Guest recognition of a tetrapyridinohemicarcerand through hydrogen bonding and constrictive binding interactions

초록

Tetrapyridinohemicarcerand 2 having four hydrogen-bonding acceptors of inward-directing pyridyl units was synthesized and their binding properties for a variety of organic guest molecules have been investigated. Tetrapyridinohemicarcerand 2 formed kinetically stable complexes with various sulfonic acids via intermolecular -SO(3)H-pyridyl hydrogen bonding and constrictive binding interactions in C(2)D(2)Cl(4) at 25 degrees C. But carboxylic acids or alcohols cannot be a stable guest at the same conditions. Tetrapyridinohemicarcerand 2 also binds various disubstituted benzenes. Especially 1,4-diiodobenzene forms stable hemicarceplex 1,4-diiodobenzene@2, which seems to be stabilized by constrictive binding as well as by -C-H center dot center dot center dot I interactions between dioxymethylene of 2 and iodo group of guest. (C) 2010 Elsevier Ltd. All rights reserved.

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