Some fundamentals of technetium chemistry

A total of seven valence electrons are available for bonding. Compounds of technetium in the formal oxidation states from +7 to -1 have been synthesized. Tc (d°) is verified for example by rc04. An example of the -1 oxidation state is the pentacar-bonyl anion [Tc(CO)5 [6], but no structure determination or magnetic susceptibility measurement have been reported. 

Some redox potentials of manganese, technetium, and rhenium are compared in Table 6.I.A. 

TCO2/TC couple turns out to be sontewhat higher than those of the correspojiding couples of manganese and rhenium. 

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