Ricerc@Sapienza

Ion receptors could be used for the extraction of toxic or radioactive cations and anions from water or the recycling of valuable raw materials, providing means for water purification and decontamination. Supramolecular chemistry has been concerned with cation receptors since the seminal work of Pedersen, Lehn, and Cram on crown ethers, cryptands, and spherands, respectively. Since then, cation receptor chemistry represents an important research field, which has also addressed the challenge of developing systems that can efficiently work in water.

Site-selective C-H functionalization of aliphatic alkyl chains is a longstanding challenge in oxidation catalysis, given the comparable relative reactivity of the different methylenes. A supramolecular, bioinspired approach is described to address this challenge. A Mn complex able to catalyze C(sp 3 )-H hydroxylation with H 2 O 2 is equipped with 18-benzocrown-6 ether receptors that bind ammonium substrates via hydrogen bonding.