Intercalation of Primary Alcohols into Layered Titanoniobates

Lamellar oxides form an important class of functional materials and are often susceptible to topotactic substitution of the ions between the layers. This opens up the structure to direct reactions with alkylammonium ions often substituting for group 1 ions forcing an increase in layer separation. Proton exchange with group 1 ions is also possible in mineral acids with the resulting protonated materials typically being acidic. These solid acids can further react with bases such as alkyl amines again causing an increase in interlayer separation. Alcohols do not readily form stable ROH₂ ⁺X^- (R alkyl chain, X halide) species and being less basic than RNH₂ are less commonly investigated for intercalation into layered oxides. Here the intercalation of simple primary alcohols of the form ROH (R = C_xH_2x+1; x = 1-10) is investigated using the layered titanoniobate HTiNbO₅ as the ceramic host. Direct reaction is found to be ineffective so instead butylamine is first intercalated followed by reaction with the primary alcohols. The butylamine remains in the final product, but intercalation of the alcohols causes a significant modification of the interlayer space of the ceramic. This shows how alcohols can be used to influence the interlayer space of oxide sheets in functional layered oxide ceramics.