Technetium-Boon or Bane?

Technetium currently has no practical applications, yet it holds enormous potential for many industrial sectors. The lack of stable isotopes for element 43 greatly complicates the study of its properties and limits its scope of application. The technetium content in nuclear waste exceeds 6%; currently, virtually all technetium produced in reactors is subject to disposal. The release of technetium compounds into the environment poses significant ecological risks due to the mobility and stability of pertechnetate ions-the thermodynamically most stable form of technetium. To determine the migration pathways of technetium in the biosphere, its behavior in living organisms, and the potential applications of its compounds, information on the chemistry and properties of the element is necessary. At present, approximately 2000 organic and inorganic technetium compounds are known, although their physicochemical and mechanical properties are often not specified by the authors of the studies. Often, the literature provides only information on synthesis, crystal structure, and a set of spectroscopic properties (IR, UV). Information on NMR, EPR, and thermochemical analysis, or very limited chemical properties, is less common. There are studies in which, apart from a description of the structural part, there is no information whatsoever on physical and chemical properties. At the same time, recent discoveries in the field of technetium chemistry indicate that this element can form a number of unique compounds, making its chemistry more diverse and less predictable, while also offering potential for practical applications. The purpose of this review was to identify some new and unresolved issues in the chemistry and technology of technetium compounds. It also presents a brief analysis of the SCDC database, based on which possible directions for further research in the field of coordination chemistry of element 43 are proposed.