this is not the case for the smaller sulfate and oxalate anions. Ligand 3-6H'binds sulfate and oxalate more strongly than the smaller cycle 1-6H'of same charge; this may be due to a higher local charge density in an ethylenediammonium group than in a propylenediammonium group. Large polyanions like citrate, 1, 3, 5-benzenetricarboxylate, CO (CN)~*, and Fe (CN) 6', form very strong complexes with the large and highly charged ...