Two-arm ferrocene amide compounds: Synclinal conformations for selective sensing of dihydrogen phosphate ion

Ferrocene compounds bearing multiple amido groups selectively bind with the H2PO4- ion over other anions. The one-arm receptors form 1:1 complexes with the H2PO4- ion, whereas the two-arm receptors can accommodate two H2PO4- ions. The complexation modes and binding strengths are deduced from the NMR, calorimetry, fluorescence, and cyclic voltammetry studies. The two-arm ferrocene hexamide receptors likely,exist in synclinal conformations to incorporate tetrahydrofuran molecules and H2PO4- ions.