A novel copper ammonium diphosphate-dimorphic Cu3(NH4)2(P2O7)2•3H2O

This article deals with the insoluble compounds, formed in CuSO4(NH4)(4)P2O7-H2O system. The solutions were analyzed by means of chemical analysis, the precipitate-by means of x-ray diffraction, chemical and thermal analysis, and FTIR spectroscopy. We have established that at least three poorly soluble compounds can form in the system CuSO4-(NH4)(4)P2O7-H2O. Their chemical formulae are Cu2P2O7-5H(2)O and polymorphic Cu-3(NH4)(2)(P2O7)(2)(.)3H(2)O. The first modification is most stable when \CU + P2O7\ = 0.25 M (n = 1.0), and, in a matter of days, Dimorph A transforms to Dimorph B, which has not been described in any publications.