Exploiting the Hydrogen Bond Donor/Acceptor Properties of PN-Heterocycles: Selective Anion Receptors for Hydrogen Sulfate.

We describe two novel hybrid receptors combining a phosphorus-/nitrogen-containing (PN) phosphonamidate heterocycle with urea recognition units in an arylethynyl backbone. Structural, spectroscopic and computational studies reveal that the origin of superior binding for hydrogen sulfate (HSO4 - ) anion is correlated with the formation of strong hetero-complementary hydrogen bonds with the phosphonamidate motif. We further demonstrate that the hybrid host system is capable of capturing/transporting the HSO4 - anion from an aqueous, biphasic system.