Ammonium thiotungstates

Normal ammonium thiotungstate, (NH4)3WS4, is prepared by the prolonged action of hydrogen sulphide on a dilute solution of ammonium... 

Several thiosalt precursors such as ammonium thiotungstate (NH4)2WS4 (known as ATT) and tetraalkylammonium thiotungstates (NR4)2WS4 were also used to synthesize WS2 (29). Besides, ammonium thiomolybdate (NH4)2MoS4 (known as ATM) and tetraalkylammonium thiomolybdates (NR4)2MoS4 were also used to obtain M0S2. 

Ammonium sulphide solution no precipitate, but if the solution is afterwards acidified with dilute hydrochloric acid, a brown precipitate of tungsten trisulphide, WS3, is produced. The precipitate dissolves in ammonium sulphide solution forming a thiotungstate ion, WS4. ... 

Related Reagents. Triphenyl Phosphine Piperidinium Tetra-thiotungstate Ammonium Tetrathiomolybdate Lawesson s Reagent. 

The complexity of the oxide-sulfide transformation leads to some difficulties in sulfiding, for example, tungsten sulfide or other sulfide phases if in interaction with a nonoptimized support. In this respect, the use of thiosalts and more particularly thiomolybdates and thiotungstates represents an interesting alternative to the classical sulfidation of oxides. Ammonium thiomolybdate (NH)2MoS4 (ATM) was first synthesized by Kruss [53] in 1884. Later, Alonso et al. described an improved way of preparing ATM [54]. The synthesis of ammonivun thiotungstate (ATT)... 

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