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Updated: Jan 7, 2026

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry
Published on: February 4, 2017
Cyclopentadienyl Complexes of Technetium
Ulrich Abram1, Maximilian Roca Jungfer2
1Institute of Chemistry and Biochemistry, Freie Universität Berlin, Fabeckstr. 34/36, 14195 Berlin, Germany.
Abstract:
The number of structurally investigated cyclopentadienyl (Cp-) complexes of technetium is limited in contrast to the situation with its heavier homolog, rhenium. Although this could be attributed to the radioactivity of all isotopes of the radioelement, there are also clear chemical differences to analogous compounds of the other group seven elements, manganese and rhenium. Technetium Cp- compounds are known with the metal in the oxidation states "+1" to "+7", with a clear dominance of Tc(I) carbonyls and nitrosyls. Corresponding carbonyl complexes also play a significant role in the development of 99mTc-based radiopharmaceuticals with the aromatic ring as an ideal position for the attachment of biomarkers. In this paper, the present status of the synthetic and structural chemistry of technetium with Cp- ligands is discussed, together with recent developments in the corresponding 99mTc labeling chemistry.
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