Reactivity of the Ruddlesden-Popper phase H₂la ₂Ti₃O₁₀ with organic compounds: Intercalation and grafting reactions

A protonated form of the Ruddlesden-Popper-type ion-exchangeable layered perovskite H₂La₂Ti₃O₁₀ (H ₂LaTi) 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 H₂LaTi, no reaction of H ₂LaTi with n-butylamine occurred in anhydrous solvent, and the addition of water was required for the successful intercalation of n-butylamine into H₂LaTi. 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 ₂LaTi with n-alcohol occurred, but the n-propoxy derivative of H ₂LaTi formed by using the intercalation compound of H₂LaTi with n-butylamine as an intermediate. In addition, reactions between the n-propoxy derivative of H₂LaTi 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 H₂LaTi, 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.