Molecular recognition: preparation and characterization of two tripodal anion receptors

Two new tripodal hydroxyl-based anion receptors (1 and 2) are reported and their 1 : 1 molecular complexes with Cl−, H2PO4−, and OAc− along with the (M − 1)− ion of 1 were characterized by negative ion photoelectron spectroscopy in the gas phase and by binding constant determinations in four solvents (i.e., CDCl3, CD2Cl2, CD3COCD3, and CD3CN). An intramolecular hydrogen bond network (HBN) in hexaol 1 was found to diminish its binding whereas the triol 2 is the strongest aliphatic hydroxyl-based receptor to date.