Anion-pi Interactions in Salts with Polyhalide Anions: Trapping of I-4(2-)

作者：Mueller Michael; Albrecht Markus^*; Gossen Verena; Peters Tanja; Hoffmann Andreas; Raabe Gerhard; Valkonen Arto; Rissanen Kari

来源：Chemistry - A European Journal, 2010, 16(41): 12446-12453.

DOI：10.1002/chem.201001534

• computational chemistry
• halogens
• polyhalides
• pi interactions
• supramolecular chemistry

The directionality of interaction of electron-deficient pi systems with spherical anions (e.g,. halides) can be controlled by secondary effects like NH or CH hydrogen bonding. In this study a series of pentafluorophenyl-substituted salts with polyhalide anions is investigated. The compounds are obtained by aerobic oxidation of the corresponding halide upon crystallization. Solid-state structures reveal that in bromide 2, directing NH-anion interactions position the bromide ion in an eta(1)-type fashion over but not in the center of the aromatic ring. The same directing forces are effective in corresponding tribromide salt 3. In the crystal, the bromide ion is paneled by four electron-deficient aromatic ring systems. In addition, compounds 4 and 6, which have triiodide and the rare tetraiodide dianion as anions, are described. Computational studies reveal that the latter is highly unstable. In the present case it is stabilized by the crystal lattice, for example, by interaction with electron-deficient pi systems.

• 出版日期2010