Ferric ion sequestering agents. 10. Selectivity of sulfonated poly(catechoylamides) for ferric ion

Complexation equilibria have been evaluated by potentiometric titration of several biologically significant divalent metals as well as Fe(III) with the sulfonated polycatecholate ligands N,N'-bis(2-3-N,N',N",N"'-tetra(2,3-dihydroxy-5-sulfobenzoyl)-1,5,lO,14-tetraazadecane [3,4,.For all ligands studied the titrations demonstrate the following relative stabilitiesThese polycatechoylamide ligands possess great selectivity for ions of high charge -to ionic radius ratios such as Fe(III) and Pu(IV); their selectivity-iS similar to that shown by desferrioxamine B, the current chelating agent for iron overload, and is greater than that demonstrated by DTPA, the chelating agent most often used for plutonium and other heavy metal ion decorporation./ .....