Water/ethanol displacement reactions in vanadyl phosphate

The course of the replacement of ethanol by water molecules in the VOPO4. 2 C(2)H(5)OH intercalate, and of water by ethanol in VOPO4. 2H(2)O has been s tudied by X-ray diffraction and infrared and Raman spectroscopy. Formation of mixed phase VOPO4. C2H5OH . H2O was not observed. The shape of the kinet ics curves indicates a transition of at least one reaction zone through the crystal. A delay in formation of the product in comparison with the decrea se in the amount of starting material can be explained by the existence of non-diffracting advancing phase boundary. In a VOPO4/ethanol/water system, VOPO4. 2C(2)H(5)OH is formed as the only product when the system contained more than 96 vol% of ethanol, whereas in the system with less than 94 vol% of ethanol only VOPO4. 2H(2)O is present.