Transformations of Ruddlesden−Popper Oxides to New Layered Perovskite Oxides by Metathesis Reactions

We report transformations of the Ruddlesden−Popper (R−P) oxide, K 2 La 2 Ti 3 O 10, to layered perovskite oxides, (Bi 2 O 2 )La 2 Ti 3 O 10, MLa 2 Ti 3 O 10 (M = Pb, Ba, Sr), and (VO)La 2 Ti 3 O 10, by a novel metathesis reaction with BiOCl, MCl 2, and VOSO 4 ·3H 2 O, respectively. The formation of (VO)La 2 Ti 3 O 10, 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/M 2 X 2 sheets, as indeed shown by the independent report of (CuX)LaNb 2 O 7 synthesis by a similar reaction.