Ammonium barium citrato peroxotitanate(IV) Ba2(NH4)2[Ti4(O2)4(Hcit)2(cit)2] · 10H2O: a molecular precursor of stoichiometric BaTi2O5

Abstract Diammonium dibarium hydrogen citrato peroxotitanate(IV), Ba 2 (NH 4 ) 2 [Ti 4 (O 2 ) 4 (Hcit) 2 (cit) 2 ] · 10H 2 O, is obtained directly from H 2 O 2 oxidation of tricitrato titanate, or from the reaction of peroxotitanate with citric acid (H 4 cit=citric acid), which is decomposed stoichiometrically into BaTi 2 O 5 at the temperature of 800 °C in air.