Substitution Studies of Second- and Third-Row Transition Metal OXO Complexes

Abstract

This chapter discusses substitution studies of second- and third-row transition metal OxO complexes and proton, oxygen, and cyanide exchange. The relative dynamics of the different exchange processes taking place on the selected second- and third-row transition metal Oxo complexes. The kinetic behavior is especially an important aspect determining the preparation, uptake, and clearance of such radiopharmaceutical agents. This distortion results in changes in the overlap of the ligandmetal orbitals and variations in the corresponding bond strengths and has definite effects on the proton, water, and cyanide exchange processes. Some aspects related to the reactivity of the Tc(V) and Re(V) complexes, where the former is widely applied as an imaging nuclide in the radiopharmaceutical industry, are also discussed in the chapter. An interesting point comes from the comparison of the in vivo data with the other ligand substitution results in general. A correlation is obtained with rhenium–oxygen bond distances as determined from crystallographic studies.