2010 Volume 24 Pages 83-90
A copper sodium triphosphate CuNa3P3O10 12H2O already known has been prepared by the method of ion exchange resin of aqueous chemistry and studied by X-Ray diffraction, thermal analyses (TGA-DTA), differential scanning calorimetry (DSC) and infrared spectrometry which show the characteristic bands of a triphosphate P3O105-. The results of differential thermal analysis, X-Ray powder diffraction and IR spectra of the compound heated at different temperatures showed that, after dehydration, CuNa3P3O10 12H2O decomposes into an amorphous compound, then it crystallizes at 500 °C in order to give the new triphosphate CuNa3P3O10. CuNa3P3O10 crystallizes in the rhomboedric system, space group P-31c, Z = 2 with the following unit-cell dimensions: a = b = 7.022(1)Å, c = 9.217(1)Å, M(20) = 81, F(20) = 117 (0.003419; 50) and V = 393,59(2)Å3. CuNa3P3O10 is stable until its melting point at 560 °C. Two different methods Ozawa and KAS have been selected in studying the kinetics of thermal behavior of the triphosphate P3O10 for the first time. The kinetic and thermodynamic characteristics of the dehydration of CuNa3P3O10 12H2O and the thermal phenomena accompanying this dehydration were determinated and discussed on the basis of the proposed crystalline structure. Quantum chemical calculations have been made for the first time for the P3O105- ion.
