New complex cyanides of vanadium

The reaction of VCl4 with NH4CN in liquid ammonia leads to a mixture of V(CN)3(NH2) and NH4Cl while VCl3 and VBr3 react with NH4CN to give mixtures of V(CN)3(NH3) and ammonium halide. Reduction of a mixture of VBr3 and KCN with potassium in ammonia yields the pyrophoric vanadium(0) cyanide K2V(CN)2 0.5NH3 which is oxidise by ammonium cyanide in ammonia to the new vanadium(II) cyanide K2V(CN)4.