Reactivity of the Ruddlesden−Popper Phase H₂La₂Ti₃O₁₀ with Organic Compounds: Intercalation and Grafting Reactions

A protonated form of the Ruddlesden−Popper-type ion-exchangeable layered perovskite H 2 La 2 Ti 3 O 10 (H 2 LaTi) has been modified with n -alkylamine and n -alcohols to yield intercalation compounds and alkoxy derivatives, respectively. As concerns the intercalation of n -alkylamines into H 2 LaTi, no reaction of H 2 LaTi with n -butylamine occurred in anhydrous solvent, and the addition of water was required for the successful intercalation of n -butylamine into H 2 LaTi. The successful uptake of n -butylammonium ions from an n -butylammonium hydroxide aqueous solution suggests that the intercalation mechanism is of the ion-exchange type rather than the acid−base type. For interlayer surface modification with n -alcohol, no direct reaction of H 2 LaTi with n -alcohol occurred, but the n -propoxy derivative of H 2 LaTi formed by using the intercalation compound of H 2 LaTi with n -butylamine as an intermediate. In addition, reactions between the n -propoxy derivative of H 2 LaTi and n -alcohols ( n -butanol, n -octanol, n -decanol, and n -dodecanol) led to the formation of various n -alkoxy derivatives via an alcohol-exchange-type reaction. As the model for n -alkoxy derivatives of H 2 LaTi, a bilayer arrangement of the n -alkyl chain possessing an all - trans ordered state with a 75° tilting angle is proposed. The reaction mechanisms of these reactions are also discussed.