Anion-directed assembly macrocycles

Anion-Directed Assembly, p. 5i Guanidinium-Based Anion Receptors, p. 615 Hydrogen Bonding, p. 658 Organometallic Anion Receptors, p. 1006 Protonated Aza-Macrocycles for Anion Complexation, p. 1170... 

One of the first anion-directed assemblies is the [12]mer-curacarborand-4 (1) reported by Hawthorne in 1991. which can be prepared in high yields by reacting 1,2-dilithio-carborane with mercuric chloride (see Fig. 1). " This compound consists of four bivalent 1 2-carborane cages linked by four mercury atoms forming a macrocycle with a chloride ion located at its center. The anion displays strong Lewis-acid-base interactions with the four mercury atoms of the macrocycle. Such interactions play an important role in directing the formation of the cyclic... 

Beer recently reported the anion-directed assembly of the [2]pseudorotaxane 17. In this system (see Fig. 5), a chloride anion has been employed as the central core about which two ligands (the macrocycle and the liner species) are orthogonally disposed by means of bonding to the anion. The formation of 17 was studied in solution by UV/Vis spectroscopy and H-NMR and confirmed in the solid state by an x-ray crystal structure. While chloride was demonstrated to be a good directing agent for the formation of 1. other anions such as Br. ... 

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