Transformations of Ruddlesden-Popper oxides to new layered perovskite oxides by metathesis reactions

Abstract

We report transformations of the Ruddlesden-Popper (R-P) oxide, K₂La₂Ti₃O₁₀, to layered perovskite oxides, (Bi₂O₂)La₂Ti₃O₁₀, MLa₂Ti₃O₁₀ (M = Pb, Ba, Sr), and (VO)La₂Ti₃O₁₀, by a novel metathesis reaction with BiOCl, MCl₂, and VOSO₄·3H₂O, respectively. The formation of (VO) La₂Ti₃O₁₀, which occurs in aqueous medium around 100°C, suggests that the reaction is most likely topotactic, where the structural integrity of the perovskite sheet is preserved. We believe that the method described here provides a new general route for the synthesis/assembly of layered perovskite materials containing MX/M₂X₂ sheets, as indeed shown by the independent report of (CuX)LaNb₂O₇ synthesis by a similar reaction.