Potassium thiocyanate argentates: K3[Ag(SCN)4], K4[Ag2(SCN)6] and K[Ag(SCN)2]

The anions of the title compounds contain [Ag(SCN)4] units, with the S atoms coordinating to Ag+ in a tetrahedral arrangement. Whereas in the isolated anions of tripotassium tetrathiocyanatoargentate(I), K3[Ag(SCN)4], (I), all SCN- groups are bonded as terminal ligands, in tetrapotassium di-mu-thiocyanato-S:S-bis[dithiocyanatoargentate(I)], K4[Ag2(SCN)6], (II), two AgS4 tetrahedra share one common edge. In poly[potassium [argentate(I)-di-mu-thiocyanato-S:S]], K[Ag(SCN)2], (III), edge- and vertex-sharing of AgS4 tetrahedra results in infinite [Ag(SCN)2]- layers.