A novel receptor for dicarboxylic acid derivatives

Abstract

A novel receptor 4 has been prepared, which binds the monopotassium salts of various dicarboxylic acids in chloroform solution, using a combination of hydrogen bonding interactions and an electrostatic association between a carboxylate anion and a crown ether bound potassium cation, the crystal structure of the receptor is reported and evidence for the proposed binding interactions is provided by consideration of various extraction experiments, intermolecular NOEs (nuclear Overhausser effect), and FAB (fast atom bombardment) mass spectrometry, where a bimolecular species, held together by hydrogen bonds, can be detected in the negative ion mass spectrum.