Abstract
The tetrakisimidazolium salt H(4) -2(Br)(4) , featuring a central benzene linker and 1,2,4,5-(nBu-imidazolium-Ph-CH=CH-) substituents reacts with Ag(2) O in the presence of AgBF(4) to yield the tetranuclear, oktakis-NHC assembly [3](BF(4) )(4) . Cation [3](4+) features four pairs of olefins from the two tetrakis-NHC ligands perfectly arranged for a subsequent [2+2] cycloaddition. Irradiation of [3](BF(4) )(4) with a high pressure Hg lamp connects the two tetra-NHC ligands through four cyclobutane linkers to give compound [4](BF(4) )(4) . Removal of the template metals yields the novel oktakisimidazolium salt H(8) -5(BF(4) )(8) . The tetrakisimidazolium salt H(4) -2(BF(4) )(4) and the oktakisimidazolium salt H(8) -5(BF(4) )(8) have been used as multivalent anion receptors and their anion binding properties towards six different anions have been compared.