Resonance Raman studies of the peroxotitanate(IV) complexes K2(Ti(O2)(SO4)2)•5H2O and K2(Ti(O2)C2O4)2)•3H2O

Abstract The resonance Raman spectra of K 2 (Ti(O 2 )(SO 4 ) 2 )·5H 2 O and K 2 (Ti(O 2 )(C 2 O 4 ) 2 )·3H 2 O are recorded. The results are consistent with the triangular structure of the peroxotitanium unit, Ti(O 2 ), with C 2ν symmetry. The ν(OO), ν s (TiO) and ν as (TiO) are observed around 890, 610 and 535 cm −1 , respectively. The resonance effects are shown to be associated with the 425 nm absorption band. This band is assigned to the O 2 2− → Ti(IV) charge-transfer transition. The calculated force constant values for the O 2 2− and TiO bonds are 320 and 275 N m −1 , respectively.