Technetium disulphide

Amorphous TcS2 is formed by the thermal decomposition of TC2S7. To prepare crystalline TcS2, a mixture of precipitated TcySy and excess sulphur is heated in a bomb for 24 h at 1000 °C. Afterwards unreacted sulphur is removed by sublimation in vacuum [23,26]. Single crystals were prepared by chemical transport reactions. TCS2 was obtained in the form of very thin and soft crystal slices [54]. 

When hydrogen sulphide is passed through a solution of TcOj in 4 M HCl or 4 M H2SO4 the highly insoluble, dark-brown 1 C2S7 precipitates [55,56]. Usually the preci- 

---