A formate based precursor for the preparation of technetium complexes

Tc-formate complexes have been prepared by electrolytic, stannous, and borohydride reduction of pertechnetate in formate buffer. Individual Tc-formate complexes were isolated from reaction mixtures with silica bonded phase anion-exchange HPLC. The predominate air stable red Tc-formate complex has a negative charge, an absorption maximum at 536 nm, and a molecular weight between 100 and 300 dalton. The isolated major Tc-formate complex was found to react with isocyanide, diphosphonate, and various nitrogenous ligands. The relevant use of Tc-formate complexes as synthetic precursors to other technetium complexes is seen as being beneficial to the understanding of technetium ligand substitution.