Optical Basicity of Titanium(IV) Oxide and Zirconium(IV) Oxide

The relationship between electronic polarizability of oxide(—II), α O 2− , and the electron donor power, expressed as the optical basicity, ∧, indicates that ∧(TiO 2 ) is much greater than ∧(SiO 2 ) and is approximately the same as ∧(CaO). Such a high basicity is supported by the trend in the Racah B parameter for the Ni 2+ ion in crystalline hosts and is also indicated from α O 2− values of glasses containing TiO 2 . Electronic polarizability and other data for zirconium(IV) media indicate that ZrO 2 also has a high basicity, but that ∧(ZrO 2 ) is somewhat less than ∧(TiO 2 ).