub>3</sub>SO<sub>3</sub>Ag) (<i>Scheme</i>). All complexes <b>4–12</b> were isolated in good yield as CF<sub>3</sub>SO<sub>3</sub><sup>-</sup> salts, and characterized by NMR and IR spectroscopy. The host–guest properties of the metallarectangles incorporating 4,4′-bipyridine and (4,4′-[(1<i>E</i>)-ethene-1,2-diyl]bis[pyridine] linkers were studied in solution by means of multiple NMR experiments (1D, ROESY, and DOSY). The largest metallarectangles <b>10–12</b> incorporating (4,4′-[(1<i>E</i>)-ethene-1,2-diyl]bis[pyridine] linkers are able to host an anthracene, pyrene, perylene, or coronene molecule in their cavity, while the medium-size metallarectangles <b>7–9</b> incorporating 4,4′-bipyridine linkers are only able to encapsulate anthracene. However, out-of-cavity interactions are observed between these 4,4′-bipyridine-containing rectangles and pyrene, perylene, or coronene. In contrast, the small pyrazine-containing metallarectangles <b>4–6</b> show no interaction in solution with this series of planar aromatic molecules.
Identifiants
Type de publication
journal article
