Synthesis of Hafnium(IV) Polyaminoacetates

The interaction of hafnium(IV) salts (oxide-dichloride, chloride, and bromide) with nitrilotriacetic acid (NTA), diethylenetriamminepentaacetic acid (DTPA), 1,2-diaminocyclohexanetetraacetic acid (CDTA), 1,3-dipropylmino-2-hydroxy N,N,N′,N′-tetraacetic acid (dpta), and N-(2-hydroxyethyl)ethylenediamine triacetic acid (HEDTA) has been studied. The corresponding complexes Na(2)[Hf(NTA)(2)]·3H(2)O (1), Na[HfDTPA]·3H(2)O (2), [HfCDTA(H(2)O)(2)] (3), and Na[Hf(2)(dpta)(2)]·7.5H(2)O·0.5C(2)H(5)OH (4) have been isolated and characterized and their structures have been determined by single crystal X-ray diffraction. Biological studies of [HfCDTA(H(2)O)(2)] have shown that in 5% glucose solution this complex has low toxicity and good contrasting ability.