Since the discovery 'of the extraordinary chelating properties of compounds containing in the molecule one or more “nitrilodiaretate” groups,-N (CH&OOH),, such as ethylenedinitrilotetraacetic acid (ethylenediaminetetraacetic acid, EDTA) and nitrilotriacetic acid (NTA), considerable effort has been undertaken to synthesize new and different chelating agents. Bersworth12 as well as Banks and Yerick13 prepared compounds with “ ...