| abstract |
Salts of the anion of di-, tri- or tetrathiophosphoric acid of the formula I n n n n n n n n n n in which Z 1 and Z 2 are each independently an oxygen or sulfur atom, and R a and R b are each independently an organic group having 1 to 20 carbon atoms, n and a cation which comprises a heterocyclic ring system having one to three nitrogen atoms. |