Ammonium Vanadyl Thiocyanate

This compound and the corresponding potassium vanadyl thiocyanate are obtained in blue, isomorphous, rhombic crystals by the addition of ammonium or potassium thiocyanate, as the case may be, to a neutral solution of vanadyl sulphate, VOSO₄. Their compositions are 2NH₄SCN.VO(SCN)₂.5H₂O and 2KSCN.VO(SCN)₂.5H₂O. Neither the corresponding sodium compound nor the free vanadyl thiocyanate, VO(CNS)₂, has been isolated, but a violet-red bismuth vanadyl thiocyanate, 2Bi(SCN)₃.3VO(SCN)₂.7H₂O or (VO)₃[Bi(SCN)₆]₂.7H₂O, has recently been prepared.