Intercalation of n-alkylamines and alkylene diamines into carboxyl functionalized lamellar-type silsesquioxane

A sol-gel- derived carboxyl-functionalized lamellar-type silsesquioxane was prepared to investigate its potential for use as a host material for intercalation reactions with n-alkylamines and alkylene diamines. Upon intercalation of n-alkylamines and alkylene diamines, the interlayer distances increased as shown by X-ray powder diffraction patterns, and IR spectra showed the presence of absorption bands attributable to ν(COO^-) and δ(NH₃⁺) modes. The amounts of intercalated n-alkylamines were determined from n-C_nH_2n+1NH₂/-COOH molar ratios which, based on CHN analysis, exhibited values from 0.76 to 0.88; whereas the values determined for the alkylene diamines were 0.83 (NH₂C₄H₈NH₂), 0.45 (NH₂C₈H₁₆NH₂) and 0.33 (NH₂C₁₂H₂₄NH₂). These results show that intercalation of n-alkylamines and alkylene diamines into lamellar-type silsesquioxane bearing carboxyl groups proceeded successfully via acid-base mechanisms.