From Tc to Tc; facile syntheses of bis-arene complexes [Tc(arene)] from pertechnetate.

Bis-arene complexes of technetium represent a fundamental class of organometallic compounds. Due to complex synthetic routes, no detailed insights into their properties have been reported so far. Reacting [TcO] with arenes in the exclusive presence of AlCl gives highly stable [Tc(arene)] in good yields. These complexes have extraordinarily high stabilities, where oxidation is found to occur at potentials higher than +1.3 V and reduction at potentials below -2 V Fc/Fc. The Tc analogues are similarly synthesised by applying a novel ionic liquid extraction pathway. Complexes of Tc with suitably functionalized arenes will represent new building blocks for bioorganometallic pharmaceuticals in molecular imaging.