Host‐Guest Bonding of Oxoanions to Guanidinium Anchor Groups

Adaptation of the recognition principle of many biogenic receptors, which make use of the interaction between the guanidinium function of arginyl side chains with carboxylate and phosphate groups of substrates, was used to design and synthesize new host compounds. The bicyclic guanidinium compounds (1, shown schematically) bind p-nitrobenzoate (NMR-titration) and acetate (X-ray structural analysis).