The proposed research involves the determination of kinetic and thermodynamic information pertinent to the understanding of ligand substitution reactions which lead to the production of technetium radiopharmaceuticals of interest to the field of nuclear medicine. The long term objective is to devise means of preparing technetium complexes as single species, thus yielding more predictable and efficacious diagnostic imaging performance. The study intends to exploit a newly discovered technetium complex, transdioxotechnetium(V) formate, as a universal precursor for the ligand-exchange production of Tc(V) complexes. The trans-dioxotechnetium(V) formate is prepared under controlled electrolysis at carbon electrode in aqueous non-toxic media. The investigation will employ photodiode array spectrophotometry and high performance liquid chromatography to study the ligand substitution of selected ligands with the trans-dioxotechnetium(V) formate complex. Also, the fundamental hydrolysis of the trans-dioxotechnetium(V) formate will be investigated. The information gained during the study will lead to the development of a flow through electrolyticsubstitution generator for the production of Tc(V)99m radiopharmaceuticals.