Different routes in aqueous media to some 99Tc complexes investigated through ultraviolet absorption spectroscopy

Different synthetic routes were followed for preparing 99Tc complexes with iminodiacetate (IDA), N-(2,6-dimethylphenylcarbamoylmethyl)iminodiacetate (HIDA) and salicylate (SAL). Each ligand was added to 99TcO4− and the reduction performed with Sn(II) or hydrazine; alternatively in the ligand exchange reaction it was mixed with chloro-complexes of 99Tc in the oxidation states +3, +4 and +5. Comparative analyses, performed through u.v. absorption spectra, showed that the ligand exchange products of the Tc(III)-IDA, Tc(III)-HIDA and Tc(V)-SAL systems were coincident with those obtained from the reduction procedure, though yield and purity were different.