Some fundamental aspects of technetium chemistry

The radioelement technetium is known to occur in 21 isotopes and numerous isomers. Its spectroscopic detection in fixed stars provided the first proof of stellar synthesis of heavy nuclides. Oxidation states of technetium from (+7) to (-1) and coordination numbers from 4 to 9 have been exemplified. Neglecting some principal differences in stability and structure of technetium and rhenium compounds, the chemistry of both elements differs gradually. There is some evidence that technetium complexes are thermodynamically less stable and kinetically more labile than the corresponding complexes of rhenium. The resemblance of technetium and rhenium chemistry should receive more attention in efforts to synthesize new technetium compounds