New process of preparation, structure, and physicochemical investigations of the new titanyl phosphate Ti2O(H2O)(PO4)2

New titanyl phosphate Ti 2 O(H 2 O)(PO 4 ) 2 has been prepared and characterized by X-ray and neutron diffraction, nuclear magnetic resonance, infrared and Raman spectroscopies and thermogravimetric analysis. The crystal structure has been solved from neutron powder diffraction data at 300 K by Rietveld method in P 2 1 space group. The refinement led to satisfactory profile factors ( R p =2.7%, R wp =3.2%) and crystal structure model indicators ( R B =5.8%, R F =3.2%). The cell is monoclinic with a =7.3735 A, b =7.0405 A, c =7.6609 A and β =121.48°, Z =4. The structure can be described as a three-dimensional framework built up by chains of [TiO 5 (OH 2 )] octahedra with alternative short bonds [Ti (1) –O (12) ; Ti (2) –O (12) , 1.88–1.84 A] and long ones [Ti (1) –O W ; Ti (2) –O W , 2.25–2.23 A] along c -axis and connected via [PO 4 ] tetrahedra. Oxygen atom denoted O (12) is only linked to two titanium atoms and Oxygen atom denoted O W is linked to two titanium atoms and two hydrogen atoms. O (12) and O W are not linked to P atoms and justify the titanyl phosphate formulation Ti 2 O(H 2 O)(PO 4 ) 2 . The infrared and Raman spectra presents peaks due to vibrations of Ti–O, P–O and O–H bonds. The 31 P MAS NMR spectrum reveals two 31 P resonance lines, in agreement with the structure which showed two crystallographic sites for phosphorus. The thermogravimetric analysis show that Ti 2 O(H 2 O)(PO 4 ) 2 is thermally stable until 400 °C. Above this temperature, it losses water and decomposes to Ti 5 O 4 (PO 4 ) 4 and TiP 2 O 7 .