Initial structural studies of charged receptors that bind to inorganic phosphate anion and to an anionic phospholipid found in bacterial membranes

ITC titration studies of a family of bis-ammonium receptors based upon a scaffold of two bis-linked phenol rings show that several of the receptors bind to both dihydrogenphosphate and phosphatidylglycerol anions in a similar binding motif. Thermodynamic properties determined from ITC show that anion binding is entropy driven. Job plots determined from (1)H NMR clearly demonstrate that anion-receptor binding stoichiometry is dependent on the receptor's length of its bis-amine linkage.