Ammoniumbis(hydroxylammonium) Pentafluoridooxidovanadate(IV): Synthesis and Characterisation of a New Fluorovanadate

Turquoise crystals of a new hydroxylammonium compound with the formula NH4(NH3OH)2{VOF5}have been synthesized by the reaction of solid NH3OHF and the aqueous solution of vanadium in HF. The compound crystallizes monoclinic, P21/n, with cell parameters: a = 10.5658(2) A, b = 6.6143(1) A, c = 11.6618(2)A, Beta= 96.282(1). Magnetic susceptibility was measured using a SQUID device over a temperature range 2–300 K at magnetic field 103 Oe giving the result μeff = 1.65 BM. The thermal decomposition was studied by TG and DSC analysis. NH4(NH3OH)2{OF5V}decomposes above 354 K in three steps, obtaining NH4VOF3 after the first step and V2O5 as the final residue.