Synthesis and properties of tetraamminecupro(2)molybdate

The conditions of the formation in a solution of a tetraamminecupromolybdate complex compound have been studied by the method of isomolar series with a constant total concentration of molybdenum and copper. It has been established that cations of copper ammiacate form with molybdate-ions an externally-spherical complex [Cu(NH3)4]42+x[MoO4]2- with an instability constant equal to 3.5x10-4. Crystal tetraamminecupromolybdate has been synthesized by passing ammonia through the ammonia solution of copper molybdate. The crystal hardness according to the Mohs scale is 1.5, the refractive index N=1.722. Upon heating the compound, the two-stage splitting of ammonia takes place: at 125 deg C three ammonia molecules are removed, and at 213 deg C one molecule