From oxo to carbonyl and arene complexes; A journey through technetium chemistry

A personal note in celebration of Professor Herrmann's 70th birthday, the author describes how the successful preparation of (H3CTcO3)-Tc-99 and the still unsolved task of preparing [Cp*(TcO3)-Tc-99] powered ultimately a plethora of organometallic Tc-99 chemistry. Driven by the need for technetium carbonyl complexes, the red wire leads from [(TcCl3)-Tc-99(CO)(3)](2-) over the related [Tc-99m(OH2)(3)(CO)(3)](+) and [(L-3)(TcO3)-Tc-99](+) finally to [Tc-99(arene)(2)](+) complexes. It is shown how, from the fundamental search for [Cp*(TcO3)-Tc-99], useful molecules for application in molecular imaging emerged. (C) 2018 Elsevier B.V. All rights reserved.