To Sandwich Technetium: Highly Functionalized Bis-Arene Complexes [Tc-99m(eta(6)-arene)(2)](+) Directly from Water and [(TcO4)-Tc-99m](-)

摘要

The labeling of (bio)molecules with metallic radionuclides such as Tc-99m demands conjugated, multidentate chelators. However, this is not always necessary since phenyl rings can directly serve as integrated, organometallic ligands. Bis-arene sandwich complexes are generally prepared by the Fischer-Hafner reaction. In extension of this, we show that [Tc-99m(eta(6)-C6R6)(2)](+)-type complexes are directly accessible from water and [(TcO4)-Tc-99m](-), even using arenes incompatible with Fischer-Hafner conditions. To unambiguously confirm the nature of these unprecedented Tc-99m complexes, their rhenium homologous have been prepared by substituting naphthalene ligands in [Re(eta(6)-C10H8)(2)](+) with the corresponding phenyl groups. The ease with which highly stable [Tc-99m(eta(6)-C6R6)(2)](+) complexes are formed under standard labeling conditions enables a multitude of new potential imaging agents based on commercial pharmaceuticals or lead structures.