Halide Recognition by Tetraoxacalix2arene2triazine Receptors: Concurrent Noncovalent Halide–π and Lone‐pair–π Interactions in Host–Halide–Water Ternary Complexes

Cleft of center: The self fine-tuning π-deficient cleft of 1, 3-dichloro-substituted tetraoxacalix2arene2triazine forms noncovalent π–halide and π–lone-pair-electron interactions with halides Cl− and Br−, and water, giving rise to ternary complexes in the solid state (see structure, N blue). In solution, the host molecule, formed by a different mechanism, complexes with fluoride, giving Ka (1: 1) of over 4000 M−1. Supporting information for this article is available on the WWW under http: //www. wiley-vch. de/contents/jc₂002/2008/z801705ₛ. pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.