Technetium binary compounds

Most chemical properties of technetium are similar to those of rhenium. The metal exhibits several oxidation states, the most stable being the hep-tavalent, Tc +. The metal forms two oxides the black dioxide Tc02 and the heptoxide TC2O7. At ambient temperature in the presence of moisture, a thin layer of dioxide, Tc02, covers the metal surface. The metal burns in fluorine to form two fluorides, the penta- and hexafluorides, TcFs and TcFe. Binary compounds also are obtained with other nonmetaUic elements. It combines with sulfur and carbon at high temperatures forming technetium disulfide and carbide, TcS2 and TcC, respectively. 

Group 7 (Mn, Tc, Re). No binary compounds are formed with manganese, and no homogeneous product could be prepared. Technetium reacts with W, forming a solid solution and a a-phase (WTcs). Timgsten-technetium alloys are of practical interest as superconductors. 

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