Synthesis, structures, and luminescence properties of ternary supramolecular hydrogen-bonded complexes involving [(o-C₆F₄)Hg]₃, carbazole, and a Lewis base

The interaction of trimeric perfluoro-ortho-phenylene mercury (1) with carbazole in dichloromethane, THF, and THF/NEt₃ leads to the crystallization of [1·C₁₂H₈NH] (2), [1·(C₁₂H₈NH·THF)] (3), and [1·(C₁₂H₈NH·NEt₃)] (4), respectively. Adducts 3 and 4 have been characterized by elemental analysis, IR spectroscopy, and luminescence spectroscopy. The crystal structures of 3 and 4 have also been determined. Both adducts have extended structures that exhibit supramolecular binary stacks, where molecules of 1 and the carbazole–Lewis base complex alternate. Short Hg–C contacts involving molecules of 1 and carbazole indicate the presence of secondary Hg–π interactions. In addition, adducts 3 and 4 display hydrogen-bonding interactions between the acidic NH moiety of carbazole and the heteroatom of the Lewis base. The presence of this hydrogen bond is also confirmed by IR spectroscopy, which shows that the ν_NH of 3 and 4 is lower than that of 2. The luminescence spectra of these adducts correspond to the phosphorescence of carbazole, which is induced by the mercury heavy atom effect. In the case of 3 and 4, additional low-energy bands are observed at 578 and 567 nm. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:195–201, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20329