Pillarplexes: A Metal-Organic Class of Supramolecular Hosts

Abstract

Novel octanuclear NHC complexes of gold(I) and silver(I) form metallocavitand structures with very defined tubular cavities and are able to selectively host linear molecules, exemplarily demonstrating 1,8-diaminooctane as a model guest molecule. The solubility of the host-compounds is easily adjusted by simple anion exchange reactions so that the compounds can be made soluble in water wherein they exhibit a high longtime stability. The gold(I) complex is emissive in aqueous solutions, which enables a determination of the binding constant to the diamine via luminescence quenching. The host-guest interaction was further investigated by isothermal titration calorimetry, NMR spectroscopy, and X-ray crystallography.