Nitrido technetium-99m core in radiopharmaceutical applications: Four decades of research

The knowledge on element 43 (Tc) of the periodic table, built over the years through the contributions given by the close relationship between chemistry and nuclear medicine, allowed the development of new and increasingly effective radiopharmaceuticals useful both as perfusion and target specific imaging agents for SPECT (single photon emission tomography). Among the manifold Tc-compounds, Tc(V) nitrido complexes played a relevant role in the search for new technetium-99m radiopharmaceuticals, providing effcient labeling procedures that can be conveniently exploited for the design and synthesis of agents, also incorporating small organic molecules or peptides having defined structural features. With this work, we present an overview of four decades of research on the chemistry and on the nuclear medicine applications of Tc(V) nitrido complexes.