ALUMINUM AND TITANIUM IMIDODIPHOSPHATES AS SINGLE PRECURSOR MOLECULES TO ALUMINUM AND TITANIUM PHOSPHATE MATERIALS

Abstract

The aluminum and titanium imidodiphosphates compounds respectively 1 and 2 are efficient single-source precursors to homogeneous aluminum and titanium phosphates materials. The conversion occurs pyrolytically at high temperature giving the corresponding compounds. Differential thermal and thermogravimetric analyses, 31P and 27Al MAS NMR, as well as vibrational spectroscopies were used to characterize the final materials. In the case of the aluminum compound 1 it was found that the 27Al MAS NMR signal representative of the octahedral aluminum observed in the material obtained at 900[ddot]C was transformed to a signal characteristic of a tetrahedrally aluminurn by increasing the temperature to 1200[ddot]C. This was confirmed by 31P MAS NMR and XPS studies. The thermal evolution of 2 was studied by using Raman spectroscopy. The conversion of the phosphate material to TiO2 in the rutile phase after a thermal treatment at 1400[ddot]C during 3 hours was observed. The synthetic route to the phosphate materials described here could represent an alternative way to the sol-gel process and may offer certain advantages.